MODY variant carriers had significantly increased odds of having diabetes compared to non-carriers in both studies (OR > 7, P < 10−4; Table 1, Supplementary Data 3); differences in risk estimates between the two studies were likely influenced by ascertainment practices in AMP-T2D-GENES, as it was a T2D case-control study and several sub-studies intentionally excluded diabetes cases with clinical features suggestive of MODY17 (Supplementary Data 1). This evidence concerns the gene HNF4A and diabetes mellitus.