BRCA1 and breast carcinoma: Genetic alterations in the BRCA1 gene represent the primary cause of hereditary breast cancer, accounting for approximately 40%–45% of cases. [12, 13] By the age of 70, it has been estimated that the cumulative risk for developing BC is 65%–80% and 45%–85% for BRCA1 and BRCA2 mutation carriers, respectively [14].