Previous validation studies have demonstrated that BOADICEA provides valid BC risks for women in the general population or women participating in screening programmes.8–10 Since BRCA1/2 PVs are rare in the population, it has not been possible to assess the model performance specifically in PV carriers who are typically seen in clinical genetics.10 Although previous studies have indicated that multiple risk factors modify the BC risks for PV carriers,2 19–22 their combined effects on risk prediction1 have not been studied. Here, BRCA1 is linked to breast cancer.