PTPN22 and type 1 diabetes mellitus: Single nucleotide polymorphisms (SNPs) comprising insulin gene (INS) presents ~ 10% of genetic predisposition of T1D [8, 11], cytotoxic T-lymphocyte–associated antigen (CTLA)-4 gene [12], protein tyrosine phosphatase non-receptor type 22 (PTPN22) [8, 13], nterferon induced with helicase C domain 1 (IFIH1) genes [14] and Interleukin-2 receptor alpha chain (IL2RA) [11].