Single Nucleotide Polymorphisms of PTPN22 Gene in Iranian Patients with Ulcerative Colitis.

OBJECTIVES: Protein tyrosine phosphatase non-receptor type 22 gene (PTPN22) single-nucleotide polymorphisms (SNP) have been associated with a number of different autoimmune diseases. This study aimed to investigate the association of five polymorphisms of PTPN22 gene with susceptibility to ulcerative colitis (UC) in Iran. MATERIALS AND METHODS: A total of 67 patients diagnosed with UC (35 female and 32 male all under 18 years) and 93 healthy subjects were selected. The samples were genotyped for the, rs12760457, rs2476601, rs1310182, rs1217414, and rs33996649 in PTPN22 gene using real-time polymerase chain reaction (PCR) allelic discrimination TaqMan genotyping assays. RESULTS: The frequencies of the rs1310182 A and G alleles, and also the AA and GG genotypes were significantly different between the patient and the control groups (p < 0.05). The carriage of G allele of rs1310182 was significantly associated with increased risk of UC (OR (95% CI) = 1.17 (0.70-1.98), p < 0.001). Moreover, the genotype GG of SNP rs1310182 was significantly associated with UC (OR (95% CI) = 2.32 (1.13-4.76), p < 0.01). No association was found between other PTPN22 gene SNPs among UC patients. CONCLUSION: PTPN22 gene polymorphism in rs1310182 could play a crucial role in susceptibility to UC.

Association of PTPN22 Single Nucleotide Polymorphisms with Celiac Disease.

OBJECTIVES: Celiac disease is a chronic autoimmune disease in which gene-environment interactions cause the immune system to unfavorably react to naturally gluten-containing foods. PTPN22 plays a crucial role in regulating the function of various cells of the immune system, particularly T cells. Polymorphisms of the PTPN22 gene have been associated with many autoimmune diseases. The present genetic association study was conducted to investigate the possible associations between PTPNTT single nucleotide polymorphisms (SNPs) and celiac disease in an Iranian population. MATERIALS AND METHODS: The study population consisted of 45 patients with celiac disease and 93 healthy controls. The study genotyped five SNPs of the PTPN22 gene: rs12760457, rs1310182, rs1217414, rs33996649, and rs2476601. RESULTS AND CONCLUSIONS: Control and patient groups did not differ on the genotype distribution of four of five investigated SNPs in the PTPN22 gene, for example, rs12760457, rs2476601, rs1217414, and rs33996649. The only investigated PTPN22 variant, which could be associated with CD, was rs1310182. A significant increase in the carriage of the T allele of rs1310182 in CD patients was observed (OR (95% CI) = 11.42 (5.41, 24.1), p value < 0.0001). The TT genotype of this SNP was significantly associated with celiac disease. Our study suggests that the rs1310182 SNP of PTPN22 gene may be a predisposing factor of celiac disease in the Iranian population. Further studies are required to investigate the issue in other racial and ethnic subgroups.