BRCA1 and breast cancer: While biallelic germline pathogenic variants (GPVs) in these genes cause FA (a syndrome characterized by morphologic abnormalities, bone marrow failure, and increased risk of malignancy development), monoallelic GPVs in five FA genes (including BRCA1/FANCS, BRCA2/FANCD1, PALB2/FANCN, BRIP1/FANCJ, RAD51C/FANCO) confer an increased risk of breast (BC) and/or ovarian (OC) cancer.