646kb-region at 16q12.2, encompassing FTO and the neighboring RPGRIP1L, were tested in more than 20,000 African Americans, identifying rs56137030 as the SNP with the most significant association with BMI.27 In Europeans ancestry populations, this SNP represents a cluster (r2CEU >0.50) of 103 (of the 3,756) SNPs, whereas in African Americans – due to weaker correlations between SNPs – this cluster includes only 29 SNPs.27 Six of the 29 SNPs locate within intronic regulatory elements, two of which are predicted to have allele-specific binding affinities for different transcription factors, including Cut-like homeobox 1 (CUX1) that possibly influences the transcriptional regulation of FTO.28,29
