Studies in non-European populations have had varied success in replicating the findings at the FTO locus. While several studies showed an association between FTO SNPs and obesity-related phenotypes in Hispanic [5], [6], [18], [19] and Asian populations [20]–[26], studies of African or African American (AA) subjects showed limited support for some of the most consistent FTO GWAS findings initially identified in subjects of European descent [2], [5], [6], [14], [18], [19], [27]–[32]. This lack of generalization in AA may be attributable to the lower levels of linkage disequilibrium (LD) with the underlying functional variant(s) at the 16q12.2/FTO locus, as compared with European Americans (EAs). SNPs discovered in GWAS (i.e. “index SNPs”) are often not the functional variants; however, they do tag genomic regions harboring strongly correlated variants, one or more of which are the potentially functional variant(s). Because different ancestral populations differ in their LD patterns, an index SNP discovered in one ancestral group (e.g. EA) may or may not be strongly correlated with the functional variant(s) in a different ancestral group (e.g. AA). Thus, the index SNP may not
