Breast cancer (BC) is the most frequently occurring cancer among women, representing a quarter of all diagnosed cancers (Bray et al., 2018). It is also the first cause of cancer-related deaths among them(DeSantis et al., 2015). In Egypt, according to the latest National Cancer Registry Program (NCRP), BC is the most common cancer among women representing 32.04% of total cancers (Ibrahim et al., 2014). BRCA1 and BRCA2 (breast cancer predisposition gene 1/2)are the strongest susceptibility genes for BCaccounting for up to half of the heritable mutations in BC and inherited in an autosomal dominant pattern with incomplete penetrance (Tung et al., 2015). Defective DNA double-strand repair is a characteristic of germline mutations in BRCA1 and BRCA2 genes in all cells expressing them (Mehrgou and Akouchekian, 2016).They are also classified as pathogenic variants or