The detection rate of PVs in the other five genes (ATM, CHEK2, PALB2, PTEN, and RAD51C) with a clear association with breast cancer susceptibility was only 3%, indicating that PVs in these genes are relatively rare in early-onset breast cancer patients and that the clinical benefit of analyzing these genes in this group of patients is limited, in line with other studies [23,30]. The gene discussed is CHEK2; the disease is breast cancer.