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Marshall GF, Fasol M, Davies FCJ, Le Seelleur M, Fernandez Alvarez A, Bennett-Ness C, Gonzalez-Sulser A, Abbott CM. Face-valid phenotypes in a mouse model of the most common mutation in EEF1A2-related neurodevelopmental disorder. Dis Model Mech 2024; 17:dmm050501. [PMID: 38179821 PMCID: PMC10855229 DOI: 10.1242/dmm.050501] [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: 09/07/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
De novo heterozygous missense mutations in EEF1A2, encoding neuromuscular translation-elongation factor eEF1A2, are associated with developmental and epileptic encephalopathies. We used CRISPR/Cas9 to recapitulate the most common mutation, E122K, in mice. Although E122K heterozygotes were not observed to have convulsive seizures, they exhibited frequent electrographic seizures and EEG abnormalities, transient early motor deficits and growth defects. Both E122K homozygotes and Eef1a2-null mice developed progressive motor abnormalities, with E122K homozygotes reaching humane endpoints by P31. The null phenotype is driven by progressive spinal neurodegeneration; however, no signs of neurodegeneration were observed in E122K homozygotes. The E122K protein was relatively stable in neurons yet highly unstable in skeletal myocytes, suggesting that the E122K/E122K phenotype is instead driven by loss of function in muscle. Nevertheless, motor abnormalities emerged far earlier in E122K homozygotes than in nulls, suggesting a toxic gain of function and/or a possible dominant-negative effect. This mouse model represents the first animal model of an EEF1A2 missense mutation with face-valid phenotypes and has provided mechanistic insights needed to inform rational treatment design.
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Affiliation(s)
- Grant F. Marshall
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Melissa Fasol
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Faith C. J. Davies
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Matthew Le Seelleur
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alejandra Fernandez Alvarez
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Cavan Bennett-Ness
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alfredo Gonzalez-Sulser
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Catherine M. Abbott
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
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