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Karimi N, Ghasemi A, Panahi A, Ziaadini B, Nafissi S. CHRNE-related congenital myasthenic syndrome in Iran: Clinical and molecular insights. Neuromuscul Disord 2025; 46:105234. [PMID: 39550999 DOI: 10.1016/j.nmd.2024.105234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 10/03/2024] [Accepted: 10/24/2024] [Indexed: 11/19/2024]
Abstract
Variants in the CHRNE gene can lead to a condition called congenital myasthenic syndrome (CMS), which affects the neuromuscular junction (NMJ). CHRNE mutations are the most common cause of CMS. Seventy-seven patients with a possible diagnosis of CMS were referred to the neuromuscular clinic of Shariati Hospital affiliated with the Tehran University of Medical Sciences. We performed whole-exome sequencing (WES) to determine the underlying defect in a group of individuals with a possible diagnosis of CMS. Clinical features and morphological and molecular data on 33 patients with mutations in CHRNE were described. Age of onset, age at diagnosis, consanguinity, family history, motor milestone delay, ophthalmoparesis, generalized fatigue, dysphagia, neurophysiologic findings, and response to treatment of the patients were assessed. Nineteen CHRNE variants including 10 novel ones were identified. The most common mutations were c.1327del; (p.Glu443LysfsTer64) in four different families and c.1252-1267dup; (p.Cys423SerfsTer38) in three families. Clinical onset was mostly at birth or under one year with bilateral fatigable ptosis, ophthalmoplegia, bulbar weakness, and proximal muscle weakness. All patients were treated with pyridostigmine ± salbutamol, which resulted in improvement of motor function, dysphagia, and breathing.
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Affiliation(s)
- Narges Karimi
- Immunogenetics Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Aida Ghasemi
- Neuromuscular Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Akram Panahi
- Department of Neurology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Bentolhoda Ziaadini
- Neurology Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Shahriar Nafissi
- Neuromuscular Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Neurology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
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2
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Theuriet J, Masingue M, Behin A, Ferreiro A, Bassez G, Jaubert P, Tarabay O, Fer F, Pegat A, Bouhour F, Svahn J, Petiot P, Jomir L, Chauplannaz G, Cornut-Chauvinc C, Manel V, Salort-Campana E, Attarian S, Fortanier E, Verschueren A, Kouton L, Camdessanché JP, Tard C, Magot A, Péréon Y, Noury JB, Minot-Myhie MC, Perie M, Taithe F, Farhat Y, Millet AL, Cintas P, Solé G, Spinazzi M, Esselin F, Renard D, Sacconi S, Ezaru A, Malfatti E, Mallaret M, Magy L, Diab E, Merle P, Michaud M, Fournier M, Pakleza AN, Chanson JB, Lefeuvre C, Laforet P, Richard P, Sternberg D, Villar-Quiles RN, Stojkovic T, Eymard B. Congenital myasthenic syndromes in adults: clinical features, diagnosis and long-term prognosis. Brain 2024; 147:3849-3862. [PMID: 38696726 PMCID: PMC11531845 DOI: 10.1093/brain/awae124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 03/05/2024] [Accepted: 03/28/2024] [Indexed: 05/04/2024] Open
Abstract
Congenital myasthenic syndromes (CMS) are clinically and genetically heterogeneous diseases caused by mutations affecting neuromuscular transmission. Even if the first symptoms mainly occur during childhood, adult neurologists must confront this challenging diagnosis and manage these patients throughout their adulthood. However, long-term follow-up data from large cohorts of CMS patients are lacking, and the long-term prognosis of these patients is largely unknown. We report the clinical features, diagnostic difficulties, and long-term prognosis of a French nationwide cohort of 235 adult patients with genetically confirmed CMS followed in 23 specialized neuromuscular centres. Data were retrospectively analysed. Of the 235 patients, 123 were female (52.3%). The diagnosis was made in adulthood in 139 patients, 110 of whom presented their first symptoms before the age of 18. Mean follow-up time between first symptoms and last visit was 34 years [standard deviation (SD) = 15.1]. Pathogenic variants were found in 19 disease-related genes. CHRNE-low expressor variants were the most common (23.8%), followed by variants in DOK7 (18.7%) and RAPSN (14%). Genotypes were clustered into four groups according to the initial presentation: ocular group (CHRNE-LE, CHRND, FCCMS), distal group (SCCMS), limb-girdle group (RAPSN, COLQ, DOK7, GMPPB, GFPT1), and a variable-phenotype group (MUSK, AGRN). The phenotypical features of CMS did not change throughout life. Only four genotypes had a proportion of patients requiring intensive care unit admission that exceeded 20%: RAPSN (54.8%), MUSK (50%), DOK7 (38.6%) and AGRN (25.0%). In RAPSN and MUSK patients most ICU admissions occurred before age 18 years and in DOK7 and AGRN patients at or after 18 years of age. Different patterns of disease course (stability, improvement and progressive worsening) may succeed one another in the same patient throughout life, particularly in AGRN, DOK7 and COLQ. At the last visit, 55% of SCCMS and 36.3% of DOK7 patients required ventilation; 36.3% of DOK7 patients, 25% of GMPPB patients and 20% of GFPT1 patients were wheelchair-bound; most of the patients who were both wheelchair-bound and ventilated were DOK7 patients. Six patients died in this cohort. The positive impact of therapy was striking, even in severely affected patients. In conclusion, even if motor and/or respiratory deterioration could occur in patients with initially moderate disease, particularly in DOK7, SCCMS and GFPT1 patients, the long-term prognosis for most CMS patients was favourable, with neither ventilation nor wheelchair needed at last visit. CHRNE-LE patients did not worsen during adulthood and RAPSN patients, often severely affected in early childhood, subsequently improved.
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Affiliation(s)
- Julian Theuriet
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
- Service d’ENMG et de pathologies neuromusculaires, centre de référence des maladies neuromusculaires PACA-Réunion-Rhône-Alpes, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, Groupement Est, 69500 Bron, France
- Pathophysiology and Genetics of Neuron and Muscle, CNRS UMR 5261, INSERM U1315, Université Lyon 1, Faculté de Médecine Lyon Est, 69008 Lyon, France
| | - Marion Masingue
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
- Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, 75013 Paris, France
| | - Anthony Behin
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
- Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, 75013 Paris, France
| | - Ana Ferreiro
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
- Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, 75013 Paris, France
- Basic and Translational Myology laboratory, Université Paris Cité, BFA, UMR 8251, CNRS, 75013 Paris, France
| | - Guillaume Bassez
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
- Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, 75013 Paris, France
| | - Pauline Jaubert
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
| | - Oriana Tarabay
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
| | - Frédéric Fer
- Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, 75013 Paris, France
| | - Antoine Pegat
- Service d’ENMG et de pathologies neuromusculaires, centre de référence des maladies neuromusculaires PACA-Réunion-Rhône-Alpes, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, Groupement Est, 69500 Bron, France
- Pathophysiology and Genetics of Neuron and Muscle, CNRS UMR 5261, INSERM U1315, Université Lyon 1, Faculté de Médecine Lyon Est, 69008 Lyon, France
| | - Françoise Bouhour
- Service d’ENMG et de pathologies neuromusculaires, centre de référence des maladies neuromusculaires PACA-Réunion-Rhône-Alpes, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, Groupement Est, 69500 Bron, France
- Pathophysiology and Genetics of Neuron and Muscle, CNRS UMR 5261, INSERM U1315, Université Lyon 1, Faculté de Médecine Lyon Est, 69008 Lyon, France
| | - Juliette Svahn
- Pathophysiology and Genetics of Neuron and Muscle, CNRS UMR 5261, INSERM U1315, Université Lyon 1, Faculté de Médecine Lyon Est, 69008 Lyon, France
- Service de Neurologie, troubles du mouvement et pathologies neuromusculaires, Hôpital Neurologique Pierre-Wertheimer, Hospices Civils de Lyon, Groupement Est, 69500 Bron, France
| | - Philippe Petiot
- Service d’ENMG et de pathologies neuromusculaires, centre de référence des maladies neuromusculaires PACA-Réunion-Rhône-Alpes, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, Groupement Est, 69500 Bron, France
| | - Laurentiu Jomir
- Service d’ENMG et de pathologies neuromusculaires, centre de référence des maladies neuromusculaires PACA-Réunion-Rhône-Alpes, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, Groupement Est, 69500 Bron, France
| | - Guy Chauplannaz
- Service d’ENMG et de pathologies neuromusculaires, centre de référence des maladies neuromusculaires PACA-Réunion-Rhône-Alpes, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, Groupement Est, 69500 Bron, France
| | - Catherine Cornut-Chauvinc
- Service de Neurologie clinique et fonctionnelle, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, 69310 Pierre-Bénite, France
| | - Véronique Manel
- Service de Médecine Physique et Réadaptation Pédiatrique, L’Escale, Hôpital Femme-Mère-Enfant, Hospices Civils de Lyon, Groupement Est, 69500 Bron, France
| | - Emmanuelle Salort-Campana
- Service de pathologies neuromusculaires, Hôpital de la Timone, Assistance Publique des Hôpitaux de Marseille, 13005 Marseille, France
| | - Shahram Attarian
- Service de pathologies neuromusculaires, Hôpital de la Timone, Assistance Publique des Hôpitaux de Marseille, 13005 Marseille, France
| | - Etienne Fortanier
- Service de pathologies neuromusculaires, Hôpital de la Timone, Assistance Publique des Hôpitaux de Marseille, 13005 Marseille, France
| | - Annie Verschueren
- Service de pathologies neuromusculaires, Hôpital de la Timone, Assistance Publique des Hôpitaux de Marseille, 13005 Marseille, France
| | - Ludivine Kouton
- Service de pathologies neuromusculaires, Hôpital de la Timone, Assistance Publique des Hôpitaux de Marseille, 13005 Marseille, France
| | - Jean-Philippe Camdessanché
- Service de neurologie, centre référent pour les maladies neuromusculaires, Hôpital Nord, CHU de Saint Etienne, 42270 Saint-Etienne, France
| | - Céline Tard
- Service de Neurologie, U1172, Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, CHU de Lille, 59000 Lille, France
| | - Armelle Magot
- Centre de référence des Maladies Neuromusculaires AOC, Euro-NMD, Filnemus, Hôtel-Dieu, CHU de Nantes, 44000 Nantes, France
| | - Yann Péréon
- Centre de référence des Maladies Neuromusculaires AOC, Euro-NMD, Filnemus, Hôtel-Dieu, CHU de Nantes, 44000 Nantes, France
| | - Jean-Baptiste Noury
- Inserm, LBAI, UMR1227, Centre de référence des Maladies Neuromusculaires AOC, CHRU de Brest, 29200 Brest, France
| | | | - Maud Perie
- Service de Neurologie, CHU Gabriel Montpied, 63000 Clermont-Ferrand, France
| | - Frederic Taithe
- Service de Neurologie, CHU Gabriel Montpied, 63000 Clermont-Ferrand, France
| | - Yacine Farhat
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
| | - Anne-Laure Millet
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, CHU Charles Nicolle, 76000 Rouen, France
| | - Pascal Cintas
- Service de Neurologie, Centre de référence des Maladies Neuromusculaires, CHU de Toulouse Purpan, 31300 Toulouse, France
| | - Guilhem Solé
- Service de Neurologie et des Maladies Neuromusculaires, Centre de référence des Maladies Neuromusculaires AOC, FILNEMUS, EURO-NMD, Hôpital Pellegrin, CHU de Bordeaux, 33000 Bordeaux, France
| | - Marco Spinazzi
