Analysis of G>A change in splicing site of intron 6 of XRCC4 gene in patients with differentiated thyroid cancer (DTC)

Background: Differentiated thyroid carcinoma (DTC) is the most prevalent thyroid neoplasm which includes papillary and follicular cell carcinoma. Exposure to ionizing radiation is a predisposing factor for developing DTC. Non Homologous End Joining (NHEJ) DNA repair pathway is important one among DNA repair pathways which rejoins ends of broken DNA strands. XRCC4 gene is one of the most important genes in this pathway and G>A polymorphism in acceptor site of splicing site of its intron, causes truncated protein production. The aim of this study was assay presence any relationship between this polymorphism and differentiated thyroid carcinoma (DTC). Material and Methods: In this case-control study, by using PCR-RFLP method, rs1805377 SNP of XRCC4 gene was analyzed in total of 172 DTC patients and 195 cancer free individuals who admitted in Shariate Hospital of Tehran. The frequencies of this single nucleotide polymorphism (SNP) in case and control groups were compared. Also, risk ratio of having DTC in genotypes was assyed using regression analysis. Results: Current results showed no significant differences in genotypes between case and control groups (p-value: 0.588, OR= 1.52, 95% CI: 0.3349-6.9638). Also, dichotomized genotypes in DTC and control groups showed no significant results. Conclusion: Although the results showed potential association of A genotype with DTC risk, but these findings should be replicated in other studies with larger sample sizes.