SLC30A8 and type 2 diabetes mellitus: SLC30A8, a gene in which loss of function is known to protect against T2DM (16), was the only other gene significantly associated with both reduced HbA1c (“flexdmg” model; β = −0.24 SD units, 95% CI: [−0.30, −0.19], P = 1.4 × 10−17) and blood glucose (β = −0.19 SD units, 95% CI: [−0.25, −0.13], P = 7.3 × 10−10) in the collapsing analysis (Fig. 1B).