- Service de Neurologie, Centre de référence des Maladies Neuromusculaires, CHU d’Angers, 49100 Angers, France
| | - Florence Esselin
- Service de Neurologie, CHU Gui de Chauliac, 34295 Montpellier, France
| | - Dimitri Renard
- Service de Neurologie, Hôpital Caremeau, CHU de Nîmes, 30900 Nîmes, France
| | - Sabrina Sacconi
- Service de Neurologie: Système nerveux périphérique, Muscle et SLA, Hôpital Pasteur 2, CHU de Nice, 06000 Nice, France
| | - Andra Ezaru
- Service de Neurologie: Système nerveux périphérique, Muscle et SLA, Hôpital Pasteur 2, CHU de Nice, 06000 Nice, France
| | - Edoardo Malfatti
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Hôpital Henry Mondor, Assistance Publique des Hôpitaux de Paris, Université Paris Est Créteil, INSERM, U955, IMRB, 94000 Créteil, France
| | - Martial Mallaret
- Service de Neurologie, CHU de Grenoble, 38700 La Tronche, France
| | - Laurent Magy
- Service de Neurologie, Centre de référence des Maladies Neuromusculaires, Hôpital Dupuytren, CHU de Limoges, 87000 Limoges, France
| | - Eva Diab
- Service de Neurophysiologie Clinique, CHU Amiens Picardie, 80000, Amiens, France
- Unité de Recherche Chimère UR 7516, Université Picardie Jules Verne, 80000 Amiens, France
| | - Philippe Merle
- Service de Neurophysiologie Clinique, CHU Amiens Picardie, 80000, Amiens, France
| | - Maud Michaud
- Service de Neurologie, Centre de référence des Maladies Neuromusculaires Nord/Est/Ile-de-France, CHU de Nancy, 54000 Nancy, France
| | | | - Aleksandra Nadaj Pakleza
- Service de Neurologie, Centre de référence des maladies neuromusculaires Nord/Est/Ile-de-France, CHU de Strasbourg, 67000 Strasbourg, France
- European Reference Network—Neuromuscular Diseases (ERN EURO-NMD), 75013 Paris, France
| | - Jean-Baptiste Chanson
- Service de Neurologie, Centre de référence des maladies neuromusculaires Nord/Est/Ile-de-France, CHU de Strasbourg, 67000 Strasbourg, France
- European Reference Network—Neuromuscular Diseases (ERN EURO-NMD), 75013 Paris, France
| | - Claire Lefeuvre
- Service de Neurologie, Centre de référence des maladies neuromusculaires Nord/Est/Ile-de-France, Hôpital Raymond-Poincaré, Assistance Publique des Hôpitaux de Paris, 92380 Garches, France
| | - Pascal Laforet
- Service de Neurologie, Centre de référence des maladies neuromusculaires Nord/Est/Ile-de-France, Hôpital Raymond-Poincaré, Assistance Publique des Hôpitaux de Paris, 92380 Garches, France
- FHU PHENIX, Université Versailles, Université Paris-Saclay, 78000 Saint-Quentin-en-Yvelines, France
| | - Pascale Richard
- Service de Biochimie Métabolique et Centre de Génétique, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
- Unité Fonctionnelle de Cardiogénétique et Myogénétique Moléculaire et cellulaire, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
| | - Damien Sternberg
- Service de Biochimie Métabolique et Centre de Génétique, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
| | - Rocio-Nur Villar-Quiles
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
- Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, 75013 Paris, France
| | - Tanya Stojkovic
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
- Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, 75013 Paris, France
| | - Bruno Eymard
- Centre de référence des Maladies Neuromusculaires Nord/Est/Ile de France, Institut de Myologie, Hôpital Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, 75013 Paris, France
- Centre de Recherche en Myologie, GH Pitié-Salpêtrière, Sorbonne Université-Inserm UMRS974, 75013 Paris, France
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Zhang Z, Zhang X, Xue H, Chu L, Hu L, Bi X, Zhu P, Zhang D, Chen J, Cui X, Kong L, Liang B, Wu X. Preimplantation genetic testing as a means of preventing hereditary congenital myasthenic syndrome caused by RAPSN. Mol Genet Genomic Med 2024; 12:e2409. [PMID: 38511267 PMCID: PMC10955331 DOI: 10.1002/mgg3.2409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/30/2024] [Accepted: 02/13/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND Congenital myasthenic syndrome is a heterogeneous group of inherited neuromuscular transmission disorders. Variants in RAPSN are a common cause of CMS, accounting for approximately 14%-27% of all CMS cases. Whether preimplantation genetic testing for monogenic disease (PGT-M) could be used to prevent the potential birth of CMS-affected children is unclear. METHODS Application of WES (whole-exome sequencing) for carrier testing and guidance for the PGT-M in the absence of a genetically characterized index patient as well as assisted reproductive technology were employed to prevent the occurrence of birth defects in subsequent pregnancy. The clinical phenotypes of stillborn fetuses were also assessed. RESULTS The family carried two likely pathogenic variants in RAPSN(NM_005055.5): c.133G>A (p.V45M) and c.280G>A (p.E94K). And the potential birth of CMS-affected child was successfully prevented, allowing the family to have offspring devoid of disease-associated variants and exhibiting a normal phenotype. CONCLUSION This report constitutes the first documented case of achieving a CMS-free offspring through PGT-M in a CMS-affected family. By broadening the known variant spectrum of RAPSN in the Chinese population, our findings underscore the feasibility and effectiveness of PGT-M for preventing CMS, offering valuable insights for similarly affected families.
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Affiliation(s)
- Zhiping Zhang
- Center of Reproductive MedicineAffiliated Children's Hospital of Shanxi & Women Health Center of Shanxi Medicine UniversityTaiyuanShanxiChina
| | - Xueluo Zhang
- Center of Reproductive MedicineAffiliated Children's Hospital of Shanxi & Women Health Center of Shanxi Medicine UniversityTaiyuanShanxiChina
| | - Huiqin Xue
- Center of Reproductive MedicineAffiliated Children's Hospital of Shanxi & Women Health Center of Shanxi Medicine UniversityTaiyuanShanxiChina
| | - Liming Chu
- Basecare Medical Device Co., LtdSuzhouChina
| | - Lina Hu
- Basecare Medical Device Co., LtdSuzhouChina
| | - Xingyu Bi
- Center of Reproductive MedicineAffiliated Children's Hospital of Shanxi & Women Health Center of Shanxi Medicine UniversityTaiyuanShanxiChina
| | - Pengfei Zhu
- Center of Reproductive MedicineAffiliated Children's Hospital of Shanxi & Women Health Center of Shanxi Medicine UniversityTaiyuanShanxiChina
| | - Dongdong Zhang
- Center of Reproductive MedicineAffiliated Children's Hospital of Shanxi & Women Health Center of Shanxi Medicine UniversityTaiyuanShanxiChina
| | - Jiayao Chen
- Center of Reproductive MedicineAffiliated Children's Hospital of Shanxi & Women Health Center of Shanxi Medicine UniversityTaiyuanShanxiChina
| | - Xiangrong Cui
- Center of Reproductive MedicineAffiliated Children's Hospital of Shanxi & Women Health Center of Shanxi Medicine UniversityTaiyuanShanxiChina
| | | | - Bo Liang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghaiChina
| | - Xueqing Wu
- Center of Reproductive MedicineAffiliated Children's Hospital of Shanxi & Women Health Center of Shanxi Medicine UniversityTaiyuanShanxiChina
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Zirek F, Özcan G, Tekin MN, Uçar Çİ, Kartal AT, Balaban B, Kendirli T, Teber ST, Çobanoğlu N. An infant with episodic stridor and respiratory crises since birth: A challenging diagnosis. Pediatr Pulmonol 2024. [PMID: 38251867 DOI: 10.1002/ppul.26866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 01/02/2024] [Accepted: 01/05/2024] [Indexed: 01/23/2024]
Affiliation(s)
- Fazılcan Zirek
- Department of Pediatrics, Division of Pediatric Pulmonology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Gizem Özcan
- Department of Pediatrics, Division of Pediatric Pulmonology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Merve Nur Tekin
- Department of Pediatrics, Division of Pediatric Pulmonology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Çiğdem İlter Uçar
- Department of Pediatrics, Division of Pediatric Neurology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Ayşe Tuğba Kartal
- Department of Pediatrics, Division of Pediatric Neurology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Burak Balaban
- Department of Pediatrics, Division of Pediatric Intensive Care Unit, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Tanıl Kendirli
- Department of Pediatrics, Division of Pediatric Intensive Care Unit, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Serap Tıraş Teber
- Department of Pediatrics, Division of Pediatric Neurology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Nazan Çobanoğlu
- Department of Pediatrics, Division of Pediatric Pulmonology, Faculty of Medicine, Ankara University, Ankara, Turkey
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5
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Polavarapu K, Sunitha B, Töpf A, Preethish-Kumar V, Thompson R, Vengalil S, Nashi S, Bardhan M, Sanka SB, Huddar A, Unnikrishnan G, Arunachal G, Girija MS, Porter A, Azuma Y, Lorenzoni PJ, Baskar D, Anjanappa RM, Keertipriya M, Padmanabh H, Harikrishna GV, Laurie S, Matalonga L, Horvath R, Nalini A, Lochmüller H. Clinical and genetic characterisation of a large Indian congenital myasthenic syndrome cohort. Brain 2024; 147:281-296. [PMID: 37721175 PMCID: PMC10766255 DOI: 10.1093/brain/awad315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/20/2023] [Accepted: 08/10/2023] [Indexed: 09/19/2023] Open
Abstract
Congenital myasthenic syndromes (CMS) are a rare group of inherited disorders caused by gene defects associated with the neuromuscular junction and potentially treatable with commonly available medications such as acetylcholinesterase inhibitors and β2 adrenergic receptor agonists. In this study, we identified and genetically characterized the largest cohort of CMS patients from India to date. Genetic testing of clinically suspected patients evaluated in a South Indian hospital during the period 2014-19 was carried out by standard diagnostic gene panel testing or using a two-step method that included hotspot screening followed by whole-exome sequencing. In total, 156 genetically diagnosed patients (141 families) were characterized and the mutational spectrum and genotype-phenotype correlation described. Overall, 87 males and 69 females were evaluated, with the age of onset ranging from congenital to fourth decade (mean 6.6 ± 9.8 years). The mean age at diagnosis was 19 ± 12.8 (1-56 years), with a mean diagnostic delay of 12.5 ± 9.9 (0-49 years). Disease-causing variants in 17 CMS-associated genes were identified in 132 families (93.6%), while in nine families (6.4%), variants in genes not associated with CMS were found. Overall, postsynaptic defects were most common (62.4%), followed by glycosylation defects (21.3%), synaptic basal lamina genes (4.3%) and presynaptic defects (2.8%). Other genes found to cause neuromuscular junction defects (DES, TEFM) in our cohort accounted for 2.8%. Among the individual CMS genes, the most commonly affected gene was CHRNE (39.4%), followed by DOK7 (14.4%), DPAGT1 (9.8%), GFPT1 (7.6%), MUSK (6.1%), GMPPB (5.3%) and COLQ (4.5%). We identified 22 recurrent variants in this study, out of which eight were found to be geographically specific to the Indian subcontinent. Apart from the known common CHRNE variants p.E443Kfs*64 (11.4%) and DOK7 p.A378Sfs*30 (9.3%), we identified seven novel recurrent variants specific to this cohort, including DPAGT1 p.T380I and DES c.1023+5G>A, for which founder haplotypes are suspected. This study highlights the geographic differences in the frequencies of various causative CMS genes and underlines the increasing significance of glycosylation genes (DPAGT1, GFPT1 and GMPPB) as a cause of neuromuscular junction defects. Myopathy and muscular dystrophy genes such as GMPPB and DES, presenting as gradually progressive limb girdle CMS, expand the phenotypic spectrum. The novel genes MACF1 and TEFM identified in this cohort add to the expanding list of genes with new mechanisms causing neuromuscular junction defects.
