Determination the CTLA-4 and PTPN22 Gene Polymorphism in Graves’ Disease Patients

Abstract

Graves’ disease (GD) is a multifactorial autoimmune disease with contribution from both genetic andepigenetic factors in its causation. Gene “protein tyrosine phosphatase non receptor 22” (PTPN22) is animportant immune regulatory gene preventing hyper responsiveness of T cells by negatively regulatingtheir signal transduction. Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4) gene polymorphisms belong to themain genetic factors determining the susceptibility to development Graves’ disease. This study aimed toanalyze whether 1858 C/T SNP in PTPN22 and 1822 C/T SNP in CLTA-4 genes have any association withGD in Iraqi population. PCR-RFLP was performed for genotyping 1858 C/T SNP and 1822 C/T SNP withinPTPN22 and CLTA-4 respectively, in patients with GD and healthy controls. Among the patients with GD,the frequencies CLTA-4 CC, CT, and TT genotypes were 43.3%, 45%, and 11.6%, respectively, whereas inhealthy controls the frequencies of CC, CT genotypes were 60%, 30%, and 10%, respectively. While thereis no mutation recorded in PTPN22 1858 C/T SNP in both PCR-RFLP and DNA sequence analysis. Theseresults indicated that there is no significant association was found between PTPN22 1858 C/T SNP andCLTA-4 in patients with GD. It has been concluded that GD is not associated with PTPN22 1858 C/T SNPand 1822 C/T SNP of CLTA-4 in Iraqi population.