Large panel sequencing studies of HRD related genes have identified a low fraction of familial cases explained by non-BRCA1/BRCA2 germline variants in HRD-genes [21, 22], and in a study by Matis et al. [23], it was concluded that the likelihood of associating more HRD-genes with familial breast cancer is low. This evidence concerns the gene BRCA1 and breast cancer.