Among 255 familial breast and/or ovarian cancer (FBOC) patients without BRCA1/2 mutation, we found one (0.4%) patient carrying a non-sense mutation (c.339G>A, W113X), which was also observed in an individual with hereditary cancer-predisposing syndrome, classified as pathogenic/likely pathogenic in ClinVar database (https://www.ncbi.nlm.nih.gov/clinvar/). Here, BRCA1 is linked to hereditary neoplastic syndrome.