Regression analysis linked DR-DQ haplotypes to T1DM and the associated conditions.<h4>Results</h4>The most frequent predisposing alleles and haplotypes were HLA-DR3 (70.27%), DQ2 (70.27%), DR3-DQ2 (70.27%), DQB1*02:01 (70.27%), A02 (54.05%), whereas the most prevalent protecting allele was DPB1*04:01 (52.63%). This evidence concerns the gene HLA-DPB1 and type 1 diabetes mellitus.