This analysis demonstrated that the discriminative EOT1D and LaOT1D haplotypes significantly influenced the age at T1D presentation, with the DRB1*04:08-DQ8 haplotype decreasing age at onset on average by 6.5 years and the DRB1*04:05-DQ8 haplotype increasing it by 5.1 years. Here, HLA-DRB1 is linked to type 1 diabetes mellitus.