A Meta-Analysis Identifies New Loci Associated with Body Mass Index in Individuals of African Ancestry

Keri Monda, Kari North, Christopher Haiman and colleagues report a meta-analysis of GWAS for body mass index that is composed of 39,144 individuals of African ancestry, followed by further genotyping in 32,268 individuals of African ancestry. The study also includes analysis of publicly available data from the GIANT consortium of ~124,000 individuals of European ancestry. The paper reports evidence for two new loci near GALNT10 and MIR148A. Genome-wide association studies (GWAS) have identified 36 loci associated with body mass index (BMI), predominantly in populations of European ancestry. We conducted a meta-analysis to examine the association of >3.2 million SNPs with BMI in 39,144 men and women of African ancestry and followed up the most significant associations in an additional 32,268 individuals of African ancestry. We identified one new locus at 5q33 (GALNT10, rs7708584, P = 3.4 × 10−11) and another at 7p15 when we included data from the GIANT consortium (MIR148A-NFE2L3, rs10261878, P = 1.2 × 10−10). We also found suggestive evidence of an association at a third locus at 6q16 in the African-ancestry sample (KLHL32, rs974417, P = 6.9 × 10−8). Thirty-two of the 36 previously established BMI variants showed directionally consistent effect estimates in our GWAS (binomial P = 9.7 × 10−7), five of which reached genome-wide significance. These findings provide strong support for shared BMI loci across populations, as well as for the utility of studying ancestrally diverse populations.