Association of X-Ray Repair Cross-Complementing Group 1 (XRCC1) Polymorphisms with Breast Cancer Susceptibility among Iranian-Azeri Women

XRCC1 protein plays an important role in the base excision and single-strand break repairment, and also, as a scaffold protein, it attaches the proteins of the DNA repair complex. Changes this system increases the occurrence of the malignancies. We examined the association of polymorphisms in codon 194 (Arg/Trp) and 399 (Arg/Gln) of XRCC1 gene and the risk of the breast cancer in Azerbaijani women in the Northwest of Iran. In this descriptive - analytical study, 91 patients with breast cancer and 91 healthy individuals as controls were studied. The DNA compliment mass extracted from peripheral blood cells and the different genotypes were determined at codons 194 and 399 of XRCC1 gene by PCR-RFLP technique and Sequencing. The P-value calculated using Fisher's exact test. There was no difference in the distribution of genotypes at codon 194 of xrcc1 gene in case and control group (all were homozygous CC) (p>0.05). The genotype distribution in the control group at codon 399 was 0, 83.51 and 16.48 percent for Arg/Arg, Gln/Arg and Gln/Gln, respectively. In the cancer group, the genotype distribution was 16.48, 46.15 and 37.36 percent, respectively for the same order of genotypes. The results indicated a significant association between genotypes of Arg/Arg and Gln/Gln at codon 399 of xrcc1 gene and breast cancer risk in this population (p<0.0001). Also, there is a significant association between Arg/Gln and loss of breast cancer risk (p<0.0001). There was no difference between genotypes at codon 194 of xrcc1 gene in case and control groups. In addition, our results illustrated a significant association between the xrcc1 codon 399 polymorphisms and the risk of breast cancer in an Azeri women.