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Affiliation(s)
- Kiran Polavarapu
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
| | - Balaraju Sunitha
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
- Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, Cambridge CB2 0SP, UK
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - Veeramani Preethish-Kumar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
- Department of Neurology, Neurofoundation, Salem, Tamil Nadu 636009, India
| | - Rachel Thompson
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Saraswati Nashi
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Mainak Bardhan
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Sai Bhargava Sanka
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Akshata Huddar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
- Department of Neurology, St Johns Medical College Hospital, Bangalore 560034, India
| | - Gopikrishnan Unnikrishnan
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
- Department of Neurology, Amruta Institute of Medical Sciences, Kochi 682041, India
| | - Gautham Arunachal
- Department of Human Genetics, National Institute of Mental Health and Neurosciences, Bengaluru 560029, India
| | - Manu Santhappan Girija
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Anna Porter
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - Yoshiteru Azuma
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - Paulo José Lorenzoni
- Neuromuscular Disorders Division, Service of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Paraná, Rua General Carneiro, Curitiba - PR 80060-900, Brazil
| | - Dipti Baskar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Ram Murthy Anjanappa
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Madassu Keertipriya
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Hansashree Padmanabh
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | | | - Steve Laurie
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia 08028, Spain
| | - Leslie Matalonga
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia 08028, Spain
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, Cambridge CB2 0SP, UK
| | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Hanns Lochmüller
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia 08028, Spain
- Brain and Mind Research Institute, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, ON K1H 8M5, Canada
- Department of Neuropediatrics and Muscle Disorders, Medical Center–University of Freiburg, Faculty of Medicine, Freiburg 79110, Germany
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Özsoy Ö, Cinleti T, Günay Ç, Sarıkaya Uzan G, Giray Bozkaya Ö, Çağlayan AO, Hız Kurul S, Yiş U. Genetic, serological and clinical evaluation of childhood myasthenia syndromes- single center subgroup analysis experience in Turkey. Acta Neurol Belg 2023; 123:2325-2335. [PMID: 37656362 DOI: 10.1007/s13760-023-02370-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/21/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND Congenital myasthenic syndrome is a disease that occurs due to several types such as mutations in different pre-synaptic, synaptic, post-synaptic proteins and, glycosylation defects associated with congenital myopathy. Juvenile myasthenia gravis is an autoimmune condition usually caused by antibodies targeting the acetylcholine receptor. AIMS Our objective is to conduct an analysis on the subgroup traits exhibited by patients who have been diagnosed with congenital myasthenic syndrome and juvenile myasthenia gravis, with a focus on their long-term monitoring and management. METHODS This study was conducted on children diagnosed with myasthenia gravis, who were under the care of Dokuz Eylul University's Department of Pediatric Neurology for a period of ten years. RESULTS A total of 22 (12 congenital myasthenic syndrome, 10 juvenile myasthenia gravis) patients were identified. Defects in the acetylcholine receptor (6/12) were the most common type in the congenital myasthenic syndrome group. Basal-lamina-related defects (5/12) were the second most prevalent. One patient had a GFPT1 gene mutation (1/12). Patients with ocular myasthenia gravis (n = 6) exhibited milder symptoms. In the generalized myasthenia gravis group (n = 4), specifically in postpubertal girls, a more severe clinical progression was observed, leading to the implementation of more aggressive treatment strategies. CONCLUSION This study highlights that clinical recognition of congenital myasthenic syndrome and knowledge of related genes will aid the rapid diagnosis and treatment of these rare neuromuscular disorders. Findings in the juvenile myasthenia gravis group demonstrate the impact of pubertal development and the need for timely and appropriate active therapy, including thymectomy, to improve prognosis.
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Affiliation(s)
- Özlem Özsoy
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey.
| | - Tayfun Cinleti
- Department of Pediatric Genetics, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - Çağatay Günay
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - Gamze Sarıkaya Uzan
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - Özlem Giray Bozkaya
- Department of Pediatric Genetics, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - Ahmet Okay Çağlayan
- Department of Medical Genetics, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
- Department of Molecular Medicine, Institute of Health Sciences, Dokuz Eylül University, İzmir, Turkey
| | - Semra Hız Kurul
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
- İzmir Biomedicine and Genome Center, Dokuz Eylül University Health Campus, İzmir, Turkey
- İzmir International Biomedicine and Genome Institute, Dokuz Eylül University, İzmir, Turkey
| | - Uluç Yiş
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
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7
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Mishra S, Nair KV, Shukla A. Delineation of molecular characteristics of congenital myasthenic syndromes in Indian families and review of literature. Clin Dysmorphol 2023; 32:162-167. [PMID: 37646703 DOI: 10.1097/mcd.0000000000000465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Congenital myasthenic syndromes (CMS) are rare, heterogeneous, and often treatable genetic disorders depending on the underlying molecular defect. We performed a detailed clinical evaluation of seven patients from five unrelated families. Exome sequencing was performed on five index patients. Clinically significant variants were identified in four CMS disease-causing genes: COLQ (3/7), CHRNE (2/7), DOK7 (1/7), and RAPSN (1/7). We identified two novel variants, c.930_933delCATG in DOK7 and c.1016_1032 + 2dup in CHRNE . A common pathogenic variant, c.955-2A>C, has been identified in COLQ -related CMS patients. Homozygosity mapping of this COLQ variant in patients from two unrelated families revealed that it was located in a common homozygous region of 3.2 Mb on chromosome 3 and was likely to be inherited from a common ancestor. Patients with COLQ variants had generalized muscle weakness, those with DOK7 and RAPSN variants had limb-girdle weakness, and those with CHRNE variants had predominant ocular weakness. Patients with COLQ and DOK7 variants showed improvement with salbutamol and CHRNE with pyridostigmine therapy. This study expands the mutational spectrum and adds a small but significant cohort of CMS patients from India. We also reviewed the literature to identify genetic subtypes of CMS in India.
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Affiliation(s)
- Shivani Mishra
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
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8
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Eshaghian T, Rabbani B, Badv RS, Mikaeeli S, Gharib B, Iyadurai S, Mahdieh N. COLQ-related congenital myasthenic syndrome: An integrative view. Neurogenetics 2023; 24:189-200. [PMID: 37231228 DOI: 10.1007/s10048-023-00719-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/15/2023] [Indexed: 05/27/2023]
Abstract
Congenital myasthenic syndromes are inherited disorders caused by mutation in components of the neuromuscular junction and manifest early in life. Mutations in COLQ gene result in congenital myasthenic syndrome. Here, we present the analysis of data from 209 patients from 195 unrelated families highlighting genotype-phenotype correlation. In addition, we describe a COLQ homozygous variant a new patient and discuss it utilizing the Phyre2 and I-TASSER programs. Clinical, molecular genetics, imaging (MRI), and electrodiagnostic (EEG, EMG/NCS) evaluations were performed. Our data showed 89 pathogenic/likely pathogenic variants including 35 missenses, 21 indels, 14 nonsense, 14 splicing, and 5 large deletions variants. Eight common variants were responsible for 48.46% of those. Weakness in proximal muscles, hypotonia, and generalized weakness were detected in all individuals tested. Apart from the weakness, extensive clinical heterogeneity was noted among patients with COLQ-related patients based on their genotypes-those with variants affecting the splice site exhibited more severe clinical features while those with missense variants displayed milder phenotypes, suggesting the role of differential splice variants in multiple functions within the muscle. Analyses and descriptions of these COLQ variants may be helpful in clinical trial readiness and potential development of novel therapies in the setting of established structure-function relationships.
