Association between gene polymorphism of protein tyrosin phosphatase non receptor type 22(PTPN22) and susceptibility for rheumatoid arthritis in an Iraqi population.

Abstract

The gene protein tyrosine phosphatase non-receptor type 22 (PTPN22), a negative regulator of T-cell activation and the polymorphism is a single nucleotide polymorphism (SNP) and is a C → T substitution (rs2476601) at nucleotide position 1858 that leads to a tryptophan (W) for arginine(R) transition at codon 620 and this lead to many autoimmune disease like RA. The rheumatoid arthritis patients were diagnosed by physicians of rheumatology in the Rheumatology Center of Al Sadder Medical Teaching Hospital in Al-Najaf Al-Ashraf city. Genomic DNA was extracted from the whole blood samples of patients and controls and by using commercial kit (FavorPrep™ Blood Genomic DNA Extraction Mini Kit). (PTPN22 C1858T SNP) genotyping was done using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to all participants in this study (60 RA patients and 36 non-autoimmune control group). The genotype and allele frequencies of these SNP were analyzed by statistical tests. There were no significant differences in alleles and genotypes of PTPN22 SNP between RA cases and control group. Patients with PTPN22 CT genotype are more susceptible to infection with rheumatoid arthritis.