BRCA1 and breast cancer: Inherited genetic variations account for 5-10% of all female breast cancers and 15-20% of all familial breast cancers, with mutations most commonly seen in the BRCA1 and BRCA2 genes.,4,5 Patients with BRCA1 and BRCA2 mutations have a significantly higher risk of developing breast and ovarian cancer, and patients with a prior diagnosis of breast cancer have a higher risk of recurrence.,6-9