@article {477, title = {A multi-omics data analysis workflow packaged as a FAIR Digital Object}, journal = {GigaScience}, volume = {13}, year = {2024}, month = {01}, pages = {giad115}, abstract = {

Applying good data management and FAIR (Findable, Accessible, Interoperable, and Reusable) data principles in research projects can help disentangle knowledge discovery, study result reproducibility, and data reuse in future studies. Based on the concepts of the original FAIR principles for research data, FAIR principles for research software were recently proposed. FAIR Digital Objects enable discovery and reuse of Research Objects, including computational workflows for both humans and machines. Practical examples can help promote the adoption of FAIR practices for computational workflows in the research community. We developed a multi-omics data analysis workflow implementing FAIR practices to share it as a FAIR Digital Object.We conducted a case study investigating shared patterns between multi-omics data and childhood externalizing behavior. The analysis workflow was implemented as a modular pipeline in the workflow manager Nextflow, including containers with software dependencies. We adhered to software development practices like version control, documentation, and licensing. Finally, the workflow was described with rich semantic metadata, packaged as a Research Object Crate, and shared via WorkflowHub.Along with the packaged multi-omics data analysis workflow, we share our experiences adopting various FAIR practices and creating a FAIR Digital Object. We hope our experiences can help other researchers who develop omics data analysis workflows to turn FAIR principles into practice.

}, issn = {2047-217X}, doi = {10.1093/gigascience/giad115}, url = {https://doi.org/10.1093/gigascience/giad115}, author = {Niehues, Anna and de~Visser, Casper and Hagenbeek, Fiona A and Kulkarni, Purva and Pool, Ren{\'e} and Karu, Naama and Kindt, Alida S D and Singh, Gurnoor and Vermeiren, Robert R J M and Boomsma, Dorret I and van~Dongen, Jenny and {\textquoteright}t~Hoen, Peter A C and van~Gool, Alain J} } @article {468, title = {Beyond the global brain differences: Intra-individual variability differences in 1q21.1 distal and 15q11.2 {BP1-BP2} deletion carriers}, journal = {Biological Psychiatry}, year = {2023}, abstract = {

BACKGROUND: The 1q21.1 distal and 15q11.2 BP1-BP2 CNVs exhibit regional and global brain differences compared to non-carriers. However, interpreting regional differences is challenging if a global difference drives the regional brain differences. Intra-individual variability measures can be used to test for regional differences beyond global differences in brain structure.

METHODS: Magnetic resonance imaging data were used to obtain regional brain values for 1q21.1 distal deletion (n=30) and duplication (n=27), and 15q11.2 BP1-BP2 deletion (n=170) and duplication (n=243) carriers and matched non-carriers (n=2,350). Regional intra-deviation (RID) scores i.e., the standardized difference between an individual\&$\#$39;s regional difference and global difference, were used to test for regional differences that diverge from the global difference.

RESULTS: For the 1q21.1 distal deletion carriers, cortical surface area for regions in the medial visual cortex, posterior cingulate and temporal pole differed less, and regions in the prefrontal and superior temporal cortex differed more than the global difference in cortical surface area. For the 15q11.2 BP1-BP2 deletion carriers, cortical thickness in regions in the medial visual cortex, auditory cortex and temporal pole differed less, and the prefrontal and somatosensory cortex differed more than the global difference in cortical thickness.

CONCLUSION: We find evidence for regional effects beyond differences in global brain measures in 1q21.1 distal and 15q11.2 BP1-BP2 CNVs. The results provide new insight into brain profiling of the 1q21.1 distal and 15q11.2 BP1-BP2 CNVs, with the potential to increase our understanding of mechanisms involved in altered neurodevelopment.

}, keywords = {15q11.2 BP1-BP2, 1q21.1 distal, brain structure, copy number variants, intra-individual variability, magnetic resonance imaging}, doi = {10.1016/j.biopsych.2023.08.018}, author = {Boen, Rune and Kaufmann, Tobias and van der Meer, Dennis and Frei, Oleksandr and Agartz, Ingrid and Ames, David and Andersson, Micael and Armstrong, Nicola J and Artiges, Eric and Atkins, Joshua R and Bauer, Jochen and Benedetti, Francesco and Boomsma, Dorret I and Brodaty, Henry and Brosch, Katharina and Buckner, Randy L and Cairns, Murray J and Calhoun, Vince and Caspers, Svenja and Cichon, Sven and Corvin, Aiden P and Facorro, Benedicto Crespo and Dannlowski, Udo and David, Friederike S and de Geus, Eco J C and de Zubicaray, Greig I and Desrivieres, Sylvane and Doherty, Joanne L and Donohoe, Gary and Ehrlich, Stefan and Eising, Else and Espeseth, Thomas and Fisher, Simon E and Forstner, Andreas J and Uy{\`a}, Lidia Fortaner and Frouin, Vincent and Fukunaga, Masaki and Ge, Tian and Glahn, David C and Goltermann, Janik and Grabe, Hans J and Green, Melissa J and Groenewold, Nynke A and Grotegerd, Dominik and Hahn, Tim and Hashimoto, Ryota and Hehir-Kwa, Jayne Y and Henskens, Frans A and Holmes, Avram J and Haberg, Asta K and Haavik, Jan and Jacquemont, S{\'e}bastien and Jansen, Andreas and Jockwitz, Christiane and J{\"o}nsson, Erik G and Kikuchi, Masataka and Kircher, Tilo and Kumar, Kuldeep and Le Hellard, Stephanie and Leu, Costin and Linden, David E and Liu, Jingyu and Loughnan, Robert and Mather, Karen A and McMahon, Katie L and McRae, Allan F and Medland, Sarah E and Meinert, Susanne and Moreau, Clara A and Morris, Derek W and Mowry, Bryan J and M{\"u}hleisen, Thomas W and Nenadi{\'c}, Igor and N{\"o}then, Markus M and Nyberg, Lars and Owen, Michael J and Paolini, Marco and Paus, Tomas and Pausova, Zdenka and Persson, Karin and Quid{\'e}, Yann and Marques, Tiago Reis and Sachdev, Perminder S and Sando, Sigrid B and Schall, Ulrich and Scott, Rodney J and Selb{\ae}k, Geir and Shumskaya, Elena and Silva, Ana I and Sisodiya, Sanjay M and Stein, Frederike and Stein, Dan J and Straube, Benjamin and Streit, Fabian and Strike, Lachlan T and Teumer, Alexander and Teutenberg, Lea and Thalamuthu, Anbupalam and Tooney, Paul A and Tordesillas-Guti{\'e}rrez, Diana and Trollor, Julian N and Ent, Dennis van {\textquoteright}t and van den Bree, Marianne B M and van Haren, Neeltje E M and Vazquez-Bourgon, Javier and V{\"o}lzke, Henry and Wen, Wei and Wittfeld, Katharina and Ching, Christopher R K and Westlye, Lars T and Thompson, Paul M and Bearden, Carrie E and Selmer, Kaja K and Aln{\ae}s, Dag and Andreassen, Ole A and Sonderby, Ida E} } @article {467, title = {Genetic ancestry estimates within dutch family units and across genotyping arrays: insights from empirical analysis using two estimation methods}, journal = {Genes (Basel)}, volume = {14}, year = {2023}, pages = {1497}, abstract = {

Accurate inference of genetic ancestry is crucial for population-based association studies, accounting for population heterogeneity and structure. This study analyzes genome-wide SNP data from the Netherlands Twin Register to compare genetic ancestry estimates. The focus is on the comparison of ancestry estimates between family members and individuals genotyped on multiple arrays (Affymetrix 6.0, Affymetrix Axiom, and Illumina GSA). Two conventional methods, principal component analysis and ADMIXTURE, were implemented to estimate ancestry, each serving its specific purpose, rather than for direct comparison. The results reveal that as the degree of genetic relatedness decreases, the Euclidean distances of genetic ancestry estimates between family members significantly increase (empirical p \< 0.001), regardless of the estimation method and genotyping array. Ancestry estimates among individuals genotyped on multiple arrays also show statistically significant differences (empirical p \< 0.001). Additionally, this study investigates the relationship between the ancestry estimates of non-identical twin offspring with ancestrally diverse parents and those with ancestrally similar parents. The results indicate a statistically significant weak correlation between the variation in ancestry estimates among offspring and differences in ancestry estimates among parents (Spearman\’s rho: 0.07, p = 0.005). This study highlights the utility of current methods in inferring genetic ancestry, emphasizing the importance of reference population composition in determining ancestry estimates.

}, keywords = {ADMIXTURE, genetic ancestry estimation, population structure, principal components analysis (PCA), within-family analysis}, doi = {10.3390/genes14071497}, author = {Beck, Jeffrey J and Ahmed, Talitha and Finnicum, Casey T and Zwinderman, Koos and Ehli, Erik A and Boomsma, Dorret I and Hottenga, Jouke Jan} } @article {470, title = {Genetics and epigenetics of human aggression}, journal = {Handbook of Clinical Neurology, Brain and Crime}, volume = {197}, year = {2023}, pages = {13{\textendash}44}, abstract = {

There is substantial variation between humans in aggressive behavior, with its biological etiology and molecular genetic basis mostly unknown. This review chapter offers an overview of genomic and omics studies revealing the genetic contribution to aggression and first insights into associations with epigenetic and other omics (e.g., metabolomics) profiles. We allowed for a broad phenotype definition including studies on \"aggression\", \"aggressive behavior\" or \"aggression-related traits\", \"antisocial behavior\", \"conduct disorder\", and \"oppositional defiant disorder\". Heritability estimates based on family and twin studies in children and adults of this broadly defined phenotype of aggression are around 50\%, with relatively small fluctuations around this estimate. Next, we review the genome-wide association studies (GWAS) which search for associations with alleles and also allow for gene-based tests and epigenome-wide association studies (EWAS) which seek to identify associations with differently methylated regions across the genome. Both GWAS and EWAS allow for construction of Polygenic and DNA methylation scores at an individual level. Currently, these predict a small percentage of variance in aggression. We expect that increases in sample size will lead to additional discoveries in GWAS and EWAS, and that multiomics approaches will lead to a more comprehensive understanding of the molecular underpinnings of aggression.

}, keywords = {Epigenome-wide association studies, Epigenomics, genome-wide association studies, Genomics, heritability, Human aggression}, doi = {10.1016/B978-0-12-821375-9.00005-0}, author = {Odintsova, Veronika V and Hagenbeek, Fiona A and Van der Laan, Camiel M and van de Weijer, Steve and Boomsma, Dorret I} } @article {456, title = {Integrative multi-omics analysis of childhood aggressive behavior}, journal = {Behavior Genetics}, volume = {53}, year = {2023}, pages = {101{\textendash}117}, abstract = {

This study introduces and illustrates the potential of an integrated multi-omics approach in investigating the underlying biology of complex traits such as childhood aggressive behavior. In 645 twins (cases\ =\ 42\%), we trained single- and integrative multi-omics models to identify biomarkers for subclinical aggression and investigated the connections among these biomarkers. Our data comprised transmitted and two non-transmitted polygenic scores (PGSs) for 15 traits, 78,772 CpGs, and 90 metabolites. The single-omics models selected 31 PGSs, 1614 CpGs, and 90 metabolites, and the multi-omics model comprised 44 PGSs, 746 CpGs, and 90 metabolites. The predictive accuracy for these models in the test (N\ =\ 277, cases\ =\ 42\%) and independent clinical data (N\ =\ 142, cases\ =\ 45\%) ranged from 43 to 57\%. We observed strong connections between DNA methylation, amino acids, and parental non-transmitted PGSs for ADHD, Autism Spectrum Disorder, intelligence, smoking initiation, and self-reported health. Aggression-related omics traits link to known and novel risk factors, including inflammation, carcinogens, and smoking.

}, keywords = {childhood aggression, DNA methylation, Genetic nurturing, metabolomics, Multi-omics, polygenic scores}, doi = {10.1007/s10519-022-10126-7}, author = {Hagenbeek, Fiona A and van Dongen, Jenny and Pool, Ren{\'e} and Roetman, Peter J and Harms, Amy C and Hottenga, Jouke Jan and Kluft, Cornelis and Colins, Olivier F and van Beijsterveldt, Catharina E M and Fanos, Vassilios and Ehli, Erik A and Hankemeier, Thomas and Vermeiren, Robert R J M and Bartels, Meike and D{\'e}jean, S{\'e}bastien and Boomsma, Dorret I} } @article {471, title = {Integrative multi-omics analysis of genomic, epigenomic, and metabolomics data leads to new insights for Attention-Deficit/Hyperactivity Disorder}, journal = {American Journal of Medical Genetics Part B: Neuropsychiatric Genetics}, year = {2023}, pages = {e32955}, abstract = {

The evolving field of multi-omics combines data and provides methods for simultaneous analysis across several omics levels. Here, we integrated genomics (transmitted and non-transmitted polygenic scores [PGSs]), epigenomics, and metabolomics data in a multi-omics framework to identify biomarkers for Attention-Deficit/Hyperactivity Disorder (ADHD) and investigated the connections among the three omics levels. We first trained single- and next multi-omics models to differentiate between cases and controls in 596 twins (cases\ =\ 14.8\%) from the Netherlands Twin Register (NTR) demonstrating reasonable in-sample prediction through cross-validation. The multi-omics model selected 30 PGSs, 143 CpGs, and 90 metabolites. We confirmed previous associations of ADHD with glucocorticoid exposure and the transmembrane protein family TMEM, show that the DNA methylation of the MAD1L1 gene associated with ADHD has a relation with parental smoking behavior, and present novel findings including associations between indirect genetic effects and CpGs of the STAP2 gene. However, out-of-sample prediction in NTR participants (N\ =\ 258, cases\ =\ 14.3\%) and in a clinical sample (N\ =\ 145, cases\ =\ 51\%) did not perform well (range misclassification was [0.40, 0.57]). The results highlighted connections between omics levels, with the strongest connections between non-transmitted PGSs, CpGs, and amino acid levels and show that multi-omics designs considering interrelated omics levels can help unravel the complex biology underlying ADHD.

}, keywords = {ADHD, DNA methylation, genetic nurture, metabolites, Multi-omics, polygenic scores}, doi = {10.1002/ajmg.b.32955}, author = {Hubers, Nikki and Hagenbeek, Fiona A and Pool, Ren{\'e} and D{\'e}jean, S{\'e}bastien and Harms, Amy C and Roetman, Peter J and van Beijsterveldt, Catharina E M and Fanos, Vassilios and Ehli, Erik A and Vermeiren, Robert R J M and Bartels, Meike and Hottenga, Jouke Jan and Hankemeier, Thomas and van Dongen, Jenny and Boomsma, Dorret I} } @unpublished {466, title = {Longitudinal multi-omics study reveals common etiology underlying association between plasma proteome and BMI trajectories in adolescent and young adult twins}, journal = {medRxiv}, year = {2023}, abstract = {

Background: The influence of genetics and environment on the association of the plasma proteome with body mass index (BMI) and changes in BMI remain underexplored, and the links to other omics in these associations remain to be investigated. We characterized protein-BMI trajectory associations in adolescents and adults and how these connect to other omics layers.

Methods: Our study included two cohorts of longitudinally followed twins: FinnTwin12 (N=651) and the Netherlands Twin Register (NTR) (N=665). Follow-up comprised four BMI measurements over approximately 6 (NTR: 23-27 years old) to 10 years (FinnTwin12: 12-22 years old), with omics data collected at the last BMI measurement. BMI changes were calculated using latent growth curve models. Mixed-effects models were used to quantify the associations between the abundance of 439 plasma proteins with BMI at blood sampling and changes in BMI. The sources of genetic and environmental variation underlying the protein abundances were quantified using twin models, as were the associations of proteins with BMI and BMI changes. In NTR, we investigated the association of gene expression of genes encoding proteins identified in FinnTwin12 with BMI and changes in BMI. We linked identified proteins and their coding genes to plasma metabolites and polygenic risk scores (PRS) using mixed-effect models and correlation networks.

Results: We identified 66 and 14 proteins associated with BMI at blood sampling and changes in BMI, respectively. The average heritability of these proteins was 35\%. Of the 66 BMI-protein associations, 43 and 12 showed genetic and environmental correlations, respectively, including 8 proteins showing both. Similarly, we observed 6 and 4 genetic and environmental correlations between changes in BMI and protein abundance, respectively. S100A8 gene expression was associated with BMI at blood sampling, and the PRG4 and CFI genes were associated with BMI changes. Proteins showed strong connections with many metabolites and PRSs, but we observed no multi-omics connections among gene expression and other omics layers.

Conclusions: Associations between the proteome and BMI trajectories are characterized by shared genetic, environmental, and metabolic etiologies. We observed few gene-protein pairs associated with BMI or changes in BMI at the proteome and transcriptome levels.

}, doi = {10.1101/2023.06.28.23291995}, author = {Drouard, Gabin and Hagenbeek, Fiona A and Whipp, Alyce and Pool, Ren{\'e} and Hottenga, Jouke-Jan and Jansen, Rick and Hubers, Nikki and Afonin, Aleksei and Willemsen, Gonneke and de Geus, Eco J C and Ripatti, Samuli and Pirinen, Matti and Kanninen, Katja M and Boomsma, Dorret I and van Dongen, Jenny and Kaprio, Jaakko and BIOS Consortium and BBMRI-NL Metabolomics Consortium} } @inbook {458, title = {Chapter 32 - Twins and omics: the role of twin studies in multi-omics}, booktitle = {Twin Research for Everyone}, year = {2022}, pages = {547-584}, publisher = {Academic Press}, organization = {Academic Press}, abstract = {

Genomics, transcriptomics, proteomics, and metabolomics are the four main omics domains, referring to high-throughput studies of the genome (DNA), transcriptome (RNA), proteome (proteins), and metabolome (metabolites). Together, these omics domains describe how proteins are formed by the transcription and translation of genetic information and how cells, tissues, and organisms\’ function at the molecular level. Other omics layers reflect regulatory and modulatory processes or exposures to the environment. Twin designs offer powerful analytical tools to study variation in omics data and the influence of omics on phenotypes and phenotypic development. Here, we review and discuss the contribution of twin studies to omics and argue that twin research plays a valuable role in omics research.

}, keywords = {epigenome, Genome, Metabolome, Omics, Transcriptome, Twin design, twins}, isbn = {978-0-12-821514-2}, doi = {https://doi.org/10.1016/B978-0-12-821514-2.00029-5}, url = {https://www.sciencedirect.com/science/article/pii/B9780128215142000295}, author = {Fiona A. Hagenbeek and Jenny van Dongen and Ren{\'e} Pool and Dorret I. Boomsma}, editor = {Adam Tarnoki and David Tarnoki and Jennifer Harris and Nancy Segal} } @article {453, title = {Developmental co-occurrence of psychopathology dimensions in childhood}, journal = {JCPP Advances}, volume = {2}, year = {2022}, pages = {e12100}, abstract = {

Background: Comorbidity between psychopathologies may be attributed to genetic and environmental differences between people as well as causal processes within individuals, where one pathology increases risk for another. Disentangling between-person (co)variance from within-person processes of psychopathology dimensions across childhood may shed light on developmental causes of comorbid mental health problems. Here, we aim to determine whether and to what extent directional relationships between psychopathology dimensions within-person, and between individuals within families, play a role in comorbidity.

Methods: We conducted random intercepts cross-lagged panel model (RI-CLPM) analyses to unravel the longitudinal co-occurrence of child psychopathology dimensions, jointly estimating between-person and within-person processes from childhood to early adolescence (age 7-12). We further developed an extension of the model to estimate sibling effects within-family (wf-RI-CLPM). Analyses were separately conducted in two large population-based cohorts, TEDS and NTR, including parent-rated measures of child problem behaviours based on the SDQ and CBCL scales respectively.

Results: We found evidence for strong between-person effects underlying the positive intercorrelation between problem behaviours across time. Beyond these time-varying within-person processes accounted for an increasing amount of trait variance, within- and cross-trait, overtime in both cohorts. Lastly, by accommodating family level data, we found evidence for reciprocal directional influences within sib-pairs longitudinally.

Conclusions: Our results indicate that within-person processes partly explain the co-occurrence of psychopathology dimensions across childhood, and within sib-pairs. Analyses provided substantive results on developmental processes underlying comorbidity in behavioural problems. Future studies should consider different developmental timeframes to shed more light on the processes contributing to developmental comorbidity.

}, keywords = {comorbidity, development, genetic and environmental effects, psychopathology, sibling effects}, doi = {10.1002/jcv2.12100}, author = {Allegrini, Andrea G and van Beijsterveldt, Toos and Boomsma, Dorret I and Rimfeld, Kaili and Pingault, Jean-Baptiste and Plomin, Robert and Bartels, Meike and Nivard, Michel G} } @article {463, title = {DNA methylation in peripheral tissues and left-handedness}, journal = {Scientific Reports}, volume = {12}, year = {2022}, pages = {5606}, abstract = {

Handedness has low heritability and epigenetic mechanisms have been proposed as an etiological mechanism. To examine this hypothesis, we performed an epigenome-wide association study of left-handedness. In a meta-analysis of 3914 adults of whole-blood DNA methylation, we observed that CpG sites located in proximity of handedness-associated genetic variants were more strongly associated with left-handedness than other CpG sites (P = 0.04), but did not identify any differentially methylated positions. In longitudinal analyses of DNA methylation in peripheral blood and buccal cells from children (N = 1737), we observed moderately stable associations across age (correlation range [0.355-0.578]), but inconsistent across tissues (correlation range [- 0.384 to 0.318]). We conclude that DNA methylation in peripheral tissues captures little of the variance in handedness. Future investigations should consider other more targeted sources of tissue, such as the brain.

}, doi = {10.1038/s41598-022-08998-0}, author = {Odintsova, Veronika V and Suderman, Matthew and Hagenbeek, Fiona A and Caramaschi, Doretta and Hottenga, Jouke-Jan and Pool, Ren{\'e} and BIOS Consortium and Dolan, Conor V and Ligthart, Lannie and van Beijsterveldt, Catharina E M and Willemsen, Gonneke and de Geus, Eco J C and Beck, Jeffrey J and Ehli, Erik A and Cuellar-Partida, Gabriel and Evans, David M and Medland, Sarah E and Relton, Caroline L and Boomsma, Dorret I and van Dongen, Jenny} } @article {459, title = {Genome-wide analyses of individual differences in quantitatively assessed reading- and language-related skills in up to 34,000 people}, journal = {Proceedings of the National Academy of Sciences (PNAS)}, volume = {119}, year = {2022}, pages = {e2202764119}, abstract = {

The use of spoken and written language is a fundamental human capacity. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30 to 80\% depending on the trait. The genetic architecture is complex, heterogeneous, and multifactorial, but investigations of contributions of single-nucleotide polymorphisms (SNPs) were thus far underpowered. We present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures (word reading, nonword reading, spelling, phoneme awareness, and nonword repetition) in samples of 13,633 to 33,959 participants aged 5 to 26 y. We identified genome-wide significant association with word reading (rs11208009, P = 1.098 \× 10\−8) at a locus that has not been associated with intelligence or educational attainment. All five reading-/language-related traits showed robust SNP heritability, accounting for 13 to 26\% of trait variability. Genomic structural equation modeling revealed a shared genetic factor explaining most of the variation in word/nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence, and educational attainment. A multivariate GWAS of word/nonword reading, spelling, and phoneme awareness maximized power for follow-up investigation. Genetic correlation analysis with neuroimaging traits identified an association with the surface area of the banks of the left superior temporal sulcus, a brain region linked to the processing of spoken and written language. Heritability was enriched for genomic elements regulating gene expression in the fetal brain and in chromosomal regions that are depleted of Neanderthal variants. Together, these results provide avenues for deciphering the biological underpinnings of uniquely human traits.

