Two-hit events occurred independently in bilateral breast cancers in a germline double heterozygous carrier for BRCA1 and BRCA2.

ABSTRACT: While patients with hereditary breast and ovarian cancer with germline double heterozygosity (GDH) for BRCA1 and BRCA2 are rare, carcinogenesis in these cases remains unclear. We examined two-hit events of heterochronous bilateral breast cancers in a patient with GDH for BRCA1 and BRCA2. A 65-year-old woman developed right breast cancer (triple-negative type) at the age of 49 and left breast cancer (triple-negative type) at 55. Family history indicated that multiple relatives on her mother's side also developed breast cancer. BRCA1/2 genetic testing (BRACAnalysis®) showed that she had variants in both the BRCA1 and BRCA2 (BRCA1:c.5193 + 2dup, BRCA2:c.6952C > T/p.Arg2318Ter). According to the data from the test, the former was interpreted as likely pathogenic at Myriad Inc. Further examinat

SUBMITTER: Semba R 

PROVIDER: S-EPMC12552342 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature