@article {457,
	title = {Heritability of urinary amines, organic acids, and steroid hormones in children},
	journal = {Metabolites},
	volume = {12},
	year = {2022},
	pages = {474},
	abstract = {<p>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.</p>
},
	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 {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 = {<p>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.</p>
},
	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}
}