}, keywords = {genome-wide association study, language, meta-analysis, reading}, doi = {10.1073/pnas.2202764119}, author = {Eising, Else and Mirza-Schreiber, Nazanin and de Zeeuw, Eveline L and Wang, Carol A and Truong, Dongnhu T and Allegrini, Andrea G and Shapland, Chin Yang and Zhu, Gu and Wigg, Karen G and Gerritse, Margot L and Molz, Barbara and Alag{\"o}z, G{\"o}kberk and Gialluisi, Alessandro and Abbondanza, Filippo and Rimfeld, Kaili and van Donkelaar, Marjolein and Liao, Zhijie and Jansen, Philip R and Andlauer, Till F M and Bates, Timothy C and Bernard, Manon and Blokland, Kirsten and Bonte, Milene and B{\o}rglum, Anders D and Bourgeron, Thomas and Brandeis, Daniel and Ceroni, Fabiola and Cs{\'e}pe, Val{\'e}ria and Dale, Philip S and de Jong, Peter F and DeFries, John C and D{\'e}monet, Jean-Fran\c cois and Demontis, Ditte and Feng, Yu and Gordon, Scott D and Guger, Sharon L and Hayiou-Thomas, Marianna E and Hern{\'a}ndez-Cabrera, Juan A and Hottenga, Jouke-Jan and Hulme, Charles and Kere, Juha and Kerr, Elizabeth N and Koomar, Tanner and Landerl, Karin and Leonard, Gabriel T and Lovett, Maureen W and Lyytinen, Heikki and Martin, Nicholas G and Martinelli, Angela and Maurer, Urs and Michaelson, Jacob J and Moll, Kristina and Monaco, Anthony P and Morgan, Angela T and N{\"o}then, Markus M and Pausova, Zdenka and Pennell, Craig E and Pennington, Bruce F and Price, Kaitlyn M and Rajagopal, Veera M and Ramus, Franck and Richer, Louis and Simpson, Nuala H and Smith, Shelley D and Snowling, Margaret J and Stein, John and Strug, Lisa J and Talcott, Joel B and Tiemeier, Henning and van der Schroeff, Marc P and Verhoef, Ellen and Watkins, Kate E and Wilkinson, Margaret and Wright, Margaret J and Barr, Cathy L and Boomsma, Dorret I and Carreiras, Manuel and Franken, Marie-Christine J and Gruen, Jeffrey R and Luciano, Michelle and M{\"u}ller-Myhsok, Bertram and Newbury, Dianne F and Olson, Richard K and Paracchini, Silvia and Paus, Tom{\'a}\v s and Plomin, Robert and Reilly, Sheena and Schulte-K{\"o}rne, Gerd and Tomblin, J Bruce and van Bergen, Elsje and Whitehouse, Andrew J O and Willcutt, Erik G and St Pourcain, Beate and Francks, Clyde and Fisher, Simon E} } @article {469, title = {Genome-wide association analyses of physical activity and sedentary behavior provide insights into underlying mechanisms and roles in disease prevention}, journal = {Nature Genetics}, volume = {54}, year = {2022}, pages = {1332{\textendash}1344}, abstract = {

Although physical activity and sedentary behavior are moderately heritable, little is known about the mechanisms that influence these traits. Combining data for up to 703,901 individuals from 51 studies in a multi-ancestry meta-analysis of genome-wide association studies yields 99 loci that associate with self-reported moderate-to-vigorous intensity physical activity during leisure time (MVPA), leisure screen time (LST) and/or sedentary behavior at work. Loci associated with LST are enriched for genes whose expression in skeletal muscle is altered by resistance training. A missense variant in ACTN3 makes the alpha-actinin-3 filaments more flexible, resulting in lower maximal force in isolated type IIA muscle fibers, and possibly protection from exercise-induced muscle damage. Finally, Mendelian randomization analyses show that beneficial effects of lower LST and higher MVPA on several risk factors and diseases are mediated or confounded by body mass index (BMI). Our results provide insights into physical activity mechanisms and its role in disease prevention.

}, doi = {10.1038/s41588-022-01165-1}, author = {Wang, Zhe and Emmerich, Andrew and Pillon, Nicolas J and Moore, Tim and Hemerich, Daiane and Cornelis, Marilyn C and Mazzaferro, Eugenia and Broos, Siacia and Ahluwalia, Tarunveer S and Bartz, Traci M and Bentley, Amy R and Bielak, Lawrence F and Chong, Mike and Chu, Audrey Y and Berry, Diane and Dorajoo, Rajkumar and Dueker, Nicole D and Kasbohm, Elisa and Feenstra, Bjarke and Feitosa, Mary F and Gieger, Christian and Graff, Mariaelisa and Hall, Leanne M and Haller, Toomas and Hartwig, Fernando P and Hillis, David A and Huikari, Ville and Heard-Costa, Nancy and Holzapfel, Christina and Jackson, Anne U and Johansson, \AAsa and J{\o}rgensen, Anja Moltke and Kaakinen, Marika A and Karlsson, Robert and Kerr, Kathleen F and Kim, Boram and Koolhaas, Chantal M and Kutalik, Zoltan and Lagou, Vasiliki and Lind, Penelope A and Lorentzon, Mattias and Lyytik{\"a}inen, Leo-Pekka and Mangino, Massimo and Metzendorf, Christoph and Monroe, Kristine R and Pacolet, Alexander and P{\'e}russe, Louis and Pool, Ren{\'e} and Richmond, Rebecca C and Rivera, Natalia V and Robiou-du-Pont, Sebastien and Schraut, Katharina E and Schulz, Christina-Alexandra and Stringham, Heather M and Tanaka, Toshiko and Teumer, Alexander and Turman, Constance and van der Most, Peter J and Vanmunster, Mathias and van Rooij, Frank J A and van Vliet-Ostaptchouk, Jana V and Zhang, Xiaoshuai and Zhao, Jing-Hua and Zhao, Wei and Balkhiyarova, Zhanna and Balslev-Harder, Marie N and Baumeister, Sebastian E and Beilby, John and Blangero, John and Boomsma, Dorret I and Brage, Soren and Braund, Peter S and Brody, Jennifer A and Bruinenberg, Marcel and Ekelund, Ulf and Liu, Ching-Ti and Cole, John W and Collins, Francis S and Cupples, L Adrienne and Esko, T{\~o}nu and Enroth, Stefan and Faul, Jessica D and Fernandez-Rhodes, Lindsay and Fohner, Alison E and Franco, Oscar H and Galesloot, Tessel E and Gordon, Scott D and Grarup, Niels and Hartman, Catharina A and Heiss, Gerardo and Hui, Jennie and Illig, Thomas and Jago, Russell and James, Alan and Joshi, Peter K and Jung, Taeyeong and K{\"a}h{\"o}nen, Mika and Kilpel{\"a}inen, Tuomas O and Koh, Woon-Puay and Kolcic, Ivana and Kraft, Peter P and Kuusisto, Johanna and Launer, Lenore J and Li, Aihua and Linneberg, Allan and Luan, Jian{\textquoteright}an and Vidal, Pedro Marques and Medland, Sarah E and Milaneschi, Yuri and Moscati, Arden and Musk, Bill and Nelson, Christopher P and Nolte, Ilja M and Pedersen, Nancy L and Peters, Annette and Peyser, Patricia A and Power, Christine and Raitakari, Olli T and Reedik, M{\"a}gi and Reiner, Alex P and Ridker, Paul M and Rudan, Igor and Ryan, Kathy and Sarzynski, Mark A and Scott, Laura J and Scott, Robert A and Sidney, Stephen and Siggeirsdottir, Kristin and Smith, Albert V and Smith, Jennifer A and Sonestedt, Emily and Str{\o}m, Marin and Tai, E Shyong and Teo, Koon K and Thorand, Barbara and T{\"o}njes, Anke and Tremblay, Angelo and Uitterlinden, Andre G and Vangipurapu, Jagadish and van Schoor, Natasja and V{\"o}lker, Uwe and Willemsen, Gonneke and Williams, Kayleen and Wong, Quenna and Xu, Huichun and Young, Kristin L and Yuan, Jian Min and Zillikens, M Carola and Zonderman, Alan B and Ameur, Adam and Bandinelli, Stefania and Bis, Joshua C and Boehnke, Michael and Bouchard, Claude and Chasman, Daniel I and Smith, George Davey and de Geus, Eco J C and Deldicque, Louise and D{\"o}rr, Marcus and Evans, Michele K and Ferrucci, Luigi and Fornage, Myriam and Fox, Caroline and Garland, Jr, Theodore and Gudnason, Vilmundur and Gyllensten, Ulf and Hansen, Torben and Hayward, Caroline and Horta, Bernardo L and Hypponen, Elina and Jarvelin, Marjo-Riitta and Johnson, W Craig and Kardia, Sharon L R and Kiemeney, Lambertus A and Laakso, Markku and Langenberg, Claudia and Lehtim{\"a}ki, Terho and Marchand, Loic Le and Lifelines Cohort Study and Magnusson, Patrik K E and Martin, Nicholas G and Melbye, Mads and Metspalu, Andres and Meyre, David and North, Kari E and Ohlsson, Claes and Oldehinkel, Albertine J and Orho-Melander, Marju and Pare, Guillaume and Park, Taesung and Pedersen, Oluf and Penninx, Brenda W J H and Pers, Tune H and Polasek, Ozren and Prokopenko, Inga and Rotimi, Charles N and Samani, Nilesh J and Sim, Xueling and Snieder, Harold and S{\o}rensen, Thorkild I A and Spector, Tim D and Timpson, Nicholas J and van Dam, Rob M and van der Velde, Nathalie and van Duijn, Cornelia M and Vollenweider, Peter and V{\"o}lzke, Henry and Voortman, Trudy and Waeber, G{\'e}rard and Wareham, Nicholas J and Weir, David R and Wichmann, Heinz-Erich and Wilson, James F and Hevener, Andrea L and Krook, Anna and Zierath, Juleen R and Thomis, Martine A I and Loos, Ruth J F and Hoed, Marcel den} } @article {460, title = {Genome-wide association meta-analysis identifies 29 new acne susceptibility loci}, journal = {Nature Communications}, volume = {13}, year = {2022}, pages = {702}, abstract = {

Acne vulgaris is a highly heritable skin disorder that primarily impacts facial skin. Severely inflamed lesions may leave permanent scars that have been associated with long-term psychosocial consequences. Here, we perform a GWAS meta-analysis comprising 20,165 individuals with acne from nine independent European ancestry cohorts. We identify 29 novel genome-wide significant loci and replicate 14 of the 17 previously identified risk loci, bringing the total number of reported acne risk loci to 46. Using fine-mapping and eQTL colocalisation approaches, we identify putative causal genes at several acne susceptibility loci that have previously been implicated in Mendelian hair and skin disorders, including pustular psoriasis. We identify shared genetic aetiology between acne, hormone levels, hormone-sensitive cancers and psychiatric traits. Finally, we show that a polygenic risk score calculated from our results explains up to 5.6\% of the variance in acne liability in an independent cohort.

}, doi = {10.1038/s41467-022-28252-5}, author = {Mitchell, Brittany L and Saklatvala, Jake R and Dand, Nick and Hagenbeek, Fiona A and Li, Xin and Min, Josine L and Thomas, Laurent and Bartels, Meike and Jan Hottenga, Jouke and Lupton, Michelle K and Boomsma, Dorret I and Dong, Xianjun and Hveem, Kristian and L{\o}set, Mari and Martin, Nicholas G and Barker, Jonathan N and Han, Jiali and Smith, Catherine H and Renter{\'\i}a, Miguel E and Simpson, Michael A} } @article {455, title = {Genome-wide association meta-analysis of childhood and adolescent internalizing symptoms}, journal = {Journal of the American Academy of Child \& Adolescent Psychiatry}, volume = {61}, year = {2022}, pages = {934{\textendash}945}, abstract = {

OBJECTIVE: To investigate the genetic architecture of internalizing symptoms in childhood and adolescence.

METHOD: In 22 cohorts, multiple univariate genome-wide association studies (GWASs) were performed using repeated assessments of internalizing symptoms, in a total of 64,561 children and adolescents between 3 and 18 years of age. Results were aggregated in meta-analyses that accounted for sample overlap, first using all available data, and then using subsets of measurements grouped by rater, age, and instrument.

RESULTS: The meta-analysis of overall internalizing symptoms (INToverall) detected no genome-wide significant hits and showed low single nucleotide polymorphism (SNP) heritability (1.66\%, 95\% CI = 0.84-2.48

}, keywords = {anxiety, Depression, genetic epidemiology, molecular genetics, repeated measures}, doi = {10.1016/j.jaac.2021.11.035}, author = {Jami, Eshim S and Hammerschlag, Anke R and Ip, Hill F and Allegrini, Andrea G and Benyamin, Beben and Border, Richard and Diemer, Elizabeth W and Jiang, Chang and Karhunen, Ville and Lu, Yi and Lu, Qing and Mallard, Travis T and Mishra, Pashupati P and Nolte, Ilja M and Palviainen, Teemu and Peterson, Roseann E and Sallis, Hannah M and Shabalin, Andrey A and Tate, Ashley E and Thiering, Elisabeth and Vilor-Tejedor, Nat{\`a}lia and Wang, Carol and Zhou, Ang and Adkins, Daniel E and Alemany, Silvia and Ask, Helga and Chen, Qi and Corley, Robin P and Ehli, Erik A and Evans, Luke M and Havdahl, Alexandra and Hagenbeek, Fiona A and Hakulinen, Christian and Henders, Anjali K and Hottenga, Jouke Jan and Korhonen, Tellervo and Mamun, Abdullah and Marrington, Shelby and Neumann, Alexander and Rimfeld, Kaili and Rivadeneira, Fernando and Silberg, Judy L and van Beijsterveldt, Catharina E and Vuoksimaa, Eero and Whipp, Alyce M and Tong, Xiaoran and Andreassen, Ole A and Boomsma, Dorret I and Brown, Sandra A and Burt, S Alexandra and Copeland, William and Dick, Danielle M and Harden, K Paige and Harris, Kathleen Mullan and Hartman, Catharina A and Heinrich, Joachim and Hewitt, John K and Hopfer, Christian and Hypponen, Elina and Jarvelin, Marjo-Riitta and Kaprio, Jaakko and Keltikangas-J{\"a}rvinen, Liisa and Klump, Kelly L and Krauter, Kenneth and Kuja-Halkola, Ralf and Larsson, Henrik and Lehtim{\"a}ki, Terho and Lichtenstein, Paul and Lundstr{\"o}m, Sebastian and Maes, Hermine H and Magnus, Per and Munaf{\`o}, Marcus R and Najman, Jake M and Nj{\o}lstad, P\aal R and Oldehinkel, Albertine J and Pennell, Craig E and Plomin, Robert and Reichborn-Kjennerud, Ted and Reynolds, Chandra and Rose, Richard J and Smolen, Andrew and Snieder, Harold and Stallings, Michael and Standl, Marie and Sunyer, Jordi and Tiemeier, Henning and Wadsworth, Sally J and Wall, Tamara L and Whitehouse, Andrew J O and Williams, Gail M and Ystr{\o}m, Eivind and Nivard, Michel G and Bartels, Meike and Middeldorp, Christel M} } @article {457, title = {Heritability of urinary amines, organic acids, and steroid hormones in children}, journal = {Metabolites}, volume = {12}, year = {2022}, pages = {474}, abstract = {

Variation in metabolite levels reflects individual differences in genetic and environmental factors. Here, we investigated the role of these factors in urinary metabolomics data in children. We examined the effects of sex and age on 86 metabolites, as measured on three metabolomics platforms that target amines, organic acids, and steroid hormones. Next, we estimated their heritability in a twin cohort of 1300 twins (age range: 5.7-12.9 years). We observed associations between age and 50 metabolites and between sex and 21 metabolites. The monozygotic (MZ) and dizygotic (DZ) correlations for the urinary metabolites indicated a role for non-additive genetic factors for 50 amines, 13 organic acids, and 6 steroids. The average broad-sense heritability for these amines, organic acids, and steroids was 0.49 (range: 0.25-0.64), 0.50 (range: 0.33-0.62), and 0.64 (range: 0.43-0.81), respectively. For 6 amines, 7 organic acids, and 4 steroids the twin correlations indicated a role for shared environmental factors and the average narrow-sense heritability was 0.50 (range: 0.37-0.68), 0.50 (range; 0.23-0.61), and 0.47 (range: 0.32-0.70) for these amines, organic acids, and steroids. We conclude that urinary metabolites in children have substantial heritability, with similar estimates for amines and organic acids, and higher estimates for steroid hormones.

}, keywords = {amines, children, classical twin design, heritability, metabolites, organic acids, steroid hormones, urine}, doi = {10.3390/metabo12060474}, author = {Hagenbeek, Fiona A and van Dongen, Jenny and Pool, Ren{\'e} and Harms, Amy C and Roetman, Peter J and Fanos, Vassilios and van Keulen, Britt J and Walker, Brian R and Karu, Naama and Hulshoff Pol, Hilleke E and Rotteveel, Joost and Finken, Martijn J J and Vermeiren, Robert R J M and Kluft, Cornelis and Bartels, Meike and Hankemeier, Thomas and Boomsma, Dorret I} } @article {461, title = {Item-level genome-wide association study of the Alcohol Use Disorders Identification Test in three population-based cohorts}, journal = {The American Journal of Psychiatry}, volume = {179}, year = {2022}, pages = {58{\textendash}70}, abstract = {

OBJECTIVE: Genome-wide association studies (GWASs) of the Alcohol Use Disorders Identification Test (AUDIT), a 10-item screen for alcohol use disorder (AUD), have elucidated novel loci for alcohol consumption and misuse. However, these studies also revealed that GWASs can be influenced by numerous biases (e.g., measurement error, selection bias), which may have led to inconsistent genetic correlations between alcohol involvement and AUD, as well as paradoxically negative genetic correlations between alcohol involvement and psychiatric disorders and/or medical conditions. The authors used genomic structural equation modeling to elucidate the genetics of alcohol consumption and problematic consequences of alcohol use as measured by AUDIT.

METHODS: To explore these unexpected differences in genetic correlations, the authors conducted the first item-level and the largest GWAS of AUDIT items (N=160,824) and applied a multivariate framework to mitigate previous biases.

RESULTS: The authors identified novel patterns of similarity (and dissimilarity) among the AUDIT items and found evidence of a correlated two-factor structure at the genetic level ({\textquoteleft}{\textquoteleft}consumption\&$\#$39;\&$\#$39; and {\textquoteleft}{\textquoteleft}problems,\&$\#$39;\&$\#$39; rg=0.80). Moreover, by applying empirically derived weights to each of the AUDIT items, the authors constructed an aggregate measure of alcohol consumption that was strongly associated with alcohol dependence (rg=0.67), moderately associated with several other psychiatric disorders, and no longer positively associated with health and positive socioeconomic outcomes. Lastly, by conducting polygenic analyses in three independent cohorts that differed in their ascertainment and prevalence of AUD, the authors identified novel genetic associations between alcohol consumption, alcohol misuse, and health.

CONCLUSIONS: This work further emphasizes the value of AUDIT for both clinical and genetic studies of AUD and the importance of using multivariate methods to study genetic associations that are more closely related to AUD.

}, keywords = {Alcohol, Alcohol Consumption, ALSPAC, Genomic Structural Equation Modeling, GWAS, Substance-Related and Addictive Disorders}, doi = {10.1176/appi.ajp.2020.20091390}, author = {Mallard, Travis T and Savage, Jeanne E and Johnson, Emma C and Huang, Yuye and Edwards, Alexis C and Hottenga, Jouke J and Grotzinger, Andrew D and Gustavson, Daniel E and Jennings, Mariela V and Anokhin, Andrey and Dick, Danielle M and Edenberg, Howard J and Kramer, John R and Lai, Dongbing and Meyers, Jacquelyn L and Pandey, Ashwini K and Harden, Kathryn Paige and Nivard, Michel G and de Geus, Eco J C and Boomsma, Dorret I and Agrawal, Arpana and Davis, Lea K and Clarke, Toni-Kim and Palmer, Abraham A and Sanchez-Roige, Sandra} } @article {464, title = {Multivariate genetic structure of externalizing behavior and structural brain development in a longitudinal adolescent twin sample}, journal = {International Journal of Molecular Sciences}, volume = {23}, year = {2022}, pages = {3176}, abstract = {

Externalizing behavior in its more extreme form is often considered a problem to the individual, their families, teachers, and society as a whole. Several brain structures have been linked to externalizing behavior and such associations may arise if the (co)development of externalizing behavior and brain structures share the same genetic and/or environmental factor(s). We assessed externalizing behavior with the Child Behavior Checklist and Youth Self Report, and the brain volumes and white matter integrity (fractional anisotropy [FA] and mean diffusivity [MD]) with magnetic resonance imaging in the BrainSCALE cohort, which consisted of twins and their older siblings from 112 families measured longitudinally at ages 10, 13, and 18 years for the twins. Genetic covariance modeling based on the classical twin design, extended to also include siblings of twins, showed that genes influence externalizing behavior and changes therein (h2 up to 88\%). More pronounced externalizing behavior was associated with higher FA (observed correlation rph up to +0.20) and lower MD (rph up to -0.20), with sizeable genetic correlations (FA ra up to +0.42; MD ra up to -0.33). The cortical gray matter (CGM; rph up to -0.20) and cerebral white matter (CWM; rph up to +0.20) volume were phenotypically but not genetically associated with externalizing behavior. These results suggest a potential mediating role for global brain structures in the display of externalizing behavior during adolescence that are both partially explained by the influence of the same genetic factor.

