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Ziaadini B, Ghaderi Yazdi B, Dirandeh E, Boostani R, Karimi N, Panahi A, Kariminejad A, Fadaee M, Ahangari F, Nafissi S. DOK7 congenital myasthenic syndrome: case series and review of literature. BMC Neurol 2024; 24:211. [PMID: 38907197 PMCID: PMC11191154 DOI: 10.1186/s12883-024-03713-0] [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: 12/15/2023] [Accepted: 06/05/2024] [Indexed: 06/23/2024] Open
Abstract
BACKGROUND Congenital myasthenic syndromes (CMS) are among the most challenging differential diagnoses in the neuromuscular domain, consisting of diverse genotypes and phenotypes. A mutation in the Docking Protein 7 (Dok-7) is a common cause of CMS. DOK7 CMS requires different treatment than other CMS types. Regarding DOK7's special considerations and challenges ahead of neurologists, we describe seven DOK7 patients and evaluate their response to treatment. METHODS The authors visited these patients in the neuromuscular clinics of Tehran and Kerman Universities of Medical Sciences Hospitals. They diagnosed these patients based on clinical findings and neurophysiological studies, which Whole Exome Sequencing confirmed. For each patient, we tried unique medications and recorded the clinical response. RESULTS The symptoms started from birth to as late as the age of 33, with the mean age of onset being 12.5. Common symptoms were: Limb-girdle weakness in 6, fluctuating symptoms in 5, ptosis in 4, bifacial weakness in 3, reduced extraocular movement in 3, bulbar symptoms in 2 and dyspnea in 2 3-Hz RNS was decremental in 5 out of 6 patients. Salbutamol was the most effective. c.1124_1127dupTGCC is the most common variant; three patients had this variant. CONCLUSION We strongly recommend that neurologists consider CMS in patients with these symptoms and a similar familial history. We recommend prescribing salbutamol as the first-choice treatment option for DOK7 patients.
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Affiliation(s)
- Bentolhoda Ziaadini
- Neurology Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Bardyia Ghaderi Yazdi
- Neuromuscular Research Center, Shariati Hospital, Tehran University of Medical Sciences, Shariati Hospital, North Karegar St, Tehran, 14117-13135, Iran
- Department of Neurology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Elham Dirandeh
- Clinical Research Development Unit, Kowsar Educational, Research and Therapeutic Hospital, Semnan University of Medical Sciences, Semnan, Iran
| | - Reza Boostani
- Department of Neurology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Narges Karimi
- Department of Neurology, School of Medicine, Immunogenetics Research Center, Toxoplasmosis Research Center, Clinical Research Development Unit of Bou Ali Sina Hospital, Mazandaran University of Medical Sciences, Sari, Iran
| | - Akram Panahi
- Neuromuscular Research Center, Shariati Hospital, Tehran University of Medical Sciences, Shariati Hospital, North Karegar St, Tehran, 14117-13135, Iran
- Department of Neurology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Mahsa Fadaee
- Kariminejad-Najmabadi Pathology & Genetics Center, Tehran, Iran
| | | | - Shahriar Nafissi
- Neuromuscular Research Center, Shariati Hospital, Tehran University of Medical Sciences, Shariati Hospital, North Karegar St, Tehran, 14117-13135, Iran.
- Department of Neurology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
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Batheja A, Bayer-Vile J, Silverstein E, Couser N. Congenital Myasthenic Syndrome associated with acetylcholine receptor deficiency: case report and review of the literature. Ophthalmic Genet 2024:1-7. [PMID: 38832364 DOI: 10.1080/13816810.2024.2352391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 05/02/2024] [Indexed: 06/05/2024]
Abstract
INTRODUCTION Congenital Myasthenic Syndromes are a diverse group of conditions with a broad array of genetic underpinnings and phenotypic presentations. Acetylcholine receptor deficiency is one form that usually involves pathogenic variants in the Cholinergic Receptor Nicotinic Epsilon Subunit (CHRNE) gene encoding the ɛ-subunit of the acetylcholine receptor. METHODS We report a case of a 4-year-old male with suspected Congenital Myasthenic Syndrome with Acetylcholine Receptor Deficiency who presented with ocular symptoms and generalized muscle weakness. We additionally summarize published findings regarding the genetic, phenotypic, and clinical considerations of Congenital Myasthenic Syndrome with Acetylcholine Receptor Deficiency. RESULTS Exome sequencing revealed biallelic variants in CHRNE gene with a pathogenic frameshift variant and a variant of uncertain significance. After suboptimal response to pyridostigmine and albuterol, the patient experienced benefit with 3,4-DAP. The most commonly reported clinical characteristics in the literature are ptosis, muscle fatigability or weakness, and ophthalmoplegia. CONCLUSION We present the case of a patient with biallelic variants in CHRNE gene including a variant of uncertain significance. Evaluation of variants of this gene, including the variant of uncertain significance identified in this case report, through further cases and studies may improve our understanding of Congenital Myasthenic Syndrome with Acetylcholine Receptor deficiency.
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Affiliation(s)
- Aashish Batheja
- School of Medicine, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Julie Bayer-Vile
- Department of Pediatrics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Evan Silverstein
- Department of Ophthalmology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Natario Couser
- Department of Pediatrics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
- Department of Ophthalmology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
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Mackels L, Servais L. The Importance of Early Treatment of Inherited Neuromuscular Conditions. J Neuromuscul Dis 2024; 11:253-274. [PMID: 38306060 DOI: 10.3233/jnd-230189] [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] [Indexed: 02/03/2024]
Abstract
There has been tremendous progress in treatment of neuromuscular diseases over the last 20 years, which has transformed the natural history of these severely debilitating conditions. Although the factors that determine the response to therapy are many and in some instance remain to be fully elucidated, early treatment clearly has a major impact on patient outcomes across a number of inherited neuromuscular conditions. To improve patient care and outcomes, clinicians should be aware of neuromuscular conditions that require prompt treatment initiation. This review describes data that underscore the importance of early treatment of children with inherited neuromuscular conditions with an emphasis on data resulting from newborn screening efforts.
