BRCA1 and breast carcinoma: The two most common high risk cancer‐predisposing genes are BRCA1 and BRCA2. Although the estimated prevalence in the general population is low (0.11% and 0.12%, respectively) (Peto et al., 1999; Whittemore, Gong, & Itnyre, 1997), carriers have an estimated 40%–87% lifetime risk of developing breast cancer, which typically occurs at a young age (Antoniou et al., 2003; Ford et al., 1998; King, Marks, & Mandell, 2003; Risch et al., 2001).