}, keywords = {Adolescence, externalizing behavior, Genetic correlation, gray matter volume, heritability, longitudinal, magnetic resonance imaging, white matter integrity}, doi = {10.3390/ijms23063176}, author = {Teeuw, Jalmar and Klein, Marieke and Mota, Nina Roth and Brouwer, Rachel M and van {\textquoteright}t Ent, Dennis and Al-Hassaan, Zyneb and Franke, Barbara and Boomsma, Dorret I and Hulshoff Pol, Hilleke E} } @article {454, title = {1q21.1 distal copy number variants are associated with cerebral and cognitive alterations in humans}, journal = {Translational Psychiatry}, volume = {11}, year = {2021}, pages = {182}, abstract = {

Low-frequency 1q21.1 distal deletion and duplication copy number variant (CNV) carriers are predisposed to multiple neurodevelopmental disorders, including schizophrenia, autism and intellectual disability. Human carriers display a high prevalence of micro- and macrocephaly in deletion and duplication carriers, respectively. The underlying brain structural diversity remains largely unknown. We systematically called CNVs in 38 cohorts from the large-scale ENIGMA-CNV collaboration and the UK Biobank and identified 28 1q21.1 distal deletion and 22 duplication carriers and 37,088 non-carriers (48\% male) derived from 15 distinct magnetic resonance imaging scanner sites. With standardized methods, we compared subcortical and cortical brain measures (all) and cognitive performance (UK Biobank only) between carrier groups also testing for mediation of brain structure on cognition. We identified positive dosage effects of copy number on intracranial volume (ICV) and total cortical surface area, with the largest effects in frontal and cingulate cortices, and negative dosage effects on caudate and hippocampal volumes. The carriers displayed distinct cognitive deficit profiles in cognitive tasks from the UK Biobank with intermediate decreases in duplication carriers and somewhat larger in deletion carriers-the latter potentially mediated by ICV or cortical surface area. These results shed light on pathobiological mechanisms of neurodevelopmental disorders, by demonstrating gene dose effect on specific brain structures and effect on cognitive function.

}, doi = { 10.1038/s41398-021-01213-0}, author = {S{\o}nderby, Ida E and van der Meer, Dennis and Moreau, Clara and Kaufmann, Tobias and Walters, G Bragi and Ellegaard, Maria and Abdellaoui, Abdel and Ames, David and Amunts, Katrin and Andersson, Micael and Armstrong, Nicola J and Bernard, Manon and Blackburn, Nicholas B and Blangero, John and Boomsma, Dorret I and Brodaty, Henry and Brouwer, Rachel M and B{\"u}low, Robin and B{\o}en, Rune and Cahn, Wiepke and Calhoun, Vince D and Caspers, Svenja and Ching, Christopher R K and Cichon, Sven and Ciufolini, Simone and Crespo-Facorro, Benedicto and Curran, Joanne E and Dale, Anders M and Dalvie, Shareefa and Dazzan, Paola and de Geus, Eco J C and de Zubicaray, Greig I and de Zwarte, Sonja M C and Desrivieres, Sylvane and Doherty, Joanne L and Donohoe, Gary and Draganski, Bogdan and Ehrlich, Stefan and Eising, Else and Espeseth, Thomas and Fejgin, Kim and Fisher, Simon E and Fladby, Tormod and Frei, Oleksandr and Frouin, Vincent and Fukunaga, Masaki and Gareau, Thomas and Ge, Tian and Glahn, David C and Grabe, Hans J and Groenewold, Nynke A and G{\'u}stafsson, {\'O}mar and Haavik, Jan and Haberg, Asta K and Hall, Jeremy and Hashimoto, Ryota and Hehir-Kwa, Jayne Y and Hibar, Derrek P and Hillegers, Manon H J and Hoffmann, Per and Holleran, Laurena and Holmes, Avram J and Homuth, Georg and Hottenga, Jouke-Jan and Hulshoff Pol, Hilleke E and Ikeda, Masashi and Jahanshad, Neda and Jockwitz, Christiane and Johansson, Stefan and J{\"o}nsson, Erik G and J{\o}rgensen, Niklas R and Kikuchi, Masataka and Knowles, Emma E M and Kumar, Kuldeep and Le Hellard, Stephanie and Leu, Costin and Linden, David E J and Liu, Jingyu and Lundervold, Arvid and Lundervold, Astri Johansen and Maillard, Anne M and Martin, Nicholas G and Martin-Brevet, Sandra and Mather, Karen A and Mathias, Samuel R and McMahon, Katie L and McRae, Allan F and Medland, Sarah E and Meyer-Lindenberg, Andreas and Moberget, Torgeir and Modenato, Claudia and S{\'a}nchez, Jennifer Monereo and Morris, Derek W and M{\"u}hleisen, Thomas W and Murray, Robin M and Nielsen, Jacob and Nordvik, Jan E and Nyberg, Lars and Loohuis, Loes M Olde and Ophoff, Roel A and Owen, Michael J and Paus, Tomas and Pausova, Zdenka and Peralta, Juan M and Pike, G Bruce and Prieto, Carlos and Quinlan, Erin B and Reinbold, C{\'e}line S and Marques, Tiago Reis and Rucker, James J H and Sachdev, Perminder S and Sando, Sigrid B and Schofield, Peter R and Schork, Andrew J and Schumann, Gunter and Shin, Jean and Shumskaya, Elena and Silva, Ana I and Sisodiya, Sanjay M and Steen, Vidar M and Stein, Dan J and Strike, Lachlan T and Suzuki, Ikuo K and Tamnes, Christian K and Teumer, Alexander and Thalamuthu, Anbupalam and Tordesillas-Guti{\'e}rrez, Diana and Uhlmann, Anne and Ulfarsson, Magnus O and van {\textquoteright}t Ent, Dennis and van den Bree, Marianne B M and Vanderhaeghen, Pierre and Vassos, Evangelos and Wen, Wei and Wittfeld, Katharina and Wright, Margaret J and Agartz, Ingrid and Djurovic, Srdjan and Westlye, Lars T and Stefansson, Hreinn and Stefansson, Kari and Jacquemont, S{\'e}bastien and Thompson, Paul M and Andreassen, Ole A and ENIGMA-CNV working group} } @inbook {444, title = {Chapter 13 - Combining twin-family designs with measured genetic variants to study the causes of epigenetic variation}, booktitle = {Twin and Family Studies of Epigenetics}, series = {Translational Epigenetics}, volume = {27}, year = {2021}, pages = {239-259}, publisher = {Academic Press}, organization = {Academic Press}, abstract = {

Classical twin and family designs can be applied to examine the contribution of genetic and environmental influences to variation in epigenetic marks. Such models can be extended to allow for more in-depth questions, such as: How much of the variation in DNA methylation is explained by methylation Quantitative Trait Loci (QTLs)? Does the contribution of genetic or environmental influences differ between males and females or between younger and older individuals? Does methylation level at CpG site X have a causal effect on trait Y and vice versa, or is the association driven by genetic pleiotropy? In this chapter, we discuss twin designs that allow to address these questions. First, we describe models that incorporate genetic relationships based on genome-wide SNP data and the application of such models to DNA methylation data from adult twins and family members. Second, we discuss the value of an integration of Mendelian Randomization (MR) with the classical twin design.

}, keywords = {Causality, Direction of causation (DOC), DNA methylation, epigenetics, Genetic relatedness matrix (GRM), heritability, Mendelian Randomization (MR), Mendelian Randomization{\textemdash}direction of causation model (MR-DoC), Single nucleotide polymorphism (SNP) heritability, twins}, isbn = {978-0-12-820951-6}, doi = {https://doi.org/10.1016/B978-0-12-820951-6.00007-7}, url = {https://www.sciencedirect.com/science/article/pii/B9780128209516000077}, author = {Camelia C. Minic{\u a} and Michael C. Neale and Dorret I. Boomsma and Jenny van Dongen}, editor = {Shuai Li and John L. Hopper} } @inbook {438, title = {Chapter 3 - Discordant monozygotic twin studies of epigenetic mechanisms in mental health}, booktitle = {Twin and Family Studies of Epigenetics}, series = {Translational Epigenetics}, volume = {27}, year = {2021}, pages = {43-66}, publisher = {Academic Press}, organization = {Academic Press}, abstract = {

The discordant monozygotic twin design is a strong method to assess causality. The design has been applied in a number of studies to investigate epigenetic mechanisms associated with mental health. These studies initially mainly focused on candidate genes and increasingly on genome-wide DNA methylation, gene expression, and X-chromosome inactivation, in various surrogate tissues such as blood and buccal cells, but also in brain tissue. In this chapter we review monozygotic twin studies of autism, aggressive behavior, ADHD, schizophrenia, bipolar disorder, and depression. We discuss the insights obtained by these studies and describe current limitations and challenges, including sample size, the use of surrogate tissues, causality, and confounders that apply to studies of cognitive and mental health such as medication use, lifestyle, and cellular heterogeneity of commonly investigated tissues.

}, keywords = {ADHD, Aggressive Behavior, Autism, Bipolar disorder, Depression, Discordant, epigenetics, Schizophrenia, twins}, isbn = {978-0-12-820951-6}, doi = {https://doi.org/10.1016/B978-0-12-820951-6.00003-X}, url = {https://www.sciencedirect.com/science/article/pii/B978012820951600003X}, author = {Jenny van Dongen and Veronika V. Odintsova and Dorret I. Boomsma}, editor = {Shuai Li and John L. Hopper} } @article {439, title = {DNA methylation signatures of aggression and closely related constructs: A meta-analysis of epigenome-wide studies across the lifespan}, journal = {Molecular Psychiatry}, volume = {26}, year = {2021}, pages = {2148{\textendash}2162}, abstract = {

DNA methylation profiles of aggressive behavior may capture lifetime cumulative effects of genetic, stochastic, and environmental influences associated with aggression. Here, we report the first large meta-analysis of epigenome-wide association studies (EWAS) of aggressive behavior (N = 15,324 participants). In peripheral blood samples of 14,434 participants from 18 cohorts with mean ages ranging from 7 to 68 years, 13 methylation sites were significantly associated with aggression (alpha = 1.2 $\times$ 10-7; Bonferroni correction). In cord blood samples of 2425 children from five cohorts with aggression assessed at mean ages ranging from 4 to 7 years, 83\% of these sites showed the same direction of association with childhood aggression (r = 0.7

}, doi = {10.1038/s41380-020-00987-x}, author = {van Dongen, Jenny and Hagenbeek, Fiona A and Suderman, Matthew and Roetman, Peter J and Sugden, Karen and Chiocchetti, Andreas G and Ismail, Khadeeja and Mulder, Rosa H and Hafferty, Jonathan D and Adams, Mark J and Walker, Rosie M and Morris, Stewart W and Lahti, Jari and K{\"u}pers, Leanne K and Escaramis, Georgia and Alemany, Silvia and Jan Bonder, Marc and Meijer, Mandy and Ip, Hill F and Jansen, Rick and Baselmans, Bart M L and Parmar, Priyanka and Lowry, Estelle and Streit, Fabian and Sirignano, Lea and Send, Tabea S and Frank, Josef and Jylh{\"a}v{\"a}, Juulia and Wang, Yunzhang and Mishra, Pashupati Prasad and Colins, Olivier F and Corcoran, David L and Poulton, Richie and Mill, Jonathan and Hannon, Eilis and Arseneault, Louise and Korhonen, Tellervo and Vuoksimaa, Eero and Felix, Janine F and Bakermans-Kranenburg, Marian J and Campbell, Archie and Czamara, Darina and Binder, Elisabeth and Corpeleijn, Eva and Gonzalez, Juan R and Grazuleviciene, Regina and Gutzkow, Kristine B and Evandt, Jorunn and Vafeiadi, Marina and Klein, Marieke and van der Meer, Dennis and Ligthart, Lannie and BIOS Consortium and Kluft, Cornelis and Davies, Gareth E and Hakulinen, Christian and Keltikangas-J{\"a}rvinen, Liisa and Franke, Barbara and Freitag, Christine M and Konrad, Kerstin and Hervas, Amaia and Fern{\'a}ndez-Rivas, Aranzazu and Vetro, Agnes and Raitakari, Olli and Lehtim{\"a}ki, Terho and Vermeiren, Robert and Strandberg, Timo and R{\"a}ikk{\"o}nen, Katri and Snieder, Harold and Witt, Stephanie H and Deuschle, Michael and Pedersen, Nancy L and H{\"a}gg, Sara and Sunyer, Jordi and Franke, Lude and Kaprio, Jaakko and Ollikainen, Miina and Moffitt, Terrie E and Tiemeier, Henning and van IJzendoorn, Marinus H and Relton, Caroline and Vrijheid, Martine and Sebert, Sylvain and Jarvelin, Marjo-Riitta and Caspi, Avshalom and Evans, Kathryn L and McIntosh, Andrew M and Bartels, Meike and Boomsma, Dorret I} } @article {437, title = {Genetic association study of childhood aggression across raters, instruments, and age}, journal = {Translational Psychiatry}, volume = {11}, year = {2021}, pages = {413}, abstract = {

Childhood aggressive behavior (AGG) has a substantial heritability of around 50\%. Here we present a genome-wide association meta-analysis (GWAMA) of childhood AGG, in which all phenotype measures across childhood ages from multiple assessors were included. We analyzed phenotype assessments for a total of 328 935 observations from 87 485 children aged between 1.5 and 18 years, while accounting for sample overlap. We also meta-analyzed within subsets of the data, i.e., within rater, instrument and age. SNP-heritability for the overall meta-analysis (AGGoverall) was 3.31\% (SE = 0.0038). We found no genome-wide significant SNPs for AGGoverall. The gene-based analysis returned three significant genes: ST3GAL3 (P = 1.6E-06), PCDH7 (P = 2.0E-06), and IPO13 (P = 2.5E-06). All three genes have previously been associated with educational traits. Polygenic scores based on our GWAMA significantly predicted aggression in a holdout sample of children (variance explained = 0.44\%) and in retrospectively assessed childhood aggression (variance explained = 0.20\%). Genetic correlations (rg) among rater-specific assessment of AGG ranged from rg = 0.46 between self- and teacher-assessment to rg = 0.81 between mother- and teacher-assessment. We obtained moderate-to-strong rgs with selected phenotypes from multiple domains, but hardly with any of the classical biomarkers thought to be associated with AGG. Significant genetic correlations were observed with most psychiatric and psychological traits (range [Formula: see text]: 0.19-1.00), except for obsessive-compulsive disorder. Aggression had a negative genetic correlation (rg = \ -0.5) with cognitive traits and age at first birth. Aggression was strongly genetically correlated with smoking phenotypes (range [Formula: see text]: 0.46-0.60). The genetic correlations between aggression and psychiatric disorders were weaker for teacher-reported AGG than for mother- and self-reported AGG. The current GWAMA of childhood aggression provides a powerful tool to interrogate the rater-specific genetic etiology of AGG.

}, doi = {10.1038/s41398-021-01480-x}, author = {Ip, Hill F and Van der Laan, Camiel M and Krapohl, Eva M L and Brikell, Isabell and S{\'a}nchez-Mora, Cristina and Nolte, Ilja M and St Pourcain, Beate and Bolhuis, Koen and Palviainen, Teemu and Zafarmand, Hadi and Colodro-Conde, Luc{\'\i}a and Gordon, Scott and Zayats, Tetyana and Aliev, Fazil and Jiang, Chang and Wang, Carol A and Saunders, Gretchen and Karhunen, Ville and Hammerschlag, Anke R and Adkins, Daniel E and Border, Richard and Peterson, Roseann E and Prinz, Joseph A and Thiering, Elisabeth and Sepp{\"a}l{\"a}, Ilkka and Vilor-Tejedor, Nat{\`a}lia and Ahluwalia, Tarunveer S and Day, Felix R and Hottenga, Jouke-Jan and Allegrini, Andrea G and Rimfeld, Kaili and Chen, Qi and Lu, Yi and Martin, Joanna and Soler Artigas, Mar{\'\i}a and Rovira, Paula and Bosch, Rosa and Espa{\~n}ol, Gemma and Ramos Quiroga, Josep Antoni and Neumann, Alexander and Ensink, Judith and Grasby, Katrina and Morosoli, Jos{\'e} J and Tong, Xiaoran and Marrington, Shelby and Middeldorp, Christel and Scott, James G and Vinkhuyzen, Anna and Shabalin, Andrey A and Corley, Robin and Evans, Luke M and Sugden, Karen and Alemany, Silvia and Sass, L{\ae}rke and Vinding, Rebecca and Ruth, Kate and Tyrrell, Jess and Davies, Gareth E and Ehli, Erik A and Hagenbeek, Fiona A and de Zeeuw, Eveline and van Beijsterveldt, Toos C E M and Larsson, Henrik and Snieder, Harold and Verhulst, Frank C and Amin, Najaf and Whipp, Alyce M and Korhonen, Tellervo and Vuoksimaa, Eero and Rose, Richard J and Uitterlinden, Andre G and Heath, Andrew C and Madden, Pamela and Haavik, Jan and Harris, Jennifer R and Helgeland, {\O}yvind and Johansson, Stefan and Knudsen, Gun Peggy S and Njolstad, Pal Rasmus and Lu, Qing and Rodriguez, Alina and Henders, Anjali K and Mamun, Abdullah and Najman, Jackob M and Brown, Sandy and Hopfer, Christian and Krauter, Kenneth and Reynolds, Chandra and Smolen, Andrew and Stallings, Michael and Wadsworth, Sally and Wall, Tamara L and Silberg, Judy L and Miller, Allison and Keltikangas-J{\"a}rvinen, Liisa and Hakulinen, Christian and Pulkki-R\aaback, Laura and Havdahl, Alexandra and Magnus, Per and Raitakari, Olli T and Perry, John R B and Llop, Sabrina and Lopez-Espinosa, Maria-Jose and B{\o}nnelykke, Klaus and Bisgaard, Hans and Sunyer, Jordi and Lehtim{\"a}ki, Terho and Arseneault, Louise and Standl, Marie and Heinrich, Joachim and Boden, Joseph and Pearson, John and Horwood, L John and Kennedy, Martin and Poulton, Richie and Eaves, Lindon J and Maes, Hermine H and Hewitt, John and Copeland, William E and Costello, Elizabeth J and Williams, Gail M and Wray, Naomi and Jarvelin, Marjo-Riitta and McGue, Matt and Iacono, William and Caspi, Avshalom and Moffitt, Terrie E and Whitehouse, Andrew and Pennell, Craig E and Klump, Kelly L and Burt, S Alexandra and Dick, Danielle M and Reichborn-Kjennerud, Ted and Martin, Nicholas G and Medland, Sarah E and Vrijkotte, Tanja and Kaprio, Jaakko and Tiemeier, Henning and Davey Smith, George and Hartman, Catharina A and Oldehinkel, Albertine J and Casas, Miquel and Ribas{\'e}s, Marta and Lichtenstein, Paul and Lundstr{\"o}m, Sebastian and Plomin, Robert and Bartels, Meike and Nivard, Michel G and Boomsma, Dorret I} } @article {433, title = {Genetic meta-analysis of twin birth weight shows high genetic correlation with singleton birth weight}, journal = {Human Molecular Genetics}, volume = {30}, year = {2021}, pages = {1894{\textendash}1905}, abstract = {

Birth weight (BW) is an important predictor of newborn survival and health and has associations with many adult health outcomes, including cardiometabolic disorders, autoimmune diseases and mental health. On average, twins have a lower BW than singletons as a result of a different pattern of fetal growth and shorter gestational duration. Therefore, investigations into the genetics of BW often exclude data from twins, leading to a reduction in sample size and remaining ambiguities concerning the genetic contribution to BW in twins. In this study, we carried out a genome-wide association meta-analysis of BW in 42 212 twin individuals and found a positive correlation of beta values (Pearson\&$\#$39;s r = 0.66, 95\% confidence interval [CI]: 0.47-0.77) with 150 previously reported genome-wide significant variants for singleton BW. We identified strong positive genetic correlations between BW in twins and numerous anthropometric traits, most notably with BW in singletons (genetic correlation [rg] = 0.92, 95\% CI: 0.66-1.18). Genetic correlations of BW in twins with a series of health-related traits closely resembled those previously observed for BW in singletons. Polygenic scores constructed from a genome-wide association study on BW in the UK Biobank demonstrated strong predictive power in a target sample of Dutch twins and singletons. Together, our results indicate that a similar genetic architecture underlies BW in twins and singletons and that future genome-wide studies might benefit from including data from large twin registers.

}, doi = {10.1093/hmg/ddab121}, author = {Beck, Jeffrey J and Pool, Ren{\'e} and van de Weijer, Margot and Chen, Xu and Krapohl, Eva and Gordon, Scott D and Nygaard, Marianne and Debrabant, Birgit and Palviainen, Teemu and van der Zee, Matthijs D and Baselmans, Bart and Finnicum, Casey T and Yi, Lu and Lundstr{\"o}m, Sebastian and van Beijsterveldt, Toos and Christiansen, Lene and Heikkil{\"a}, Kauko and Kittelsrud, Julie and Loukola, Anu and Ollikainen, Miina and Christensen, Kaare and Martin, Nicholas G and Plomin, Robert and Nivard, Michel and Bartels, Meike and Dolan, Conor and Willemsen, Gonneke and de Geus, Eco and Almqvist, Catarina and Magnusson, Patrik K E and Mbarek, Hamdi and Ehli, Erik A and Boomsma, Dorret I and Hottenga, Jouke-Jan} } @article {434, title = {Genetically informed regression analysis: Application to aggression prediction by inattention and hyperactivity in children and adults}, journal = {Behavior Genetics}, volume = {51}, year = {2021}, pages = {250{\textendash}263}, abstract = {

We present a procedure to simultaneously fit a genetic covariance structure model and a regression model to multivariate data from mono- and dizygotic twin pairs to test for the prediction of a dependent trait by multiple correlated predictors. We applied the model to aggressive behavior as an outcome trait and investigated the prediction of aggression from inattention (InA) and hyperactivity (HA) in two age groups. Predictions were examined in twins with an average age of 10 years (11,345 pairs), and in adult twins with an average age of 30 years (7433 pairs). All phenotypes were assessed by the same, but age-appropriate, instruments in children and adults. Because of the different genetic architecture of aggression, InA and HA, a model was fitted to these data that specified additive and non-additive genetic factors (A and D) plus common and unique environmental (C and E) influences. Given appropriate identifying constraints, this ADCE model is identified in trivariate data. We obtained different results for the prediction of aggression in children, where HA was the more important predictor, and in adults, where InA was the more important predictor. In children, about 36\% of the total aggression variance was explained by the genetic and environmental components of HA and InA. Most of this was explained by the genetic components of HA and InA, i.e., 29.7\%, with 22.6\% due to the genetic component of HA. In adults, about 21\% of the aggression variance was explained. Most was this was again explained by the genetic components of InA and HA (16.2\%), with 8.6\% due to the genetic component of InA.

