{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T05:31:47Z","timestamp":1782883907265,"version":"3.54.5"},"reference-count":33,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T00:00:00Z","timestamp":1782172800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100014013","name":"UK Research and Innovation Medical Research Council","doi-asserted-by":"publisher","award":["MR\/S007180\/1"],"award-info":[{"award-number":["MR\/S007180\/1"]}],"id":[{"id":"10.13039\/100014013","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100014013","name":"UK Research and Innovation Medical Research Council","doi-asserted-by":"publisher","award":["MR\/Z504099\/1"],"award-info":[{"award-number":["MR\/Z504099\/1"]}],"id":[{"id":"10.13039\/100014013","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biomolecules"],"abstract":"<jats:p>Fast-channel genetic myasthenic syndromes (FCGMSs) are caused by genetic variants in muscle nicotinic acetylcholine receptor (AChR) subunits that reduce channel open times and impair neuromuscular transmission. Among these, the CHRNE p.P141L variant (\u03b5P141L) is associated with particularly severe disease. Here, we characterized a knock-in mouse model harboring the homologous p.P141L variant in Chrne (\u03b5P141L)\u2014C57BL\/6J-Chrneem1H\/H made by the MRC GEMM program. Homozygous mutant mice fail to thrive, with early lethality (median survival of 16 days), closely recapitulating the severity observed in patients. Despite a preserved neuromuscular junction (NMJ) morphology and robust AChR expression, electrophysiological analyses revealed marked reductions in miniature and evoked endplate potential amplitudes and areas, accompanied by prolonged depolarization kinetics (contrary to expectations for AChR with reduced open times) and increased quantal content, indicative of impaired post-synaptic function with compensatory pre-synaptic adaptation. Notably, disease severity exceeded that of Chrne null mice, likely through competition with more functional g-subunit-containing fetal AChRs. Consistent with this, crossing \u03b5P141L mice with CHRNG-expressing mice provided little survival benefit. These findings demonstrate that dysfunctional AChR incorporation is more deleterious than receptor absence and highlight the critical role of subunit composition in sustaining neuromuscular transmission. Pharmacological enhancement of pre-synaptic release with 3,4-diaminopyridine partially improved synaptic parameters. In addition, the AChR-positive allosteric modulator DC-98 modestly improved neurotransmission. Thus, this mouse model provides a faithful platform for mechanistic studies and therapeutic development in FCGMS.<\/jats:p>","DOI":"10.3390\/biom16070931","type":"journal-article","created":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T03:06:34Z","timestamp":1782875194000},"page":"931","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Mouse Model of Fast-Channel Genetic Myasthenic Syndrome Carrying Chrne p.P141L Mutation"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7893-1348","authenticated-orcid":false,"given":"Richard G.","family":"Webster","sequence":"first","affiliation":[{"name":"Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DS, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-6514-149X","authenticated-orcid":false,"given":"Susan","family":"Maxwell","sequence":"additional","affiliation":[{"name":"Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DS, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8600-6988","authenticated-orcid":false,"given":"Yin Y.","family":"Dong","sequence":"additional","affiliation":[{"name":"Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DS, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5641","DOI":"10.1002\/j.2040-4603.2024.tb00303.x","article-title":"Neuromuscular Transmission in a Biological Context","volume":"14","author":"Slater","year":"2024","journal-title":"Compr. Physiol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1915","DOI":"10.1016\/j.bpj.2024.01.003","article-title":"Dynamics of receptor activation by agonists","volume":"123","author":"Auerbach","year":"2024","journal-title":"Biophys. J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1097\/WCO.0000000000001300","article-title":"Congenital myasthenic syndromes: Increasingly complex","volume":"37","author":"Ramdas","year":"2024","journal-title":"Curr. Opin. Neurol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/B978-0-323-90820-7.00013-6","article-title":"Congenital myasthenic syndromes","volume":"Volume 203","author":"Beeson","year":"2024","journal-title":"Handbook of Clinical Neurology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"973","DOI":"10.1136\/jnnp.2009.177816","article-title":"Molecular characterisation of congenital myasthenic syndromes in Southern Brazil","volume":"81","author":"Mihaylova","year":"2010","journal-title":"J. Neurol. Neurosurg. Psychiatry"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1087","DOI":"10.1016\/j.nmd.2017.08.003","article-title":"Molecular characterization of congenital myasthenic syndromes in Spain","volume":"27","author":"Topf","year":"2017","journal-title":"Neuromuscul. Disord."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"909","DOI":"10.1007\/s00415-022-11440-0","article-title":"The clinical and molecular landscape of congenital myasthenic syndromes in Austria: A nationwide study","volume":"270","author":"Krenn","year":"2023","journal-title":"J. Neurol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.pediatrneurol.2024.06.002","article-title":"Congenital Myasthenic Syndromes in Belgium: Genetic and Clinical Characterization of Pediatric and Adult Patients","volume":"158","author":"Smeets","year":"2024","journal-title":"Pediatr. Neurol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1136\/archdischild-2013-304788","article-title":"How common is childhood myasthenia? The UK incidence and prevalence of autoimmune and congenital myasthenia","volume":"99","author":"Parr","year":"2014","journal-title":"Arch. Dis. Child."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.ejpn.2020.02.002","article-title":"Prevalence and genetic subtypes of congenital myasthenic syndromes in the pediatric population of Slovenia","volume":"26","author":"Neubauer","year":"2020","journal-title":"Eur. J. Paediatr. Neurol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Ohno, K., Ito, M., and Ohkawara, B. (2025). Review of 40 genes causing congenital myasthenic syndromes. J. Hum. Genet.","DOI":"10.1038\/s10038-025-01355-9"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1196\/annals.1254.015","article-title":"Mechanistic diversity underlying fast channel congenital myasthenic syndromes","volume":"998","author":"Sine","year":"2003","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.nmd.2011.08.002","article-title":"Clinical features in a series of fast channel congenital myasthenia syndrome","volume":"22","author":"Palace","year":"2012","journal-title":"Neuromuscul. Disord."