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Ohno K, Ohkawara B, Shen XM, Selcen D, Engel AG. Clinical and Pathologic Features of Congenital Myasthenic Syndromes Caused by 35 Genes-A Comprehensive Review. Int J Mol Sci 2023; 24:ijms24043730. [PMID: 36835142 PMCID: PMC9961056 DOI: 10.3390/ijms24043730] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/09/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Congenital myasthenic syndromes (CMS) are a heterogeneous group of disorders characterized by impaired neuromuscular signal transmission due to germline pathogenic variants in genes expressed at the neuromuscular junction (NMJ). A total of 35 genes have been reported in CMS (AGRN, ALG14, ALG2, CHAT, CHD8, CHRNA1, CHRNB1, CHRND, CHRNE, CHRNG, COL13A1, COLQ, DOK7, DPAGT1, GFPT1, GMPPB, LAMA5, LAMB2, LRP4, MUSK, MYO9A, PLEC, PREPL, PURA, RAPSN, RPH3A, SCN4A, SLC18A3, SLC25A1, SLC5A7, SNAP25, SYT2, TOR1AIP1, UNC13A, VAMP1). The 35 genes can be classified into 14 groups according to the pathomechanical, clinical, and therapeutic features of CMS patients. Measurement of compound muscle action potentials elicited by repetitive nerve stimulation is required to diagnose CMS. Clinical and electrophysiological features are not sufficient to identify a defective molecule, and genetic studies are always required for accurate diagnosis. From a pharmacological point of view, cholinesterase inhibitors are effective in most groups of CMS, but are contraindicated in some groups of CMS. Similarly, ephedrine, salbutamol (albuterol), amifampridine are effective in most but not all groups of CMS. This review extensively covers pathomechanical and clinical features of CMS by citing 442 relevant articles.
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Affiliation(s)
- Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Correspondence: (K.O.); (A.G.E.)
| | - Bisei Ohkawara
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Xin-Ming Shen
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
| | - Duygu Selcen
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
| | - Andrew G. Engel
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
- Correspondence: (K.O.); (A.G.E.)
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Lorenzoni PJ, Ducci RDP, Arndt RC, Hrysay NMC, Fustes OJH, Töpf A, Lochmüller H, Werneck LC, Kay CSK, Scola RH. Congenital myasthenic syndrome in a cohort of patients with 'double' seronegative myasthenia gravis. ARQUIVOS DE NEURO-PSIQUIATRIA 2021; 80:69-74. [PMID: 34932651 PMCID: PMC9651496 DOI: 10.1590/0004-282x-anp-2020-0575] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/27/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Congenital myasthenic syndromes (CMS) have some phenotypic overlap with seronegative myasthenia gravis (SNMG). OBJECTIVE The aim of this single center study was to assess the minimum occurrence of CMS misdiagnosed as double SNMG in a Brazilian cohort. METHODS The genetic analysis of the most common mutations in CHRNE, RAPSN, and DOK7 genes was used as the main screening tool. RESULTS We performed genetic analysis in 22 patients with a previous diagnosis of 'double' SNMG. In this study, one CMS patient was confirmed due to the presence of compound heterozygous variants in the CHRNE gene (c.130insG/p.Cys210Phe). CONCLUSIONS This study confirmed that CMS due to CHNRE mutations can be mistaken for SNMG. In addition, our study estimated the prevalence of misdiagnosed CMS to be 4.5% in 'double' SNMG patients of our center. Based on our findings, genetic screening could be helpful in the diagnostic workup of patients with 'double' SNMG in whom differential diagnosis is recommended.