}, keywords = {Aggression, Genetic and environmental prediction, Hyperactivity, Inattention, Regression, Structural equation model}, doi = {10.1007/s10519-020-10025-9}, author = {Boomsma, Dorret I and van Beijsterveldt, Toos C E M and Odintsova, Veronika V and Neale, Michael C and Dolan, Conor V} } @article {442, title = {The heritability of Type D personality by an extended twin-pedigree analysis in the Netherlands Twin Register}, journal = {Behavior Genetics}, volume = {51}, year = {2021}, pages = {1{\textendash}11}, abstract = {

Type D (Distressed) personality combines negative affectivity (NA) and social inhibition (SI) and is associated with an increased risk of cardiovascular disease. We aimed to (1) validate a new proxy based on the Achenbach System of Empirically Based Assessment (ASEBA) for Type D personality and its NA and SI subcomponents and (2) estimate the heritability of the Type D proxy in an extended twin-pedigree design in the Netherlands Twin Register (NTR). Proxies for the dichotomous Type D classification, and continuous NA, SI, and NAxSI (the continuous measure of Type D) scales were created based on 12 ASEBA items for 30,433 NTR participants (16,449 twins and 13,984 relatives from 11,106 pedigrees) and sources of variation were analyzed in the \&$\#$39;Mendel\&$\#$39; software package. We estimated additive and non-additive genetic variance components, shared household and unique environmental variance components and ran bivariate models to estimate the genetic and non-genetic covariance between NA and SI. The Type D proxy showed good reliability and construct validity. The best fitting genetic model included additive and non-additive genetic effects with broad-sense heritabilities for NA, SI and NAxSI estimated at 49\%, 50\% and 49\%, respectively. Household effects showed small contributions (4-9\%) to the total phenotypic variation. The genetic correlation between NA and SI was .66 (reflecting both additive and non-additive genetic components). Thus, Type D personality and its NA and SI subcomponents are heritable, with a shared genetic basis for the two subcomponents.

}, keywords = {Extended twin-family design, Genetic non-additivity, heritability, Negative affectivity, Netherlands Twin Register, Pedigree analysis, Shared household effect, Social inhibition, Type D personality}, doi = {10.1007/s10519-020-10023-x}, author = {Li-Gao, Ruifang and Boomsma, Dorret I and de Geus, Eco J C and Denollet, Johan and Kupper, Nina} } @article {428, title = {Higher aggression is related to poorer academic performance in compulsory education}, journal = {Journal of Child Psychology and Psychiatry}, volume = {62}, year = {2021}, pages = {327{\textendash}338}, abstract = {

BACKGROUND: To conduct a comprehensive assessment of the association between aggression and academic performance in compulsory education.

METHOD: We studied aggression and academic performance in over 27,000 individuals from four European twin cohorts participating in the ACTION consortium (Aggression in Children: Unraveling gene-environment interplay to inform Treatment and InterventiON strategies). Individual level data on aggression at ages 7-16 were assessed by three instruments (Achenbach System of Empirically Based Assessment, Multidimensional Peer Nomination Inventory, Strengths and Difficulties Questionnaire) including parental, teacher and self-reports. Academic performance was measured with teacher-rated grade point averages (ages 12-14) or standardized test scores (ages 12-16). Random effect meta-analytical correlations with academic performance were estimated for parental ratings (in all four cohorts) and self-ratings (in three cohorts).

RESULTS: All between-family analyses indicated significant negative aggression-academic performance associations with correlations ranging from -.06 to -.33. Results were similar across different ages, instruments and raters and either with teacher-rated grade point averages or standardized test scores as measures of academic performance. Meta-analytical r\&$\#$39;s were -.20 and -.23 for parental and self-ratings, respectively. In within-family analyses of all twin pairs, the negative aggression-academic performance associations were statistically significant in 14 out of 17 analyses (r = -.17 for parental- and r = -.16 for self-ratings). Separate analyses in monozygotic (r = -.07 for parental and self-ratings), same-sex dizygotic (r\&$\#$39;s = -.16 and -.17 for parental and self-ratings) and opposite-sex dizygotic (r\&$\#$39;s = -.21 and -.19 for parental and self-ratings) twin pairs suggested partial confounding by genetic effects.

CONCLUSIONS: There is a robust negative association between aggression and academic performance in compulsory education. Part of these associations were explained by shared genetic effects, but some evidence of a negative association between aggression and academic performance remained even in within-family analyses of monozygotic twin pairs.

}, keywords = {Aggression, cognition, development, educational attainment, school performance}, doi = {10.1111/jcpp.13273}, author = {Vuoksimaa, Eero and Rose, Richard J and Pulkkinen, Lea and Palviainen, Teemu and Rimfeld, Kaili and Lundstr{\"o}m, Sebastian and Bartels, Meike and van Beijsterveldt, Catharina and Hendriks, Anne and de Zeeuw, Eveline L and Plomin, Robert and Lichtenstein, Paul and Boomsma, Dorret I and Kaprio, Jaakko} } @article {449, title = {Higher aggression is related to poorer academic performance in compulsory education}, journal = {Journal of Child Psychology and Psychiatry}, volume = {62}, year = {2021}, pages = {327{\textendash}338}, abstract = {

BACKGROUND: To conduct a comprehensive assessment of the association between aggression and academic performance in compulsory education.

METHOD: We studied aggression and academic performance in over 27,000 individuals from four European twin cohorts participating in the ACTION consortium (Aggression in Children: Unraveling gene-environment interplay to inform Treatment and InterventiON strategies). Individual level data on aggression at ages 7-16 were assessed by three instruments (Achenbach System of Empirically Based Assessment, Multidimensional Peer Nomination Inventory, Strengths and Difficulties Questionnaire) including parental, teacher and self-reports. Academic performance was measured with teacher-rated grade point averages (ages 12-14) or standardized test scores (ages 12-16). Random effect meta-analytical correlations with academic performance were estimated for parental ratings (in all four cohorts) and self-ratings (in three cohorts).

RESULTS: All between-family analyses indicated significant negative aggression-academic performance associations with correlations ranging from -.06 to -.33. Results were similar across different ages, instruments and raters and either with teacher-rated grade point averages or standardized test scores as measures of academic performance. Meta-analytical r\&$\#$39;s were -.20 and -.23 for parental and self-ratings, respectively. In within-family analyses of all twin pairs, the negative aggression-academic performance associations were statistically significant in 14 out of 17 analyses (r = -.17 for parental- and r = -.16 for self-ratings). Separate analyses in monozygotic (r = -.07 for parental and self-ratings), same-sex dizygotic (r\&$\#$39;s = -.16 and -.17 for parental and self-ratings) and opposite-sex dizygotic (r\&$\#$39;s = -.21 and -.19 for parental and self-ratings) twin pairs suggested partial confounding by genetic effects.

CONCLUSIONS: There is a robust negative association between aggression and academic performance in compulsory education. Part of these associations were explained by shared genetic effects, but some evidence of a negative association between aggression and academic performance remained even in within-family analyses of monozygotic twin pairs.

}, keywords = {Aggression, cognition, development, educational attainment, school performance}, doi = {10.1111/jcpp.13273}, author = {Vuoksimaa, Eero and Rose, Richard J and Pulkkinen, Lea and Palviainen, Teemu and Rimfeld, Kaili and Lundstr{\"o}m, Sebastian and Bartels, Meike and van Beijsterveldt, Catharina and Hendriks, Anne and de Zeeuw, Eveline L and Plomin, Robert and Lichtenstein, Paul and Boomsma, Dorret I and Kaprio, Jaakko} } @article {440, title = {Identical twins carry a persistent epigenetic signature of early genome programming}, journal = {Nature Communications}, volume = {12}, year = {2021}, pages = {5618}, abstract = {

Monozygotic (MZ) twins and higher-order multiples arise when a zygote splits during pre-implantation stages of development. The mechanisms underpinning this event have remained a mystery. Because MZ twinning rarely runs in families, the leading hypothesis is that it occurs at random. Here, we show that MZ twinning is strongly associated with a stable DNA methylation signature in adult somatic tissues. This signature spans regions near telomeres and centromeres, Polycomb-repressed regions and heterochromatin, genes involved in cell-adhesion, WNT signaling, cell fate, and putative human metastable epialleles. Our study also demonstrates a never-anticipated corollary: because identical twins keep a lifelong molecular signature, we can retrospectively diagnose if a person was conceived as monozygotic twin.

}, doi = {10.1038/s41467-021-25583-7}, author = {van Dongen, Jenny and Gordon, Scott D and McRae, Allan F and Odintsova, Veronika V and Mbarek, Hamdi and Breeze, Charles E and Sugden, Karen and Lundgren, Sara and Castillo-Fernandez, Juan E and Hannon, Eilis and Moffitt, Terrie E and Hagenbeek, Fiona A and van Beijsterveldt, Catharina E M and Jan Hottenga, Jouke and Tsai, Pei-Chien and BIOS Consortium and Genetics of DNA Methylation Consortium and Min, Josine L and Hemani, Gibran and Ehli, Erik A and Paul, Franziska and Stern, Claudio D and Heijmans, Bastiaan T and Slagboom, P Eline and Daxinger, Lucia and van der Maarel, Silv{\`e}re M and de Geus, Eco J C and Willemsen, Gonneke and Montgomery, Grant W and Reversade, Bruno and Ollikainen, Miina and Kaprio, Jaakko and Spector, Tim D and Bell, Jordana T and Mill, Jonathan and Caspi, Avshalom and Martin, Nicholas G and Boomsma, Dorret I} } @article {435, title = {Investigating the genetic architecture of noncognitive skills using GWAS-by-subtraction}, journal = {Nature Genetics}, volume = {53}, year = {2021}, pages = {35{\textendash}44}, abstract = {

Little is known about the genetic architecture of traits affecting educational attainment other than cognitive ability. We used genomic structural equation modeling and prior genome-wide association studies (GWASs) of educational attainment (n = 1,131,881) and cognitive test performance (n = 257,841) to estimate SNP associations with educational attainment variation that is independent of cognitive ability. We identified 157 genome-wide-significant loci and a polygenic architecture accounting for 57\% of genetic variance in educational attainment. Noncognitive genetics were enriched in the same brain tissues and cell types as cognitive performance, but showed different associations with gray-matter brain volumes. Noncognitive genetics were further distinguished by associations with personality traits, less risky behavior and increased risk for certain psychiatric disorders. For socioeconomic success and longevity, noncognitive and cognitive-performance genetics demonstrated associations of similar magnitude. By conducting a GWAS of a phenotype that was not directly measured, we offer a view of genetic architecture of noncognitive skills influencing educational success.

}, doi = {10.1038/s41588-020-00754-2}, author = {Demange, Perline A and Malanchini, Margherita and Mallard, Travis T and Biroli, Pietro and Cox, Simon R and Grotzinger, Andrew D and Tucker-Drob, Elliot M and Abdellaoui, Abdel and Arseneault, Louise and van Bergen, Elsje and Boomsma, Dorret I and Caspi, Avshalom and Corcoran, David L and Domingue, Benjamin W and Harris, Kathleen Mullan and Ip, Hill F and Mitchell, Colter and Moffitt, Terrie E and Poulton, Richie and Prinz, Joseph A and Sugden, Karen and Wertz, Jasmin and Williams, Benjamin S and de Zeeuw, Eveline L and Belsky, Daniel W and Harden, K Paige and Nivard, Michel G} } @article {436, title = {Large-scale association analyses identify host factors influencing human gut microbiome composition}, journal = {Nature Genetics}, volume = {53}, year = {2021}, pages = {156{\textendash}165}, abstract = {

To study the effect of host genetics on gut microbiome composition, the MiBioGen consortium curated and analyzed genome-wide genotypes and 16S fecal microbiome data from 18,340 individuals (24 cohorts). Microbial composition showed high variability across cohorts: only 9 of 410 genera were detected in more than 95\% of samples. A genome-wide association study of host genetic variation regarding microbial taxa identified 31 loci affecting the microbiome at a genome-wide significant (P \< 5 $\times$ 10-8) threshold. One locus, the lactase (LCT) gene locus, reached study-wide significance (genome-wide association study signal: P = 1.28 $\times$ 10-20), and it showed an age-dependent association with Bifidobacterium abundance. Other associations were suggestive (1.95 $\times$ 10-10 \< P \< 5 $\times$ 10-8) but enriched for taxa showing high heritability and for genes expressed in the intestine and brain. A phenome-wide association study and Mendelian randomization identified enrichment of microbiome trait loci in the metabolic, nutrition and environment domains and suggested the microbiome might have causal effects in ulcerative colitis and rheumatoid arthritis.

}, doi = {10.1038/s41588-020-00763-1}, author = {Kurilshikov, Alexander and Medina-Gomez, Carolina and Bacigalupe, Rodrigo and Radjabzadeh, Djawad and Wang, Jun and Demirkan, Ayse and Le Roy, Caroline I and Raygoza Garay, Juan Antonio and Finnicum, Casey T and Liu, Xingrong and Zhernakova, Daria V and Bonder, Marc Jan and Hansen, Tue H and Frost, Fabian and R{\"u}hlemann, Malte C and Turpin, Williams and Moon, Jee-Young and Kim, Han-Na and L{\"u}ll, Kreete and Barkan, Elad and Shah, Shiraz A and Fornage, Myriam and Szopinska-Tokov, Joanna and Wallen, Zachary D and Borisevich, Dmitrii and Agreus, Lars and Andreasson, Anna and Bang, Corinna and Bedrani, Larbi and Bell, Jordana T and Bisgaard, Hans and Boehnke, Michael and Boomsma, Dorret I and Burk, Robert D and Claringbould, Annique and Croitoru, Kenneth and Davies, Gareth E and van Duijn, Cornelia M and Duijts, Liesbeth and Falony, Gwen and Fu, Jingyuan and van der Graaf, Adriaan and Hansen, Torben and Homuth, Georg and Hughes, David A and Ijzerman, Richard G and Jackson, Matthew A and Jaddoe, Vincent W V and Joossens, Marie and J{\o}rgensen, Torben and Keszthelyi, Daniel and Knight, Rob and Laakso, Markku and Laudes, Matthias and Launer, Lenore J and Lieb, Wolfgang and Lusis, Aldons J and Masclee, Ad A M and Moll, Henriette A and Mujagic, Zlatan and Qibin, Qi and Rothschild, Daphna and Shin, Hocheol and S{\o}rensen, S{\o}ren J and Steves, Claire J and Thorsen, Jonathan and Timpson, Nicholas J and Tito, Raul Y and Vieira-Silva, Sara and V{\"o}lker, Uwe and V{\"o}lzke, Henry and V{\~o}sa, Urmo and Wade, Kaitlin H and Walter, Susanna and Watanabe, Kyoko and Weiss, Stefan and Weiss, Frank U and Weissbrod, Omer and Westra, Harm-Jan and Willemsen, Gonneke and Payami, Haydeh and Jonkers, Daisy M A E and Arias Vasquez, Alejandro and de Geus, Eco J C and Meyer, Katie A and Stokholm, Jakob and Segal, Eran and Org, Elin and Wijmenga, Cisca and Kim, Hyung-Lae and Kaplan, Robert C and Spector, Tim D and Uitterlinden, Andre G and Rivadeneira, Fernando and Franke, Andre and Lerch, Markus M and Franke, Lude and Sanna, Serena and D{\textquoteright}Amato, Mauro and Pedersen, Oluf and Paterson, Andrew D and Kraaij, Robert and Raes, Jeroen and Zhernakova, Alexandra} } @article {445, title = {Large-scale collaboration in ENIGMA-EEG: A perspective on the meta-analytic approach to link neurological and psychiatric liability genes to electrophysiological brain activity}, journal = {Brain and Behavior}, volume = {11}, year = {2021}, pages = {e02188}, abstract = {

BACKGROUND AND PURPOSE: The ENIGMA-EEG working group was established to enable large-scale international collaborations among cohorts that investigate the genetics of brain function measured with electroencephalography (EEG). In this perspective, we will discuss why analyzing the genetics of functional brain activity may be crucial for understanding how neurological and psychiatric liability genes affect the brain.

METHODS: We summarize how we have performed our currently largest genome-wide association study of oscillatory brain activity in EEG recordings by meta-analyzing the results across five participating cohorts, resulting in the first genome-wide significant hits for oscillatory brain function located in/near genes that were previously associated with psychiatric disorders. We describe how we have tackled methodological issues surrounding genetic meta-analysis of EEG features. We discuss the importance of harmonizing EEG signal processing, cleaning, and feature extraction. Finally, we explain our selection of EEG features currently being investigated, including the temporal dynamics of oscillations and the connectivity network based on synchronization of oscillations.

RESULTS: We present data that show how to perform systematic quality control and evaluate how choices in reference electrode and montage affect individual differences in EEG parameters.

CONCLUSION: The long list of potential challenges to our large-scale meta-analytic approach requires extensive effort and organization between participating cohorts; however, our perspective shows that these challenges are surmountable. Our perspective argues that elucidating the genetic of EEG oscillatory activity is a worthwhile effort in order to elucidate the pathway from gene to disease liability.

}, keywords = {brain disorders, electroencephalography, ENIGMA, harmonization, imaging genetics, open science}, doi = {10.1002/brb3.2188}, author = {Smit, Dirk J A and Andreassen, Ole A and Boomsma, Dorret I and Burwell, Scott J and Chorlian, David B and de Geus, Eco J C and Elvs\aashagen, Torbj{\o}rn and Gordon, Reyna L and Harper, Jeremy and Hegerl, Ulrich and Hensch, Tilman and Iacono, William G and Jawinski, Philippe and J{\"o}nsson, Erik G and Luykx, Jurjen J and Magne, Cyrille L and Malone, Stephen M and Medland, Sarah E and Meyers, Jacquelyn L and Moberget, Torgeir and Porjesz, Bernice and Sander, Christian and Sisodiya, Sanjay M and Thompson, Paul M and van Beijsterveldt, Catharina E M and van Dellen, Edwin and Via, Marc and Wright, Margaret J} } @article {446, title = {Predicting complex traits and exposures from polygenic scores and blood and buccal DNA methylation profiles}, journal = {Frontiers in Psychiatry}, volume = {12}, year = {2021}, pages = {688464}, abstract = {

We examined the performance of methylation scores (MS) and polygenic scores (PGS) for birth weight, BMI, prenatal maternal smoking exposure, and smoking status to assess the extent to which MS could predict these traits and exposures over and above the PGS in a multi-omics prediction model. MS may be seen as the epigenetic equivalent of PGS, but because of their dynamic nature and sensitivity of non-genetic exposures may add to complex trait prediction independently of PGS. MS and PGS were calculated based on genotype data and DNA-methylation data in blood samples from adults (Illumina 450 K; N = 2,431; mean age 35.6) and in buccal samples from children (Illumina EPIC; N = 1,128; mean age 9.6) from the Netherlands Twin Register. Weights to construct the scores were obtained from results of large epigenome-wide association studies (EWASs) based on whole blood or cord blood methylation data and genome-wide association studies (GWASs). In adults, MSs in blood predicted independently from PGSs, and outperformed PGSs for BMI, prenatal maternal smoking, and smoking status, but not for birth weight. The largest amount of variance explained by the multi-omics prediction model was for current vs. never smoking (54.6\%) of which 54.4\% was captured by the MS. The two predictors captured 16\% of former vs. never smoking initiation variance (MS:15.5\%, PGS: 0.5\%), 17.7\% of prenatal maternal smoking variance (MS:16.9\%, PGS: 0.8\%), 11.9\% of BMI variance (MS: 6.4\%, PGS 5.5\%), and 1.9\% of birth weight variance (MS: 0.4\%, PGS: 1.5\%). In children, MSs in buccal samples did not show independent predictive value. The largest amount of variance explained by the two predictors was for prenatal maternal smoking (2.6\%), where the MSs contributed 1.5\%. These results demonstrate that blood DNA MS in adults explain substantial variance in current smoking, large variance in former smoking, prenatal smoking, and BMI, but not in birth weight. Buccal cell DNA methylation scores have lower predictive value, which could be due to different tissues in the EWAS discovery studies and target sample, as well as to different ages. This study illustrates the value of combining polygenic scores with information from methylation data for complex traits and exposure prediction.

}, keywords = {birth weight, BMI, DNA methylation, maternal smoking, methylation scores, multi-omics prediction, polygenic scores, smoking}, doi = {10.3389/fpsyt.2021.688464}, author = {Odintsova, Veronika V and Rebattu, Valerie and Hagenbeek, Fiona A and Pool, Ren{\'e} and Beck, Jeffrey J and Ehli, Erik A and van Beijsterveldt, Catharina E M and Ligthart, Lannie and Willemsen, Gonneke and de Geus, Eco J C and Hottenga, Jouke-Jan and Boomsma, Dorret I and van Dongen, Jenny} } @article {443, title = {Sex-dimorphic genetic effects and novel loci for fasting glucose and insulin variability}, journal = {Nature Communications}, volume = {12}, year = {2021}, pages = {24}, abstract = {

Differences between sexes contribute to variation in the levels of fasting glucose and insulin. Epidemiological studies established a higher prevalence of impaired fasting glucose in men and impaired glucose tolerance in women, however, the genetic component underlying this phenomenon is not established. We assess sex-dimorphic (73,089/50,404 women and 67,506/47,806 men) and sex-combined (151,188/105,056 individuals) fasting glucose/fasting insulin genetic effects via genome-wide association study meta-analyses in individuals of European descent without diabetes. Here we report sex dimorphism in allelic effects on fasting insulin at IRS1 and ZNF12 loci, the latter showing higher RNA expression in whole blood in women compared to men. We also observe sex-homogeneous effects on fasting glucose at seven novel loci. Fasting insulin in women shows stronger genetic correlations than in men with waist-to-hip ratio and anorexia nervosa. Furthermore, waist-to-hip ratio is causally related to insulin resistance in women, but not in men. These results position dissection of metabolic and glycemic health sex dimorphism as a steppingstone for understanding differences in genetic effects between women and men in related phenotypes.

