We initially conducted a transethnic MHC fine-mapping of T1D, and successfully disentangled a set of 5 risk-associated amino acid polymorphisms of position 71 and 74 in HLA-DRβ1, and 30, 70, and 185 in HLA-DQβ1. Here, HLA-DRB1 is linked to type 1 diabetes mellitus.