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Affiliation(s)
- Laurane Mackels
- MDUK Oxford Neuromuscular Centre, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- Adult Neurology Department, Citadelle Hospital, Liège, Belgium
| | - Laurent Servais
- Neuromuscular Centre, Division of Paediatrics, University and University Hospital of Liège, Liège, Belgium
- MDUK Oxford Neuromuscular Centre, Department of Paediatrics, University of Oxford & NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
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Mukhtiar K, Raza M, Tejani I, Ali F, Ibrahim S. Diagnostic dilemmas and challenges in the management of myasthenia in infants and toddlers: A case report. SAGE Open Med Case Rep 2023; 11:2050313X231211047. [PMID: 38022851 PMCID: PMC10631333 DOI: 10.1177/2050313x231211047] [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] [Received: 07/05/2023] [Accepted: 10/12/2023] [Indexed: 12/01/2023] Open
Abstract
Myasthenia in the infancy and toddler age group is rare and often presents a challenge to treating pediatric neurologists. Our report addresses the challenges encountered when distinguishing myasthenia in infants and toddlers from similar illnesses, as well as the differentiation between congenital myasthenia, transient myasthenia, and autoimmune myasthenia. We present four cases of myasthenia between the ages of 10 and 30 months. The diagnosis and management of these cases were challenging due to the variability in clinical presentation. Four cases of myasthenia were diagnosed, with three having autoimmune myasthenia and one having congenital myasthenic syndrome. One patient initially tested negative for acetylcholine receptor antibodies, but later tested positive after 4 months and had a rare facial diplegia finding. The patient with congenital myasthenic syndrome had a novel genetic mutation, DPAGT1 homozygous variants, and also had false positive acetylcholine receptor antibodies. These cases highlight the importance of genetic testing for all infants and toddlers suspected of having myasthenia.
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Affiliation(s)
- Khairunnisa Mukhtiar
- Department of Pediatrics & Child Health, Section of Pediatric Neurology, Aga Khan University Hospital, Karachi, Pakistan
| | - Mohammad Raza
- Department of Pediatrics & Child Health, Section of Pediatric Neurology, Aga Khan University Hospital, Karachi, Pakistan
| | | | - Farhan Ali
- Department of Pediatrics & Child Health, Section of Pediatric Neurology, Aga Khan University Hospital, Karachi, Pakistan
| | - Shahnaz Ibrahim
- Department of Pediatrics & Child Health, Section of Pediatric Neurology, Aga Khan University Hospital, Karachi, Pakistan
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Kaya O, Kirik S. Can Scoliosis Help the Early Diagnosis of Congenital Myasthenic Syndrome? Cureus 2023; 15:e45875. [PMID: 37766777 PMCID: PMC10520996 DOI: 10.7759/cureus.45875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/24/2023] [Indexed: 09/29/2023] Open
Abstract
Background Congenital myasthenic syndromes (CMS) are a group of hereditary diseases of the neuromuscular junction. CMS are extremely rare diseases that cause hypotonia; however, scoliosis may theoretically be helpful in early diagnosis of CMS. The objective of this study was to emphasize the clinical features of the patients we followed up with the diagnosis of CMS and demonstrate that scoliosis is an important finding in the diagnosis of CMS in the presence of hypotonia/weakness. Materials and methods In this retrospective study, data were retrieved by examining the digital files of the patients who presented to Aydın Maternity and Children's Hospital and Elazığ Fethi Sekin City Hospital Pediatric Neurology Clinics between 2018 and 2023. The diagnosis of CMS was strongly supported by a combination of clinical characteristics, neurophysiological studies, genetic tests, AChR antibodies, and serum creatine kinase measurement. The presence of scoliosis was evaluated by an orthopedics and traumatology specialist. Results Eleven CMS patients with accompanying scoliosis were included in the study. The mean age of the patients was 69.4±39.28 months. The age of the patients at the time of diagnosis was 42.7±35.19 months. Among the patients, eight were males (72.7%), and three were females (27.2%). Seven patients (63.6%) had COLQ mutations. Electromyography was conducted on eight patients, with one of them showing no pathological findings, while seven exhibited decremental responses. All patients had ptosis, while six (54.5%) had bulbar signs. Ten patients (90.9%) had weakness. Nine patients (81.8%) experienced frequent recurrent lower respiratory tract infections. Both the patient with CHAT mutation and RAPSN mutation had arthrogryposis. Conclusion In this study, CMS stands out as an essential consideration in the differential diagnosis, particularly when scoliosis accompanies early-onset muscle weakness.
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Affiliation(s)
- Oğuz Kaya
- Orthopaedics and Traumatology, Elazığ Fethi Sekin City Hospital, Elazığ, TUR
| | - Serkan Kirik
- Pediatric Neurology, Fırat University School of Medicine, Elazığ, TUR
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Horibe T, Shimomura H, Tokunaga S, Taniguchi N, Lee T, Kimura S, Takeshima Y. A Pediatric Case of COLQ-Related Congenital Myasthenic Syndrome with Marked Fatigue. CHILDREN (BASEL, SWITZERLAND) 2023; 10:children10050769. [PMID: 37238317 DOI: 10.3390/children10050769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023]
Abstract
Congenital myasthenic syndrome (CMS) is a clinically and genetically heterogeneous inherited disorder that is treatable. Although the disease usually develops at birth or during infancy, some patients develop the disease in the second to third decades of life. Collagen-like tail subunit of asymmetric acetylcholinesterase (COLQ)-related CMS is CMS with mutations in the COLQ, which results in end-plate acetylcholinesterase deficiency. Diagnostic delay is common in patients with later-onset CMS due to slow progression and fluctuating symptoms. Understanding CMS with atypical and unusual presentations is important to treat this condition effectively. Here, we report a case of COLQ-related CMS. A 10-year-old girl presented with only marked fatigue, which was provoked by exercise but improved after 30-60 min of rest. While motor nerve conduction velocity was normal, a compound muscle action potential (CMAP) with four peaks was recorded. Repetitive stimulation of the accessory nerve exhibited a decrease in CMAP amplitude. Genetic tests revealed compound heterozygous mutations in COLQ (c.1196-1_1197delinsTG and c.1354C>T). Treatment with salbutamol improved fatigue but not the electrophysiological markers. Thus, significant fatigue is a hallmark of COLQ-related CMS; early diagnosis is essential for ensuring appropriate treatment.
