1. The coexistence of a BRCA2 germline and a DICER1 somatic variant in two first-degree cousins suggests their potential synergic effect
- Author
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Giada Del Baldo, Angela Mastronuzzi, Selene Cipri, Emanuele Agolini, Marta Matraxia, Antonio Novelli, Antonella Cacchione, Annalisa Serra, Andrea Carai, Luigi Boccuto, Giovanna Stefania Colafati, Pier Luigi Di Paolo, Evelina Miele, Sabina Barresi, Rita Alaggio, Sabrina Rossi, and Isabella Giovannoni
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Cancer predisposition syndrome ,Pediatric oncology ,BRCA genes ,DICER1 ,Cystic nephroma ,Primary intracranial DICER1-mutated sarcoma ,Medicine ,Science - Abstract
Abstract Cancer predisposition syndromes are recognized in about 10% of pediatric malignancies with several genes specifically involved in a subset of pediatric tumors such as DICER1, in pleuropulmonary blastoma, cystic nephroma, and brain sarcomas. By contrast, the role of BRCA1/2 in pediatric cancer predisposition is still under investigation. We present two cases of young first-degree cousins, both carrying a germline BRCA2 variant and developing tumors characterized by somatic DICER1 mutations. Patient 1 presented with a cystic nephroma harboring a somatic DICER1 variant (p.Asp1810Tyr), while patient 2 had a primary intracranial DICER1-mutated sarcoma showing a distinct somatic DICER1 variant (p.Asp1709Glu) as well as biallelic inactivation of TP53 (p.Val173Leu, VAF 91%) and APC (p.Ile1307Lys, VAF 95%) and a pathogenic variant in KRAS (p.Gln61His). Both patients carried the same germline BRCA2 variant (p.Arg2842Cys) of unknown significance. The same variant was found in the mother of patient 2 and in the father of patient 1, who are siblings. A homologous recombination deficiency signature was not identified in any of the two tumors, possibly suggesting a reduction of BRCA2 activity. The association of BRCA2 and DICER1 variants in our cases hints at a potential cooperative role in cancer pathogenesis. Further studies are warranted to elucidate the interplay between BRCA1/2 and DICER1 variants and their implications for cancer predisposition and treatment in pediatric patients.
- Published
- 2024
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