Low-level constitutional mosaicism of a de novoBRCA1 gene mutation.
Br J Cancer 2015;
112:765-8. [PMID:
25633036 PMCID:
PMC4333503 DOI:
10.1038/bjc.2015.14]
[Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 12/24/2014] [Accepted: 12/30/2014] [Indexed: 12/22/2022] Open
Abstract
Background:
Pathogenic BRCA1 mutations are usually inherited. Constitutional low-level BRCA1 mosaicism has never been reported.
Methods:
Next-generation sequencing (NGS) of cancer gene panel of germline and tumour DNA in a patient with early onset, triple-negative breast cancer.
Results:
Constitutional de novo mosaicism (5%) for a pathogenic (c.1953dupG; p.Lys652Glufs*21) BRCA1mutation was detected in leukocytes, buccal tissue and normal breast tissue DNA, with ∼50% mutation in tumorous breast tissue.
Conclusion:
This is the first reported case of low-level, multiple tissue, constitutional mosaicism in BRCA1, and highlights the need to consider deep sequencing in affected individuals clinically suspected of having cancer predisposition whose tumours display a BRCA mutation.
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