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Affiliation(s)
- Takuya Horibe
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Hideki Shimomura
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Sachi Tokunaga
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Naoko Taniguchi
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Tomoko Lee
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Shigemi Kimura
- Children's Rehabilitation, Sleep and Development Medical Center, Hyogo Prefectural Rehabilitation Central Hospital, Kobe 651-2134, Japan
| | - Yasuhiro Takeshima
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
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Zhang Q, Sha Q, Qiao K, Liu X, Gong X, Du A. Two patients with congenital myasthenic syndrome caused by COLQ gene mutations and the consequent ColQ protein defect. Heliyon 2023; 9:e13272. [PMID: 36798769 PMCID: PMC9925971 DOI: 10.1016/j.heliyon.2023.e13272] [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] [Received: 08/06/2022] [Revised: 12/12/2022] [Accepted: 01/24/2023] [Indexed: 01/27/2023] Open
Abstract
Objective To report two cases of congenital myasthenic syndromes (CMS) in a Chinese family with mutations in the COLQ gene and to prove the consequence defect of the ColQ protein. Method Clinical characteristics of the two children from the same family were described. Next-generation sequencing (NGS) and sanger sequencing was performed on the proband and family members. The consequence of the mutation was predicted by 3D protein structure prediction using I-TASSER. The wild type and mutant were transfected to 293T cells, and ColQ protein was detected by Western Blot. Results The diagnosis of CMS was based on a symptom combination of fatigable muscle weakness, ptosis, scoliosis, and hypotonia, aggravation of muscle weakness after the neostigmine test, and a 46% decrement in repetitive nerve stimulation. A muscle biopsy was performed on the proband, revealing mild variation in the myofiber size. NGS data revealed two compound heterozygous mutations at c.173delC (p.Pro58Hisfs*22) and c.C706T (p.R236X) in the COLQ gene, where the former was a novel mutation. A 3D structure prediction showed two truncated ColQ proteins with 78aa and 235aa, respectively. The truncated ColQ protein was proved in 293T cells transfected with c.173delC or c.C706T mutants by Western Blot. Conclusions The mutations of c.173delC and c.C706T in the COLQ gene led to truncated ColQ protein and contributed to the pathogenesis of CMS in this Chinese family.
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Affiliation(s)
- Qiting Zhang
- Department of Neurology, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200336, China
| | - Qianqian Sha
- Department of Neurology, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200336, China
| | - Kai Qiao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Xiaoli Liu
- Department of Neurology, Shanghai Fengxian District Central Hospital, Shanghai Jiao Tong University Affiliated Sixth People's Hospital South Campus, Shanghai, 201406, China
| | - Xiaohui Gong
- Department of Neonatology, Shanghai Children's Hospital, Shanghai, 200062, China
- Corresponding author.
| | - Ailian Du
- Department of Neurology, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200336, China
- Corresponding author.
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Stojkovic T, Masingue M, Turmel H, Hezode-Arzel M, Béhin A, Leonard-Louis S, Bassez G, Bauché S, Blondy P, Richard P, Sternberg D, Eymard B, Fournier E, Villar-Quiles RN. Diagnostic yield of a practical electrodiagnostic protocol discriminating between different congenital myasthenic syndromes. Neuromuscul Disord 2022; 32:870-878. [PMID: 36522822 DOI: 10.1016/j.nmd.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/28/2022] [Accepted: 10/02/2022] [Indexed: 11/07/2022]
Abstract
Congenital myasthenic syndromes (CMS) are a group of heterogeneous diseases of the neuromuscular junction. We report electrodiagnostic testing (EDX) and genetic findings in a series of 120 CMS patients tested with a simple non-invasive EDX workup with surface recording of CMAPs and 3Hz repetitive nerve stimulation of accessory, radial and deep fibular nerves. Five ENMG phenotypes were retrieved based on the presence or not of R-CMAPs and the distribution pattern of decremental CMAP responses which significantly correlated with genetic findings (p <0.00001). R-CMAPs were found in all COLQ-mutated patients (CMS1A) and Slow Channel CMS (SCCMS) (CMS1B). CMS1A exhibited greater decrements in accessory nerve RNS than CMS1B. Patients without R-CMAPs were classified into CMS2A (DOK7-, MUSK-, GFPT1-, GMPPB-, TOR1AIP-mutated) when exhibiting predominant accessory nerve RNS decrements, CMS2B (CHRNE, CHRND, RAPSN) with predominant radial nerve RNS decrements, or CMS2C (AGRN) if there were predominant fibular decrements. Our algorithm may have a major impact on diagnostic and therapeutic monitoring in CMS patients, as well as for validation of the pathogenicity of genetic variants. It should also be part of the evaluation of unexplained muscle weakness or complex neuromuscular phenotypes.
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Affiliation(s)
- Tanya Stojkovic
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France; Centre de Recherche en Myologie, Sorbonne Université-Inserm UMRS974, Paris, France
| | - Marion Masingue
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Helène Turmel
- Department of Neurophysiology, APHP, Pitié Salpetrière hospital, Paris, France
| | | | - Anthony Béhin
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Sarah Leonard-Louis
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Guillaume Bassez
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France; Centre de Recherche en Myologie, Sorbonne Université-Inserm UMRS974, Paris, France
| | - Stéphanie Bauché
- Centre de Recherche en Myologie, Sorbonne Université-Inserm UMRS974, Paris, France
| | - Patricia Blondy
- National Reference Center for Muscle Channelopathies, APHP, Pitié Salpetrière hospital, Paris, France; Biochemistry Department, Center of Molecular and Cellular Genetics, APHP, Pitié Salpetrière hospital, Paris, France
| | - Pascale Richard
- Biochemistry Department, Center of Molecular and Cellular Genetics, APHP, Pitié Salpetrière hospital, Paris, France
| | - Damien Sternberg
- National Reference Center for Muscle Channelopathies, APHP, Pitié Salpetrière hospital, Paris, France; Biochemistry Department, Center of Molecular and Cellular Genetics, APHP, Pitié Salpetrière hospital, Paris, France
| | - Bruno Eymard
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Emmanuel Fournier
- Department of Neurophysiology, APHP, Pitié Salpetrière hospital, Paris, France; National Reference Center for Muscle Channelopathies, APHP, Pitié Salpetrière hospital, Paris, France; Department of Physiology, Sorbonne University, Faculté de médecine Pitié-Salpêtrière, Paris, France
| | - Rocío Nur Villar-Quiles
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France; Centre de Recherche en Myologie, Sorbonne Université-Inserm UMRS974, Paris, France
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Study on the Potential Mechanism of Semen Strychni against Myasthenia Gravis Based on Network Pharmacology and Molecular Docking with Experimental Verification. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:3056802. [PMID: 36217431 PMCID: PMC9547686 DOI: 10.1155/2022/3056802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/19/2022] [Indexed: 11/07/2022]
Abstract
Background Semen Strychni (SS) is an effective Chinese medicine formula for treating myasthenia gravis (MG) in clinics. Nonetheless, its molecular mechanism is largely unknown. Objective Using network pharmacology, molecular docking, and experimental validation, we aim to identify the therapeutic effect of SS on MG and its underlying mechanism. Methods The main ingredients of SS and their targets and potential disease targets for MG were extracted from public databases. The protein-protein interaction (PPI) network was constructed using the STRING 11.0 database, and Cytoscape was used to identify the hub targets. In addition, Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to identify molecular biological processes and signaling pathways. Then, AutoDock Via conducted molecular docking. The experimental autoimmune myasthenia gravis (EAMG) model in female Lewis rats, quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and enzyme-linked immunosorbent assay (ELISA) were performed to confirm the effect and mechanism of SS on MG. Results The following active compounds and hub targets were identified by screening and analyzing: isobrucine, vomicine, (S)-stylopine, strychnine, brucine-N-oxide, brucine and AKT1, MAPK1, MAPK14, CHRM1, ACHE, and CHRNA4. KEGG enrichment analyses indicated that the cholinergic synapse and neuroactive ligand-receptor interaction signaling pathway may be necessary. The results of molecular docking revealed that the main active ingredients bind well to the hub targets. In vivo experiments proved that SS could improve the weight loss and Lennon scores in the EAMG model. Experiments in molecular biology showed that SS could treat MG by affecting the cholinergic synapse through the respective antibody, receptor, and key enzymes in the cholinergic pathway. Conclusion This study provided a preliminary overview of the active constituents, primary targets, and potential pathways of SS against MG. SS ameliorated EAMG by regulating the cholinergic synaptic junction.
