This finding was consistent with the uppermost part of the range of previous estimates, especially the cumulative incidence recently estimated by Kuchenbaecker et al. in the largest prospective study published to date [8,10,11]: 5.9% (95% CI 3.4–10.1) for BC between age 21 and 30 for BRCA1 and 4.8% (95% CI 2.0–11.5) for BRCA2. Here, BRCA1 is linked to breast cancer.