The main syndrome associated with hereditary BC is known as Hereditary Breast and Ovarian Cancer Predisposition Syndrome (HBOC) (Miki et al., 1994; Wooster et al., 1994), whose main associated genes are BRCA1 (Miki et al., 1994) and BRCA2 (Wooster et al., 1994). Here, BRCA1 is linked to breast cancer.