Association of FTO gene variants with adiposity in African-American adolescents.

The prevalence of obesity continues to increase significantly, with the largest rise in the African-American adolescents. Genetic contributions to obesity are being identified with the advent of genome-wide association studies (GWAS). Specifically, variants of the fat mass and obesity associated (FTO) gene have been associated with obesity in populations of European descent. The studies in African Americans have been inconclusive. To further evaluate the association of the FTO gene and adiposity in African Americans, we genotyped 47 single-nucleotide polymorphisms (SNPs), including seven SNPs previously reported to be significant in the literature in a cohort consisting of 561 non-Hispanic white and 497 African-American individuals. Analysis of our data showed 17 SNPs to be associated with BMI Z-score (BMI-Z) in our study population. The strongest association was found in the African Americans. The most significant SNP was rs8057044, which was associated with BMI-Z in the African Americans (P = 0.00054). SNP rs9939609 was found to be significant in the non-Hispanic white population (P = 0.028). Our data confirm the association between FTO and adiposity suggesting that FTO is a childhood obesity susceptibility gene. Our data also identify a novel SNP of the FTO gene (rs8057044) that is associated with measures of adiposity in the African-American population.