BRCA1 and breast cancer: It is thought that approximately 10-15% of breast cancer cases are hereditary and associated with mutations in BRCA1 or BRCA2 genes and some other genes having high to moderate penetrance such as TP53, PTEN, ATM, CHEK2, PALB2 and BRIP1 and ATR, which account for approximately 5% of the risk [4-10].