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Affiliation(s)
- Paulo José Lorenzoni
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Renata Dal-Pra Ducci
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Raquel Cristina Arndt
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Nyvia Milicio Coblinski Hrysay
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Otto Jesus Hernandez Fustes
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Ana Töpf
- Newcastle University, Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, Newcastle upon Tyne, UK
| | - Hanns Lochmüller
- University of Ottawa, Children's Hospital of Eastern Ontario Research Institute, Department of Medicine, Division of Neurology, Ottawa, Canada.,University of Ottawa, The Ottawa Hospital, Brain and Mind Research Institute, Ottawa, Canada
| | - Lineu Cesar Werneck
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Cláudia Suemi Kamoi Kay
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Rosana Herminia Scola
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
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Yan C, Zhao R, Song J, Feng X, Xi J, Luo S, Zhong H, Zhou S, Li W, Zhao C. Comparison of anti-acetylcholine receptor profiles between Chinese cases of adult- and juvenile-onset myasthenia gravis using cell-based assays. J Neuroimmunol 2020; 349:577403. [PMID: 32992216 DOI: 10.1016/j.jneuroim.2020.577403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/29/2020] [Accepted: 09/19/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Juvenile-onset myasthenia gravis (JOMG) is a unique clinical subtype in China, featured by a higher prevalence of ocular myasthenia gravis (OMG), higher seronegativity of acetylcholine receptor (AChR) antibodies, and better prognosis than that in adult-onset myasthenia gravis (AOMG). We previously identified low-affinity AChR antibodies in Chinese JOMG patients using cell-based assays (CBAs), indicating a predominantly AChR antibody-positive profile. Here, we further screened AChR antibodies in both Chinese AOMG and JOMG patients by CBAs. MATERIALS AND METHODS We recruited patients with MG who had not received prednisone or immunosuppressive therapies between June 2015 and June 2019, and divided them into AOMG and JOMG subgroups according to their ages at the time of recruitment. Clinical information and blood samples were collected. Serum AChR antibodies were detected by CBAs in HEK293T cells expressing clustered adult and fetal AChRs, as well as by enzyme-linked immunosorbent assays (ELISAs). Differences in AChR antibody profiles between AOMG and JOMG subgroups were determined. RESULTS A total of 239 patients with MG were enrolled in the present study, including 121 AOMG and 118 JOMG patients. Based on ELISAs, 74.4% of AOMG (90/121) and 59.3% of JOMG (70/118) patients were anti-AChR positive (p = 0.02). However, CBAs yielded equal anti-AChR positivities (p = 0.64), as indicated by 80.2% of AOMG patients (97/121) and 77.1% of JOMG patients (91/118). Furthermore, among AOMG patients, 67.8% (82/121) were positive for both adult and fetal AChR antibodies, 5.8% (7/121) were positive for only adult AChR antibodies, and 6.6% (8/121) were positive for only fetal AChR antibodies, while these rates were 50.8% (60/118), 21.2% (25/118), and 5.1% (6/118), respectively, in JOMG cohorts (p < 0.01). Twenty-nine AOMG patients and 10 JOMG patients underwent IgG subclassification of AChR antibodies, which were all confirmed to be predominantly IgG1. CONCLUSIONS The positive rates of AChR antibodies did not differ between Chinese AOMG and JOMG patients, as revealed by CBAs. Furthermore, the screened AChR antibodies were predominantly IgG1 in both AOMG and JOMG patients.
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Affiliation(s)
- Chong Yan
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Rui Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Jie Song
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Xuelin Feng
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong 510080, China
| | - Jianying Xi
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Sushan Luo
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Huahua Zhong
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Shuizhen Zhou
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 200040, China
| | - Wenhui Li
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 200040, China.
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China; Department of Neurology, Jing'an District Center Hospital of Shanghai, Fudan University, Shanghai 200040, China.
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Estephan EDP, Zambon AA, Marchiori PE, da Silva AMS, Caldas VM, Moreno CAM, Reed UC, Horvath R, Töpf A, Lochmüller H, Zanoteli E. Clinical variability of early-onset congenital myasthenic syndrome due to biallelic RAPSN mutations in Brazil. Neuromuscul Disord 2018; 28:961-964. [DOI: 10.1016/j.nmd.2018.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 08/22/2018] [Indexed: 10/28/2022]
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Garg N, Yiannikas C, Hardy TA, Belaya K, Cheung J, Beeson D, Reddel SW. Late presentations of congenital myasthenic syndromes: How many do we miss? Muscle Nerve 2016; 54:721-7. [DOI: 10.1002/mus.25085] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Nidhi Garg
- Neuroimmunology Clinic; Concord Hospital and University of Sydney; NSW Australia
| | - Con Yiannikas
- Departments of Neurology and Molecular Medicine; University of Sydney, Concord Hospital; Sydney New South Wales 2139 Australia
| | - Todd A. Hardy
- Neuroimmunology Clinic; Concord Hospital and University of Sydney; NSW Australia
| | - Katsiaryna Belaya
- The Weatherall Institute of Molecular Medicine; University of Oxford, John Radcliffe Hospital; Oxford UK
| | - Jonathan Cheung
- The Weatherall Institute of Molecular Medicine; University of Oxford, John Radcliffe Hospital; Oxford UK
| | - David Beeson
- The Weatherall Institute of Molecular Medicine; University of Oxford, John Radcliffe Hospital; Oxford UK
| | - Stephen W. Reddel
- Neuroimmunology Clinic; Concord Hospital and University of Sydney; NSW Australia
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Blum S, Lee D, Gillis D, McEniery DF, Reddel S, McCombe P. Clinical features and impact of myasthenia gravis disease in Australian patients. J Clin Neurosci 2015; 22:1164-9. [PMID: 26021730 DOI: 10.1016/j.jocn.2015.01.022] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 01/05/2015] [Accepted: 01/06/2015] [Indexed: 12/21/2022]
Abstract
We performed a community-based survey of 165 Australian patients with a physician-confirmed diagnosis of myasthenia gravis (MG). MG is an autoimmune disease of the neuromuscular junction causing fatiguable muscle weakness. Patients with early onset MG (<40 years of age) were more frequently female (22 males, 60 females) whereas patients with late onset MG (>40 years of age) were more frequently male (50 males, 28 females; p < 0.001). Triggering and exacerbating factors included physical and emotional stress, infections, surgery or trauma, seasonal changes and medications. The co-occurrence of other immune-related diseases was reported by 54% of patients. The median MG quality of life (QOL) score was 92 (range: 24-186). The factor most strongly associated with poor QOL was depression. Only 40.6% of patients were working at the time of the survey and of these, almost half had required sick leave due to MG in the past 12 months. A further 39.4% had stopped work due to MG and 19.4% having to change occupation. Full-time or part-time care was required by 29% of patients and government financial support was received by 52.7%.
