Copy number variations associated with obesity related traits in African Americans: a joint analysis between GENOA and HyperGEN

Obesity is a highly heritable trait and a growing public health problem. African Americans are a genetically diverse, yet understudied population with a high prevalence of obesity (body mass index (BMI) greater than 30 kg/m(2)). Recent studies based upon single nucleotide polymorphisms (SNPs) have identified genetic markers associated with obesity. However, a large proportion of the heritability of obesity remains unexplained. Copy number variation (CNV) has been cited as a possible source of missing heritability in common diseases such as obesity. We conducted a CNV genome-wide association study of BMI in two African American cohorts from GENOA and HyperGEN. We performed independent and identical association analyses in each study, then combined the results in a meta-analysis. We identified three CNVs associated with BMI, obesity, and other obesity-related traits after adjusting for multiple testing. These CNVs overlap the PARK2, GYPA and SGCZ genes. Our results suggest that CNV may play a role in the etiology of obesity in African Americans.