Apart from TCF7L2, the scan reveals two signals for T2D with P values less than 5×10-7 (Table 3, Fig. 5). The first of these maps within the FTO (fat-mass and obesity-associated) gene on chromosome 16q. Several adjacent SNPs (including rs9939609, rs7193144 and rs8050136) generate signals characterized by a perallele OR for T2D of ~1.25 and a risk-allele frequency of ~40% in controls. As recently described in follow-up studies prompted by this finding, the effect of these variants on T2D-risk has been replicated and is mediated entirely by their marked effect on adiposity24.
