Compared with the previous AMP-T2D-GENES study for adult-onset T2D, the single-variant associations showed a mean OR increase of 1.14-fold (Supplementary Table 5), while the MC4R (OR 3.49, P = 1.7 × 10−11, combined MAF 0.011 for 25 variants) and HNF1A (OR 7.54, P = 1.2 × 10−10, combined MAF 0.0038 for 21 variants) gene-level associations had 1.69- and 6.13-fold higher effect sizes. This evidence concerns the gene HNF1A and type 2 diabetes mellitus.