}, doi = {10.1038/s41467-020-19366-9}, author = {Lagou, Vasiliki and M{\"a}gi, Reedik and Hottenga, Jouke- Jan and Grallert, Harald and Perry, John R B and Bouatia-Naji, Nabila and Marullo, Letizia and Rybin, Denis and Jansen, Rick and Min, Josine L and Dimas, Antigone S and Ulrich, Anna and Zudina, Liudmila and G\aadin, Jesper R and Jiang, Longda and Faggian, Alessia and Bonnefond, Am{\'e}lie and Fadista, Joao and Stathopoulou, Maria G and Isaacs, Aaron and Willems, Sara M and Navarro, Pau and Tanaka, Toshiko and Jackson, Anne U and Montasser, May E and O{\textquoteright}Connell, Jeff R and Bielak, Lawrence F and Webster, Rebecca J and Saxena, Richa and Stafford, Jeanette M and Pourcain, Beate St and Timpson, Nicholas J and Salo, Perttu and Shin, So-Youn and Amin, Najaf and Smith, Albert V and Li, Guo and Verweij, Niek and Goel, Anuj and Ford, Ian and Johnson, Paul C D and Johnson, Toby and Kapur, Karen and Thorleifsson, Gudmar and Strawbridge, Rona J and Rasmussen-Torvik, Laura J and Esko, T{\~o}nu and Mihailov, Evelin and Fall, Tove and Fraser, Ross M and Mahajan, Anubha and Kanoni, Stavroula and Giedraitis, Vilmantas and Kleber, Marcus E and Silbernagel, G{\"u}nther and Meyer, Julia and M{\"u}ller-Nurasyid, Martina and Ganna, Andrea and Sarin, Antti-Pekka and Yengo, Loic and Shungin, Dmitry and Luan, Jian{\textquoteright}an and Horikoshi, Momoko and An, Ping and Sanna, Serena and Boettcher, Yvonne and Rayner, N William and Nolte, Ilja M and Zemunik, Tatijana and van Iperen, Erik and Kovacs, Peter and Hastie, Nicholas D and Wild, Sarah H and McLachlan, Stela and Campbell, Susan and Polasek, Ozren and Carlson, Olga and Egan, Josephine and Kiess, Wieland and Willemsen, Gonneke and Kuusisto, Johanna and Laakso, Markku and Dimitriou, Maria and Hicks, Andrew A and Rauramaa, Rainer and Bandinelli, Stefania and Thorand, Barbara and Liu, Yongmei and Miljkovic, Iva and Lind, Lars and Doney, Alex and Perola, Markus and Hingorani, Aroon and Kivimaki, Mika and Kumari, Meena and Bennett, Amanda J and Groves, Christopher J and Herder, Christian and Koistinen, Heikki A and Kinnunen, Leena and Faire, Ulf de and Bakker, Stephan J L and Uusitupa, Matti and Palmer, Colin N A and Jukema, J Wouter and Sattar, Naveed and Pouta, Anneli and Snieder, Harold and Boerwinkle, Eric and Pankow, James S and Magnusson, Patrik K and Krus, Ulrika and Scapoli, Chiara and de Geus, Eco J C N and Bl{\"u}her, Matthias and Wolffenbuttel, Bruce H R and Province, Michael A and Abecasis, Goncalo R and Meigs, James B and Hovingh, G Kees and Lindstr{\"o}m, Jaana and Wilson, James F and Wright, Alan F and Dedoussis, George V and Bornstein, Stefan R and Schwarz, Peter E H and T{\"o}njes, Anke and Winkelmann, Bernhard R and Boehm, Bernhard O and M{\"a}rz, Winfried and Metspalu, Andres and Price, Jackie F and Deloukas, Panos and K{\"o}rner, Antje and Lakka, Timo A and Keinanen-Kiukaanniemi, Sirkka M and Saaristo, Timo E and Bergman, Richard N and Tuomilehto, Jaakko and Wareham, Nicholas J and Langenberg, Claudia and M{\"a}nnist{\"o}, Satu and Franks, Paul W and Hayward, Caroline and Vitart, Veronique and Kaprio, Jaakko and Visvikis-Siest, Sophie and Balkau, Beverley and Altshuler, David and Rudan, Igor and Stumvoll, Michael and Campbell, Harry and van Duijn, Cornelia M and Gieger, Christian and Illig, Thomas and Ferrucci, Luigi and Pedersen, Nancy L and Pramstaller, Peter P and Boehnke, Michael and Frayling, Timothy M and Shuldiner, Alan R and Peyser, Patricia A and Kardia, Sharon L R and Palmer, Lyle J and Penninx, Brenda W and Meneton, Pierre and Harris, Tamara B and Navis, Gerjan and Harst, Pim van der and Smith, George Davey and Forouhi, Nita G and Loos, Ruth J F and Salomaa, Veikko and Soranzo, Nicole and Boomsma, Dorret I and Groop, Leif and Tuomi, Tiinamaija and Hofman, Albert and Munroe, Patricia B and Gudnason, Vilmundur and Siscovick, David S and Watkins, Hugh and Lecoeur, Cecile and Vollenweider, Peter and Franco-Cereceda, Anders and Eriksson, Per and Jarvelin, Marjo-Riitta and Stefansson, Kari and Hamsten, Anders and Nicholson, George and Karpe, Fredrik and Dermitzakis, Emmanouil T and Lindgren, Cecilia M and McCarthy, Mark I and Froguel, Philippe and Kaakinen, Marika A and Lyssenko, Valeriya and Watanabe, Richard M and Ingelsson, Erik and Florez, Jose C and Dupuis, Jos{\'e}e and Barroso, In{\^e}s and Morris, Andrew P and Prokopenko, Inga and Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC)} } @article {450, title = {Teacher-rated aggression and co-occurring behaviors and emotional problems among schoolchildren in four population-based European cohorts}, journal = {PLoS One}, volume = {16}, year = {2021}, pages = {e0238667}, abstract = {

Aggressive behavior in school is an ongoing concern. The current focus is on specific manifestations such as bullying, but the behavior is broad and heterogenous. Children spend a substantial amount of time in school, but their behaviors in the school setting tend to be less well characterized than at home. Because aggression may index multiple behavioral problems, we used three validated instruments to assess means, correlations and gender differences of teacher-rated aggressive behavior with co-occurring externalizing/internalizing problems and social behavior in 39,936 schoolchildren aged 7-14 from 4 population-based cohorts from Finland, the Netherlands, and the UK. Correlations of aggressive behavior were high with all other externalizing problems (r: 0.47-0.80) and lower with internalizing problems (r: 0.02-0.39). A negative association was observed with prosocial behavior (r: -0.33 to -0.54). Mean levels of aggressive behavior differed significantly by gender. Despite the higher mean levels of aggressive behavior in boys, the correlations were notably similar for boys and girls (e.g., aggressive-hyperactivity correlations: 0.51-0.75 boys, 0.47-0.70 girls) and did not vary greatly with respect to age, instrument or cohort. Thus, teacher-rated aggressive behavior rarely occurs in isolation; boys and girls with problems of aggressive behavior likely require help with other behavioral and emotional problems. Important to note, higher aggressive behavior is not only associated with higher amounts of other externalizing and internalizing problems but also with lower levels of prosocial behavior.

}, doi = {10.1371/journal.pone.0238667}, author = {Whipp, Alyce M and Vuoksimaa, Eero and Bolhuis, Koen and de Zeeuw, Eveline L and Korhonen, Tellervo and Mauri, Matteo and Pulkkinen, Lea and Rimfeld, Kaili and Rose, Richard J and van Beijsterveldt, Catharina Toos E M and Bartels, Meike and Plomin, Robert and Tiemeier, Henning and Kaprio, Jaakko and Boomsma, Dorret I} } @article {421, title = {The (broad-sense) genetic correlations among four measures of inattention and hyperactivity in 12 year Olds}, journal = {Behavior Genetics}, volume = {50}, year = {2020}, pages = {273{\textendash}288}, abstract = {

We estimated the genetic covariance matrix among four inattention (INATT) and four hyperactivity (HYP) measures in the classical twin design. Data on INATT and HYP symptom counts were obtained in mono- and dizygotic twin pairs (N = 1593) with an average age of 12.2 years (sd = .51). We analyzed maternal ratings of INATT and HYP based on the Conners\&$\#$39; Parent Rating Scale (CPRS), the Strengths and Weaknesses of ADHD-symptoms and Normal-behavior (SWAN), and teacher ratings based on the Conners\&$\#$39; Teacher rating scale (CTRS) and the ASEBA Teacher Rating Form (TRF). Broad-sense heritabilities, corrected for the main effects of sex and for random teacher rater effects, were large (ranging from .658 to .912). The results reveal pervasive and strong broad-sense genetic effects on INATT and HYP phenotypes with the phenotypic covariance among the phenotypes largely due to correlated genetic effects. Specifically between 79.9 and 99.9\% of the phenotypic covariance among the HYP measures, and between 81.0 and 93.5\% of the INATT measures are attributable to broad-sense genetic effects. Overall, the present results, pertaining to the broad-sense heritabilities and shared genetic effects, support the current genome-wide association meta-analytic approach to identifying pleiotropic genetic variants.

}, keywords = {ADHD, Genetic correlation, Hyperactivity, Inattention, Multivariate genetic model, Twin design}, doi = {10.1186/s12966-019-0779-4}, author = {Dolan, Conor V and de Zeeuw, Eveline L and Zayats, Tetyana and van Beijsterveldt, C E M and Boomsma, Dorret I} } @article {424, title = {Genetics and not shared environment explains familial resemblance in adult metabolomics data}, journal = {Human Genetics}, volume = {23}, year = {2020}, pages = {145{\textendash}155}, abstract = {

Metabolites are small molecules involved in cellular metabolism where they act as reaction substrates or products. The term \&$\#$39;metabolomics\&$\#$39; refers to the comprehensive study of these molecules. The concentrations of metabolites in biological tissues are under genetic control, but this is limited by environmental factors such as diet. In adult mono- and dizygotic twin pairs, we estimated the contribution of genetic and shared environmental influences on metabolite levels by structural equation modeling and tested whether the familial resemblance for metabolite levels is mainly explained by genetic or by environmental factors that are shared by family members. Metabolites were measured across three platforms: two based on proton nuclear magnetic resonance techniques and one employing mass spectrometry. These three platforms comprised 237 single metabolic traits of several chemical classes. For the three platforms, metabolites were assessed in 1407, 1037 and 1116 twin pairs, respectively. We carried out power calculations to establish what percentage of shared environmental variance could be detected given these sample sizes. Our study did not find evidence for a systematic contribution of shared environment, defined as the influence of growing up together in the same household, on metabolites assessed in adulthood. Significant heritability was observed for nearly all 237 metabolites; significant contribution of the shared environment was limited to 6 metabolites. The top quartile of the heritability distribution was populated by 5 of the 11 investigated chemical classes. In this quartile, metabolites of the class lipoprotein were significantly overrepresented, whereas metabolites of classes glycerophospholipids and glycerolipids were significantly underrepresented.

}, keywords = {classical twin design, enrichment analysis, heritability, metabolite classes, shared environment}, doi = {DOI: 10.1017/thg.2020.53}, author = {Pool, Ren{\'e} and Hagenbeek, Fiona A and Hendriks, Anne M and van Dongen, Jenny and Willemsen, Gonneke and de Geus, Eco and BBMRI Metabolomics Consortium and Willems van Dijk, Ko and Verhoeven, Aswin and Suchiman, H Eka and Beekman, Marian and Slagboom, P Eline and Harms, Amy C and Hankemeier, Thomas and Boomsma, Dorret I} } @article {422, title = {Harmonizing behavioral outcomes across studies, raters, and countries: application to the genetic analysis of aggression in the ACTION Consortium}, journal = {Journal of Child Psychology and Psychiatry}, volume = {61}, year = {2020}, pages = {807{\textendash}817}, abstract = {

BACKGROUND: Aggression in children has genetic and environmental causes. Studies of aggression can pool existing datasets to include more complex models of social effects. Such analyses require large datasets with harmonized outcome measures. Here, we made use of a reference panel for phenotype data to harmonize multiple aggression measures in school-aged children to jointly analyze data from five large twin cohorts.

METHODS: Individual level aggression data on 86,559 children (42,468 twin pairs) were available in five European twin cohorts measured by different instruments. A phenotypic reference panel was collected which enabled a model-based phenotype harmonization approach. A bi-factor integration model in the integrative data analysis framework was developed to model aggression across studies while adjusting for rater, age, and sex. Finally, harmonized aggression scores were analyzed to estimate contributions of genes, environment, and social interaction to aggression. The large sample size allowed adequate power to test for sibling interaction effects, with unique dynamics permitted for opposite-sex twins.

RESULTS: The best-fitting model found a high level of overall heritability of aggression (\ 60\%). Different heritability rates of aggression across sex were marginally significant, with heritability estimates in boys of \ 64\% and \ 58\% in girls. Sibling interaction effects were only significant in the opposite-sex twin pairs: the interaction effect of males on their female co-twin differed from the effect of females on their male co-twin. An aggressive female had a positive effect on male co-twin aggression, whereas more aggression in males had a negative influence on a female co-twin.

CONCLUSIONS: Opposite-sex twins displayed unique social dynamics of aggressive behaviors in a joint analysis of a large, multinational dataset. The integrative data analysis framework, applied in combination with a reference panel, has the potential to elucidate broad, generalizable results in the investigation of common psychological traits in children.

}, keywords = {Aggression, developmental psychopathology, integrative data analysis, phenotype reference panel, twin modeling}, doi = {10.1111/jcpp.13188}, author = {Luningham, Justin M and Hendriks, Anne M and Krapohl, Eva and Fung Ip, Hill and van Beijsterveldt, Catharina E M and Lundstr{\"o}m, Sebastian and Vuoksimaa, Eero and Korhonen, Tellervo and Lichtenstein, Paul and Plomin, Robert and Pulkkinen, Lea and Rose, Richard J and Kaprio, Jaakko and Bartels, Meike and Boomsma, Dorret I and Lubke, Gitta H} } @article {427, title = {Heritability estimates for 361 blood metabolites across 40 genome-wide association studies}, journal = {Nature Communications}, volume = {11}, year = {2020}, pages = {39}, abstract = {

Metabolomics examines the small molecules involved in cellular metabolism. Approximately 50\% of total phenotypic differences in metabolite levels is due to genetic variance, but heritability estimates differ across metabolite classes. We perform a review of all genome-wide association and (exome-) sequencing studies published between November 2008 and October 2018, and identify \>800 class-specific metabolite loci associated with metabolite levels. In a twin-family cohort (N = 5117), these metabolite loci are leveraged to simultaneously estimate total heritability (h2total), and the proportion of heritability captured by known metabolite loci (h2Metabolite-hits) for 309 lipids and 52 organic acids. Our study reveals significant differences in h2Metabolite-hits among different classes of lipids and organic acids. Furthermore, phosphatidylcholines with a high degree of unsaturation have higher h2Metabolite-hits estimates than phosphatidylcholines with low degrees of unsaturation. This study highlights the importance of common genetic variants for metabolite levels, and elucidates the genetic architecture of metabolite classes.

}, doi = {DOI: 10.1038/s41467-019-13770-6}, author = {Hagenbeek, Fiona A and Pool, Ren{\'e} and van Dongen, Jenny and Draisma, Harmen H M and Jan Hottenga, Jouke and Willemsen, Gonneke and Abdellaoui, Abdel and Fedko, Iryna O and den Braber, Anouk and Visser, Pieter Jelle and de Geus, Eco J C N and Willems van Dijk, Ko and Verhoeven, Aswin and Suchiman, H Eka and Beekman, Marian and Slagboom, P Eline and van Duijn, Cornelia M and BBMRI Metabolomics Consortium and Harms, Amy C and Hankemeier, Thomas and Bartels, Meike and Nivard, Michel G and Boomsma, Dorret I} } @article {423, title = {Identification, heritability, and relation with gene expression of novel DNA methylation loci for blood pressure}, journal = {Hypertension}, volume = {76}, year = {2020}, pages = {195{\textendash}205}, abstract = {

We conducted an epigenome-wide association study meta-analysis on blood pressure (BP) in 4820 individuals of European and African ancestry aged 14 to 69. Genome-wide DNA methylation data from peripheral leukocytes were obtained using the Infinium Human Methylation 450k BeadChip. The epigenome-wide association study meta-analysis identified 39 BP-related CpG sites with P\<1$\times$10-5. In silico replication in the CHARGE consortium of 17 010 individuals validated 16 of these CpG sites. Out of the 16 CpG sites, 13 showed novel association with BP. Conversely, out of the 126 CpG sites identified as being associated (P\<1$\times$10-7) with BP in the CHARGE consortium, 21 were replicated in the current study. Methylation levels of all the 34 CpG sites that were cross-validated by the current study and the CHARGE consortium were heritable and 6 showed association with gene expression. Furthermore, 9 CpG sites also showed association with BP with P\<0.05 and consistent direction of the effect in the meta-analysis of the Finnish Twin Cohort (199 twin pairs and 4 singletons; 61\% monozygous) and the Netherlands Twin Register (266 twin pairs and 62 singletons; 84\% monozygous). Bivariate quantitative genetic modeling of the twin data showed that a majority of the phenotypic correlations between methylation levels of these CpG sites and BP could be explained by shared unique environmental rather than genetic factors, with 100\% of the correlations of systolic BP with cg19693031 (TXNIP) and cg00716257 (JDP2) determined by environmental effects acting on both systolic BP and methylation levels.

}, keywords = {blood pressure, DNA methylation, epigenome, hypertension, twin study}, doi = {10.1161/HYPERTENSIONAHA.120.14973}, author = {Huang, Yisong and Ollikainen, Miina and Muniandy, Maheswary and Zhang, Tao and van Dongen, Jenny and Hao, Guang and van der Most, Peter J and Pan, Yue and Pervjakova, Natalia and Sun, Yan V and Hui, Qin and Lahti, Jari and Fraszczyk, Eliza and Lu, Xueling and Sun, Dianjianyi and Richard, Melissa A and Willemsen, Gonneke and Heikkil{\"a}, Kauko and Mateo Leach, Irene and Mononen, Nina and K{\"a}h{\"o}nen, Mika and Hurme, Mikko A and Raitakari, Olli T and Drake, Amanda J and Perola, Markus and Nuotio, Marja-Liisa and Huang, Yunfeng and Khulan, Batbayar and R{\"a}ikk{\"o}nen, Katri and Wolffenbuttel, Bruce H R and Zhernakova, Alexandra and Fu, Jingyuan and Zhu, Haidong and Dong, Yanbin and van Vliet-Ostaptchouk, Jana V and Franke, Lude and Eriksson, Johan G and Fornage, Myriam and Milani, Lili and Lehtim{\"a}ki, Terho and Vaccarino, Viola and Boomsma, Dorret I and van der Harst, Pim and de Geus, Eco J C and Salomaa, Veikko and Li, Shengxu and Chen, Wei and Su, Shaoyong and Wilson, James and Snieder, Harold and Kaprio, Jaakko and Wang, Xiaoling} } @article {441, title = {Measurement and genetic architecture of lifetime depression in the Netherlands as assessed by LIDAS (Lifetime Depression Assessment Self-report)}, journal = {Psychological Medicine}, volume = {51}, year = {2020}, pages = {1{\textendash}10}, abstract = {

BACKGROUND: Major depressive disorder (MDD) is a common mood disorder, with a heritability of around 34\%. Molecular genetic studies made significant progress and identified genetic markers associated with the risk of MDD; however, progress is slowed down by substantial heterogeneity as MDD is assessed differently across international cohorts. Here, we used a standardized online approach to measure MDD in multiple cohorts in the Netherlands and evaluated whether this approach can be used in epidemiological and genetic association studies of depression. METHODS: Within the Biobank Netherlands Internet Collaboration (BIONIC) project, we collected MDD data in eight cohorts involving 31 936 participants, using the online Lifetime Depression Assessment Self-report (LIDAS), and estimated the prevalence of current and lifetime MDD in 22 623 unrelated individuals. In a large Netherlands Twin Register (NTR) twin-family dataset (n $\approx$ 18 000), we estimated the heritability of MDD, and the prediction of MDD in a subset (n = 4782) through Polygenic Risk Score (PRS). RESULTS: Estimates of current and lifetime MDD prevalence were 6.7\% and 18.1\%, respectively, in line with population estimates based on validated psychiatric interviews. In the NTR heritability estimates were 0.34/0.30 (s.e. = 0.02/0.02) for current/lifetime MDD, respectively, showing that the LIDAS gives similar heritability rates for MDD as reported in the literature. The PRS predicted risk of MDD (OR 1.23, 95\% CI 1.15-1.3

}, keywords = {LIDAS, Lifetime Depression Assessment Self-report, major depressive disorder, online assessment tool, prevalence}, doi = {10.1017/S0033291720000100}, author = {Fedko, Iryna O and Hottenga, Jouke-Jan and Helmer, Quinta and Mbarek, Hamdi and Huider, Floris and Amin, Najaf and Beulens, Joline W and Bremmer, Marijke A and Elders, Petra J and Galesloot, Tessel E and Kiemeney, Lambertus A and van Loo, Hanna M and Picavet, H Susan J and Rutters, Femke and van der Spek, Ashley and van de Wiel, Anne M and van Duijn, Cornelia and de Geus, Eco J C and Feskens, Edith J M and Hartman, Catharina A and Oldehinkel, Albertine J and Smit, Jan H and Verschuren, W M Monique and Penninx, Brenda W J H and Boomsma, Dorret I and Bot, Mariska} } @article {429, title = {Out of control: Examining the association between family conflict and self-control in adolescence in a genetically sensitive design}, journal = {Journal of the American Academy of Child \& Adolescent }, volume = {59}, year = {2020}, pages = {254{\textendash}262}, abstract = {

OBJECTIVE: Family conflict is associated with low self-control in adolescence. Thus far research about the direction of this association is inconclusive. In this study, we sort out whether this association reflects a causal effect or whether it is explained by a common underlying cause, including genetic factors.

METHOD: In twin data, we fitted a series of causal models, and compared models for the association of family conflict and self-control including reciprocal causation, unidirectional causation from family conflict to low self-control, unidirectional causation from low self-control to family conflict, and common genetic susceptibility. We included data from a large sample of twins aged 14 years (N = 9,173), all enrolled in the Netherlands Twin Register.

RESULTS: The results suggested a unidirectional pathway model in which family conflict leads to low self-control in adolescence, with genetic factors also playing a role in explaining the association.

CONCLUSION: Adolescents experiencing family conflict are at risk for showing hampered self-control capacities, with family conflict being a robust predictor of low self-control through common genetic factors but also through direct causal influences.

}, keywords = {environment, family conflict, genetics, self-control, twins}, doi = {10.1016/j.jaac.2019.02.017}, author = {Willems, Yayouk E and de Zeeuw, Eveline L and van Beijsterveldt, Catharina E M and Boomsma, Dorret I and Bartels, Meike and Finkenauer, Catrin} } @article {431, title = {Parental age and offspring childhood mental health: A multi-cohort, population-based investigation}, journal = {Child Development}, volume = {91}, year = {2020}, pages = {964{\textendash}982}, abstract = {

To examine the contributions of maternal and paternal age on offspring externalizing and internalizing problems, this study analyzed problem behaviors at age 10-12 years from four Dutch population-based cohorts (N = 32,892) by a multiple informant design. Bayesian evidence synthesis was used to combine results across cohorts with 50\% of the data analyzed for discovery and 50\% for confirmation. There was evidence of a robust negative linear relation between parental age and externalizing problems as reported by parents. In teacher-reports, this relation was largely explained by parental socio-economic status. Parental age had limited to no association with internalizing problems. Thus, in this large population-based study, either a beneficial or no effect of advanced parenthood on child problem behavior was observed.

