Association of PTPN 22+1858 C / T polymorphism with T ype 1 diabetes in the N orth I ndian population

Summary A nonsynonymous SNP +1858 C / T (rs2476601) in the protein tyrosine phosphatase, nonreceptor type 22( PTPN 22) gene leading to A rg 620 T rp substitution is known to be associated with susceptibility to type 1 diabetes ( T 1 D ) and several other autoimmune diseases. We studied this polymorphism in 145 T 1 D patients and 210 healthy controls from N orth I ndia. The minor allele +1858 T was observed to be significantly increased among patients as compared to healthy controls (2.76% vs 0.5%, P  = 0.027, OR  = 5.93; 95% CI  = 1.4–24.8). The association was also observed at the level of heterozygous C/T genotype (5.5% vs 0.95%, P  = 0.026, OR  = 6.07; 95% CI  = 1.43–25.6). The T allele and C / T genotype were predominantly found among patients who were positive for both glutamic acid decarboxylase 65 ( GAD 65) and insulin antigen 2 ( IA 2) autoantibodies and showed significantly increased frequencies (10%, P  = 0.034, OR  = 11.67; 95% CI  = 1.58–84.1 and 20%, P  = 0.031, OR  = 13.0; 95% CI  = 1.66–97.5, respectively) as compared to patients negative for these autoantibodies (0.95% and 1.9%, respectively). The results suggest that the PTPN 22+1858 T allele is positively associated with T 1 D in the N orth I ndian population.