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Affiliation(s)
- Stefan Blum
- Royal Brisbane and Women's Hospital, Butterfield Street, Herston, QLD 4029, Australia; University of Queensland, Centre of Clinical Research, Herston, QLD, Australia.
| | - David Lee
- Royal Brisbane and Women's Hospital, Butterfield Street, Herston, QLD 4029, Australia
| | - David Gillis
- Royal Brisbane and Women's Hospital, Butterfield Street, Herston, QLD 4029, Australia; Pathology Queensland, Herston, QLD, Australia
| | | | - Stephen Reddel
- University of Sydney, Concord Hospital, Concord, NSW, Australia
| | - Pamela McCombe
- Royal Brisbane and Women's Hospital, Butterfield Street, Herston, QLD 4029, Australia; University of Queensland, Centre of Clinical Research, Herston, QLD, Australia
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Heng HS, Lim M, Absoud M, Austin C, Clarke D, Wraige E, Reid C, Robb SA, Jungbluth H. Outcome of children with acetylcholine receptor (AChR) antibody positive juvenile myasthenia gravis following thymectomy. Neuromuscul Disord 2013; 24:25-30. [PMID: 24239058 DOI: 10.1016/j.nmd.2013.09.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 09/16/2013] [Accepted: 09/23/2013] [Indexed: 11/18/2022]
Abstract
Most evidence supporting the benefit of thymectomy in juvenile myasthenia gravis (JMG) is extrapolated from adult studies, with only little data concerning paediatric populations. Here we evaluate the outcome of children with generalized JMG who underwent thymectomy between 1996 and 2010 at 2 tertiary paediatric neurology referral centres in the United Kingdom. Twenty patients (15 female, 5 male), aged 13months to 15.5years (median 10.4years) at disease onset, were identified. Prior to thymectomy, disease severity was graded as IIb in 3, III in 11, and IV in 6 patients according to the Osserman classification. All demonstrated positive anti-acetylcholine receptor (AChR) antibody titres. All patients received pyridostigmine and 14 received additional steroid therapy. Transternal thymectomy was performed at the age of 2.7-16.6years (median 11.1years). At the last follow-up (10months to 10.9years, median 2.7years, after thymectomy), the majority of children demonstrated substantial improvement, although some had required additional immune-modulatory therapies. About one third achieved complete remission. The postoperative morbidity was low. No benefit was observed in one patient with thymoma. We conclude that thymectomy should be considered as a treatment option early in the course of generalised AChR antibody-positive JMG.
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Affiliation(s)
- H S Heng
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK; Paediatric Neurology Unit, Institute of Paediatrics, Kuala Lumpur Hospital, Kuala Lumpur, Malaysia
| | - M Lim
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - M Absoud
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - C Austin
- Department of Cardiothoracic Surgery, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - D Clarke
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - E Wraige
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - C Reid
- Department of Paediatric Nephrology, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
| | - S A Robb
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
| | - H Jungbluth
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK; Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK; Clinical Neuroscience Division, IoP, King's College, London, UK.
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Abicht A, Dusl M, Gallenmüller C, Guergueltcheva V, Schara U, Della Marina A, Wibbeler E, Almaras S, Mihaylova V, von der Hagen M, Huebner A, Chaouch A, Müller JS, Lochmüller H. Congenital myasthenic syndromes: Achievements and limitations of phenotype-guided gene-after-gene sequencing in diagnostic practice: A study of 680 patients. Hum Mutat 2012; 33:1474-84. [DOI: 10.1002/humu.22130] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 04/30/2012] [Indexed: 11/09/2022]
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