HLA-DRB1 and type 1 diabetes mellitus: We compared by DRB1 gene’s N/N, DR3 and DR4 risk alleles in patients with T1D, most case patients had DR3 risk alleles: 31 (51.67 %) patient had DR3 alleles, 13 (21.67 %) patients had DR4 alleles and 4 (6.67 %) patients had DR3/DR4 alleles.