Milad Pezeshki - Department of genetics, Faculty of Science, University of Arak, Arak, Iran.
Jamshid Ansari - Assistant Professor of Department of Oncology, Ayatollah Khansari Hospital, University of Medical Sciences, Arak, Iran.

Introduction & Aim: Breast cancer is the most frequent cancer in women worldwide. Single nucleotide polymorphisms in DNA repair genes associated with breast cancer. The XRCC3 protein participates in DNA double-strand breaks and recombination repair. The haplotypes of XRCC3 gene can plays critical roles in breast cancer development. The aim of the present study was evaluate associations between haplotypes of T241M and 4541 A > G polymorphisms of XRCC3 gene with the risk of breast cancer among Iranian women population. Methods: In this study that done between October 2016 and March 2017 on population-based case-control study inclusive 160 patients and 160 healthy women of Markazi Province in Ayatollah Khansari Hospital, haplotypes of T241M and 4541 A > G polymorphisms of XRCC3 gene were evaluated by PCR-RFLP techniques. Statistical analysis were done using SNP Analyzer software s. Results: Statistically significant difference was observed between the two groups of patients and controls for three genotypes the site rs861539 (P = 0.000). While, no statistically significant difference was observed between the two groups of patients and controls for three genotypes the site 4541 A > G (P = 0.435). In addition to statistically significant difference was observed between the TA (P = 0.000) and CG (P = 0.000) haplotypes with the risk of breast cancer.Conclusion: This study showed that there is significant association between TA and CG haplotypes of the XRCC3 gene, so that this two haplotypes can be used as a biomarkers in clinical predictive in relation with the risk of breast cancer.