BRCA1 and breast cancer: Such pathogenic, or disease-causing, genetic variants result in a 40% to 80% lifetime risk of developing breast cancer, an 11% to 40% risk of ovarian cancer, and striking increases in the risk of male breast, pancreatic, and prostate cancers.1,2 Up to 10% of breast cancers are caused by these genes.3,4 Approximately one in 250 individuals of European descent are born with a pathogenic variant in BRCA1/2, and prevalence is much higher in certain populations—for example, Ashkenazi Jews.5,6