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Gómez-García de la Banda M, Simental-Aldaba E, Fahmy N, Sternberg D, Blondy P, Quijano-Roy S, Malfatti E. Case Report: A Novel AChR Epsilon Variant Causing a Clinically Discordant Salbutamol Responsive Congenital Myasthenic Syndrome in Two Egyptian Siblings. Front Neurol 2022; 13:909715. [PMID: 35720108 PMCID: PMC9201482 DOI: 10.3389/fneur.2022.909715] [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: 03/31/2022] [Accepted: 05/02/2022] [Indexed: 12/05/2022] Open
Abstract
Congenital myasthenic syndromes (CMS) are inherited disorders that lead to abnormal neuromuscular transmission. Post-synaptic mutations are the main cause of CMS, particularly mutations in CHRNE. We report a novel homozygous CHRNE pathogenic variant in two Egyptian siblings showing a CMS. Interestingly, they showed different degrees of extraocular and skeletal muscle involvement; both presented only a partial response to cholinesterase inhibitors, and rapidly and substantially ameliorated after the addition of oral β2 adrenergic agonists. Here, we enlarge the genetic spectrum of CHRNE-related congenital myasthenic syndromes and highlight the importance of a β2 adrenergic agonists treatment.
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Affiliation(s)
- Marta Gómez-García de la Banda
- Pediatric Neurology and ICU Department, AP-HP Université Paris Saclay, Hôpital Raymond Poincaré, Garches, France
- Reference Center for Neuromuscular Diseases Centre “Nord- Est- Ile de France”, FILNEMUS, Creteil, France
- European Reference Center Network (Euro-NMD ERN), Paris, France
| | - Emmanuel Simental-Aldaba
- APHP, Centre de Référence de Pathologie Neuromusculaire Nord-Est-Ile-de-France, Henri Mondor University Hospital, Créteil, France
- Department of Neurorehabilitation, Instituto Nacional de Rehabilitación “LGII”, Mexico City, Mexico
| | - Nagia Fahmy
- Neuromuscular Unit, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Damien Sternberg
- European Reference Center Network (Euro-NMD ERN), Paris, France
- Service de Biochimie Métabolique, Centre de Génétique, Groupe Hospitalier Pitié-Salpêtrière, APHP Sorbonne Université, Paris, France
| | - Patricia Blondy
- European Reference Center Network (Euro-NMD ERN), Paris, France
| | - Susana Quijano-Roy
- Pediatric Neurology and ICU Department, AP-HP Université Paris Saclay, Hôpital Raymond Poincaré, Garches, France
- Reference Center for Neuromuscular Diseases Centre “Nord- Est- Ile de France”, FILNEMUS, Creteil, France
- European Reference Center Network (Euro-NMD ERN), Paris, France
- Centre de Recherche en Myologie, UMRS974, Paris, France
| | - Edoardo Malfatti
- Reference Center for Neuromuscular Diseases Centre “Nord- Est- Ile de France”, FILNEMUS, Creteil, France
- APHP, Centre de Référence de Pathologie Neuromusculaire Nord-Est-Ile-de-France, Henri Mondor University Hospital, Créteil, France
- Univ Paris Est Créteil, INSERM, IMRB, Créteil, France
- AP-HP, Hôpital Mondor, Service d'histologie, Créteil, France
- *Correspondence: Edoardo Malfatti
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Abstract
The patient had suffered from both proximal and distal limb weakness since her early childhood, without the involvement of ocular or respiratory muscles. Repetitive nerve stimulation (RNS) at 3 Hz showed significant decrement in the area and amplitude of the compound muscle action potential (CMAP) on the right abductor digiti minimi (26%) and trapezius (17%). Whole-exon sequencing revealed two novel heterozygous mutations (p.Q1406Rfs*29 and p.R1521H) in the LG1 domain of agrin, which were deemed likely pathogenic for congenital myasthenic syndromes (CMS) according to a bioinformatics analysis. The patient showed remarkable improvement after treatment with salbutamol. This case expanded the mutation spectrum of AGRN.
