The recognition of strong familial clustering of breast and ovarian cancer [1], followed by the discovery of the BRCA1 and BRCA2 (BRCA1/2) genes in 1994 [2] and 1995 [3], respectively, has led to the study and characterization of BRCA1/2-related hereditary breast and ovarian cancer syndrome (HBOC). This evidence concerns the gene BRCA1 and Hereditary breast and ovarian cancer syndrome.