Population-based and family-based studies on the protein tyrosine phosphatase non-receptor 22 gene polymorphism and type 1 diabetes: A meta-analysis

Purpose: Studies investigating the association between PTPN22 gene C1858T polymorphism and type 1 diabetes (T1D) susceptibility among Caucasian population have reported conflicting results. To investigate this inconsistency, we performed a meta-analysis of all available studies dealing with the relationship between the PTPN22 C1858T polymorphism and T1D. Methods: Databases including PubMed, Web of Science, and EMBASE were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. Results: In total, 33 population-based studies with 22,485 cases and 35, 292 controls, 9 family-based studies involving 7276 families were included. Under the random-effects model, the per-allele overall OR of the C1858T polymorphism for T1D was 1.89 (95% Cl: 1.76-2.02, P<10(-5)) by. pooling all available case-control studies. In addition, we found significant evidence for overtransmission of the risk T allele in family-based studies (overall OR (TDT)= 1.58, 95% CI: 1.43-1.74; P<10(-5)). The summary OR from case-control and family-based association studies was 1.81 (95% CI: 1.70-1.93, P<10(-5)). Conclusions: In conclusion, this meta-analysis suggests that C1858T polymorphism in PTPN22 is associated with elevated T1D risk among Caucasian population. (C) 2012 Elsevier B.V. All rights reserved.