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Affiliation(s)
- Ping Xia
- Department of Neurology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, China
| | - Fei Xie
- Department of Neurology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, China
| | - Zhi-Jie Zhou
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, China
| | - Wen Lv
- Department of Neurology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, China
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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: 2.0] [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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Saito M, Ogasawara M, Inaba Y, Osawa Y, Nishioka M, Yamauchi S, Atsumi K, Takeuchi S, Imai K, Motobayashi M, Misawa Y, Iida A, Nishino I. Successful treatment of congenital myasthenic syndrome caused by a novel compound heterozygous variant in RAPSN. Brain Dev 2022; 44:50-55. [PMID: 34565654 DOI: 10.1016/j.braindev.2021.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/29/2021] [Accepted: 09/05/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Congenital myasthenic syndrome (CMS) is a clinically and genetically heterogeneous neuromuscular disorder characterized by muscle weakness and caused by mutations in more than 35 different genes. This condition should not be overlooked as a subset of patients with CMS are treatable. However, the diagnosis of CMS is often difficult due to the broad variability in disease severity and course. CASE REPORT A five-year-old boy without remarkable family history was born with marked general muscle hypotonia and weakness, respiratory insufficiency, anomalies, and multiple joint contractures. Congenital myopathy was suspected based upon type 1 fiber predominance on muscle biopsy. However, he was diagnosed with CMS at age 4 years when his ptosis and ophthalmoplegia were found to be improved by edrophonium chloride and repetitive nerve stimulation showed attenuation of compound muscle action potentials. An exome sequencing identified a compound heterozygous missense variant of c.737C > T (p.A246V) and a novel intronic insertion c.1166 + 4_1166 + 5insAAGCCCACCAC in RAPSN. RT-PCR analysis which showed the skipping of exon 7 in a skeletal muscle sample confirmed that the intronic insertion was pathogenic. His myasthenic symptoms were remarkably improved by pyridostigmine. CONCLUSION The patient's diagnosis of CMS was confirmed by exome sequencing, and RT-PCR revealed that the skipping of exon 7 in RAPSN was caused by a novel intronic insertion. The genetic information uncovered in this case should therefore be added to the collection of tools for diagnosing and treating CMS.
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Affiliation(s)
- Maki Saito
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Masashi Ogasawara
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan; Medical Genome Center, NCNP, Kodaira, Tokyo, Japan
| | - Yuji Inaba
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan; Life Science Research Center, Nagano Children's Hospital, Azumino, Japan.
| | - Yoshihiro Osawa
- Department of Pediatrics, Iida Municipal Hospital, Iida, Japan
| | - Makoto Nishioka
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan; Life Science Research Center, Nagano Children's Hospital, Azumino, Japan
| | - Shoko Yamauchi
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Kana Atsumi
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Shihoko Takeuchi
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Ken Imai
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Mitsuo Motobayashi
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan; Life Science Research Center, Nagano Children's Hospital, Azumino, Japan
| | - Yuka Misawa
- Division of Rehabilitation, Nagano Children's Hospital, Azumino, Japan
| | | | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan; Medical Genome Center, NCNP, Kodaira, Tokyo, Japan
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14
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Avrutsky MI, Troy CM. Caspase-9: A Multimodal Therapeutic Target With Diverse Cellular Expression in Human Disease. Front Pharmacol 2021; 12:701301. [PMID: 34305609 PMCID: PMC8299054 DOI: 10.3389/fphar.2021.701301] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/28/2021] [Indexed: 11/22/2022] Open
Abstract
Caspase-9, a cysteine-aspartic protease known for its role as an initiator of intrinsic apoptosis, regulates physiological cell death and pathological tissue degeneration. Its nonapoptotic functions, including regulation of cellular differentiation/maturation, innate immunity, mitochondrial homeostasis, and autophagy, reveal a multimodal landscape of caspase-9 functions in health and disease. Recent work has demonstrated that caspase-9 can drive neurovascular injury through nonapoptotic endothelial cell dysfunction. CASP9 polymorphisms have been linked with various cancers, neurological disorders, autoimmune pathologies and lumbar disc disease. Clinical reports suggest alterations in caspase-9 expression, activity or function may be associated with acute and chronic neurodegeneration, retinal neuropathy, slow-channel myasthenic syndrome, lumbar disc disease, cardiomyopathies, atherosclerosis and autoimmune disease. Healthy tissues maintain caspase-9 activity at low basal levels, rendering supraphysiological caspase-9 activation a tractable target for therapeutic interventions. Strategies for selective inhibition of caspase-9 include dominant negative caspase-9 mutants and pharmacological inhibitors derived from the XIAP protein, whose Bir3 domain is an endogenous highly selective caspase-9 inhibitor. However, the mechanistic implications of caspase-9 expression and activation remain indeterminate in many pathologies. By assembling clinical reports of caspase-9 genetics, signaling and cellular localization in human tissues, this review identifies gaps between experimental and clinical studies on caspase-9, and presents opportunities for further investigations to examine the consequences of caspase activity in human disease.
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Affiliation(s)
- Maria I Avrutsky
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Carol M Troy
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States.,Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States.,The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
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15
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Prior DE, Ghosh PS. Congenital Myasthenic Syndrome From a Single Center: Phenotypic and Genotypic features. J Child Neurol 2021; 36:610-617. [PMID: 33471587 DOI: 10.1177/0883073820987755] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Congenital myasthenic syndrome is a group of rare genetic disorders affecting transmission across the neuromuscular junction. Patients present with variable ocular, bulbar, respiratory, and extremity weakness that may respond to symptomatic therapies. METHODS We identified 18 patients with congenital myasthenic syndrome from a pediatric neuromuscular center over a decade. Through a retrospective chart review, we characterize demographic profile, clinical features, genetic variants, treatment, and follow-up of these patients. RESULTS Patients had the following genetic subtypes: CHRNE (6), CHAT (2), MUSK (2), DOK7 (2), COLQ (1), RAPSN (1), PREPL (1), GFPT1 (1), CHRBB1 (1), and CHRNA1 (1). The phenotype varied based on the genetic variants, though most patients have generalized fatigable weakness affecting ocular, bulbar, and extremity muscles. There was a significant delay in the diagnosis of this condition from the onset of symptoms. Although most patients improved with pyridostigmine, some subtypes showed worsening with pyridostigmine and others benefited from albuterol, ephedrine, or 3,4-diaminopyridine treatment. CONCLUSION Increasing recognition of this rare syndrome will lead to early diagnosis and prompt treatment. Prompt utilization of genetic testing will identify novel variants and the expanding phenotype of this condition.