}, doi = {10.1111/cdev.13267}, author = {Zondervan-Zwijnenburg, Maria A J and Veldkamp, Sabine A M and Neumann, Alexander and Barzeva, Stefania A and Nelemans, Stefanie A and van Beijsterveldt, Catharina E M and Branje, Susan J T and Hillegers, Manon H J and Meeus, Wim H J and Tiemeier, Henning and Hoijtink, Herbert J A and Oldehinkel, Albertine J and Boomsma, Dorret I} } @article {426, title = {Urinary Amine and organic acid metabolites evaluated as markers for childhood aggression: The ACTION biomarker study}, journal = {Frontiers in Psychiatry}, volume = {11}, year = {2020}, pages = {165}, abstract = {

Biomarkers are of interest as potential diagnostic and predictive instruments in personalized medicine. We present the first urinary metabolomics biomarker study of childhood aggression. We aim to examine the association of urinary metabolites and neurotransmitter ratios involved in key metabolic and neurotransmitter pathways in a large cohort of twins (N = 1,347) and clinic-referred children (N = 183) with an average age of 9.7 years. This study is part of ACTION (Aggression in Children: Unraveling gene-environment interplay to inform Treatment and InterventiON strategies), in which we developed a standardized protocol for large-scale collection of urine samples in children. Our analytical design consisted of three phases: a discovery phase in twins scoring low or high on aggression (N = 783); a replication phase in twin pairs discordant for aggression (N = 378); and a validation phase in clinical cases and matched twin controls (N = 367). In the discovery phase, 6 biomarkers were significantly associated with childhood aggression, of which the association of O-phosphoserine ($\beta$ = 0.36; SE = 0.09; p = 0.004), and gamma-L-glutamyl-L-alanine ($\beta$ = 0.32; SE = 0.09; p = 0.01) remained significant after multiple testing. Although non-significant, the directions of effect were congruent between the discovery and replication analyses for six biomarkers and two neurotransmitter ratios and the concentrations of 6 amines differed between low and high aggressive twins. In the validation analyses, the top biomarkers and neurotransmitter ratios, with congruent directions of effect, showed no significant associations with childhood aggression. We find suggestive evidence for associations of childhood aggression with metabolic dysregulation of neurotransmission, oxidative stress, and energy metabolism. Although replication is required, our findings provide starting points to investigate causal and pleiotropic effects of these dysregulations on childhood aggression.

}, keywords = {amines, biomarkers, childhood aggression, metabolites, metabolomics, neurotransmitters, organic acids, oxidative stress}, doi = {10.3389/fpsyt.2020.00165}, author = {Hagenbeek, Fiona A and Roetman, Peter J and Pool, Ren{\'e} and Kluft, Cornelis and Harms, Amy C and van Dongen, Jenny and Colins, Olivier F and Talens, Simone and van Beijsterveldt, Catharina E M and Vandenbosch, Marjolein M L J Z and de Zeeuw, Eveline L and D{\'e}jean, S{\'e}bastien and Fanos, Vassilios and Ehli, Erik A and Davies, Gareth E and Hottenga, Jouke Jan and Hankemeier, Thomas and Bartels, Meike and Vermeiren, Robert R J M and Boomsma, Dorret I} } @article {412, title = {Biological insights into multiple birth: genetic findings from UK Biobank}, journal = {European Journal of Human Genetics}, volume = {27}, year = {2019}, pages = {970{\textendash}979}, abstract = {

The tendency to conceive spontaneous dizygotic (DZ) twins is a complex trait with important contributions from both environmental factors and genetic disposition. In earlier work, we identified the first two genes as maternal susceptibility loci for DZ twinning. The aim of this study was to identify genetic variants influencing multiple births and to genetically correlate the findings across a broad range of traits. We performed a genome-wide association study (GWAS) in 8962 participants with Caucasian ancestry from UK Biobank who reported being part of a multiple birth, and 409,591 singleton controls. We replicated the association between FSHB, SMAD3 and twinning in the gene-based (but not SNP-based) test, which had been established in previous genome-wide association analyses in mothers with dizygotic twin offspring. Additionally, we report a novel genetic variant associated with multiple birth, rs428022 at 15q23 (p = 2.84 $\times$ 10-8) close to two genes: PIAS1 and SKOR1. Finally, we identified meaningful genetic correlations between being part of a multiple birth and other phenotypes (anthropometric traits, health-related traits, and fertility-related measures). The outcomes of this study provide important new insights into the genetic aetiology of multiple births and fertility, and open up novel directions for fertility and reproduction research.

}, doi = {10.1038/s41431-019-0355-z}, author = {Mbarek, Hamdi and van de Weijer, Margot P and van der Zee, Mathijs D and Ip, Hill F and Beck, Jeffrey J and Abdellaoui, Abdel and Ehli, Erik A and Davies, Gareth E and Baselmans, Bart M L and Nivard, Michel G and Bartels, Meike and de Geus, Eco J and Boomsma, Dorret I} } @article {415, title = {Data integration methods for phenotype harmonization in multi-cohort genome-wide association studies with behavioral outcomes}, journal = {Frontiers in Genetics}, volume = {10}, year = {2019}, pages = {1227}, abstract = {

Parallel meta-analysis is a popular approach for increasing the power to detect genetic effects in genome-wide association studies across multiple cohorts. Consortia studying the genetics of behavioral phenotypes are oftentimes faced with systematic differences in phenotype measurement across cohorts, introducing heterogeneity into the meta-analysis and reducing statistical power. This study investigated integrative data analysis (IDA) as an approach for jointly modeling the phenotype across multiple datasets. We put forth a bi-factor integration model (BFIM) that provides a single common phenotype score and accounts for sources of study-specific variability in the phenotype. In order to capitalize on this modeling strategy, a phenotype reference panel was utilized as a supplemental sample with complete data on all behavioral measures. A simulation study showed that a mega-analysis of genetic variant effects in a BFIM were more powerful than meta-analysis of genetic effects on a cohort-specific sum score of items. Saving the factor scores from the BFIM and using those as the outcome in meta-analysis was also more powerful than the sum score in most simulation conditions, but a small degree of bias was introduced by this approach. The reference panel was necessary to realize these power gains. An empirical demonstration used the BFIM to harmonize aggression scores in 9-year old children across the Netherlands Twin Register and the Child and Adolescent Twin Study in Sweden, providing a template for application of the BFIM to a range of different phenotypes. A supplemental data collection in the Netherlands Twin Register served as a reference panel for phenotype modeling across both cohorts. Our results indicate that model-based harmonization for the study of complex traits is a useful step within genetic consortia.

}, keywords = {consortia, data integration, genome-wide association studies, latent variable modeling, phenotype harmonization}, doi = {10.3389/fgene.2019.01227}, author = {Luningham, Justin M and McArtor, Daniel B and Hendriks, Anne M and van Beijsterveldt, Catharina E M and Lichtenstein, Paul and Lundstr{\"o}m, Sebastian and Larsson, Henrik and Bartels, Meike and Boomsma, Dorret I and Lubke, Gitta H} } @article {417, title = {DNA methylation signatures of breastfeeding in buccal cells collected in mid-childhood}, journal = {Nutrients}, volume = {11}, year = {2019}, pages = {2804}, abstract = {

Breastfeeding has long-term benefits for children that may be mediated via the epigenome. This pathway has been hypothesized, but the number of empirical studies in humans is small and mostly done by using peripheral blood as the DNA source. We performed an epigenome-wide association study (EWAS) in buccal cells collected around age nine (mean = 9.5) from 1006 twins recruited by the Netherlands Twin Register (NTR). An age-stratified analysis examined if effects attenuate with age (median split at 10 years; n10 = 489, mean age = 11.2). We performed replication analyses in two independent cohorts from the NTR (buccal cells) and the Avon Longitudinal Study of Parents and Children (ALSPAC) (peripheral blood), and we tested loci previously associated with breastfeeding in epigenetic studies. Genome-wide DNA methylation was assessed with the Illumina Infinium MethylationEPIC BeadChip (Illumina, San Diego, CA, USA) in the NTR and with the HumanMethylation450 Bead Chip in the ALSPAC. The duration of breastfeeding was dichotomized (\&$\#$39;never\&$\#$39; vs. \&$\#$39;ever\&$\#$39;). In the total sample, no robustly associated epigenome-wide significant CpGs were identified ($\alpha$ = 6.34 $\times$ 10-8). In the sub-group of children younger than 10 years, four significant CpGs were associated with breastfeeding after adjusting for child and maternal characteristics. In children older than 10 years, methylation differences at these CpGs were smaller and non-significant. The findings did not replicate in the NTR sample (n = 98; mean age = 7.5 years), and no nearby sites were associated with breastfeeding in the ALSPAC study (n = 938; mean age = 7.4). Of the CpG sites previously reported in the literature, three were associated with breastfeeding in children younger than 10 years, thus showing that these CpGs are associated with breastfeeding in buccal and blood cells. Our study is the first to show that breastfeeding is associated with epigenetic variation in buccal cells in children. Further studies are needed to investigate if methylation differences at these loci are caused by breastfeeding or by other unmeasured confounders, as well as what mechanism drives changes in associations with age.

}, keywords = {ALSPAC., breastfeeding, DNA methylation, EPIC, EWAS, NTR, twins}, doi = {10.3390/nu11112804}, author = {Odintsova, Veronika V and Hagenbeek, Fiona A and Suderman, Matthew and Caramaschi, Doretta and van Beijsterveldt, Catharina E M and Kallsen, Noah A and Ehli, Erik A and Davies, Gareth E and Sukhikh, Gennady T and Fanos, Vassilios and Relton, Caroline and Bartels, Meike and Boomsma, Dorret I and van Dongen, Jenny} } @article {411, title = {Epigenome-wide association study of attention-deficit/hyperactivity disorder symptoms in adults}, journal = {Biological Psychiatry}, volume = {86}, year = {2019}, pages = {599{\textendash}607}, abstract = {

BACKGROUND: Previous studies have reported associations between attention-deficit/hyperactivity disorder symptoms and DNA methylation in children. We report the first epigenome-wide association study meta-analysis of adult attention-deficit/hyperactivity disorder symptoms, based on peripheral blood DNA methylation (Infinium HumanMethylation450K array) in three population-based adult cohorts.

METHODS: An epigenome-wide association study was performed in the Netherlands Twin Register (N = 2258, mean age 37 years), Dunedin Multidisciplinary Health and Development Study (N = 800, age 38 years), and Environmental Risk Longitudinal Twin Study (N = 1631, age 18 years), and results were combined through meta-analysis (total sample size N = 4689). Region-based analyses accounting for the correlation between nearby methylation sites were also performed.

RESULTS: One epigenome-wide significant differentially methylated position was detected in the Dunedin study, but meta-analysis did not detect differentially methylated positions that were robustly associated across cohorts. In region-based analyses, six significant differentially methylation regions (DMRs) were identified in the Netherlands Twin Register, 19 in the Dunedin study, and none in the Environmental Risk Longitudinal Twin Study. Of these DMRs, 92\% were associated with methylation quantitative trait loci, and 68\% showed moderate to large blood-brain correlations for DNA methylation levels. DMRs included six nonoverlapping DMRs (three in the Netherlands Twin Register, three in the Dunedin study) in the major histocompatibility complex, which were associated with expression of genes in the major histocompatibility complex, including C4A and C4B, previously implicated in schizophrenia.

CONCLUSIONS: Our findings point at new candidate loci involved in immune and neuronal functions that await further replication. Our work also illustrates the need for further research to examine to what extent epigenetic associations with psychiatric traits depend on characteristics such as age, comorbidities, exposures, and genetic background.

}, keywords = {ADHD, CAARS, DNA methylation, Epigenetic, EWAS, meta-analysis}, doi = {10.1016/j.biopsych.2019.02.016}, author = {van Dongen, Jenny and Zilh{\~a}o, Nuno R and Sugden, Karen and BIOS Consortium and Hannon, Eilis J and Mill, Jonathan and Caspi, Avshalom and Agnew-Blais, Jessica and Arseneault, Louise and Corcoran, David L and Moffitt, Terrie E and Poulton, Richie and Franke, Barbara and Boomsma, Dorret I} } @article {418, title = {Genetic and environmental influences on different forms of bullying perpetration, bullying victimization, and their co-occurrence}, journal = {Behavior Genetics}, volume = {49}, year = {2019}, pages = {432{\textendash}443}, abstract = {

Bullying comes in different forms, yet most previous genetically-sensitive studies have not distinguished between them. Given the serious consequences and the high prevalence of bullying, it is remarkable that the aetiology of bullying and its different forms has been under-researched. We present the first study to investigate the genetic architecture of bullying perpetration, bullying victimization, and their co-occurrence for verbal, physical and relational bullying. Primary-school teachers rated 8215 twin children on bullying perpetration and bullying victimization. For each form of bullying, we investigated, through genetic structural equation modelling, the genetic and environmental influences on being a bully, a victim or both. 34\% of the children were involved as bully, victim, or both. The correlation between being a bully and being a victim varied from 0.59 (relational) to 0.85 (physical). Heritability was \  70\% for perpetration and \  65\% for victimization, similar in girls and boys, yet both were somewhat lower for the relational form. Shared environmental influences were modest and more pronounced among girls. The correlation between being a bully and being a victim was explained mostly by genetic factors for verbal (\  71\%) and especially physical (\  77\%) and mostly by environmental factors for relational perpetration and victimization (\  60\%). Genes play a large role in explaining which children are at high risk of being a victim, bully, or both. For victimization this suggests an evocative gene-environment correlation: some children are at risk of being exposed to bullying, partly due to genetically influenced traits. So, genetic influences make some children more vulnerable to become a bully, victim or both.

}, keywords = {Bully-victims, Bullying, heritability, School, twins, Victimization}, doi = {10.1007/s10519-019-09968-5}, author = {Veldkamp, Sabine A M and Boomsma, Dorret I and de Zeeuw, Eveline L and van Beijsterveldt, Catharina E M and Bartels, Meike and Dolan, Conor V and van Bergen, Elsje} } @article {413, title = {Genomics of human aggression: current state of genome-wide studies and an automated systematic review tool}, journal = {Psychiatric Genetics}, volume = {29}, year = {2019}, pages = {170{\textendash}190}, abstract = {

There are substantial differences, or variation, between humans in aggression, with its molecular genetic basis mostly unknown. This review summarizes knowledge on the genetic contribution to variation in aggression with the following three foci: (1) a comprehensive overview of reviews on the genetics of human aggression, (2) a systematic review of genome-wide association studies (GWASs), and (3) an automated tool for the selection of literature based on supervised machine learning. The phenotype definition \&$\#$39;aggression\&$\#$39; (or \&$\#$39;aggressive behaviour\&$\#$39;, or \&$\#$39;aggression-related traits\&$\#$39;) included anger, antisocial behaviour, conduct disorder, and oppositional defiant disorder. The literature search was performed in multiple databases, manually and using a novel automated selection tool, resulting in 18 reviews and 17 GWASs of aggression. Heritability estimates of aggression in children and adults are around 50\%, with relatively small fluctuations around this estimate. In 17 GWASs, 817 variants were reported as suggestive (P \≤ 1.0E), including 10 significant associations (P \≤ 5.0E). Nominal associations (P \≤ 1E) were found in gene-based tests for genes involved in immune, endocrine, and nervous systems. Associations were not replicated across GWASs. A complete list of variants and their position in genes and chromosomes are available online. The automated literature search tool produced literature not found by regular search strategies. Aggression in humans is heritable, but its genetic basis remains to be uncovered. No sufficiently large GWASs have been carried out yet. With increases in sample size, we expect aggression to behave like other complex human traits for which GWAS has been successful.

}, doi = {10.1097/YPG.0000000000000239}, author = {Odintsova, Veronika V and Roetman, Peter J and Ip, Hill F and Pool, Ren{\'e} and Van der Laan, Camiel M and Tona, Klodiana-Daphne and Vermeiren, Robert R J M and Boomsma, Dorret I} } @article {409, title = {Meta-analysis of epigenome-wide association studies in neonates reveals widespread differential DNA methylation associated with birthweight}, journal = {Nature Communications}, volume = {10}, year = {2019}, pages = {1893}, abstract = {

Birthweight is associated with health outcomes across the life course, DNA methylation may be an underlying mechanism. In this meta-analysis of epigenome-wide association studies of 8,825 neonates from 24 birth cohorts in the Pregnancy And Childhood Epigenetics Consortium, we find that DNA methylation in neonatal blood is associated with birthweight at 914 sites, with a difference in birthweight ranging from \−183 to 178 grams per 10\% increase in methylation (PBonferroni\ \<\ 1.06\ x\ 10\−7). In additional analyses in 7,278 participants, \<1.3\% of birthweight-associated differential methylation is also observed in childhood and adolescence, but not adulthood.\ Birthweight-related CpGs overlap with some Bonferroni-significant CpGs that were previously reported to be related to maternal smoking (55/914, p\ = 6.12\ x\ 10\−74) and BMI in pregnancy (3/914, p = 1.13x10\−3), but not with those related to folate levels in pregnancy. Whether the associations that we observe are causal or explained by confounding or fetal growth influencing DNA methylation (i.e. reverse causality) requires further research.

}, doi = {10.1038/s41467-019-09671-3}, author = {K{\"u}pers, Leanne K and Monnereau, Claire and Sharp, Gemma C and Yousefi, Paul and Salas, Lucas A and Ghantous, Akram and Page, Christian M and Reese, Sarah E and Wilcox, Allen J and Czamara, Darina and Starling, Anne P and Novoloaca, Alexei and Lent, Samantha and Roy, Ritu and Hoyo, Cathrine and Breton, Carrie V and Allard, Catherine and Just, Allan C and Bakulski, Kelly M and Holloway, John W and Everson, Todd M and Xu, Cheng-Jian and Huang, Rae-Chi and van der Plaat, Diana A and Wielscher, Matthias and Merid, Simon Kebede and Ullemar, Vilhelmina and Rezwan, Faisal I and Lahti, Jari and van Dongen, Jenny and Langie, Sabine A S and Richardson, Tom G and Magnus, Maria C and Nohr, Ellen A and Xu, Zongli and Duijts, Liesbeth and Zhao, Shanshan and Zhang, Weiming and Plusquin, Michelle and DeMeo, Dawn L and Solomon, Olivia and Heimovaara, Joosje H and Jima, Dereje D and Gao, Lu and Bustamante, Mariona and Perron, Patrice and Wright, Robert O and Hertz-Picciotto, Irva and Zhang, Hongmei and Karagas, Margaret R and Gehring, Ulrike and Marsit, Carmen J and Beilin, Lawrence J and Vonk, Judith M and Jarvelin, Marjo-Riitta and Bergstr{\"o}m, Anna and {\"O}rtqvist, Anne K and Ewart, Susan and Villa, Pia M and Moore, Sophie E and Willemsen, Gonneke and Standaert, Arnout R L and H\aaberg, Siri E and S{\o}rensen, Thorkild I A and Taylor, Jack A and R{\"a}ikk{\"o}nen, Katri and Yang, Ivana V and Kechris, Katerina and Nawrot, Tim S and Silver, Matt J and Gong, Yun Yun and Richiardi, Lorenzo and Kogevinas, Manolis and Litonjua, Augusto A and Eskenazi, Brenda and Huen, Karen and Mbarek, Hamdi and Maguire, Rachel L and Dwyer, Terence and Vrijheid, Martine and Bouchard, Luigi and Baccarelli, Andrea A and Croen, Lisa A and Karmaus, Wilfried and Anderson, Denise and de Vries, Maaike and Sebert, Sylvain and Kere, Juha and Karlsson, Robert and Arshad, Syed Hasan and H{\"a}m{\"a}l{\"a}inen, Esa and Routledge, Michael N and Boomsma, Dorret I and Feinberg, Andrew P and Newschaffer, Craig J and Govarts, Eva and Moisse, Matthieu and Fallin, M Daniele and Mel{\'e}n, Erik and Prentice, Andrew M and Kajantie, Eero and Almqvist, Catarina and Oken, Emily and Dabelea, Dana and Boezen, H Marike and Melton, Phillip E and Wright, Rosalind J and Koppelman, Gerard H and Trevisi, Letizia and Hivert, Marie-France and Sunyer, Jordi and Munthe-Kaas, Monica C and Murphy, Susan K and Corpeleijn, Eva and Wiemels, Joseph and Holland, Nina and Herceg, Zdenko and Binder, Elisabeth B and Davey Smith, George and Jaddoe, Vincent W V and Lie, Rolv T and Nystad, Wenche and London, Stephanie J and Lawlor, Debbie A and Relton, Caroline L and Snieder, Harold and Felix, Janine F} } @article {414, title = {The Netherlands Twin Register: Longitudinal research based on twin and twin-family designs}, journal = {Twin Research and Human Genetics}, volume = {22}, year = {2019}, pages = {623{\textendash}636}, abstract = {

The Netherlands Twin Register (NTR) is a national register in which twins, multiples and their parents, siblings, spouses and other family members participate. Here we describe the NTR resources that were created from more than 30 years of data collections; the development and maintenance of the newly developed database systems, and the possibilities these resources create for future research. Since the early 1980s, the NTR has enrolled around 120,000 twins and a roughly equal number of their relatives. The majority of twin families have participated in survey studies, and subsamples took part in biomaterial collection (e.g., DNA) and dedicated projects, for example, for neuropsychological, biomarker and behavioral traits. The recruitment into the NTR is all inclusive without any restrictions on enrollment. These resources - the longitudinal phenotyping, the extended pedigree structures and the multigeneration genotyping - allow for future twin-family research that will contribute to gene discovery, causality modeling, and studies of genetic and cultural inheritance.

}, keywords = {biobank, endophenotyping, longitudinal phenotyping, multigeneration pedigree, twins, zygosity}, doi = {10.1017/thg.2019.93}, author = {Ligthart, Lannie and van Beijsterveldt, Catharina E M and Kevenaar, Sofieke T and de Zeeuw, Eveline and van Bergen, Elsje and Bruins, Susanne and Pool, Ren{\'e} and Helmer, Quinta and van Dongen, Jenny and Hottenga, Jouke-Jan and Van{\textquoteright}t Ent, Dennis and Dolan, Conor V and Davies, Gareth E and Ehli, Erik A and Bartels, Meike and Willemsen, Gonneke and de Geus, Eco J C and Boomsma, Dorret I} } @article {408, title = {Testing bidirectional associations between childhood aggression and BMI: Results from three cohorts}, journal = {Obesity (Silver Spring)}, volume = {27}, year = {2019}, pages = {822{\textendash}829}, abstract = {

OBJECTIVE: This study examined the prospective, potentially bidirectional association of aggressive behavior with BMI and body composition across childhood in three population-based cohorts.

METHODS: Repeated measures of aggression and BMI were available from the Generation R Study between ages 6 and 10 years (N = 3,974), the Netherlands Twin Register (NTR) between ages 7 and 10 years (N = 10,328), and the Swedish Twin Study of Child and Adolescent Development (TCHAD) between ages 9 and 14 years (N = 1,462). In all samples, aggression was assessed with the Child Behavior Checklist. Fat mass and fat-free mass were available in the Generation R Study. Associations were examined with cross-lagged modeling.

RESULTS: Aggressive behavior at baseline was associated with higher BMI at follow-up in the Generation R Study ($\beta$ = 0.02, 95\% CI: 0.00 to 0.04), in NTR ($\beta$ = 0.04, 95\% CI: 0.02 to 0.06), and in TCHAD ($\beta$ = 0.03, 95\% CI: -0.02 to 0.07). Aggressive behavior was prospectively associated with higher fat mass ($\beta$ = 0.03, 95\% CI: 0.01 to 0.05) but not fat-free mass. There was no evidence that BMI or body composition preceded aggressive behavior.

CONCLUSIONS: More aggressive behavior was prospectively associated with higher BMI and fat mass. This suggests that aggression contributes to the obesity problem, and future research should study whether these behavioral pathways to childhood obesity are modifiable.

