Six patients (3.6%) were found to carry a pathogenic or likely pathogenic (P/LP) variant in one of five known breast cancer susceptibility genes: 1.2% in BRCA1, 0.6% in each of BRCA2, ATM, CHEK2 and PALB. A further seven patients carried deleterious variants in one of five hereditary cancer predisposition genes exclusively investigated for truncating variants, specifically ALK, BUB1B, FANCG, RB1 and XPC (Table 1). This evidence concerns the gene RB1 and breast carcinoma.