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Affiliation(s)
- Tina Eshaghian
- Growth and Development Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Bahareh Rabbani
- Growth and Development Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Shervin Badv
- Growth and Development Research, Tehran University of Medical Sciences, Tehran, Iran
- Children's Hospital Center, Pediatric Center of Excellence, Tehran University of Medical Center, Tehran, Iran
| | - Sahar Mikaeeli
- Growth and Development Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Behdad Gharib
- Children's Hospital Center, Pediatric Center of Excellence, Tehran University of Medical Center, Tehran, Iran
| | - Stanley Iyadurai
- Johns Hopkins All Children's Hospital, Division of Neurology, 601 5th Street S, St. Petersburg, FL, 33701, USA
| | - Nejat Mahdieh
- Growth and Development Research, Tehran University of Medical Sciences, Tehran, Iran.
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Niayesh-Vali asr Intersection, Tehran, Iran.
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9
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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: 57] [Impact Index Per Article: 28.5] [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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10
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Krenn M, Sener M, Rath J, Zulehner G, Keritam O, Wagner M, Laccone F, Iglseder S, Marte S, Baumgartner M, Eisenkölbl A, Liechtenstein C, Rudnik S, Quasthoff S, Grinzinger S, Spenger J, Wortmann SB, Löscher WN, Zimprich F, Kellersmann A, Rappold M, Bernert G, Freilinger M, Cetin H. The clinical and molecular landscape of congenital myasthenic syndromes in Austria: a nationwide study. J Neurol 2023; 270:909-916. [PMID: 36308527 PMCID: PMC9886627 DOI: 10.1007/s00415-022-11440-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND Congenital myasthenic syndromes (CMS) are a heterogeneous group of disorders caused by genetic defects resulting in impaired neuromuscular transmission. Although effective treatments are available, CMS is probably underdiagnosed, and systematic clinico-genetic investigations are warranted. METHODS We used a nationwide approach to collect Austrian patients with genetically confirmed CMS. We provide a clinical and molecular characterization of this cohort and aimed to ascertain the current frequency of CMS in Austria. RESULTS Twenty-eight cases with genetically confirmed CMS were identified, corresponding to an overall prevalence of 3.1 per million (95% CI 2.0-4.3) in Austria. The most frequent genetic etiology was CHRNE (n = 13), accounting for 46.4% of the cohort. Within this subgroup, the variant c.1327del, p.(Glu443Lysfs*64) was detected in nine individuals. Moreover, causative variants were found in DOK7 (n = 4), RAPSN (n = 3), COLQ (n = 2), GMPPB (n = 2), CHAT (n = 1), COL13A1 (n = 1), MUSK (n = 1) and AGRN (n = 1). Clinical onset within the first year of life was reported in one half of the patients. Across all subtypes, the most common symptoms were ptosis (85.7%), lower limb (67.9%), upper limb (60.7%) and facial weakness (60.7%). The majority of patients (96.4%) received specific treatment, including acetylcholinesterase inhibitors in 20, adrenergic agonists in 11 and 3,4-diaminopyridine in nine patients. CONCLUSIONS Our study presents the first systematic characterization of individuals with CMS in Austria, providing prevalence estimates and genotype-phenotype correlations that may help to improve the diagnostic approach and patient management.
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Affiliation(s)
- Martin Krenn
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Merve Sener
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Jakob Rath
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Gudrun Zulehner
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Omar Keritam
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Matias Wagner
- Institute of Human Genetics, Technical University of Munich, Munich, Germany.,Institute for Neurogenomics, Helmholtz Center Munich, Munich, Germany
| | - Franco Laccone
- Institute of Medical Genetics, Medical University of Vienna, Vienna, Austria
| | - Stephan Iglseder
- Department of Neurology, Krankenhaus Barmherzige Brüder, Linz, Austria
| | | | - Manuela Baumgartner
- Department of Neuropaediatrics, Hospital Barmherzige Schwestern Linz, Linz, Austria
| | - Astrid Eisenkölbl
- Department of Paediatrics and Adolescent Medicine, Johannes Kepler University Linz, Linz, Austria
| | - Christian Liechtenstein
- Department of Paediatrics and Adolescent Medicine, Villach Regional Hospital, Villach, Austria
| | - Sabine Rudnik
- Institute of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Stefan Quasthoff
- Department of Neurology, Medical University of Graz, Graz, Austria
| | - Susanne Grinzinger
- Department of Neurology, Salzburger Landeskliniken, Paracelsus Medical University, Salzburg, Austria
| | - Johannes Spenger
- University Children's Hospital, Paracelsus Medical University, Salzburg, Austria
| | - Saskia B Wortmann
- University Children's Hospital, Paracelsus Medical University, Salzburg, Austria.,Amalia Children's Hospital, Radboudumc, Nijmegen, The Netherlands
| | - Wolfgang N Löscher
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | | | - Mika Rappold
- Department of Pediatrics, Klinik Favoriten, Vienna, Austria
| | | | - Michael Freilinger
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Hakan Cetin
- Department of Neurology, Medical University of Vienna, Vienna, Austria.
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11
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An R, Chen H, Lei S, Li Y, Xu Y, He C. Abnormal decrement on high-frequency repetitive nerve stimulation in congenital myasthenic syndrome with GFPT1 mutations and review of literature. Front Neurol 2022; 13:926786. [PMID: 36188410 PMCID: PMC9520358 DOI: 10.3389/fneur.2022.926786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 08/01/2022] [Indexed: 11/22/2022] Open
Abstract
Objectives Congenital myasthenic syndrome (CMS) is a clinically and genetically heterogeneous group of inherited disorders characterized by neuromuscular junction defects. Mutations in GFPT1 have been shown to underlie CMS. An increasing number of patients with CMS due to mutations in GFPT1 have been reported. However, a comprehensive review of clinical and genetic analyses of GFPT-related CMS worldwide is lacking, especially, given that the common or hotspot mutations in GFPT1 have not been reported. Here, we described the clinical and genetic findings of three patients with GFPT1 mutations from southwestern China and reviewed the clinical and genetic features of patients with GFPT1-related CMS worldwide. Methods Clinical, laboratory, electrophysiological, myopathological, and genetic analyses of three patients with GFPT1-related CMS from southwestern China were conducted, and a review of previously published or reported cases about congenital myasthenic syndrome with GFPT1 mutations in the PubMed database was made. Results The clinical, laboratory, electrophysiological, and myopathological features by muscle biopsy of three patients with GFPT1-related CMS were consistent with those of previously reported patients with GFPT1 mutations. Additionally, an abnormal decrement in high-frequency RNS was found. Two different homozygous missense mutations (c.331C>T, p.R111C; c.44C>T, p.T15M) were detected by whole-exome sequencing (WES) or targeted neuromuscular disorder gene panels. Conclusion A distinct decremental response to high-frequency RNS was found in three patients with GFPT1-related CMS from southwestern China, which has never been reported thus far. In addition, the location and degree of tubular aggregates (TAs) seemed to be associated with the severity of clinical symptoms and serum creatine kinase levels, further expanding the phenotypic spectrum of GFPT1-related CMS. Lastly, some potential hotspot mutations in GFPT1 have been found in GFPT1-CMS worldwide.
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Affiliation(s)
- Ran An
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, China
| | - Huijiao Chen
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, China
| | - Song Lei
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, China
| | - Yi Li
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, China
| | - Yanming Xu
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Yanming Xu
| | - Chengqi He
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, China
- Chengqi He
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12
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Jiang K, Zheng Y, Lin J, Wu X, Yu Y, Zhu M, Fang X, Zhou M, Li X, Hong D. Diverse myopathological features in the congenital myasthenia syndrome with GFPT1 mutation. Brain Behav 2022; 12:e2469. [PMID: 34978387 PMCID: PMC8865156 DOI: 10.1002/brb3.2469] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 11/14/2021] [Accepted: 12/07/2021] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Mutations in the GFPT1 gene are associated with a particular subtype of congenital myasthenia syndrome (CMS) called limb-girdle myasthenia with tubular aggregates. However, not all patients show tubular aggregates in muscle biopsy, suggesting the diversity of myopathology should be further investigated. METHODS In this study, we reported two unrelated patients clinically characterized by easy fatigability, limb-girdle muscle weakness, positive decrements of repetitive stimulation, and response to pyridostigmine. The routine examinations of myopathology were conducted. The causative gene was explored by whole-exome screening. In addition, we summarized all GFPT1-related CMS patients with muscle biopsy in the literature. RESULTS Pathogenic biallelic GFPT1 mutations were identified in the two patients. In patient one, muscle biopsy indicated vacuolar myopathic changes and atypical pathological changes of myofibrillar myopathy characterized by desmin deposits, Z-disc disorganization, and electronic dense granulofilamentous aggregation. In patient two, muscle biopsy showed typical myopathy with tubular aggregates. Among the 51 reported GFPT1-related CMS patients with muscle biopsy, most of them showed tubular aggregates myopathy, while rimmed vacuolar myopathy, autophagic vacuolar myopathy, mitochondria-like myopathy, neurogenic myopathy, and unspecific myopathic changes were also observed in some patients. These extra-synaptic pathological changes might be associated with GFPT1-deficiency hypoglycosylation and altered function of muscle-specific glycoproteins, as well as partly responsible for the permanent muscle weakness and resistance to acetylcholinesterase inhibitor therapy. CONCLUSIONS Most patients with GFPT1-related CMS had tubular aggregates in the muscle biopsy, but some patients could show great diversities of the pathological change. The myopathological findings might be a biomarker to predict the prognosis of the disease.
