Association Of PTPN22 Gene Polymorphisms in Patients with Graves’ Disease in Iranian Papulation

Background: Graves’ disease (GD) is an autoimmune disease that is associated with increased thyroid gland irritation and, consequently, hyperthyroidism. Autoimmune diseases are common in the general population and are influenced by genetic and environmental factors. PTPN22, which was reported as a susceptible locus for GD in several populations, acts as a negative regulator for activation of primary T-cells, and LYP polymorphism could potentially increase susceptibility to Graves' disease, which may play a role in other autoimmune conditions as well. In this study, we investigated the association of several PTPN22 single nucleotide polymorphisms (SNPs) with Graves patients. Methods: After DNA extraction from peripheral blood cells, SNP Genotyping was performed through real-time PCR with allelic discrimination TaqMan genotyping assays (ABI Applied Biosystems, 7300 Real-Time PCR System, USA) based on manufacturer protocols. The frequencies of alleles and genotypes of PTPN22 SNPs (rs12760457, rs2476601, rs1310182, and rs1217414) were recorded. Results: In our study, the rs1310182 was significantly more frequent in patients with GD than in healthy individuals. While the C allele of rs1310182 was 1.78 times more frequent in GD patients (95%CI: 1.18- 2.69, P=0.005), the T allele was more frequent in healthy subjects (OR=0.56, 95% CI: 0.37-0.84, P=0.005). In addition, the CC genotype of this SNP was 1.86 times more common in patients (P=0.05). No significant differences were observed between the other SNPs of this gene in case and control. Conclusion: The results demonstrate that one SNP (rs1310182) of the PTPN22 gene is associated with susceptibility to GD in an Iranian population. Further studies, including functional analyses, are required.