Heritability and genetic correlations of obesity-related phenotypes among Roma people

Abstract

Background: The Roma people are particularly vulnerable to developing obesity and related diseases, due to their social and ethnic backgrounds. However, little is known about the genetic and/or environmental factors affecting the variability of obesity-related traits among the Roma population.

Aim: The aim of the present study was to estimate heritabilities and common genetic and environmental influences of obesity-related phenotypes in a sample of Roma people living in the Greater Bilbao region (Basque Country; Spain).

Subjects and methods: Three hundred and seventy-two individuals from 50 large, extended and highly consanguineous pedigrees were phenotyped for anthropometric traits related to obesity. Heritability estimates were assessed for all quantitative traits and bivariate analyses were conducted to assess the phenotypic, genetic and environmental correlations among these traits.

Results: Significant heritable components (p < 0.01) ranging from 0.25–0.68 exist for the studied phenotypes. Heritability for WHR (h² = 0.60) considerably surpasses the usual heritability estimates on family-based studies ( < 0.30). Measures of overall fatness (BMI, CF and SF) show stronger correlations with each other than body fat distribution traits (WHR, CI and TER).

Conclusions: The study concluded that the Greater Bilbao Roma population is genetically predisposed to abdominal fat distribution. Variation in body mass is highly associated with variation in adiposity. However, overall fatness and adiposity distribution does not seem to share major common genetic factors, although common environmental factors operate between them.

Keywords::

• Adiposity, pleiotropy, ethnic groups, family studies

Acknowledgements

We would like to thank the outpatient departments of health centres and the education centres who allowed us to carry out the study. We also would like to express our gratitude to Kale Dor Kayiko for their collaboration. Special thanks also go to the families enrolled in the study for their participation.

Declaration of interest: This study was supported by grants of the Bilbao Bizkaia Kutxa (BBK; 87014/97012/07007), of the Spanish Ministry of Science and Innovation (MICINN; GCL2010-15511), of the Industry Department of the Basque Government (SAIOTEK; SA2010/00035) and by two pre-doctoral grants one of the Ministry of Education of Spain (for A.P) and the other from the University of the Basque Country (for M.E.I.). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.