}, doi = {10.1002/oby.22419}, author = {Derks, Ivonne P M and Bolhuis, Koen and Yalcin, Zeynep and Gaillard, Romy and Hillegers, Manon H J and Larsson, Henrik and Lundstr{\"o}m, Sebastian and Lichtenstein, Paul and van Beijsterveldt, Catharina E M and Bartels, Meike and Boomsma, Dorret I and Tiemeier, Henning and Jansen, Pauline W} } @article {236, title = {Adult aggressive behavior in humans and biomarkers: a focus on lipids and methylation}, journal = {Journal of Pediatric and Neonatal Individualized Medicine (JPNIM)}, volume = {7}, year = {2018}, month = {04/2018}, abstract = {

Aggression shows large variation between individuals, with about 50\% explained by genetic factors. Biomarkers related to aggression have been reported for lipid metabolism and for epigenetic marks. Methylation and blood lipid levels are not independent and differential methylation can be a consequence of variation in blood lipid levels. We hypothesized that the methylation level of such loci in blood can inform us if aggression is associated with long-term exposure to lipid levels. If this is the case, we expect to find that loci where methylation levels are influenced by lipid levels to show differential methylation in aggressive individuals. Such loci might complement classic lipid level measures as a biomarker for lipid-related disturbances in aggression. As a first step, we examined the association of lipid levels and related biomarkers with aggression in a large adult population cohort (N = 5,588) and in 31 monozygotic (MZ) twin pairs who were discordant for aggression, as well as 12 extremely discordant MZ pairs. Biomarkers were not significantly associated with aggression in the population cohort. In the discordant MZ pairs we identified significant within-pair differences for glucose and marginally significant differences for lipids and cytokines, with the more aggressive twin showing lower levels of glucose and low density lipoprotein cholesterol and higher levels of fibrinogen, C-reactive protein and interleukin-6. The analysis of epigenetic data in the MZ pairs discordant for aggression did not show enrichment for lipid cytosine guanine dinucleotides (CpGs) and we observed no enrichment of lipid CpGs in an epigenome-wide association study of aggression in the population cohort. These results did not support the hypothesis that lipid CpGs show differential methylation in adult aggression. A next step will be to examine the role of biomarkers in aggression across the lifespan, including childhood, and to explore a more holistic biomarker approach, such as offered by metabolomics.

PDF Available here

}, keywords = {adult aggression, biomarkers, discordant twin pairs, epigenetics, lipids}, doi = {10.7363/070204}, url = {http://www.jpnim.com/index.php/jpnim/article/view/070204}, author = {Fiona Hagenbeek and Jenny van Dongen and Kluft, Cornelis and Thomas Hankemeier and Lannie Ligthart and Gonneke Willemsen and de Geus, Eco J.C. and Vink, Jacqueline M. and Meike Bartels and Dorret I. Boomsma} } @article {249, title = {Characterizing the Relation Between Expression QTLs and Complex Traits: Exploring the Role of Tissue Specificity}, journal = {Behavior Genetics}, volume = {48}, year = {2018}, month = {Sep}, pages = {374{\textendash}385}, abstract = {

Measurement of gene expression levels and detection of eQTLs (expression quantitative trait loci) are difficult in tissues with limited sample availability, such as the brain. However, eQTL overlap between tissues might be high, which would allow for inference of eQTL functioning in the brain via eQTLs detected in readily accessible tissues, e.g. whole blood. Applying Stratified Linkage Disequilibrium Score Regression (SLDSR), we quantified the enrichment in polygenic signal of blood and brain eQTLs in genome-wide association studies (GWAS) of 11 complex traits. We looked at eQTLs discovered in 44 tissues by the Genotype-Tissue Expression (GTEx) consortium and two other large representative studies, and found no tissue-specific eQTL effects. Next, we integrated the GTEx eQTLs with regions associated with tissue-specific histone modifiers, and interrogated their effect on rheumatoid arthritis and schizophrenia. We observed substantially enriched effects of eQTLs located inside regions bearing modification H3K4me1 on schizophrenia, but not rheumatoid arthritis, and not tissue-specific. Finally, we extracted eQTLs associated with tissue-specific differentially expressed genes and determined their effects on rheumatoid arthritis and schizophrenia, these analysis revealed limited enrichment of eQTLs associated with gene specifically expressed in specific tissues. Our results pointed to strong enrichment of eQTLs in their effect on complex traits, without evidence for tissue-specific effects. Lack of tissue-specificity can be either due to a lack of statistical power or due to the true absence of tissue-specific effects. We conclude that eQTLs are strongly enriched in GWAS signal and that the enrichment is not specific to the eQTL discovery tissue. Until sample sizes for eQTL discovery grow sufficiently large, working with relatively accessible tissues as proxy for eQTL discovery is sensible and restricting lookups for GWAS hits to a specific tissue for which limited samples are available might not be advisable.

}, issn = {1573-3297}, doi = {10.1007/s10519-018-9914-2}, url = {https://doi.org/10.1007/s10519-018-9914-2}, author = {Ip, Hill F. and Jansen, Rick and Abdellaoui, Abdel and Meike Bartels and UK Brain Expression Consortium and Ryten, Mina and Hardy, John and Weale, Michael E. and Ramasamy, Adaikalavan and Forabosco, Paola and Matarin, Mar and Vandrovcova, Jana and Botia, Juan A. and D{\textquoteright}Sa, Karishma and Guelfi, Sebastian and Smith, Colin and Walker, Robert and Reynolds, Regina H. and Zhang, David and Trabzuni, Daniah and Dorret I. Boomsma and Michel G. Nivard} } @article {230, title = {Childhood aggression and the co-occurrence of behavioural and emotional problems: results across ages 3{\textendash}16~years from multiple raters in six cohorts in the EU-ACTION project}, journal = {European Child {\&} Adolescent Psychiatry}, year = {2018}, month = {May}, abstract = {

Childhood aggression and its resulting consequences inflict a huge burden on affected children, their relatives, teachers, peers and society as a whole. Aggression during childhood rarely occurs in isolation and is correlated with other symptoms of childhood psychopathology. In this paper, we aim to describe and improve the understanding of the co-occurrence of aggression with other forms of childhood psychopathology. We focus on the co-occurrence of aggression and other childhood behavioural and emotional problems, including other externalising problems, attention problems and anxiety\–depression. The data were brought together within the EU-ACTION (Aggression in Children: unravelling gene-environment interplay to inform Treatment and InterventiON strategies) project. We analysed the co-occurrence of aggression and other childhood behavioural and emotional problems as a function of the child\&$\#$39;s age (ages 3 through 16\ years), gender, the person rating the behaviour (father, mother or self) and assessment instrument. The data came from six large population-based European cohort studies from the Netherlands (2x), the UK, Finland and Sweden (2x). Multiple assessment instruments, including the Child Behaviour Checklist (CBCL), the Strengths and Difficulties Questionnaire (SDQ) and Multidimensional Peer Nomination Inventory (MPNI), were used. There was a good representation of boys and girls in each age category, with data for 30,523 3- to 4-year-olds (49.5{\%} boys), 20,958 5- to 6-year-olds (49.6{\%} boys), 18,291 7- to 8-year-olds (49.0{\%} boys), 27,218 9- to 10-year-olds (49.4{\%} boys), 18,543 12- to 13-year-olds (48.9{\%} boys) and 10,088 15- to 16-year-olds (46.6{\%} boys). We replicated the well-established gender differences in average aggression scores at most ages for parental ratings. The gender differences decreased with age and were not present for self-reports. Aggression co-occurred with the majority of other behavioural and social problems, from both externalising and internalising domains. At each age, the co-occurrence was particularly prevalent for aggression and oppositional and ADHD-related problems, with correlations of around 0.5 in general. Aggression also showed substantial associations with anxiety\–depression and other internalizing symptoms (correlations around 0.4). Co-occurrence for self-reported problems was somewhat higher than for parental reports, but we found neither rater differences, nor differences across assessment instruments in co-occurrence patterns. There were large similarities in co-occurrence patterns across the different European countries. Finally, co-occurrence was generally stable across age and sex, and if any change was observed, it indicated stronger correlations when children grew older. We present an online tool to visualise these associations as a function of rater, gender, instrument and cohort. In addition, we present a description of the full EU-ACTION projects, its first results and the future perspectives.

Related interactive tool here.

}, issn = {1435-165X}, doi = {10.1007/s00787-018-1169-1}, url = {https://doi.org/10.1007/s00787-018-1169-1}, author = {Meike Bartels and Anne Hendriks and Matteo Mauri and Eva Krapohl and Alyce Whipp and Koen Bolhuis and Conde, Lucia Colodro and Luningham, Justin and Fung Ip, Hill and Fiona Hagenbeek and Roetman, Peter and Gatej, Raluca and Lamers, Audri and Michel G. Nivard and Jenny van Dongen and Lu, Yi and Christel Middeldorp and van Beijsterveldt, Toos and Vermeiren, Robert and Thomas Hankemeier and Kluft, Cees and Medland, Sarah and Lundstr{\"o}m, Sebastian and Richard J. Rose and Pulkkinen, Lea and Vuoksimaa, Eero and Korhonen, Tellervo and Martin, Nicholas G. and Gitta Lubke and Catrin Finkenauer and Vassilios Fanos and Henning Tiemeier and Lichtenstein, Paul and Robert Plomin and Kaprio, Jaakko and Dorret I. Boomsma} } @article {261, title = {DNA methylation age is associated with an altered hemostatic profile in a multi-ethnic meta-analysis}, journal = {Blood}, year = {2018}, abstract = {

Elevated epigenetic age is associated with an altered hemostatic factor profile and lower clotting time (aPTT).DNA methylation age is associated with mRNA levels of fibrinogen in multiple tissues. Many hemostatic factors are associated with age and age-related diseases, however much remains unknown about the biological mechanisms linking aging and hemostatic factors. DNA methylation is a novel means by which to assess epigenetic aging, which is a measure of age and the aging processes as determined by altered epigenetic states. We used a meta-analysis approach to examine the association between measures of epigenetic aging and hemostatic factors, as well as a clotting time measure. For fibrinogen, we used European and African-ancestry participants who were meta-analyzed separately and combined via a random effects meta-analysis. All other measures only included participants of European-ancestry. We found that 1-year higher extrinsic epigenetic age as compared to chronological age was associated with higher fibrinogen (0.004 g/L per year; 95\% CI: 0.001, 0.007; P = 0.01) and plasminogen activator inhibitor 1 (PAI-1; 0.13 U/mL per year; 95\% CI: 0.07, 0.20; P = 6.6x10-5) concentrations as well as lower activated partial thromboplastin time, a measure of clotting time. We replicated PAI-1 associations using an independent cohort. To further elucidate potential functional mechanisms we associated epigenetic aging with expression levels of the PAI-1 protein encoding gene (SERPINE1) and the three fibrinogen subunit-encoding genes (FGA, FGG, and FGB), in both peripheral blood and aorta intima-media samples. We observed associations between accelerated epigenetic aging and transcription of FGG in both tissues. Collectively, our results indicate that accelerated epigenetic aging is associated with a pro-coagulation hemostatic profile, and that epigenetic aging may regulate hemostasis in part via gene transcription.

}, issn = {0006-4971}, doi = {10.1182/blood-2018-02-831347}, url = {http://www.bloodjournal.org/content/early/2018/07/24/blood-2018-02-831347}, author = {Ward-Caviness, Cavin K. and Huffman, Jennifer E. and Evertt, Karl and Germain, Marine and van Dongen, Jenny and Hill, W. David and Jhun, Min A. and Brody, Jennifer A. and Ghanbari, Mohsen and Du, Lei and Roetker, Nicholas S. and de Vries, Paul S. and Waldenberger, Melanie and Gieger, Christian and Wolf, Petra and Prokisch, Holger and Koenig, Wolfgang and O{\textquoteright}Donnell, Christopher J. and Levy, Daniel and Liu, Chunyu and Truong, Vinh and Wells, Philip S. and Tr{\'e}gou{\"e}t, David-Alexandre and Tang, Weihong and Morrison, Alanna C. and Boerwinkle, Eric and Wiggins, Kerri L. and McKnight, Barbara and Guo, Xiuqing and Psaty, Bruce M. and Sotoodenia, Nona and Dorret I. Boomsma and Gonneke Willemsen and Lannie Ligthart and Deary, Ian J. and Zhao, Wei and Ware, Erin B. and Kardia, Sharon L.R. and Joyce B.J. Van Meurs and Uitterlinden, Andre G. and Franco, Oscar H. and Eriksson, Per and Franco-Cereceda, Anders and Pankow, James S. and Johnson, Andrew D. and Gagnon, France and Morange, Pierre-Emmanuel and de Geus, Eco J.C. and Starr, John M. and Smith, Jennifer A. and Dehghan, Abbas and Bj{\"o}rck, Hanna M. and Smith, Nicholas L. and Peters, Annette} } @article {227, title = {DNA methylation signatures of educational attainment}, volume = {3}, year = {2018}, month = {2018/03/23}, pages = {7}, abstract = {

Educational attainment is a key behavioural measure in studies of cognitive and physical health, and socioeconomic status. We measured DNA methylation at 410,746 CpGs (N\ =\ 4152) and identified 58 CpGs associated with educational attainment at loci characterized by pleiotropic functions shared with neuronal, immune and developmental processes. Associations overlapped with those for smoking behaviour, but remained after accounting for smoking at many CpGs: Effect sizes were on average 28\% smaller and genome-wide significant at 11 CpGs after adjusting for smoking and were 62\% smaller in never smokers. We examined sources and biological implications of education-related methylation differences, demonstrating correlations with maternal prenatal folate, smoking and air pollution signatures, and associations with gene expression in cis, dynamic methylation in foetal brain, and correlations between blood and brain. Our findings show that the methylome of lower-educated people resembles that of smokers beyond effects of their own smoking behaviour and shows traces of various other exposures.

}, isbn = {2056-7936}, url = {https://doi.org/10.1038/s41539-018-0020-2}, author = {Jenny van Dongen and Bonder, Marc Jan and Dekkers, Koen F. and Michel G. Nivard and van Iterson, Maarten and Gonneke Willemsen and Beekman, Marian and van der Spek, Ashley and Joyce B.J. Van Meurs and Franke, Lude and Bastiaan T. Heijmans and van Duijn, Cornelia M. and Slagboom, P. Eline and Dorret I. Boomsma} } @article {288, title = {Focused issue on conduct disorder and aggressive behaviour}, journal = {European Child {\&} Adolescent Psychiatry}, volume = {27}, year = {2018}, month = {Sep}, pages = {1231{\textendash}1234}, issn = {1435-165X}, doi = {10.1007/s00787-018-1216-y}, url = {https://doi.org/10.1007/s00787-018-1216-y}, author = {Freitag, Christine M. and Dorret I. Boomsma and Glennon, Jeffrey C. and Franke, Barbara and Holtel, Andreas} } @article {228, title = {Genetic and environmental contributions to the development of childhood aggression.}, journal = {Developmental psychology}, volume = {54 1}, year = {2018}, pages = {39-50}, abstract = {

Longitudinal data from a large sample of twins participating in the Netherlands Twin Register (n = 42,827, age range 3-16) were analyzed to investigate the genetic and environmental contributions to childhood aggression. Genetic auto-regressive (simplex) models were used to assess whether the same genes are involved or whether new genes come into play as children grow up. The authors compared 2 different simplex models to disentangle potentially changing behavioral expressions from changes in genetic and environmental effects. One model provided estimates of genetic and environmental effects at the level of individual aggression questionnaire items, and the other model assessed the effects at the level of an aggression sum score computed from the individual items. The results from both models provided evidence for largely stable genetic effects throughout childhood. The results also highlighted the differential heritability of the different indicators of aggression measured with the Childhood Behavior Checklist, with destruction of property showing a very high genetic component during early childhood and fighting behaviors being more heritable in early adolescence. (PsycINFO Database Record.

}, author = {Gitta Lubke and Daniel B. McArtor and Dorret I. Boomsma and Meike Bartels} } @article {235, title = {Genome-wide analysis of DNA methylation in buccal cells: a study of monozygotic twins and mQTLs}, journal = {Epigenetics {\&} Chromatin}, volume = {11}, year = {2018}, month = {Sep}, pages = {54}, abstract = {

DNA methylation arrays are widely used in epigenome-wide association studies and methylation quantitative trait locus (mQTL) studies. Here, we performed the first genome-wide analysis of monozygotic (MZ) twin correlations and mQTLs on data obtained with the Illumina MethylationEPIC BeadChip (EPIC array) and compared the performance of the EPIC array to the Illumina HumanMethylation450 BeadChip (HM450 array) for buccal-derived DNA.

}, issn = {1756-8935}, doi = {10.1186/s13072-018-0225-x}, url = {https://doi.org/10.1186/s13072-018-0225-x}, author = {Jenny van Dongen and Ehli, Erik A. and Jansen, Rick and Catharina E. M. van Beijsterveldt and Gonneke Willemsen and Hottenga, Jouke J. and Kallsen, Noah A. and Peyton, Shanna A. and Breeze, Charles E. and Kluft, Cornelis and Bastiaan T. Heijmans and Meike Bartels and Gareth E Davies and Dorret I. Boomsma} } @article {283, title = {Unraveling the Genetic and Environmental Relationship Between Well-Being and Depressive Symptoms Throughout the Lifespan}, journal = {Frontiers in Psychiatry}, volume = {9}, year = {2018}, pages = {261}, abstract = {

Whether well-being and depressive symptoms can be considered as two sides of the same coin is widely debated. The aim of this study was to gain insight into the etiology of the association between well-being and depressive symptoms across the lifespan. In a large twin-design, including data from 43,427 twins between age 7 and 99, we estimated the association between well-being and depressive symptoms throughout the lifespan and assessed genetic and environmental contributions to the observed overlap. For both well-being (range 31\% \–47\%) and depressive symptoms (range 50\%-61\%), genetic factors explained a substantial part of the phenotypic variance across the lifespan. Phenotypic correlations between well-being and depressive symptoms across ages ranged from -.34 in childhood to -.49 in adulthood. In children, genetic effects explained 49\% of the phenotypic correlation while in adolescents and young adults, genetic effects explained 60\% to 77\% of the phenotypic correlations. Moderate to high genetic correlations (ranging from -0.60 to -0.66) were observed in adolescence and adulthood, while in childhood environmental correlations were substantial but genetic correlations small. Our results suggest that in childhood genetic and environmental effects are about equally important in explaining the relationship between well-being and depressive symptoms. From adolescence onwards, the role of genetic effects increases compared to environmental effects. These results provided more insights into the etiological underpinnings of well-being and depressive symptoms, possibly allowing to articulate better strategies for health promotion and resource allocation in the future.

}, issn = {1664-0640}, doi = {10.3389/fpsyt.2018.00261}, url = {https://www.frontiersin.org/article/10.3389/fpsyt.2018.00261}, author = {Bart M. L. Baselmans and Willems, Yayouk E. and Catharina E. M. van Beijsterveldt and Lannie Ligthart and Gonneke Willemsen and Conor V Dolan and Dorret I. Boomsma and Meike Bartels} } @article {403, title = {Why do children read more? The influence of reading ability on voluntary reading practices}, journal = {Journal of Child Psychology and Psychiatry}, volume = {59}, year = {2018}, pages = {1205{\textendash}1214}, abstract = {

BACKGROUND: This study investigates the causal relationships between reading and print exposure and investigates whether the amount children read outside school determines how well they read, or vice versa. Previous findings from behavioural studies suggest that reading predicts print exposure. Here, we use twin-data and apply the behaviour-genetic approach of direction of causality modelling, suggested by Heath et al. (), to investigate the causal relationships between these two traits.

METHOD: Partial data were available for a large sample of twin children (N = 11,559) and 262 siblings, all enrolled in the Netherlands Twin Register. Children were assessed around 7.5 years of age. Mothers completed questionnaires reporting children\&$\#$39;s time spent on reading activities and reading ability. Additional information on reading ability was available through teacher ratings and performance on national reading tests. For siblings reading test, results were available.

RESULTS: The reading ability of the twins was comparable to that of the siblings and national norms, showing that twin findings can be generalized to the population. A measurement model was specified with two latent variables, Reading Ability and Print Exposure, which correlated .41. Heritability analyses showed that Reading Ability was highly heritable, while genetic and environmental influences were equally important for Print Exposure. We exploited the fact that the two constructs differ in genetic architecture and fitted direction of causality models. The results supported a causal relationship running from Reading Ability to Print Exposure.

CONCLUSIONS: How much and how well children read are moderately correlated. Individual differences in print exposure are less heritable than individual differences in reading ability. Importantly, the present results suggest that it is the children\&$\#$39;s reading ability that determines how much they choose to read, rather than vice versa.

}, keywords = {behaviour-genetics, causal modelling, Direction of causality models, print exposure, reading skills, twin studies}, doi = {10.1111/jcpp.12910}, author = {van Bergen, Elsje and Snowling, Margaret J and de Zeeuw, Eveline L and van Beijsterveldt, Catharina E M and Dolan, Conor V and Boomsma, Dorret I} } @article {192, title = {Disentangling Heterogeneity of Childhood Disruptive Behavior Problems Into Dimensions and Subgroups}, journal = {American Academy of Child and Adolescent Psychiatry. Journal}, volume = {56}, year = {2017}, pages = {678{\textendash}686}, abstract = {

OBJECTIVE:

Irritable and oppositional behaviors are increasingly considered as distinct dimensions of oppositional defiant disorder. However, few studies have explored this multidimensionality across the broader spectrum of disruptive behavior problems (DBPs). This study examined the presence of dimensions and distinct subgroups of childhood DBPs, and the cross-sectional and longitudinal associations between these dimensions.

METHOD:

Using factor mixture models (FMMs), the presence of dimensions and subgroups of DBPs was assessed in the Generation R Study at ages 6 (n\ = 6,209) and 10 (n\ =\ 4,724) years. Replications were performed in two population-based cohorts (Netherlands Twin Registry, n\ = 4,402, and Swedish Twin Study of Child and Adolescent Development, n\ = 1,089) and a clinical sample (n\ = 1,933). We used cross-lagged modeling in the Generation R Study to assess cross-sectional and longitudinal associations between dimensions. DBPs were assessed using mother-reported responses to the Child Behavior Checklist.

RESULTS:

Empirically obtained dimensions of DBPs were oppositional behavior (age 6 years), disobedient behavior, rule-breaking behavior (age 10 years), physical aggression, and irritability (both ages). FMMs suggested that one-class solutions had the best model fit for all dimensions in all three population-based cohorts. Similar results were obtained in the clinical sample. All three dimensions, including irritability, predicted subsequent physical aggression (range, 0.08-0.16).

CONCLUSION:

This study showed that childhood DBPs should be regarded as a multidimensional phenotype rather than comprising distinct subgroups. Incorporating multidimensionality will improve diagnostic accuracy and refine treatment. Future studies need to address the biological validity of the DBP dimensions observed in this study; herein lies an important opportunity for neuroimaging and genetic measures.

