Somatic BRCA Mutation in Cholangiocarcinoma Patient Utilized to Individualize an HBOC Syndrome

BRCA-associated hereditary breast and ovarian cancer syndrome (HBOC) implies increased absolute risk also for other malignancies such as cholangiocarcinoma (CCA). However, even if somatic mutations in CCA have been reported, there are no data on its utilization as predisposing genetic factor in a family. For the first time, we utilized CCA somatic BRCA mutation to individualize a family with HBOC. A 47-year-old woman (daughter of a patient died for CCA) accessed to our Genetic Councelling to evaluate her personal cancer risk. We performed a somatic BRCA1/2 NGS analysis on DNA extracted from formalin-fixed, paraffin-embedded CCA-tissue of her mother. After demonstration of pathogenic variant c.6468_6469delTC in BRCA2 gene mutation, the same germline pathogenic variant was found in DNA blood of one of two daugthers. So far, CCA tissue can be utilized, in addition to patient’s selection to specific therapeutic strategies, also to individualize families belonging to HBOC syndrome.