Notably, for patients with breast cancer, age at diagnosis in the DH PSV group (n = 10; 9 carriers of either BRCA1 or BRCA2; 42.3 ± 13.0 years) was similar to the age at diagnosis among single BRCA1 PSV carriers (n = 59, 43.8 ± 8.7 years, p = 0.76) and single BRCA2 PSV carriers (n = 52, 47.9 ± 13.0 years, p = 0.17). This evidence concerns the gene BRCA1 and breast cancer.