}, doi = {10.1016/j.jaac.2017.05.019}, author = {Koen Bolhuis and Gitta Lubke and van der Ende, Jan and Meike Bartels and van Beijsterveldt, Toos and Paul Lichtenstein and Henrik Larsson and Vincent W.V. Jaddoe and Steven A. Kushner and Frank Verhulst and Dorret I. Boomsma and Henning Tiemeier} } @article {194, title = {Genetic and environmental influences on conduct and antisocial personality problems in childhood, adolescence, and adulthood}, journal = {European Child {\&} Adolescent Psychiatry}, year = {2017}, month = {Jun}, abstract = {

Conduct problems in children and adolescents can predict antisocial personality disorder and related problems, such as crime and conviction. We sought an explanation for such predictions by performing a genetic longitudinal analysis. We estimated the effects of genetic, shared environmental, and unique environmental factors on variation in conduct problems measured at childhood and adolescence and antisocial personality problems measured at adulthood and on the covariation across ages. We also tested whether these estimates differed by sex. Longitudinal data were collected in the Netherlands Twin Register over a period of 27\ years. Age appropriate and comparable measures of conduct and antisocial personality problems, assessed with the Achenbach System of Empirically Based Assessment, were available for 9783 9\–10-year-old, 6839 13\–18-year-old, and 7909 19\–65-year-old twin pairs, respectively; 5114 twins have two or more assessments. At all ages, men scored higher than women. There were no sex differences in the estimates of the genetic and environmental influences. During childhood, genetic and environmental factors shared by children in families explained 43 and 44{\%} of the variance of conduct problems, with the remaining variance due to unique environment. During adolescence and adulthood, genetic and unique environmental factors equally explained the variation. Longitudinal correlations across age varied between 0.20 and 0.38 and were mainly due to stable genetic factors. We conclude that shared environment is mainly of importance during childhood, while genetic factors contribute to variation in conduct and antisocial personality problems at all ages, and also underlie its stability over age.

}, issn = {1435-165X}, doi = {10.1007/s00787-017-1014-y}, url = {https://doi.org/10.1007/s00787-017-1014-y}, author = {Laura W. Wesseldijk and Meike Bartels and Vink, Jacqueline M. and Catharina E. M. van Beijsterveldt and Lannie Ligthart and Dorret I. Boomsma and Christel Middeldorp} } @article {193, title = {Heritability of Behavioral Problems in 7-Year Olds Based on Shared and Unique Aspects of Parental Views}, journal = {Behavior Genetics}, volume = {47}, year = {2017}, month = {Mar}, pages = {152{\textendash}163}, abstract = {

In studies of child psychopathology, phenotypes of interest are often obtained by parental ratings. When behavioral ratings are obtained in the context of a twin study, this allows for the decomposition of the phenotypic variance, into a genetic and a non-genetic part. If a phenotype is assessed by a single rater, heritability is based on the child\&$\#$39;s behavior as expressed in the presence of that particular rater, whereas heritability based on assessments by multiple raters allows for the estimation of the heritability of the phenotype based on rater agreement, as well as the heritability of the rater specific view of the behavior. The aim of this twin study was to quantify the rater\ common and rater specific contributions to the variation in children\&$\#$39;s behavioral problems. We estimated the heritability of maternal and paternal ratings of the Child Behavior Checklist (CBCL) 6\–18 empirical emotional and behavioral problem scales in a large sample of 12,310 7-year old Dutch twin pairs. Between 30 and 59{\%} of variation in the part of the phenotype parents agree upon was explained by genetic effects. Common environmental effects that make children in the same family similar explained less variance, ranging between 0 and 32{\%}. For unique views of their children\&$\#$39;s behavioral problems, heritability ranged between 0 and 20{\%} for maternal and between 0 and 22{\%} for paternal views. Between 7 and 24{\%} of the variance was accounted for by common environmental factors specific to mother and father\&$\#$39;s views. The proportion of rater shared and rater specific heritability can be translated into genetic correlations between parental views and inform the design and interpretation of results of molecular genetic studies. Genetic correlations were nearly or above 0.7 for all CBCL based psychopathology scales. Such large genetic correlations suggest two practical guidelines for genome-wide association studies (GWAS): when studies have collected data from either fathers or mothers, the shared genetic aetiology in parental ratings indicates that is possible to analyze paternal and maternal assessments in a single GWAS or meta-analysis. Secondly, if a study has collected information from both parents, a gain in statistical power may be realized in GWAS by the simultaneous analysis of the data.

}, issn = {1573-3297}, doi = {10.1007/s10519-016-9823-1}, url = {https://doi.org/10.1007/s10519-016-9823-1}, author = {Fedko, Iryna O. and Laura W. Wesseldijk and Michel G. Nivard and Hottenga, Jouke-Jan and Catharina E. M. van Beijsterveldt and Christel Middeldorp and Meike Bartels and Dorret I. Boomsma} } @article {402, title = {Psychopathology in 7-year-old children: Differences in maternal and paternal ratings and the genetic epidemiology}, journal = {American Journal of Medical Genetics Part B: Neuropsychiatric Genetics}, volume = {174}, year = {2017}, pages = {251{\textendash}260}, abstract = {

The assessment of children\&$\#$39;s psychopathology is often based on parental report. Earlier studies have suggested that rater bias can affect the estimates of genetic, shared environmental and unique environmental influences on differences between children. The availability of a large dataset of maternal as well as paternal ratings of psychopathology in 7-year old children enabled (i) the analysis of informant effects on these assessments, and (ii) to obtain more reliable estimates of the genetic and non-genetic effects. DSM-oriented measures of affective, anxiety, somatic, attention-deficit/hyperactivity, oppositional-defiant, conduct, and obsessive-compulsive problems were rated for 12,310 twin pairs from the Netherlands Twin Register by mothers (N = 12,085) and fathers (N = 8,516). The effects of genetic and non-genetic effects were estimated on the common and rater-specific variance. For all scales, mean scores on maternal ratings exceeded paternal ratings. Parents largely agreed on the ranking of their child\&$\#$39;s problems (r 0.60-0.75). The heritability was estimated over 55\% for maternal and paternal ratings for all scales, except for conduct problems (44-46\%). Unbiased shared environmental influences, i.e., on the common variance, were significant for affective (13\%), oppositional (13\%), and conduct problems (37\%). In clinical settings, different cutoffs for (sub)clinical scores could be applied to paternal and maternal ratings of their child\&$\#$39;s psychopathology. Only for conduct problems, shared environmental and genetic influences explain an equal amount in differences between children. For the other scales, genetic factors explain the majority of the variance, especially for the common part that is free of rater bias. \copyright{} 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

}, keywords = {parental ratings, psychopathology, rater bias, shared environment, twins}, doi = {10.1002/ajmg.b.32500}, author = {Wesseldijk, Laura W and Fedko, Iryna O and Bartels, Meike and Nivard, Michel G and van Beijsterveldt, Catharina E M and Boomsma, Dorret I and Middeldorp, Christel M} } @article {212, title = {Selected Abstracts of the 13th International Workshop on Neonatology. ABS 72, An interactive tool shows comorbidities of child aggression with other childhood psychopathologies. Utilities and statistics of the website www.action-euproject.eu}, journal = {Journal of Pediatric and Neonatal Individualized Medicine (JPNIM)}, volume = {6}, year = {2017}, month = {10/2017}, type = {Proceedings of the 13{\textdegree} International Workshop on Neonatology, Twins: identical but different, Cagliari (Italy), October 25-28}, doi = {10.7363/060234}, url = {http://www.jpnim.com/index.php/jpnim/article/view/060234/468}, author = {Matteo Mauri and Anne Hendriks and Vassilios Fanos and Dorret I. Boomsma and Meike Bartels} } @article {190, title = {Sum Scores in Twin Growth Curve Models: Practicality Versus Bias}, journal = {Behavior Genetics}, volume = {47}, year = {2017}, month = {9}, pages = {516{\textendash}536}, abstract = {

To study behavioral or psychiatric phenotypes, multiple indices of the behavior or disorder are often collected that are thought to best reflect the phenotype. Combining these items into a single score (e.g. a sum score) is a simple and practical approach for modeling such data, but this simplicity can come at a cost in longitudinal studies, where the relevance of individual items often changes as a function of age. Such changes violate the assumptions of longitudinal measurement invariance (MI), and this violation has the potential to obfuscate the interpretation of the results of latent growth models fit to sum scores. The objectives of this study are (1) to investigate the extent to which violations of longitudinal MI lead to bias in parameter estimates of the average growth curve trajectory, and (2) whether absence of MI affects estimates of the heritability of these growth curve parameters. To this end, we analytically derive the bias in the estimated means and variances of the latent growth factors fit to sum scores when the assumption of longitudinal MI is violated. This bias is further quantified via Monte Carlo simulation, and is illustrated in an empirical analysis of aggression in children aged 3\–12\ years. These analyses show that measurement non-invariance across age can indeed bias growth curve mean and variance estimates, and our quantification of this bias permits researchers to weigh the costs of using a simple sum score in longitudinal studies. Simulation results indicate that the genetic variance decomposition of growth factors is, however, not biased due to measurement non-invariance across age, provided the phenotype is measurement invariant across birth-order and zygosity in twins.

}, issn = {0001-8244}, doi = {10.1007/s10519-017-9864-0}, url = {https://doi.org/10.1007/s10519-017-9864-0}, author = {Luningham, Justin M. and Daniel B. McArtor and Meike Bartels and Dorret I. Boomsma and Gitta Lubke} } @article {129, title = {Discovery of biochemical biomarkers for aggression: A role for metabolomics in psychiatry.}, journal = {Am J Med Genet B Neuropsychiatr Genet}, year = {2016}, month = {2016 Feb 23}, abstract = {

Human aggression encompasses a wide range of behaviors and is related to many psychiatric disorders. We introduce the different classification systems of aggression and related disorders as a basis for discussing biochemical biomarkers and then present an overview of studies in humans (published between 1990 and 2015) that reported statistically significant associations of biochemical biomarkers with aggression, DSM-IV disorders involving aggression, and their subtypes. The markers are of different types, including inflammation markers, neurotransmitters, lipoproteins, and hormones from various classes. Most studies focused on only a limited portfolio of biomarkers, frequently a specific class only. When integrating the data, it is clear that compounds from several biological pathways have been found to be associated with aggressive behavior, indicating complexity and the need for a broad approach. In the second part of the paper, using examples from the aggression literature and psychiatric metabolomics studies, we argue that a better understanding of aggression would benefit from a more holistic approach such as provided by metabolomics. \© 2016 Wiley Periodicals, Inc.

}, issn = {1552-485X}, doi = {10.1002/ajmg.b.32435}, author = {Fiona Hagenbeek and Kluft, Cornelis and Thomas Hankemeier and Meike Bartels and Draisma, Harmen H M and Christel Middeldorp and Berger, Ruud and Antonio Noto and Lussu, Milena and Pool, Ren{\'e} and Faa, Gavino and Dorret I. Boomsma} } @article {128, title = {Genetic and environmental influences interact with age and sex in shaping the human methylome}, journal = {Nat Commun}, volume = {7}, year = {2016}, month = {2016/04/07}, abstract = {

The methylome is subject to genetic and environmental effects. Their impact may depend on sex and age, resulting in sex- and age-related physiological variation and disease susceptibility. Here we estimate the total heritability of DNA methylation levels in whole blood and estimate the variance explained by common single nucleotide polymorphisms at 411,169 sites in 2,603 individuals from twin families, to establish a catalogue of between-individual variation in DNA methylation. Heritability estimates vary across the genome (mean=19\%) and interaction analyses reveal thousands of sites with sex-specific heritability as well as sites where the environmental variance increases with age. Integration with previously published data illustrates the impact of genome and environment across the lifespan at methylation sites associated with metabolic traits, smoking and ageing. These findings demonstrate that our catalogue holds valuable information on locations in the genome where methylation variation between people may reflect disease-relevant environmental exposures or genetic variation.

}, url = {http://dx.doi.org/10.1038/ncomms11115}, author = {Jenny van Dongen and Michel G. Nivard and Gonneke Willemsen and Hottenga, Jouke-Jan and Helmer, Quinta and Conor V Dolan and Ehli, Erik A. and Gareth E Davies and van Iterson, Maarten and Breeze, Charles E. and Beck, Stephan and BIOS Consortium and Suchiman, H. Eka and Jansen, Rick and Joyce B.J. Van Meurs and Bastiaan T. Heijmans and Slagboom, P. Eline and Dorret I. Boomsma} } @article {102, title = {Longitudinal heritability of childhood aggression.}, journal = {Am J Med Genet B Neuropsychiatr Genet}, year = {2016}, month = {2016 Jan 19}, abstract = {

The genetic and environmental contributions to the variation and longitudinal stability in childhood aggressive behavior were assessed in two large twin cohorts, the Netherlands Twin Register (NTR), and the Twins Early Development Study (TEDS; United Kingdom). In NTR, maternal ratings on aggression from the Child Behavior Checklist (CBCL) were available for 10,765 twin pairs at age 7, for 8,557 twin pairs at age 9/10, and for 7,176 twin pairs at age 12. In TEDS, parental ratings of conduct disorder from the Strength and Difficulty Questionnaire (SDQ) were available for 6,897 twin pairs at age 7, for 3,028 twin pairs at age 9 and for 5,716 twin pairs at age 12. In both studies, stability and heritability of aggressive behavioral problems was high. Heritability was on average somewhat, but significantly, lower in TEDS (around 60\%) than in NTR (between 50\% and 80\%) and sex differences were slightly larger in the NTR sample. In both studies, the influence of shared environment was similar: in boys shared environment explained around 20\% of the variation in aggression across all ages while in girls its influence was absent around age 7 and only came into play at later ages. Longitudinal genetic correlations were the main reason for stability of aggressive behavior. Individual differences in CBCL-Aggressive Behavior and SDQ-Conduct disorder throughout childhood are driven by a comparable but significantly different genetic architecture. \© 2016 Wiley Periodicals, Inc.

}, issn = {1552-485X}, doi = {10.1002/ajmg.b.32420}, author = {Porsch, Robert M and Christel Middeldorp and Cherny, Stacey S and Eva Krapohl and Catharina E. M. van Beijsterveldt and Loukola, Anu and Korhonen, Tellervo and Pulkkinen, Lea and Corley, Robin and Rhee, Soo and Kaprio, Jaakko and Rose, Richard R and Hewitt, John K and Sham, Pak and Robert Plomin and Dorret I. Boomsma and Meike Bartels} } @article {258, title = {Spousal resemblance in psychopathology: A comparison of parents of children with and without psychopathology}, journal = {European PsychiatryEuropean Psychiatry}, volume = {34}, year = {2016}, month = {2016/04/01}, pages = {49 - 55}, abstract = {

BACKGROUND:

Spouses resemble each other for psychopathology, but data regarding spousal resemblance in externalizing psychopathology, and data regarding spousal resemblance across different syndromes (e.g. anxiety in wives and attention deficit/hyperactivity disorder [ADHD] in husbands) are limited. Moreover, knowledge is lacking regarding spousal resemblance in parents of children with psychiatric disorders. We investigated and compared spousal resemblance within and across internalizing and externalizing symptom domains in parents of children with and without psychopathology.

METHODS:

Symptoms of depression, anxiety, avoidant personality, ADHD, and antisocial personality were assessed with the Adult Self Report in 728 mothers and 544 fathers of 778 children seen in child and adolescent psychiatric outpatient clinics and in 2075 mothers and 1623 fathers of 2784 children from a population-based sample. Differences in symptom scores and spousal correlations between the samples were tested.

RESULTS:

Parents in the clinical sample had higher symptom scores than in the population-based sample. In both samples, correlations within and across internalizing and externalizing domains of psychopathology were significant. Importantly, correlations were significantly higher in the clinical sample (P=0.03). Correlations, within and across symptoms, ranged from 0.14 to 0.30 in the clinical sample and from 0.05 to 0.23 in the population-based sample.

CONCLUSIONS:

This large study shows that spousal resemblance is not only present within but also across symptom domains. Especially in the clinical sample, ADHD symptoms in fathers and antisocial personality symptoms in mothers were correlated with a range of psychiatric symptoms in their spouses. Clinicians need to be alert of these multiple affected families.

}, isbn = {0924-9338}, url = {https://doi.org/10.1016/j.eurpsy.2016.01.2423}, author = {Laura W. Wesseldijk and Dieleman, G.C. and Lindauer, R.J.L. and Meike Bartels and Gonneke Willemsen and J.J. Hudziak and Dorret I. Boomsma and Christel Middeldorp} } @article {76, title = {Aggression in children: unravelling the interplay of genes and environment through (epi)genetics and metabolomics}, journal = {Journal of Pediatric and Neonatal Individualized Medicine (JPNIM)}, volume = {4}, year = {2015}, month = {10/2015}, pages = {97-102}, type = {Proceedings of the 11{\textdegree} International Workshop on Neonatology and Satellite Meetings, Cagliari (Italy), October 26-31}, abstract = {

Aggression inflicts a huge burden on affected children, their families, and society. Estimates for the prevalence of clinical aggression in children range between 2 and 16\%, and childhood aggression tends to continue into adulthood. Current psychological treatments and pharmacological interventions are not effective for all children with aggressive behaviors and there is a huge need for more personalized approaches, which requires insight into the heterogeneity and the mechanisms underlying aggression and its associated comorbidities. Here we discuss what is currently known with regard to individual differences in childhood aggression. Studies employing new opportunities in large scale genotyping, epigenetics and metabolomics technology will in future help to explain heterogeneity and highlight pathways from molecule to phenotype. The FP7-ACTION project (Aggression in Children: Unravelling gene-environment interplay to inform Treatment and InterventiON strategies) aims to contribute to knowledge that will help children, their families, teachers and society at large.

Complete Article

}, keywords = {aggression; childhood; twin studies; biomarkers}, doi = {10.7363/040251}, url = {http://www.jpnim.com/index.php/jpnim/article/view/040251}, author = {Dorret I. Boomsma} } @article {94, title = {Epigenome-Wide Association Study of Aggressive Behavior}, journal = {Twin Research and Human Genetics}, volume = {FirstView}, year = {2015}, month = {11}, pages = {1{\textendash}13}, issn = {1839-2628}, doi = {10.1017/thg.2015.74}, url = {http://journals.cambridge.org/article_S1832427415000742}, author = {Jenny van Dongen and Michel G. Nivard and Bart M. L. Baselmans and Zilh{\~a}o,Nuno R. and Lannie Ligthart and Bastiaan T. Heijmans and Meike Bartels and Dorret I. Boomsma} } @article {101, title = {A genome-wide approach to children{\textquoteright}s aggressive behavior: The EAGLE consortium.}, journal = {Am J Med Genet B Neuropsychiatr Genet}, year = {2015}, month = {2015 Jun 18}, abstract = {

Individual differences in aggressive behavior emerge in early childhood and predict persisting behavioral problems and disorders. Studies of antisocial and severe aggression in adulthood indicate substantial underlying biology. However, little attention has been given to genome-wide approaches of aggressive behavior in children. We analyzed data from nine population-based studies and assessed aggressive behavior using well-validated parent-reported questionnaires. This is the largest sample exploring children\&$\#$39;s aggressive behavior to date (N\ =\ 18,988), with measures in two developmental stages (N\ =\ 15,668 early childhood and N\ =\ 16,311 middle childhood/early adolescence). First, we estimated the additive genetic variance of children\&$\#$39;s aggressive behavior based on genome-wide SNP information, using genome-wide complex trait analysis (GCTA). Second, genetic associations within each study were assessed using a quasi-Poisson regression approach, capturing the highly right-skewed distribution of aggressive behavior. Third, we performed meta-analyses of genome-wide associations for both the total age-mixed sample and the two developmental stages. Finally, we performed a gene-based test using the summary statistics of the total sample. GCTA quantified variance tagged by common SNPs (10-54\%). The meta-analysis of the total sample identified one region in chromosome 2 (2p12) at near genome-wide significance (top SNP rs11126630, P\ =\ 5.30\ \×\ 10(-8) ). The separate meta-analyses of the two developmental stages revealed suggestive evidence of association at the same locus. The gene-based analysis indicated association of variation within AVPR1A with aggressive behavior. We conclude that common variants at 2p12 show suggestive evidence for association with childhood aggression. Replication of these initial findings is needed, and further studies should clarify its biological meaning. \© 2015 Wiley Periodicals, Inc.

}, issn = {1552-485X}, doi = {10.1002/ajmg.b.32333}, author = {Pappa, Irene and St Pourcain, Beate and Benke, Kelly and Cavadino, Alana and Hakulinen, Christian and Michel G. Nivard and Nolte, Ilja M and Tiesler, Carla M T and Marian J Bakermans-Kranenburg and Gareth E Davies and David M Evans and Geoffroy, Marie-Claude and Grallert, Harald and Groen-Blokhuis, Maria M and J.J. Hudziak and Kemp, John P and Keltikangas-J{\"a}rvinen, Liisa and McMahon, George and Mileva-Seitz, Viara R and Motazedi, Ehsan and Power, Christine and Raitakari, Olli T and Ring, Susan M and Rivadeneira, Fernando and Rodriguez, Alina and Scheet, Paul A and Sepp{\"a}l{\"a}, Ilkka and Snieder, Harold and Standl, Marie and Thiering, Elisabeth and Timpson, Nicholas J and Veenstra, Ren{\'e} and Velders, Fleur P and Whitehouse, Andrew J O and Smith, George Davey and Heinrich, Joachim and Hypponen, Elina and Lehtim{\"a}ki, Terho and Christel Middeldorp and Oldehinkel, Albertine J and Pennell, Craig E and Dorret I. Boomsma and Henning Tiemeier} } @article {95, title = {Methylation as an epigenetic source of random genetic effects in the classical twin design}, journal = {Advances in Genomics and Genetics, Dove Medical Press}, volume = {5}, year = {2015}, month = {09/2015}, pages = {305{\textendash}315}, abstract = {

The epigenetic effects of cytosine methylation on gene expression are an acknowledged source of phenotypic variance. The discordant monozygotic (MZ) twin design has been used to demonstrate the role of methylation in disease. Application of the classical twin design, featuring both monozygotic and dizygotic twins, has demonstrated that individual differences in methylation levels are attributable to genetic and environmental (including stochastic) factors, with the latter explaining most of the variance. What implications epigenetic sources of variance have for the twin modeling of (non-epigenetic) phenotypes such as height and IQ is an open question. One possibility is that epigenetic effects are absorbed by the variance component attributable to unshared environmental. Another possibility is that such effects form an independent source of variance distinguishable in principle from standard genetic and environmental sources. In the present paper, we conceptualized epigenetic processes as giving rise to randomness in the effects of polygenetic influences. This means that the regression coefficient in the regression of the phenotype on the polygenic factor, as specified in the twin model, varies over individuals. We investigate the consequences of ignoring this randomness in the standard twin model.

}, keywords = {classical twin design, epigenetics, heritability, methylation, parameter randomness}, doi = {http://dx.doi.org/10.2147/AGG.S46909}, url = {https://www.dovepress.com/methylation-as-an-epigenetic-source-of-random-genetic-effects-in-the-c-peer-reviewed-article-AGG}, author = {Conor V Dolan and Michel G. Nivard and Jenny van Dongen and van der Sluis,Sophie and Dorret I. Boomsma} }