BRCA2 and maternal uniparental disomy of chromosome 20: Genetic analysis revealed an inherited condition involving MBC in 10 out of 37 (27%) cases, including 7 carriers of BRCA1/2 germline pathogenic variants (3 BRCA1 and 4 BRCA2) and 3 carriers of pathogenic variants of other genes including APC, MUTYH, and CDH1. Invasive ductal carcinomas were diagnosed in 35 out of 37 MBCs including sporadic and inherited cases.