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Affiliation(s)
- Devin E Prior
- Department of Neurology, 2094Mount Auburn Hospital, Cambridge, MA, USA.,Department of Neurology, 1862Boston Children's Hospital, Boston MA, USA
| | - Partha S Ghosh
- Department of Neurology, 1862Boston Children's Hospital, Boston MA, USA
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16
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Inherited Neuromuscular Disorders: Which Role for Serum Biomarkers? Brain Sci 2021; 11:brainsci11030398. [PMID: 33801069 PMCID: PMC8004068 DOI: 10.3390/brainsci11030398] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/08/2021] [Accepted: 03/18/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited neuromuscular disorders (INMD) are a heterogeneous group of rare diseases that involve muscles, motor neurons, peripheral nerves or the neuromuscular junction. Several different lab abnormalities have been linked to INMD: sometimes they are typical of the disorder, but they usually appear to be less specific. Sometimes serum biomarkers can point out abnormalities in presymtomatic or otherwise asymptomatic patients (e.g., carriers). More often a biomarker of INMD is evaluated by multiple clinicians other than expert in NMD before the diagnosis, because of the multisystemic involvement in INMD. The authors performed a literature search on biomarkers in inherited neuromuscular disorders to provide a practical approach to the diagnosis and the correct management of INMD. A considerable number of biomarkers have been reported that support the diagnosis of INMD, but the role of an expert clinician is crucial. Hence, the complete knowledge of such abnormalities can accelerate the diagnostic workup supporting the referral to specialists in neuromuscular disorders.
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17
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François-Heude MC, Walther-Louvier U, Espil-Taris C, Beze-Beyrie P, Rivier F, Baudou E, Uro-Coste E, Rigau V, Martin Negrier ML, Rendu J, Morales RJ, Pégeot H, Thèze C, Lacourt D, Coville AC, Cossée M, Cances C. Evaluating next-generation sequencing in neuromuscular diseases with neonatal respiratory distress. Eur J Paediatr Neurol 2021; 31:78-87. [PMID: 33667896 DOI: 10.1016/j.ejpn.2021.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/18/2020] [Accepted: 01/19/2021] [Indexed: 02/09/2023]
Abstract
With the exception of infantile spinal muscular atrophy (SMA) and congenital myotonic dystrophy 1 (DM1), congenital myopathies and muscular dystrophies with neonatal respiratory distress pose diagnostic challenges. Next-generation sequencing (NGS) provides hope for the diagnosis of these rare diseases. We evaluated the efficiency of next-generation sequencing (NGS) in ventilated newborns with peripheral hypotonia. We compared the results of our previous study in a cohort of 19 patients analysed by Sanger sequencing from 2007 to 2012, with a diagnostic yield of 26% (5/19), and those of a new retrospective study in 28 patients from 2007 to 2018 diagnosed using MyoPanel, a neuromuscular disease panel, with a diagnostic yield of 43% (12/28 patients). Pathogenic variants were found in five genes: ACTA1 (n = 4 patients), RYR1 (n = 2), CACNA1S (n = 1), NEB (n = 3), and MTM1 (n = 2). Myopanel increased the diagnosis of congenital neuromuscular diseases, but more than half the patients remained undiagnosed. Whole exome sequencing did not seem to fully respond to this diagnostic limitation. Therefore, explorations with whole genome sequencing will be the next step.
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Affiliation(s)
- Marie-Céline François-Heude
- AOC (Atlantique-Occitanie-Caraïbe) Reference Centre for Neuromuscular Disorders, Neuropaediatric Department, Toulouse University Hospital, Toulouse, France
| | - Ulrike Walther-Louvier
- AOC (Atlantique-Occitanie-Caraïbe) Reference Centre for Neuromuscular Disorders, Neuropaediatric Department, Montpellier University Hospital, Montpellier, France
| | - Caroline Espil-Taris
- AOC (Atlantique-Occitanie-Caraïbe) Reference Centre for Neuromuscular Disorders, Neuropaediatric Department, Bordeaux University Hospital, Aquitaine, France
| | | | - François Rivier
- AOC (Atlantique-Occitanie-Caraïbe) Reference Centre for Neuromuscular Disorders, Neuropaediatric Department, Montpellier University Hospital, Montpellier, France
| | - Eloise Baudou
- AOC (Atlantique-Occitanie-Caraïbe) Reference Centre for Neuromuscular Disorders, Neuropaediatric Department, Toulouse University Hospital, Toulouse, France
| | - Emmanuelle Uro-Coste
- Department of Pathology, Toulouse University Hospital, Toulouse, France; INSERM U1037, Cancer Research Centre of Toulouse (CRCT), Toulouse, France
| | - Valérie Rigau
- AOC (Atlantique-Occitanie-Caraïbe) Reference Centre for Neuromuscular Disorders, Aquitaine, France; Department of Pathology, Centre Hospitalier Universitaire Montpellier, Montpellier, France
| | | | - John Rendu
- INSERM U1216, Grenoble Alpes University Hospital, University of Grenoble Alpes, Grenoble, France
| | - Raul Juntas Morales
- Laboratory of Rare Genetic Diseases (LGMR), University of Montpellier, Montpellier, France
| | - Henri Pégeot
- Molecular Genetics Laboratory, Montpellier University Hospital Centre, Montpellier, France
| | - Corinne Thèze
- Molecular Genetics Laboratory, Montpellier University Hospital Centre, Montpellier, France
| | - Delphine Lacourt
- Molecular Genetics Laboratory, Montpellier University Hospital Centre, Montpellier, France
| | - Anne Cécile Coville
- AOC (Atlantique-Occitanie-Caraïbe) Reference Centre for Neuromuscular Disorders, Neuropaediatric Department, Toulouse University Hospital, Toulouse, France
| | - Mireille Cossée
- Laboratory of Rare Genetic Diseases (LGMR), University of Montpellier, Montpellier, France; Molecular Genetics Laboratory, Montpellier University Hospital Centre, Montpellier, France
| | - Claude Cances
- AOC (Atlantique-Occitanie-Caraïbe) Reference Centre for Neuromuscular Disorders, Neuropaediatric Department, Toulouse University Hospital, Toulouse, France.
