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Cogliati F, Straniero L, Rimoldi V, Masciadri M, Perego S, Rinaldi B, Milani D, Gentilini D, Larizza L, Asselta R, Russo S, Bedeschi MF. Low-grade parental gonosomal mosaicism in CHD2 siblings with Smith-Magenis-like syndrome. Am J Med Genet B Neuropsychiatr Genet 2024:e32976. [PMID: 38385826 DOI: 10.1002/ajmg.b.32976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/01/2024] [Accepted: 02/12/2024] [Indexed: 02/23/2024]
Abstract
Loss-of-function CHD2 (chromodomain helicase DNA-binding protein 2) mutations are associated with a spectrum of neurodevelopmental disorders often including early-onset generalized seizures, photosensitivity, and epileptic encephalopathies. Patients show psychomotor delay/intellectual disability (ID), autistic features, and behavior disorders, such as aggression and impulsivity. Most reported cases are sporadic with description of germline mosaicism only in two families. We detect the first case of parental gonosomal CHD2 mosaicism disclosed by two brothers showing mild ID, born to healthy parents. The eldest brother has a history of drug-controlled generalized tonic-clonic seizures and displays sleep disorder and aggressive behavior suggestive of Smith-Magenis syndrome (SMS). Analysis of brothers' DNAs by next-generation sequencing (NGS) custom gene panel for pediatric epilepsy and/or ID disclosed in both the same pathogenic CHD2 variant. Additional NGS experiment on genomic DNA from parents' peripheral blood and from buccal swab raised the suspicion of low-grade gonosomal mosaicism in the unaffected mother subsequently confirmed by digital polymerase chain reaction (dPCR). This report underlines as worthwhile CHD2 screening in individuals presenting ID/developmental delay, with/without epilepsy, and behavior and sleep disorders suggestive of SMS. Detecting a CHD2 variant should prime testing probands' parents by NGS coupled to dPCR on different tissues to exclude/confirm gonosomal mosaicism and define the recurrence risk.
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Affiliation(s)
- Francesca Cogliati
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Letizia Straniero
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- IRCCS Humanitas Research Hospital, Milan, Italy
| | - Valeria Rimoldi
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- IRCCS Humanitas Research Hospital, Milan, Italy
| | - Maura Masciadri
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Sara Perego
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Berardo Rinaldi
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Medical Genetics Unit, Milan, Italy
| | - Donatella Milani
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Davide Gentilini
- Bioinformatics and Statistical Genomics Unit, IRCCS Istituto Auxologico Italiano, Cusano Milanino, Italy
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Lidia Larizza
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Rosanna Asselta
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- IRCCS Humanitas Research Hospital, Milan, Italy
| | - Silvia Russo
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
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Willison AG, Thomas RH. The neurodevelopmental spectrum seen with
CHD2
variants. Pediatr Investig 2022; 6:147-148. [PMID: 35774518 PMCID: PMC9218968 DOI: 10.1002/ped4.12323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 03/29/2022] [Indexed: 12/02/2022] Open
Affiliation(s)
- Alice G Willison
- Faculty of Medical Sciences Translational and Clinical Research Institute Newcastle University Newcastle UK
- Royal Victoria Infirmary Newcastle Upon Tyne NHS Foundation Trust Newcastle UK
| | - Rhys H Thomas
- Faculty of Medical Sciences Translational and Clinical Research Institute Newcastle University Newcastle UK
- Royal Victoria Infirmary Newcastle Upon Tyne NHS Foundation Trust Newcastle UK
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