BRCA1 and BRCA2 gene mutations cause 20% to 25% of hereditary BCs8 and 5% to 10% of all BCs.9 Inheritance of germline mutations in BRCA1 and BRCA2 genes is autosomal dominant,10 and one in 400 to 1,000 persons in the general population are estimated to have a BRCA1 or BRCA2 mutation.7 In addition to BC, deleterious BRCA1/2 mutations also predispose individuals to ovarian cancer; the average cumulative risk of ovarian cancer by age 70 years is 39% in BRCA1 mutation carriers and 11% to 17% in BRCA2 mutation carriers.11,12. This evidence concerns the gene BRCA1 and breast cancer.