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18
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Tawara N, Yamashita S, Takamatsu K, Yamasaki Y, Mukaino A, Nakane S, Farshadyeganeh P, Ohno K, Ando Y. Efficacy of salbutamol monotherapy in slow-channel congenital myasthenic syndrome caused by a novel mutation in CHRND. Muscle Nerve 2021; 63:E30-E32. [PMID: 33428214 DOI: 10.1002/mus.27166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/02/2021] [Accepted: 01/06/2021] [Indexed: 11/09/2022]
Affiliation(s)
- Nozomu Tawara
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Satoshi Yamashita
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Koutaro Takamatsu
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Yoshimune Yamasaki
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Akihiro Mukaino
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Shunya Nakane
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Paniz Farshadyeganeh
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yukio Ando
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
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19
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Stephens BD, Kang MK. Pearls & Oy-sters: The Myasthenic Double Humps. Neurology 2020; 96:545-547. [PMID: 33277409 DOI: 10.1212/wnl.0000000000011287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Brian D Stephens
- From the Department of Neurology, University of California, San Francisco.
| | - Min K Kang
- From the Department of Neurology, University of California, San Francisco
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20
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De Giglio L, Cortese F, Pennisi EM. Aminopiridines in the treatment of multiple sclerosis and other neurological disorders. Neurodegener Dis Manag 2020; 10:409-423. [PMID: 33054615 DOI: 10.2217/nmt-2020-0018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Symptomatic treatment has a great relevance for the management of patients with neurologic diseases, since it reduces disease burden and improves quality of life. Aminopyridines (APs) are a group of potassium (K+) channel blocking agents that exert their activity both at central nervous system level and on neuromuscular junction. This review describes the use of APs for the symptomatic treatment of neurological conditions. We will describe trials leading to the approval of the extended-release 4-aminopyridine for MS and evidence in support of the use in other neurological diseases.
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Affiliation(s)
- Laura De Giglio
- Department of Medicine, San Filippo Neri Hospital, Neurology Unit, Rome, Italy
| | - Francesca Cortese
- Department of Medicine, San Filippo Neri Hospital, Neurology Unit, Rome, Italy
| | - Elena Maria Pennisi
- Department of Medicine, San Filippo Neri Hospital, Neurology Unit, Rome, Italy
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21
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Mignan T, Targett M, Lowrie M. Classification of myasthenia gravis and congenital myasthenic syndromes in dogs and cats. J Vet Intern Med 2020; 34:1707-1717. [PMID: 32668077 PMCID: PMC7517852 DOI: 10.1111/jvim.15855] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 06/22/2020] [Accepted: 06/26/2020] [Indexed: 12/19/2022] Open
Abstract
Myasthenia, a syndrome of impaired neuromuscular transmission, occurs as either an acquired or congenital condition. Myasthenia gravis (MG) is an acquired autoimmune disorder with autoantibodies against the neuromuscular junction (NMJ) of skeletal muscle whereas congenital myasthenic syndromes (CMSs) are a clinically heterogeneous group of genetic disorders affecting the NMJ with a young age of onset. Both conditions are diseases for which recognition is important with regard to treatment and outcome. We review the published literature on MG and CMSs in dogs and cats, and by comparison with published classification used in humans, propose a classification system for MG and CMSs in dogs and cats. Myasthenia gravis is first classified based on focal, generalized, or acute fulminating presentation. It then is subclassified according to the autoimmune disease mechanism or seronegativity. Autoimmune disease mechanism relates to the presence or absence of a thymoma, or administration of thiourylene medication in cats. Congenital myasthenic syndromes are classified according to the affected NMJ component, the mechanism of the defect of neuromuscular transmission, the affected protein, and ultimately the mutated gene responsible. In proposing this categorization of MG and CMSs, we hope to aid recognition of the disease groups for both conditions, as well as guide treatment, refine prognosis, and provide a framework for additional studies of these conditions.
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Affiliation(s)
| | - Mike Targett
- School of Veterinary Medicine and Science, University of Nottingham, Leicestershire, UK
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22
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The congenital myasthenic syndromes: expanding genetic and phenotypic spectrums and refining treatment strategies. Curr Opin Neurol 2020; 32:696-703. [PMID: 31361628 PMCID: PMC6735524 DOI: 10.1097/wco.0000000000000736] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Congenital myasthenic syndromes (CMS) are a group of heterogeneous inherited disorders caused by mutations in genes encoding proteins whose function is essential for the integrity of neuromuscular transmission. This review updates the reader on the expanding phenotypic spectrum and suggested improved treatment strategies.
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23
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Zhang Y, Cheng X, Luo C, Lei M, Mao F, Shi Z, Cao W, Zhang J, Zhang Q. Congenital Myasthenic Syndrome Caused by a Novel Hemizygous CHAT Mutation. Front Pediatr 2020; 8:185. [PMID: 32411636 PMCID: PMC7198756 DOI: 10.3389/fped.2020.00185] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 03/30/2020] [Indexed: 02/02/2023] Open
Abstract
Congenital myasthenic syndrome (CMS) is a neuromuscular transmission disorder caused by mutations in genes encoding neuromuscular junction proteins. CMS due to choline acetyltransferase (CHAT) gene mutation is characterized by episodic apnoea. To date, 52 cases of CMS caused by CHAT gene mutations have been reported. Here, we report a neonate with the third hemizygous mutation [a 4.9 Mb deletion [10q11.22-10q11.23 (chr10: 46123781-51028772)] containing the whole CHAT gene and c.1976A>T (p.Gln659Leu in the CHAT gene)]. The c.1976A>T (p.Gln659Leu) variant had not been reported in the ExAC or gnomAD databases and was predicted to be pathogenic. The alignment of amino acid sequences revealed that glutamine at codon 659 is highly conserved in different species and causes structural changes in the substrate-binding site. Our female patient with neonate-onset CMS presented with apnoea, dyspnoea, feeding difficulties, weak crying, and seizure-like episodes, and her respiration was ventilator dependent. The prostigmine test was positive. This case may help to further elucidate clinical features and treatment methods in neonate-onset CMS caused by CHAT gene mutations.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Qian Zhang
- Neonatal Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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24
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Abstract
BACKGROUND The neuromuscular disorders encountered in the pediatric intensive care unit (PICU) encompass a broad spectrum of pathologies. These include acute disorders (eg, Guillain-Barre syndrome), acute-on-chronic disorders (eg, myasthenia gravis), progressive disorders (eg, muscular dystrophy), and disorders that develop in the PICU (eg, critical illness myopathy/polyneuropathy). Familiarity with the presenting features of these disorders is of paramount importance in facilitating timely diagnosis. METHODS We conducted a retrospective review of the medical records of patients admitted to the PICU or Intermediate Care Program (ICP) at a single tertiary children's hospital from 2006 to 2017 with an acute or acute-on-chronic neuromuscular disorder. We did not include patients with a known progressive neuromuscular disorder or critical illness myopathy/polyneuropathy. RESULTS Twenty-four patients were admitted to the PICU/ICP with acute or acute-on-chronic neuromuscular disorders. Diagnosis and indication for ICU/ICP admission were Guillain-Barre syndrome (n = 6; respiratory failure: 3, respiratory monitoring: 2, autonomic instability: 1), myasthenia gravis (n = 5; airway clearance: 3, respiratory failure: 2), acute flaccid myelitis (n = 3; respiratory failure: 2, respiratory monitoring: 1), periodic paralysis (n = 3; intravenous potassium replacement), rhabdomyolysis (n = 3; monitoring for electrolyte derangements), infant botulism (n = 2; respiratory failure), chronic demyelinating polyneuropathy (n = 1; respiratory failure), and congenital myasthenic syndrome (n = 1; apnea). No patients were admitted to the PICU/ICP with a diagnosis of tick paralysis, acute intermittent porphyria, or inflammatory myopathy. CONCLUSIONS Although acute and acute-on-chronic neuromuscular disorders are encountered relatively rarely in the PICU, familiarity with the presenting features of these disorders is important in facilitating timely diagnosis. This, in turn, enables the institution of effective management strategies, thereby avoiding complications associated with diagnostic delays.
