Asadollahi R, Britschgi C, Joset P, Oneda B, Schindler D, Meier UR, Rauch A. Severe reaction to radiotherapy provoked by hypomorphic germline mutations in ATM (ataxia-telangiectasia mutated gene).
Mol Genet Genomic Med 2020;
8:e1409. [PMID:
32748564 PMCID:
PMC7549565 DOI:
10.1002/mgg3.1409]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/05/2020] [Indexed: 12/13/2022] Open
Abstract
Background
A minority of breast cancer (BC) patients suffer from severe reaction to adjuvant radiotherapy (RT). Although deficient DNA double‐strand break repair is considered the main basis for the reactions, pretreatment identification of high‐risk patients has been challenging.
Methods
To retrospectively determine the etiology of severe local reaction to RT in a 39‐year‐old woman with BC, we performed next‐generation sequencing followed by further clinical and functional studies.
Results
We found a −4 intronic variant (c.2251‐4A>G) in trans with a synonymous (c.3576G>A) variant affecting the ATM DNA‐repair gene (NG_009830.1, NM_000051.3) which is linked to autosomal recessive ataxia–telangiectasia (A–T). We verified abnormal transcripts resulting from both variants, next to a minor wild‐type transcript leading to a residual ATM kinase activity and genomic instability. Follow‐up examination of the patient revealed no classic sign of A–T but previously unnoticed head dystonia and mild dysarthria, a family history of BC and late‐onset ataxia segregating with the variants. Additionally, her serum level of alpha‐fetoprotein (AFP) was elevated similar to A–T patients.
Conclusion
Considering the variable presentations of A–T and devastating impact of severe reactions to RT, we suggest a routine measurement of AFP in RT‐candidate BC patients followed by next‐generation sequencing with special attention to non‐canonical splice site and synonymous variants in ATM.
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