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/S0896-6273(00)80289-5","article-title":"Congenital myasthenic syndrome caused by decreased agonist binding affinity due to a mutation in the acetylcholine receptor epsilon subunit","volume":"17","author":"Ohno","year":"1996","journal-title":"Neuron"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1016\/S1474-4422(14)70201-7","article-title":"Congenital myasthenic syndromes: Pathogenesis, diagnosis, and treatment","volume":"14","author":"Engel","year":"2015","journal-title":"Lancet Neurol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.ymeth.2017.03.016","article-title":"Analysing the outcome of CRISPR-aided genome editing in embryos: Screening, genotyping and quality control","volume":"121\u2013122","author":"Mianne","year":"2017","journal-title":"Methods"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1113\/jphysiol.1957.sp005811","article-title":"On the factors which determine the amplitude of the miniature end-plate potential","volume":"137","author":"Katz","year":"1957","journal-title":"J. Physiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1113\/jphysiol.1981.sp013586","article-title":"Non-linear summation of end-plate potentials in the frog and mouse","volume":"311","author":"McLachlan","year":"1981","journal-title":"J. Physiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2947","DOI":"10.1093\/hmg\/ddh320","article-title":"A mouse model of AChR deficiency syndrome with a phenotype reflecting the human condition","volume":"13","author":"Cossins","year":"2004","journal-title":"Hum. Mol. Genet."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Cetin, H., Beeson, D., Vincent, A., and Webster, R. (2020). The Structure, Function, and Physiology of the Fetal and Adult Acetylcholine Receptor in Muscle. Front. Mol. Neurosci., 13.","DOI":"10.3389\/fnmol.2020.581097"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/0896-6273(90)90305-Y","article-title":"Properties of embryonic and adult muscle acetylcholine receptors transiently expressed in COS cells","volume":"5","author":"Gu","year":"1990","journal-title":"Neuron"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e2504146123","DOI":"10.1073\/pnas.2504146123","article-title":"Positive allosteric modulator selective for adult muscle nicotinic acetylcholine receptor","volume":"123","author":"Webster","year":"2026","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1085\/jgp.201812215","article-title":"Efficiency measures the conversion of agonist binding energy into receptor conformational change","volume":"151","author":"Nayak","year":"2019","journal-title":"J. Gen. Physiol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1038\/321406a0","article-title":"Molecular distinction between fetal and adult forms of muscle acetylcholine receptor","volume":"321","author":"Mishina","year":"1986","journal-title":"Nature"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1395","DOI":"10.1016\/0896-6273(94)90424-3","article-title":"Structural basis of the different gating kinetics of fetal and adult acetylcholine receptors","volume":"13","author":"Bouzat","year":"1994","journal-title":"Neuron"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"674","DOI":"10.1093\/embo-reports\/kvf128","article-title":"Spontaneous muscle action potentials fail to develop without fetal-type acetylcholine receptors","volume":"3","author":"Takahashi","year":"2002","journal-title":"EMBO Rep."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1376","DOI":"10.1111\/j.1460-9568.1995.tb01129.x","article-title":"Differential expression patterns of five acetylcholine receptor subunit genes in rat muscle during development","volume":"7","author":"Kues","year":"1995","journal-title":"Eur. J. Neurosci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3905","DOI":"10.1523\/JNEUROSCI.10-12-03905.1990","article-title":"Effect of reinnervation on the degradation rate of junctional acetylcholine receptors synthesized in denervated skeletal muscles","volume":"10","author":"Shyng","year":"1990","journal-title":"J. Neurosci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1362","DOI":"10.1093\/brain\/124.7.1362","article-title":"End-plate gamma- and epsilon-subunit mRNA levels in AChR deficiency syndrome due to epsilon-subunit null mutations","volume":"124","author":"Croxen","year":"2001","journal-title":"Brain"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"13286","DOI":"10.1073\/pnas.93.23.13286","article-title":"Acetylcholine receptor epsilon-subunit deletion causes muscle weakness and atrophy in juvenile and adult mice","volume":"93","author":"Witzemann","year":"1996","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"5075","DOI":"10.1242\/dev.124.24.5075","article-title":"Deficient development and maintenance of postsynaptic specializations in mutant mice lacking an \u2018adult\u2019 acetylcholine receptor subunit","volume":"124","author":"Missias","year":"1997","journal-title":"Development"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"17433","DOI":"10.1074\/jbc.271.29.17433","article-title":"Identification of an element crucial for the sub-synaptic expression of the acetylcholine receptor epsilon-subunit gene","volume":"271","author":"Duclert","year":"1996","journal-title":"J. Biol. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1006\/mcne.1997.0622","article-title":"\u03b3-AChR\/\u03f5-AChR switch at agrin-induced postsynaptic-like apparatus in skeletal muscle","volume":"9","author":"Rimer","year":"1997","journal-title":"Mol. Cell Neurosci."}],"container-title":["Biomolecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2218-273X\/16\/7\/931\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T04:20:40Z","timestamp":1782879640000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2218-273X\/16\/7\/931"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,23]]},"references-count":33,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["biom16070931"],"URL":"https:\/\/doi.org\/10.3390\/biom16070931","relation":{},"ISSN":["2218-273X"],"issn-type":[{"value":"2218-273X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,23]]}}}