Association of the PTPN22 gene (+1858C/T, −1123G/C) polymorphisms with type 1 diabetes mellitus: A systematic review and meta-analysis

ObjectiveA meta-analysis was conducted to evaluate the association of PTPN22 gene (+1858C/T −1123G/C) polymorphism with T1DM susceptibility.MethodsElectronic databases were used to identify published studies before September 2011. We adopted the most appropriate genetic model. The combined odds ratio (OR) with 95% confidence interval (95% CI) was calculated to estimate the strength of the association in a fixed or random effect model. Heterogeneity and publication bias were also assessed.ResultsTotally, 25 case–control studies including 8613 T1DM cases and 10,133 healthy controls (24 studies containing 8129 cases and 9641 controls for PTPN22 +1858C/T, 5 studies including 1460 cases and 1609 controls for PTPN22 −1123G/C) were identified as eligible and analyzed. The most appropriate co-dominant model was adopted. A significant association of PTPN22 +1858C/T gene polymorphism was found in overall population. When stratified by race, significance was observed in Europe and America, but not in Asia. We did not detect any association for PTPN22 −1123G/C polymorphism.ConclusionsOur study indicated that T1DM is associated with PTPN22 +1858C/T gene polymorphism, and targeting this promoter polymorphism should be dependent on ethnicity. Whether −1123G/C polymorphism is a susceptibility locus for T1DM, further studies with well-designed among different ethnicity populations are required.