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Affiliation(s)
- Kaiyan Jiang
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yilei Zheng
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jing Lin
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Medical Genetics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiaorong Wu
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yanyan Yu
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Min Zhu
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Medical Genetics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xin Fang
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Medical Genetics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Meihong Zhou
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiaobing Li
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Daojun Hong
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Medical Genetics, The First Affiliated Hospital of Nanchang University, Nanchang, China
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13
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Gül Mert G, Özcan N, Hergüner Ö, Altunbaşak Ş, Incecik F, Bişgin A, Ceylaner S. Congenital myasthenic syndrome in Turkey: clinical and genetic features in the long-term follow-up of patients. Acta Neurol Belg 2021; 121:529-534. [PMID: 31773638 DOI: 10.1007/s13760-019-01246-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 11/12/2019] [Indexed: 11/29/2022]
Abstract
Congenital Myasthenic Syndromes (CMS) are rare disorders that occur as a result of defects in the structure and in the function of neuromuscular junctions. Molecular genetic diagnosis is important to select the most suitable therapeutic option and treatment. Eight patients with congenital myasthenic syndromes who presented to the Çukurova University Pediatric Neurology Department Outpatient Clinic between June 2015 and May 2018 were reviewed. Mutations in the acetylcholine receptor (subunits in epsilon) (CHRNE) in three and mutations in the collagenic tail of endplate acetylcholinesterase (COLQ) gene in five patients were identified; p.W148 mutation was detected to be homozygous in four, c.1169A > G novel mutation in COLQ gene was homozygous in one, c452_454delAGG mutation was homozygous in the other patient, IVS7 + 2T > C(c.802 + 2T > C) mutation was homozygous in a patient and compound heterozygous mutations of c.865C > T(p.Leu289Phe) and c.872C > G(p.A2916)(p.Arg291Gly) in the CHRNE gene in the last patient. The parents of all the evaluated patients were consanguineous. Ptosis, ophthalmoplegia, generalized hypotonia, bulbar weakness, and respiratory crisis were the main findings at the time of presentation. Pyridostigmine is the first-line drug therapy in primary AChR deficiency. Beta adrenergic agonists, ephedrine, and albuterol are the other treatment options for CMS subtypes caused by mutations in COLQ. This study points out the genetic and phenotypic features of CMS patients in the Turkish population and it also reports previously unreported mutations in the literature. CHRNE and COLQ gene mutations are common in the Turkish population. Patients can get serious benefits and recover after the treatment. The treatment should be planned according to genetic tests and clinical findings.
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Affiliation(s)
- Gülen Gül Mert
- Department of Pediatrics, Division of Pediatric Neurology, Cukurova University, Adana, Turkey.
| | - Neslihan Özcan
- Department of Pediatrics, Division of Pediatric Neurology, Cukurova University, Adana, Turkey
| | - Özlem Hergüner
- Department of Pediatrics, Division of Pediatric Neurology, Cukurova University, Adana, Turkey
| | - Şakir Altunbaşak
- Department of Pediatrics, Division of Pediatric Neurology, Cukurova University, Adana, Turkey
| | - Faruk Incecik
- Department of Pediatrics, Division of Pediatric Neurology, Cukurova University, Adana, Turkey
| | - Atıl Bişgin
- Department of Medical Genetics, Cukurova University Faculty of Medicine, Adana, Turkey
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Zhao Y, Li Y, Bian Y, Yao S, Liu P, Yu M, Zhang W, Wang Z, Yuan Y. Congenital myasthenic syndrome in China: genetic and myopathological characterization. Ann Clin Transl Neurol 2021; 8:898-907. [PMID: 33756069 PMCID: PMC8045908 DOI: 10.1002/acn3.51346] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 03/01/2021] [Accepted: 03/02/2021] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE We aimed to summarize the clinical, genetic, and myopathological features of a cohort of Chinese patients with congenital myasthenic syndrome, and follow up on therapeutic outcomes. METHODS The clinical spectrum, mutational frequency of genes, and pathological diagnostic clues of various subtypes of patients with congenital myasthenic syndrome were summarized. Therapeutic effects were followed up. RESULTS Thirty-five patients from 29 families were recruited. Ten genes were identified: GFPT1 (27.6%), AGRN (17.2%), CHRNE (17.2%), COLQ (13.8%), GMPPB (6.9%), CHAT, CHRNA1, DOK7, COG7, and SLC25A1 (3.4% each, respectively). Sole limb-girdle weakness was found in patients with AGRN (1/8) and GFPT1 (7/8) mutations, whereas distal weakness was all observed in patients with AGRN (6/8) mutations. Tubular aggregates were only found in patients with GFPT1 mutations (5/6). The patients with GMPPB mutations (2/2) had decreased alpha-dystroglycan. Acetylcholinesterase inhibitor therapy resulted in no response or worsened symptoms in patients with COLQ mutations, a diverse response in patients with AGRN mutations, and a good response in patients with other subtypes. Albuterol therapy was effective or harmless in most subtypes. Therapy effects became attenuated with long-term use in patients with COLQ or AGRN mutations. INTERPRETATION The genetic distribution of congenital myasthenic syndrome in China is distinct from that of other ethnic origins. The appearance of distal weakness, selective limb-girdle myasthenic syndrome, tubular aggregates, and decreased alpha-dystroglycan were indicative of the specific subtypes. Based on the follow-up findings, we suggest cautious evaluation of the long-term efficacy of therapeutic agents in congenital myasthenic syndrome.
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Affiliation(s)
- Yawen Zhao
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Ying Li
- Department of Neurology, Capital Medical University Affiliated Anzhen Hospital, Chaoyang-qu, China
| | - Yang Bian
- Department of Neurology, Sixth Medical Center of PLA General Hospital, Beijing, China
| | - Sheng Yao
- Department of Neurology, Sixth Medical Center of PLA General Hospital, Beijing, China
| | - Penju Liu
- Department of Neurology, Capital Medical University Affiliated Anzhen Hospital, Chaoyang-qu, China
| | - Meng Yu
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Wei Zhang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
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Congenital myasthenic syndromes in the Thai population: Clinical findings and novel mutations. Neuromuscul Disord 2020; 30:851-858. [PMID: 32978031 DOI: 10.1016/j.nmd.2020.08.362] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 11/23/2022]
Abstract
Congenital myasthenic syndromes (CMS) comprise a heterogeneous group of genetic disorders of the neuromuscular junction. Next generation sequencing has been increasingly used for molecular diagnosis in CMS patients. This study aimed to identify the disease-causing variants in Thai patients. We recruited patients with a diagnosis of CMS based on clinical and electrophysiologic findings, and whole exome sequencing was performed. Thirteen patients aged from 2 to 54 years (median: 8 years) from 12 families were enrolled. Variants were identified in 9 of 13 patients (69%). Five novel variants and two previously reported variant were found in the COLQ, RAPSN and CHRND gene. The previously reported c.393+1G>A splice site variant in the COLQ gene was found in a majority of patients. Five patients harbor the homozygous splice site c.393+1G>A variant, and two patients carry compound heterozygous c.393+1G>A, c.718-1G>T, and c.393+1G>A, c.865G>T (p.Gly289Ter) variants. The novel variants were also found in RAPSN (p.Cys251del, p.Arg282Cys) and CHRND (p.Met481del). Molecular diagnosis in CMS patients can guide treatment decisions and may be life changing, especially in patients with COLQ mutations.
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Al-Muhaizea MA, AlQuait L, AlRasheed A, AlHarbi S, Albader AA, AlMass R, Albakheet A, Alhumaidan A, AlRasheed MM, Colak D, Kaya N. Pyrostigmine therapy in a patient with VAMP1-related congenital myasthenic syndrome. Neuromuscul Disord 2020; 30:611-615. [DOI: 10.1016/j.nmd.2020.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 03/25/2020] [Accepted: 04/27/2020] [Indexed: 12/19/2022]
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17
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Severe congenital myasthenic syndrome associated with novel biallelic mutation of the CHRND gene. Neuromuscul Disord 2020; 30:336-339. [DOI: 10.1016/j.nmd.2020.02.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 01/14/2020] [Accepted: 02/16/2020] [Indexed: 11/20/2022]
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Congenital myasthenic syndrome: Ten years clinical experience from a quaternary care south-Indian hospital. J Clin Neurosci 2019; 72:238-243. [PMID: 31889643 DOI: 10.1016/j.jocn.2019.11.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 11/27/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND To ascertain the frequency, clinical spectrum and outcome of congenital myasthenic syndrome (CMS) patients who reported to the neuromuscular division of our quaternary medical center during the past ten years. METHODS We performed a retrospective analysis of all the CMS patients who reported to us during the study period. RESULTS Twenty-one patients of CMS attended our quaternary hospital over the past ten years. The median follow-up was 24 (IQR: 16.5-67.3) months. All the patients showed an overall improvement in the last follow up. The diagnosis of CMS could be genetically confirmed in seven cases. Four patients had COLQ mutation, two had CHRNε mutation and one had MUSK mutation. All the cases of COLQ mutation and one case of MUSK mutation had a limb-girdle (LG) presentation. Our study and review of literature imply that CMS should be suspected in cases of seronegative myasthenia gravis cases if the onset is at less than 20 years and strongly so if the onset is within the first two years of life. In addition, a positive family history, delayed motor milestones, and a poor response to immune-modulators should be actively sought for as indicators of CMS.
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A Novel c.973G>T Mutation in the ε-subunit of the Acetylcholine Receptor Causing Congenital Myasthenic Syndrome in an Iranian Family. Balkan J Med Genet 2019; 22:95-98. [PMID: 31523627 PMCID: PMC6714341 DOI: 10.2478/bjmg-2019-0010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Congenital myasthenic syndrome (CMS) constitutes a group of inherited disorders of neuromuscular junctions. The majority of postsynaptic syndromes result from mutations in the CHRNE gene that causes muscle nicotine acetylcholine deficiency. In this study, we report on a 2 and a half-year-old boy with normal developmental milestones and bilateral ptosis. Clinical courses, electrophysiological studies and molecular genetic analysis were assessed. Polymerase chain reaction (PCR) and direct DNA sequencing of the CHRNE gene were performed for the proband and all the family members. A novel homozygous missense mutation of c.973G>T was found in the CHRNE gene. Segregation studies were suggested to be the genetic cause of the disease. Using three in silico tools and the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) variant classification guidelines indicated that the novel variant c.973G>T was likely pathogenic. Our results recommended first screening of the CHRNE gene for pathogenic mutations in Iranian origin.
