1
|
Guerrini-Rousseau L, Pasmant E, Muleris M, Abbou S, Adam-De-Beaumais T, Brugieres L, Cabaret O, Colas C, Cotteret S, Decq P, Dufour C, Guillerm E, Rouleau E, Varlet P, Zili S, Vidaud D, Grill J. Neurofibromatosis type 1 mosaicism in patients with constitutional mismatch repair deficiency. J Med Genet 2024; 61:158-162. [PMID: 37775264 PMCID: PMC10850717 DOI: 10.1136/jmg-2023-109235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 08/21/2023] [Indexed: 10/01/2023]
Abstract
Differential diagnosis between constitutional mismatch repair deficiency (CMMRD) and neurofibromatosis type 1 (NF1) is crucial as treatment and surveillance differ. We report the case of a girl with a clinical diagnosis of sporadic NF1 who developed a glioblastoma. Immunohistochemistry for MMR proteins identified PMS2 loss in tumour and normal cells and WES showed the tumour had an ultra-hypermutated phenotype, supporting the diagnosis of CMMRD. Germline analyses identified two variants (one pathogenic variant and one classified as variant(s) of unknown significance) in the PMS2 gene and subsequent functional assays on blood lymphocytes confirmed the diagnosis of CMMRD. The large plexiform neurofibroma of the thigh and the freckling were however more compatible with NF1. Indeed, a NF1 PV (variant allele frequencies of 20%, 3% and 9% and in blood, skin and saliva samples, respectively) was identified confirming a mosaicism for NF1. Retrospective analysis of a French cohort identified NF1 mosaicism in blood DNA in 2 out of 22 patients with CMMRD, underlining the existence of early postzygotic PV of NF1 gene in patients with CMMRD whose tumours have been frequently reported to exhibit somatic NF1 mutations. It highlights the potential role of this pathway in the pathogenesis of CMMRD-associated gliomas and argues in favour of testing MEK inhibitors in this context.
Collapse
Affiliation(s)
- Léa Guerrini-Rousseau
- Department of Pediatric and Adolescent Oncology, Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
- Molecular Predictors and New Targets in Oncology, Inserm U981 Team "Genomics and Oncogenesis of pediatric Brain Tumors", Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
| | - Eric Pasmant
- Department of Molecular Genetics, Hôpital Cochin, DMU BioPhyGen, AP-HP Centre-Université Paris Cité, Paris, France
- Inserm U1016-CNRS UMR8104, Institut Cochin, Université Paris Cité, CARPEM, Paris, France
| | - Martine Muleris
- Department of Genetics, Hôpital Pitié-Salpêtrière. AP-HP. Sorbonne Université, Paris, France
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, CRSA, Equipe Instabilité des Microsatellites et Cancer, Equipe labellisée par la Ligue Nationale contre le Cancer, F-75012 Paris, France
| | - Samuel Abbou
- Department of Pediatric and Adolescent Oncology, Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
- Molecular Predictors and New Targets in Oncology, Inserm U981 Team "Genomics and Oncogenesis of pediatric Brain Tumors", Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
| | - Tiphaine Adam-De-Beaumais
- Department of Pediatric and Adolescent Oncology, Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
| | - Laurence Brugieres
- Department of Pediatric and Adolescent Oncology, Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
- Molecular Predictors and New Targets in Oncology, Inserm U981 Team "Genomics and Oncogenesis of pediatric Brain Tumors", Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
| | - Odile Cabaret
- Department of Medical Biology and Pathology, Gustave Roussy Cancer Campus, Villejuif, France
| | - Chrystelle Colas
- Department of Genetics, Institut Curie, PSL Research University, Paris, France
- Inserm U830, DNA Repair and Uveal Melanoma (D.R.U.M.), Equipe Labellisée Par la Ligue Nationale Contre le Cancer, Institut Curie, PSL Research University, Paris, France
| | - Sophie Cotteret
- Department of Medical Biology and Pathology, Gustave Roussy Cancer Campus, Villejuif, France
| | - Philippe Decq
- Neurosurgery Department, Beaujon Hospital, Paris Cité University, Paris, France
| | - Christelle Dufour
- Department of Pediatric and Adolescent Oncology, Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
- Molecular Predictors and New Targets in Oncology, Inserm U981 Team "Genomics and Oncogenesis of pediatric Brain Tumors", Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
| | - Erell Guillerm
- Department of Genetics, Hôpital Pitié-Salpêtrière. AP-HP. Sorbonne Université, Paris, France
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, CRSA, Equipe Instabilité des Microsatellites et Cancer, Equipe labellisée par la Ligue Nationale contre le Cancer, F-75012 Paris, France
| | - Etienne Rouleau
- Department of Medical Biology and Pathology, Gustave Roussy Cancer Campus, Villejuif, France
| | - Pascale Varlet
- Service de Neuropathologie, GHU Psychiatrie et Neurosciences, site Sainte-Anne, Paris, France
| | - Saïma Zili
- Molecular Predictors and New Targets in Oncology, Inserm U981 Team "Genomics and Oncogenesis of pediatric Brain Tumors", Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
| | - Dominique Vidaud
- Department of Molecular Genetics, Hôpital Cochin, DMU BioPhyGen, AP-HP Centre-Université Paris Cité, Paris, France
| | - Jacques Grill
- Department of Pediatric and Adolescent Oncology, Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
- Molecular Predictors and New Targets in Oncology, Inserm U981 Team "Genomics and Oncogenesis of pediatric Brain Tumors", Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif, France
| |
Collapse
|