In the framework of genetic counseling for persons at risk for familial BC/OC, CNV detection should be included in routine germline diagnostics for all BC/OC predisposition genes and may not be restricted to BRCA1/2, as a relevant proportion of women in our study sample (0.76%) were affected by CNVs in non-BRCA1/2 genes. Here, BRCA1 is linked to breast cancer.