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20
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Mansukhani SA, Bothun ED, Diehl NN, Mohney BG. Incidence and Ocular Features of Pediatric Myasthenias. Am J Ophthalmol 2019; 200:242-249. [PMID: 30653958 PMCID: PMC6587184 DOI: 10.1016/j.ajo.2019.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 01/05/2019] [Accepted: 01/05/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE To report the incidence, demographics, and ocular findings of children with myasthenia. DESIGN Retrospective cohort study. METHODS The medical records of all children (<19 years) examined at Mayo Clinic with any form of myasthenia from January 1 1966, through December 31, 2015, were retrospectively reviewed. RESULTS A total of 364 children were evaluated during the study period, of which 6 children were residents of the Olmsted County at the time of their diagnosis, yielding an annual age- and sex-adjusted incidence of 0.35 per 100 000 <19 years, or 1 in 285 714 <19 years. The incidence of juvenile myasthenia gravis (JMG) and congenital myasthenic syndrome (CMS) was 0.12 and 0.23 per 100 000, respectively. Of the 364 study children, 217 (59.6%) had JMG, 141 (38.7%) had CMS, and 6 (1.7%) had Lambert-Eaton syndrome, diagnosed at a median age of 13.5, 5.1, and 12.6 years, respectively. A majority of the JMG and CMS patients had ocular involvement (90.3% and 85.1%, respectively), including ptosis and ocular movement deficits. Among children with at least 1 year of follow-up (JMG; median, 7.1 years, CMS; median, 7.0 years), improvement was seen in 88.8% of JMG patients (complete remission in 31.3%) and in 58.3% of CMS patients. CONCLUSION Although relatively rare, myasthenia gravis in children has 2 predominant forms, CMS and JMG, both of which commonly have ocular involvement. Improvement is more likely in children with the juvenile form.
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21
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Abstract
OBJECTIVES Congenital myasthenic syndromes (CMSs) are a genotypically and phenotypically heterogeneous group of neuromuscular disorders, which have in common an impaired neuromuscular transmission. Since the field of CMSs is steadily expanding, the present review aimed at summarizing and discussing current knowledge and recent advances concerning the etiology, clinical presentation, diagnosis, and treatment of CMSs. METHODS Systematic literature review. RESULTS Currently, mutations in 32 genes are made responsible for autosomal dominant or autosomal recessive CMSs. These mutations concern 8 presynaptic, 4 synaptic, 15 post-synaptic, and 5 glycosilation proteins. These proteins function as ion-channels, enzymes, or structural, signalling, sensor, or transporter proteins. The most common causative genes are CHAT, COLQ, RAPSN, CHRNE, DOK7, and GFPT1. Phenotypically, these mutations manifest as abnormal fatigability or permanent or fluctuating weakness of extra-ocular, facial, bulbar, axial, respiratory, or limb muscles, hypotonia, or developmental delay. Cognitive disability, dysmorphism, neuropathy, or epilepsy are rare. Low- or high-frequency repetitive nerve stimulation may show an abnormal increment or decrement, and SF-EMG an increased jitter or blockings. Most CMSs respond favourably to acetylcholine-esterase inhibitors, 3,4-diamino-pyridine, salbutamol, albuterol, ephedrine, fluoxetine, or atracurium. CONCLUSIONS CMSs are an increasingly recognised group of genetically transmitted defects, which usually respond favorably to drugs enhancing the neuromuscular transmission. CMSs need to be differentiated from neuromuscular disorders due to muscle or nerve dysfunction.
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Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Messerli Institute, Veterinary University of Vienna, Postfach 20, 1180, Vienna, Austria.
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22
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PARVIZI OMRAN S, HOUSHMAND M, DOMINIC D, FARJAMI Z, KARIMZADEH P. No Hot Spot Mutations CHRNE c.1327 delG, CHAT c.914T>C, and RAPSN c.264C>A in Iranian Patients with Congenital Myasthenic Syndrome. IRANIAN JOURNAL OF CHILD NEUROLOGY 2019; 13:135-143. [PMID: 31037086 PMCID: PMC6451864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 08/18/2018] [Accepted: 11/18/2018] [Indexed: 11/11/2022]
Abstract
OBJECTIVES We aimed to perform genetic testing and clinical data of patients with Congenital Myasthenic Syndrome, a rare disorder caused by mutations in genes encoding molecules expressed in the neuromuscular junction and constitutes fatigable muscle weakness. MATERIALS & METHODS Sixteen patients were screened in Taban Clinic, Tehran, Iran from 2014 to 2015 for the hot spot mutations in known CMSs genes (CHRNE, CHAT, RAPSN) based on clinical data. PCR was performed and then direct DNA sequencing was done for mutation identification. RESULTS Most patients represented the criteria of Congenital Myasthenic Syndrome in view of early ptosis, motor delay, normal mental development, easy fatigability, decrement in repetitive nerve stimulation test of EMG-NCV and a negative result for antibody against of acetylcholine receptor. No variations were found in the mutational analysis of the CHRNE gene. Analysis of CHAT gene revealed c.358G>A (P. A120T) variation in 9 patients. In the gene RAPSN, polymorphism c.456T>C )P.Y152Y) and polymorphism c.193-15C>T (IVS1-15C>T) were identified in 11 and one patients, respectively. CONCLUSION The common founder mutations of involved genes in CMSs could be very rare among ethnic Iranian. Screening of the entire genes would be efficient to distinguish the specific mutations in specific ethnicity.
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Affiliation(s)
- Sima PARVIZI OMRAN
- Department of Biology, Damghan Branch, Islamic Azad University, Damghan, Iran
| | - Massod HOUSHMAND
- Department of Human Genetics, National Institute of Genetic Engineerin -Biotechnology, Tehran, Iran
| | - Donkor DOMINIC
- Department of Biology, Concordia University, Montreal, Canada
| | - Zahra FARJAMI
- Department of Modern Sciences and Technologies, Faculty of Medicine, Mashhad University of Medical Sciences
| | - Parvaneh KARIMZADEH
- Pediatric Neurology Research Center, Research Institute for Children’s Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran,6.Pediatric Neurology Department, Mofid Children’s Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Selvam P, Arunachal G, Danda S, Chapla A, Sivadasan A, Alexander M, Thomas MM, Thomas NJ. Congenital Myasthenic Syndrome: Spectrum of Mutations in an Indian Cohort. J Clin Neuromuscul Dis 2018; 20:14-27. [PMID: 30124556 DOI: 10.1097/cnd.0000000000000222] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVES To investigate the mutational spectrum and genotype-phenotype correlation in Indian patients with congenital myasthenic syndrome (CMS), using next-generation sequencing of 5 genes. METHODS CHRNE, COLQ, DOK7, RAPSN, and GFPT1 were sequenced in 25 affected patients. RESULTS We found clinically significant variants in 18 patients, of which variants in CHRNE were the most common, and 9 were novel. A common pathogenic COLQ variant was also detected in 4 patients with isolated limb-girdle congenital myasthenia. CONCLUSIONS Targeted screening of 5 genes is an effective alternate test for CMS, and an affordable one even in a developing country such as India. In addition, we recommend that patients with isolated limb-girdle congenital myasthenia be screened initially for the common COLQ pathogenic variant. This study throws the first light on the genetic landscape of CMSs in India.
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Affiliation(s)
- Pavalan Selvam
- Department of Medical Genetics, Christian Medical College, Vellore, India
| | - Gautham Arunachal
- Department of Medical Genetics, Christian Medical College, Vellore, India
| | - Sumita Danda
- Department of Medical Genetics, Christian Medical College, Vellore, India
| | - Aaron Chapla
- Department of Endocrinology, Diabetes and Metabolism, Christian Medical College, Vellore, India
| | - Ajith Sivadasan
- Department of Neurological Sciences, Christian Medical College, Vellore, India
| | - Mathew Alexander
- Department of Neurological Sciences, Christian Medical College, Vellore, India
| | - Maya Mary Thomas
- Department of Neurological Sciences, Christian Medical College, Vellore, India
| | - Nihal J Thomas
- Department of Endocrinology, Diabetes and Metabolism, Christian Medical College, Vellore, India
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Durmus H, Shen XM, Serdaroglu-Oflazer P, Kara B, Parman-Gulsen Y, Ozdemir C, Brengman J, Deymeer F, Engel AG. Congenital myasthenic syndromes in Turkey: Clinical clues and prognosis with long term follow-up. Neuromuscul Disord 2018; 28:315-322. [PMID: 29395675 PMCID: PMC5924610 DOI: 10.1016/j.nmd.2017.11.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 11/07/2017] [Accepted: 11/20/2017] [Indexed: 11/28/2022]
Abstract
Congenital myasthenic syndromes (CMS) are a group of hereditary disorders affecting the neuromuscular junction. Here, we present clinical, electrophysiological and genetic findings of 69 patients from 51 unrelated kinships from Turkey. Genetic tests of 60 patients were performed at Mayo Clinic. Median follow-up time was 9.8 years (range 1-22 years). The most common CMS was primary acetylcholine receptor (AChR) deficiency (31/51) and the most common mutations in AChR were c.1219 + 2T > G (12/51) and c.1327delG (6/51) in CHRNE. Four of our 5 kinships with AChE deficiency carried p.W148X that truncates the collagen domain of COLQ, and was previously reported only in patients from Turkey. These were followed by GFPT1 deficiency (4/51), DOK7 deficiency (3/51), slow channel CMS (3/51), fast channel CMS (3/51), choline acetyltransferase deficiency (1/51) and a CMS associated with desmin deficiency (1/51). Distribution of muscle weakness was sometimes useful in giving a clue to the CMS subtype. Presence of repetitive compound muscle action potentials pointed to AChE deficiency or slow channel CMS. Our experience confirms that one needs to be cautious using pyridostigmine, since it can worsen some types of CMS. Ephedrine/salbutamol were very effective in AChE and DOK7 deficiencies and were useful as adjuncts in other types of CMS. Long follow-up gave us a chance to assess progression of the disease, and to witness 12 mainly uneventful pregnancies in 8 patients. In this study, we describe some new phenotypes and detail the clinical features of the well-known CMS.
