The Potential Role of PTPN-22 C1858T Gene Polymorphism in the Pathogenesis of Type 1 Diabetes in Saudi Population.

Background: Recent investigations have reported an association between protein tyrosine phosphatase non-receptor type-22 (PTPN-22) gene polymorphism and susceptibility to the development of type 1 diabetes (T1D) in some populations and not in others. In this study, we aimed to investigate the association of PTPN-22 C1858T polymorphism with T1D in Saudi children. Methods: A cohort of 372 type 1 diabetic children and 372 diabetes-free subjects was enrolled in the current investigation. The PTPN-22 C1858T polymorphism was identified using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: Our data showed that the frequency of CT and TT genotypes of PTPN-22 C1858T was higher in T1D children (17.7% and 4.3%, respectively) compared to healthy controls (4.8% and 1.6%, respectively), and both genotypes were statistically associated with T1D patients (OR = 4.4, 95% CI: 2.55 - 7.58, p < 0.001; and OR = 3.2, 95% CI: 1.23-8.28, p = 0.017, respectively). Moreover, the 1858T allele was significantly associated with T1D patients compared to the C allele (OR = 3.2, 95% CI: 1.59-6.88, p < 0.001). In addition, the T allele was significantly associated with elevated levels of HbA1c, anti-GAD, and anti-insulin antibodies (p < 0.001) and a lower concentration of C-peptide (p < 0.001) in T1D children. Conclusion: The data presented here suggests that the T allele of PTPN-22 C1858T polymorphism might be a risk factor for T1D development in Saudi children.