Our study revealed that HLA-DRB1∗03, DQB1∗02 alleles, and their haplotypes strongly associate with the presence of autoantibodies against GAD65 while HLA-DRB1∗04, DQB1∗03 alleles, and their haplotypes are associated with autoantibodies against IA-2 in T1D patients. The gene discussed is PTPRN; the disease is type 1 diabetes mellitus.