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Affiliation(s)
- Hacer Durmus
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Xin-Ming Shen
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Piraye Serdaroglu-Oflazer
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Bulent Kara
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Yesim Parman-Gulsen
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Coskun Ozdemir
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Joan Brengman
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Feza Deymeer
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey.
| | - Andrew G Engel
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
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Yang K, Cheng H, Yuan F, Meng L, Yin R, Zhang Y, Wang S, Wang C, Lu Y, Xi J, Lu Q, Chen Y. CHRNE compound heterozygous mutations in congenital myasthenic syndrome: A case report. Medicine (Baltimore) 2018; 97:e0347. [PMID: 29702980 PMCID: PMC5944527 DOI: 10.1097/md.0000000000010347] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
RATIONALE Congenital myasthenic syndrome (CMSs) are a group of rare genetic disorders of the neurological junction, which can result in structural or functional weakness. Here, we characterized a case of CMS in order to clarify the diagnosis and expand the understanding of it. The molecular diagnosis had implications for choice of treatment and genetic counseling. PATIENT CONCERNS A 3-year-old male patient with CMS had ptosis and limb weakness for 2 months after birth. Clinical course and electrophysiological, imaging, and genetic findings were assessed. Protein structure/function was predicted. A novel mutation of c.295C>T (exon 4) and another known mutation of c.442T>A (exon 5) were found in CHRNE. Both mutations localized in conserved sequences. The c.442T>A (p.C148S) missense mutation in CHRNE was predicted to be damaging/deleterious. The iterative threading assembly refinement (I-TASSER) server generated vastly different 3-dimensional (3D) atomic models based on protein sequences from wide-type and novel nonsense mutation of c.295C>T (p.R99X) in CHRNE. DIAGNOSES The diagnosis of CMS with CHRNE mutations in Han Chinese was confirmed. INTERVENTIONS The patient was given prednisone (10 mg, once daily, taken orally) and pyridostigmine (15 mg, three times a day, taken orally). OUTCOMES The patient had a moderate response to prednisone and pyridostigmine. LESSONS We expanded the genotype and phenotype of CMS with CHRNE mutations in Han Chinese and provided new insights into the molecular mechanism of CMS and help to the diagnosis and treatment of CMS.
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Affiliation(s)
| | | | | | - Linyi Meng
- Department of Pharmacy, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
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Shalev SA. Characteristics of genetic diseases in consanguineous populations in the genomic era: Lessons from Arab communities in North Israel. Clin Genet 2018; 95:3-9. [PMID: 29427439 DOI: 10.1111/cge.13231] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/01/2018] [Accepted: 02/06/2018] [Indexed: 01/15/2023]
Abstract
The health outcome of consanguineous/endogamous unions is an increased risk of autosomal recessive disorders in their progeny. This manuscript is focused on consanguineous/endogamous populations living in North Israel. Molecular tools show that spouses' relatedness and hence their risks for congenital diseases among offspring are often greater than the risk calculated on the basis of reported pedigrees. Revealing founder mutations allow for effective genetic counseling, but also induce genetic screening of the whole community in case the mutations are found to be frequent. More complex genetic mechanisms, such as co-inheritance of more than one condition, allelic and even locus heterogeneity, have been identified. These mechanisms make genetic counseling more challenging but with the advancement of molecular techniques, diseases can be better deciphered. Yet, the presence of multiple mutations responsible for genetic diseases in isolated populations, and occasionally locus heterogeneity of diseases, is an unexpected phenomenon that still needs mechanistic clarification. It seems probably that addressing genetic counseling challenges and estimations of risks for genetic morbidity in consanguineous/endogamous couples will be achieved by introducing high-throughput genetic technologies into daily practice. The genomic era has expanded dramatically the translation of research products to genetic counseling tools, and this tendency is expected to yield a stronger impact in a near future.
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Affiliation(s)
- S A Shalev
- The Genetic Institute Emek Medical Center, Afula, Israel.,Rappaport Faculty of Medicine, Technion, Haifa, Israel
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27
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Estephan EDP, Sobreira CFDR, Dos Santos ACJ, Tomaselli PJ, Marques W, Ortega RPM, Costa MCM, da Silva AMS, Mendonça RH, Caldas VM, Zambon AA, Abath Neto O, Marchiori PE, Heise CO, Reed UC, Azuma Y, Töpf A, Lochmüller H, Zanoteli E. A common CHRNE mutation in Brazilian patients with congenital myasthenic syndrome. J Neurol 2018; 265:708-713. [PMID: 29383513 PMCID: PMC7115868 DOI: 10.1007/s00415-018-8736-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/16/2017] [Accepted: 01/04/2018] [Indexed: 11/29/2022]
Abstract
The most common causes of congenital myasthenic syndromes (CMS) are CHRNE mutations, and some pathogenic allelic variants in this gene are especially frequent in certain ethnic groups. In the southern region of Brazil, a study found the c.130dupG CHRNE mutation in up to 33% of families with CMS. Here, we aimed to verify the frequency of this mutation among individuals with CMS in a larger cohort of CMS patients from different areas of Brazil and to characterize clinical features of these patients. Eighty-four patients with CMS, from 72 families, were clinically evaluated and submitted to direct sequencing of the exon 2 of CHRNE. The c.130dupG mutation was found in 32 patients (23 families), with 26 patients (19 families, 26.3%) in homozygosis, confirming its high prevalence in different regions of Brazil. Among the homozygous patients, the following characteristics were frequent: onset of symptoms before 2 years of age (92.3%), little functional restriction (92.3%), fluctuating symptoms (100%), ocular muscle impairment (96.1%), ptosis (100%), limb weakness (88.4%), response to pyridostigmine (100%), facial involvement (77%), and bulbar symptoms (70.8%). The pretest probability of finding at least one allele harbouring the c.130dupG mutation was 38.1%. Selecting only patients with impaired eye movement together with limb weakness and improvement with pyridostigmine, the probability increases to 72.2%. This clinical pre-selection of patients is likely a useful tool for regions where CHRNE mutations have a founder effect. In conclusion, the CHRNE mutation c.130dupG leads to fairly benign natural course of the disease with relative homogeneity.
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Affiliation(s)
- Eduardo de Paula Estephan
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil
| | | | | | - Pedro José Tomaselli
- Department of Neurosciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Wilson Marques
- Department of Neurosciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | | | - André Macedo Serafim da Silva
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil
| | - Rodrigo Holanda Mendonça
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil
| | - Vitor Marques Caldas
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil
| | - Antonio Alberto Zambon
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil
| | - Osório Abath Neto
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil
| | - Paulo Eurípedes Marchiori
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil
| | - Carlos Otto Heise
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil
| | - Umbertina Conti Reed
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil
| | - Yoshiteru Azuma
- Institute of Genetic Medicine, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
| | - Ana Töpf
- Institute of Genetic Medicine, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
| | - Hanns Lochmüller
- Institute of Genetic Medicine, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
| | - Edmar Zanoteli
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Av. Enéas de Carvalho Aguiar, 255, 5o andar, sala 5084, Cerqueira César, São Paulo, 05403-900, Brazil.
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28
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Natera-de Benito D, Töpf A, Vilchez JJ, González-Quereda L, Domínguez-Carral J, Díaz-Manera J, Ortez C, Bestué M, Gallano P, Dusl M, Abicht A, Müller JS, Senderek J, García-Ribes A, Muelas N, Evangelista T, Azuma Y, McMacken G, Paipa Merchan A, Rodríguez Cruz PM, Camacho A, Jiménez E, Miranda-Herrero MC, Santana-Artiles A, García-Campos O, Dominguez-Rubio R, Olivé M, Colomer J, Beeson D, Lochmüller H, Nascimento A. Molecular characterization of congenital myasthenic syndromes in Spain. Neuromuscul Disord 2017; 27:1087-1098. [PMID: 29054425 DOI: 10.1016/j.nmd.2017.08.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/08/2017] [Accepted: 08/10/2017] [Indexed: 10/19/2022]
Abstract
Congenital myasthenic syndromes (CMS) are a heterogeneous group of genetic disorders, all of which impair neuromuscular transmission. Epidemiological data and frequencies of gene mutations are scarce in the literature. Here we describe the molecular genetic and clinical findings of sixty-four genetically confirmed CMS patients from Spain. Thirty-six mutations in the CHRNE, RAPSN, COLQ, GFPT1, DOK7, CHRNG, GMPPB, CHAT, CHRNA1, and CHRNB1 genes were identified in our patients, with five of them not reported so far. These data provide an overview on the relative frequencies of the different CMS subtypes in a large Spanish population. CHRNE mutations are the most common cause of CMS in Spain, accounting for 27% of the total. The second most common are RAPSN mutations. We found a higher rate of GFPT1 mutations in comparison with other populations. Remarkably, several founder mutations made a large contribution to CMS in Spain: RAPSN c.264C > A (p.Asn88Lys), CHRNE c.130insG (Glu44Glyfs*3), CHRNE c.1353insG (p.Asn542Gluf*4), DOK7 c.1124_1127dup (p.Ala378Serfs*30), and particularly frequent in Spain in comparison with other populations, COLQ c.1289A > C (p.Tyr430Ser). Furthermore, we describe phenotypes and distinguishing clinical signs associated with the various CMS genes which might help to identify specific CMS subtypes to guide diagnosis and management.
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Affiliation(s)
- D Natera-de Benito
- Department of Neuromuscular Diseases, Hospital Sant Joan de Déu, CIBERER U703, Barcelona, Spain.
