Role of C1858T Polymorphism of Lymphoid Tyrosine Phosphatase in Egyptian Children and Adolescents with Type 1 Diabetes

BACKGROUND: Type 1 diabetes mellitus (T1DM) is a multifactorial autoimmune disease. The protein tyrosine phosphatase non-receptor 22 (PTPN22) gene is an important negative regulator of signal transduction through the T-cell receptors (TCR). A PTPN22 polymorphism, C1858T, has been found to be a risk determinant for several autoimmune diseases, including T1DM, in different populations. OBJECTIVE: The present study was aimed to analyze a possible association between the C1858T polymorphism in Egyptian children with T1DM. METHODS: This case-control study included 240 children divided evenly between T1DM patients and controls. The PTPN22 C1858T polymorphism was genotyped using polymerase chain reaction with restriction fragment length polymorphism (RFLP). RESULTS: Both the 1858CΤ and 1858ΤΤ genotypes and the 1858T allele were found more frequently in patients (32.5% and 18.7%, respectively) than in controls (10% and 5.0%, respectively), P=0.013 and P=0.007, respectively. Among females, the 1858T allele was more common in patients (18%) than in controls (2.6%), P=0.014. CONCLUSION: These findings suggest that the PTPN22 1858T allele could be a T1DM susceptibility factor in the Egyptian population and that it might play a different role in susceptibility to T1DM according to gender in T1DM patients.