Fig. 1

Flow chart showing the study population selection from the Hereditary Cancer Biobank from the Norwegian Radium Hospital, Norway. It contains ascertained BC and breast/ovarian cancer kindreds by family history that were all subjected to genetic testing. The identification of phenocopies involved 48 women with prospective detected BC or gynecological cancer at follow-up, who were tested negative for their respective families’ path_BRCA1/2 variants. Among these cases, 13 were identified in non-carriers of the family’s path_BRCA1 variant and in 35 non-carriers of the family’s path_BRCA2 variant (n = 30 from the Department of Genomic Medicine from the University of Manchester). Pathogenic variants were identified in 5/48 (10%) BC or gynecological cancer cases