association of arg194trp and arg399gln polymorphisms of xrcc1 gene and risk of differentiated thyroid carcinoma in iranianazeri patients

Background: the thyroid cancer (tc) is one of endocrine malignancies which contributes to more than 50% of all deaths from endocrine cancers. gene polymorphisms including dna repair genes such as xrcc1 (x-ray repair cross-complementing group 1) gene are thought to modify dna repair capacity and relate to cancer risk. objectives: the aim of the study was to detect the association between xrcc1 polymorphisms and increased risk of thyroid carcinoma among iranian-azeri patients. methods: this case-control study was performed on 114 differentiated thyroid carcinoma patients and 91 normal control subjects. single nucleotide polymorphisms (snps) of 194 c > t and 399 g > a of xrcc1 gene were genotyped by polymerase chain reactionrestriction fragment length polymorphism (pcr-rflp). results: in the present study, polymorphism at codon 194 of the xrcc1 gene was not found in case and control groups (p = nc (not calculated). all of the case and control subjects were 194c/c. unlike 399 g > a genotype (p < 0.001, or = 0.184, ci = 0.09 - 0.372), there was a positive association for 399g/g (p < 0.001, or = 3.304, ci = 1.624 - 6.780) and 399 a/a (p < 0.001, or = 14.143, ci = 1.861 - 296.277) genotypes with differentiated thyroid carcinoma. the frequency of variant 399 a allele among the cases was slightly higher than that in controls (p = 0.269, or = 0.798, ci = 0.535 - 1.190). conclusions: based on these results, the xrcc1 399g> a genotype could be used as a useful molecular biomarker to predict genetic susceptibility for differentiated thyroid carcinoma in iranian-azeri patients.