Twenty-four individuals (16.8% [95% CI, 11.1%-23.9%]) with germline testing had PGVs in breast cancer susceptibility genes, including BRCA1 (n = 17 [70.8%]), BRCA2 (n = 5 [20.8%]), PALB2 (n = 1 [4.2%]), and CHEK2 (n = 1 [4.2%]). This evidence concerns the gene CHEK2 and breast cancer.