HLA-DQA1 and type 1 diabetes mellitus: In the Caucasian population, T1D is strongly associated with HLA-DR3-DQA1*0501-DQB1*0201 (DR3) and DR4-DQA1*0301-DQB1*0302 (DR4) haplotypes, whereas HLA DR3/DR4 are the highest risk genotype (16).