| | - A Töpf
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - J J Vilchez
- Department of Neurology, Hospital Universitari La Fe, Universitat de Valencia, CIBERER U763, Valencia, Spain
| | - L González-Quereda
- Department of Genetics, Hospital de la Santa Creu i Sant Pau and CIBERER U705, Barcelona, Spain
| | - J Domínguez-Carral
- Department of Pediatrics, Hospital Universitario Marqués de Valdecilla, Santander, Spain
| | - J Díaz-Manera
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona and Centre for Biomedical Network Research on Rare Diseases (CIBERER), Barcelona, Spain
| | - C Ortez
- Department of Neuromuscular Diseases, Hospital Sant Joan de Déu, CIBERER U703, Barcelona, Spain
| | - M Bestué
- Department of Neurology, Hospital General San Jorge, Huesca, Spain
| | - P Gallano
- Department of Genetics, Hospital de la Santa Creu i Sant Pau and CIBERER U705, Barcelona, Spain
| | - M Dusl
- Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, 80336 Munich, Germany
| | - A Abicht
- Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, 80336 Munich, Germany; Medical Genetics Center, Munich, Germany
| | - J S Müller
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - J Senderek
- Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, 80336 Munich, Germany
| | - A García-Ribes
- Department of Pediatrics, Hospital Universitario Cruces, Bilbao, Spain
| | - N Muelas
- Department of Neurology, Hospital Universitari La Fe, Universitat de Valencia, CIBERER U763, Valencia, Spain
| | - T Evangelista
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - Y Azuma
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - G McMacken
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - A Paipa Merchan
- Neuropathology Unit, Department of Pathology and Neuromuscular Unit, IDIBELL-Hospital Universitari de Bellvitge, Barcelona, Spain
| | - P M Rodríguez Cruz
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - A Camacho
- Department of Pediatric Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - E Jiménez
- Department of Pediatrics, Hospital Universitario Rey Juan Carlos, Madrid, Spain
| | - M C Miranda-Herrero
- Department of Neuropediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - A Santana-Artiles
- Department of Neuropediatrics, Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain
| | - O García-Campos
- Department of Neuropediatrics, Hospital Virgen de la Salud, Toledo, Spain
| | - R Dominguez-Rubio
- Neuropathology Unit, Department of Pathology and Neuromuscular Unit, IDIBELL-Hospital Universitari de Bellvitge, Barcelona, Spain
| | - M Olivé
- Neuropathology Unit, Department of Pathology and Neuromuscular Unit, IDIBELL-Hospital Universitari de Bellvitge, Barcelona, Spain
| | - J Colomer
- Department of Neuromuscular Diseases, Hospital Sant Joan de Déu, CIBERER U703, Barcelona, Spain
| | - D Beeson
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - H Lochmüller
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - A Nascimento
- Department of Neuromuscular Diseases, Hospital Sant Joan de Déu, CIBERER U703, Barcelona, Spain
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29
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Feng H, Zhou H. New compound heterozygous variants of the cholinergic receptor nicotinic delta subunit gene in a Chinese male with congenital myasthenic syndrome: A case report. Medicine (Baltimore) 2017; 96:e8981. [PMID: 29390429 PMCID: PMC5758131 DOI: 10.1097/md.0000000000008981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
INTRODUCTION Congenital myasthenic syndromes (CMS) are a group of genetic disorders that stem mostly from molecular defects in nicotinic acetylcholine receptors (AChRs). Defects in the cholinergic receptor nicotinic delta subunit (CHRND) gene can cause a series of myasthenic syndromes. Here, we report 2 new compound heterozygous variants of the CHRND gene in a Chinese male with CMS. CASE PRESENTATION A 43-year-old Chinese male presented with progressive muscle weakness, difficulty chewing, and an inability to lift his head from the time he was 8 years old. He was treated with pyridostigmine, which was partially effective. Two weeks prior, he was hospitalized for dyspnea. Upon examination, he was unable to drum his cheeks and exhibited fatigable muscle weakness and facial muscle atrophy. Sequencing of his exome revealed 2 previously unreported mutations in CHRND, c.59G>A (exon2) and c.423G>C (exon5). CONCLUSIONS We identified a new mutational site that contributes to the onset of CMS.
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30
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Yiş U, Becker K, Kurul SH, Uyanik G, Bayram E, Haliloğlu G, Polat Aİ, Ayanoğlu M, Okur D, Tosun AF, Serdaroğlu G, Yilmaz S, Topaloğlu H, Anlar B, Cirak S, Engel AG. Genetic Landscape of Congenital Myasthenic Syndromes From Turkey: Novel Mutations and Clinical Insights. J Child Neurol 2017; 32:759-765. [PMID: 28464723 PMCID: PMC5655993 DOI: 10.1177/0883073817705252] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Congenital myasthenic syndromes are clinically and genetically heterogeneous disorders of neuromuscular transmission. Most are treatable, but certain subtypes worsen with cholinesterase inhibitors. This underlines the importance of genetic diagnosis. Here, the authors report on cases with genetically proven congenital myasthenic syndromes from Turkey. The authors retrospectively reviewed their experience of all patients with congenital myasthenic syndromes, referred over a 5-year period (2011-2016) to the Child Neurology Department of Dokuz Eylül University, Izmir, Turkey. In addition, PubMed was searched for published cases of genetically proven congenital myasthenic syndromes originating from Turkey. In total, the authors identified 43 (8 new patients, 35 recently published patients) cases. Defects in the acetylcholine receptor (n = 15; 35%) were the most common type, followed by synaptic basal-lamina associated (n = 14; 33%) and presynaptic syndromes (n = 10; 23%). The authors had only 3 cases (7%) who had defects in endplate development. One patient had mutation GFPT1 gene (n = 1; 2%). Knowledge on congenital myasthenic syndromes and related genes in Turkey will lead to prompt diagnosis and treatment of these rare neuromuscular disorders.
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Affiliation(s)
- Uluç Yiş
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Kerstin Becker
- Cologne University, Department of Pediatrics, Center for Molecular Medicine Cologne, Cologne, GERMANY
| | - Semra Hız Kurul
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Gökhan Uyanik
- Center for Medical Genetics, Hanusch Hospital, Vienna, AUSTRIA
- Medical Faculty, Sigmund Freud University, Vienna, AUSTRIA
| | - Erhan Bayram
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Göknur Haliloğlu
- Hacettepe University, School of Medicine, Department of Pediatrics, Division of Child Neurology, Ankara, TURKEY
| | - Ayşe İpek Polat
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Müge Ayanoğlu
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Derya Okur
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Ayşe Fahriye Tosun
- Adnan Menderes University, School of Medicine, Department of Pediatrics, Division of Child Neurology, Aydın, TURKEY
| | - Gül Serdaroğlu
- Ege University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Sanem Yilmaz
- Ege University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Haluk Topaloğlu
- Hacettepe University, School of Medicine, Department of Pediatrics, Division of Child Neurology, Ankara, TURKEY
| | - Banu Anlar
- Hacettepe University, School of Medicine, Department of Pediatrics, Division of Child Neurology, Ankara, TURKEY
| | - Sebahattin Cirak
- Cologne University, Department of Pediatrics, Center for Molecular Medicine Cologne, Cologne, GERMANY
| | - Andrew G. Engel
- Mayo Clinic, Rochester, Department of Neurology, MN 55905, USA
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31
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Salpietro V, Lin W, Vedove AD, Storbeck M, Liu Y, Efthymiou S, Manole A, Wiethoff S, Ye Q, Saggar A, McElreavey K, Krishnakumar SS, SYNAPS Study Group, Pitt M, Bello OD, Rothman JE, Basel‐Vanagaite L, Hubshman MW, Aharoni S, Manzur AY, Wirth B, Houlden H. Homozygous mutations in VAMP1 cause a presynaptic congenital myasthenic syndrome. Ann Neurol 2017; 81:597-603. [PMID: 28253535 PMCID: PMC5413866 DOI: 10.1002/ana.24905] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 02/24/2017] [Accepted: 02/24/2017] [Indexed: 11/07/2022]
Abstract
We report 2 families with undiagnosed recessive presynaptic congenital myasthenic syndrome (CMS). Whole exome or genome sequencing identified segregating homozygous variants in VAMP1: c.51_64delAGGTGGGGGTCCCC in a Kuwaiti family and c.146G>C in an Israeli family. VAMP1 is crucial for vesicle fusion at presynaptic neuromuscular junction (NMJ). Electrodiagnostic examination showed severely low compound muscle action potentials and presynaptic impairment. We assessed the effect of the nonsense mutation on mRNA levels and evaluated the NMJ transmission in VAMP1lew/lew mice, observing neurophysiological features of presynaptic impairment, similar to the patients. Taken together, our findings highlight VAMP1 homozygous mutations as a cause of presynaptic CMS. Ann Neurol 2017;81:597–603
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Affiliation(s)
- Vincenzo Salpietro
- Department of Molecular Neuroscience, Institute of NeurologyUniversity College London Institute of NeurologyLondonUnited Kingdom
| | - Weichun Lin
- Department of NeuroscienceUniversity of Texas Southwestern Medical CenterDallasTX
| | - Andrea Delle Vedove
- Institute of Human Genetics, Center for Molecular Medicine CologneCologneGermany
- Institute for GeneticsUniversity of CologneCologneGermany
| | - Markus Storbeck
- Institute of Human Genetics, Center for Molecular Medicine CologneCologneGermany
- Institute for GeneticsUniversity of CologneCologneGermany
| | - Yun Liu
- Department of NeuroscienceUniversity of Texas Southwestern Medical CenterDallasTX
| | - Stephanie Efthymiou
- Department of Molecular Neuroscience, Institute of NeurologyUniversity College London Institute of NeurologyLondonUnited Kingdom
| | - Andreea Manole
- Department of Molecular Neuroscience, Institute of NeurologyUniversity College London Institute of NeurologyLondonUnited Kingdom
| | - Sarah Wiethoff
- Department of Molecular Neuroscience, Institute of NeurologyUniversity College London Institute of NeurologyLondonUnited Kingdom
| | - Qiaohong Ye
- Department of NeuroscienceUniversity of Texas Southwestern Medical CenterDallasTX
| | - Anand Saggar
- St George's Hospital, National Health Service Foundation TrustLondonUnited Kingdom
| | | | - Shyam S. Krishnakumar
- Department of Cell BiologyYale School of MedicineNew HavenCT
- Department of Clinical and Experimental EpilepsyUniversity College London Institute of NeurologyLondonUnited Kingdom
| | | | - Matthew Pitt
- Department of Clinical NeurophysiologyGreat Ormond Street Hospital for Children, National Health Service Foundation TrustLondonUnited Kingdom
| | - Oscar D. Bello
- Department of Cell BiologyYale School of MedicineNew HavenCT
- Department of Clinical and Experimental EpilepsyUniversity College London Institute of NeurologyLondonUnited Kingdom
| | - James E. Rothman
- Department of Cell BiologyYale School of MedicineNew HavenCT
- Department of Clinical and Experimental EpilepsyUniversity College London Institute of NeurologyLondonUnited Kingdom
| | - Lina Basel‐Vanagaite
- Pediatric Genetics Unit, Schneider Children's Medical Center of IsraelPetach TikvaIsrael
- Raphael Recanati Genetic Institute, Rabin Medical CenterPetach TikvaIsrael
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Monika Weisz Hubshman
- Pediatric Genetics Unit, Schneider Children's Medical Center of IsraelPetach TikvaIsrael
- Raphael Recanati Genetic Institute, Rabin Medical CenterPetach TikvaIsrael
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Sharon Aharoni
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
- Institute of Child Neurology, Schneider Children's Medical Center of IsraelPetach TikvaIsrael
| | - Adnan Y. Manzur
- Department of Pediatric NeurologyDubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children National Health Service Foundation TrustLondonUnited Kingdom
| | - Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine CologneCologneGermany
| | - Henry Houlden
- Department of Molecular Neuroscience, Institute of NeurologyUniversity College London Institute of NeurologyLondonUnited Kingdom
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