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Affiliation(s)
- Dana B Harrar
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA.,Division of Neurology, Children's National Medical Center, Washington, DC, USA
| | - Basil T Darras
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Partha S Ghosh
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
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25
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Tay CG, Fong CY, Li L, Ganesan V, Teh CM, Gan CS, Thong MK. Congenital myasthenic syndrome with novel pathogenic variants in the COLQ gene associated with the presence of antibodies to acetylcholine receptors. J Clin Neurosci 2019; 72:468-471. [PMID: 31831253 DOI: 10.1016/j.jocn.2019.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 12/01/2019] [Indexed: 11/19/2022]
Abstract
Congenital myasthenic syndrome (CMS) is a heterogeneous group of inherited disorder which does not associate with anti-acetylcholine receptor (AChR) antibody. The presence of AChR autoantibody is pathogenic and highly sensitive and specific for autoimmune myasthenia gravis (MG). We describe 2 children from unrelated families who presented with hypotonia, ptosis and fatigability in early infancy with anti-AChR antibodies detected via ELISA on 2 separate occasions in the sera. Both were treated as refractory autoimmune MG due to poor clinical response to acetylcholinesterase inhibitor and immunotherapy. In view of the atypical clinical features, genetic studies of CMS were performed and both were confirmed to have novel pathogenic mutations in the COLQ gene. To the best of our knowledge, the presence of anti-AChR antibody in COLQ-related CMS has never been reported in the literature. The clinical presentation of early onset phenotype, and refractoriness to acetylcholinesterase inhibitor and immunotherapy should prompt CMS as a differential diagnosis.
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Affiliation(s)
- Chee Geap Tay
- Division of Paediatric Neurology, Department of Paediatrics, University of Malaya Medical Centre, Kuala Lumpur, Malaysia
| | - Choong Yi Fong
- Division of Paediatric Neurology, Department of Paediatrics, University of Malaya Medical Centre, Kuala Lumpur, Malaysia
| | - Limin Li
- Division of Paediatric Neurology, Department of Paediatrics, University of Malaya Medical Centre, Kuala Lumpur, Malaysia
| | | | - Chee Ming Teh
- Department of Paediatrics, Penang General Hospital, Penang, Malaysia
| | - Chin Seng Gan
- Division of Paediatric Intensive Care, Department of Paediatrics, University of Malaya Medical Centre, Kuala Lumpur, Malaysia
| | - Meow-Keong Thong
- Genetic Medicine Unit, Department of Paediatrics, University of Malaya Medical Centre, Kuala Lumpur, Malaysia.
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Barnett C, Tabasinejad R, Bril V. Current pharmacotherapeutic options for myasthenia gravis. Expert Opin Pharmacother 2019; 20:2295-2303. [PMID: 31670984 DOI: 10.1080/14656566.2019.1682548] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Introduction: Novel options for immune-based therapy in myasthenia gravis are improving the therapeutic outlook for patients. Multiple clinical trials on immunomodulation, complement inhibitors, and FcR inhibitors are providing evidence for novel immune-based therapies that promise to improve outcomes in myasthenia patients. These more focused immune treatments are reviewed in this paper.Areas covered: This paper outlines classical treatment for myasthenia gravis and then reviews recent clinical trial evidence for novel immune therapies, particularly complement inhibitors and FcR inhibitors. Further, as immune therapies expand in other areas of medicine, such as oncology, iatrogenic myasthenia is being observed as a complication of some novel treatments.Expert opinion: Exciting new options to help patients with myasthenia gravis are now available or in phase 3 trials based on promising phase 2 results. Manipulation of the immune system can also lead to iatrogenic MG. Although novel treatments can improve care for myasthenia gravis patients, future developments that prevent the production of specific abnormal auto-antibodies are desirable.
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Affiliation(s)
- Carolina Barnett
- Department of Medicine (Neurology), University Health Network, University of Toronto - Neurology, Toronto, Ontario, Canada
| | - Raha Tabasinejad
- Department of Medicine (Neurology), University Health Network, University of Toronto - Neurology, Toronto, Ontario, Canada
| | - Vera Bril
- Department of Medicine (Neurology), University Health Network, University of Toronto - Neurology, Toronto, Ontario, Canada
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Targeted therapies for congenital myasthenic syndromes: systematic review and steps towards a treatabolome. Emerg Top Life Sci 2019; 3:19-37. [PMID: 30931400 PMCID: PMC6436731 DOI: 10.1042/etls20180100] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Despite recent scientific advances, most rare genetic diseases — including most neuromuscular diseases — do not currently have curative gene-based therapies available. However, in some cases, such as vitamin, cofactor or enzyme deficiencies, channelopathies and disorders of the neuromuscular junction, a confirmed genetic diagnosis provides guidance on treatment, with drugs available that may significantly alter the disease course, improve functional ability and extend life expectancy. Nevertheless, many treatable patients remain undiagnosed or do not receive treatment even after genetic diagnosis. The growth of computer-aided genetic analysis systems that enable clinicians to diagnose their undiagnosed patients has not yet been matched by genetics-based decision-support systems for treatment guidance. Generating a ‘treatabolome’ of treatable variants and the evidence for the treatment has the potential to increase treatment rates for treatable conditions. Here, we use the congenital myasthenic syndromes (CMS), a group of clinically and genetically heterogeneous but frequently treatable neuromuscular conditions, to illustrate the steps in the creation of a treatabolome for rare inherited diseases. We perform a systematic review of the evidence for pharmacological treatment of each CMS type, gathering evidence from 207 studies of over 1000 patients and stratifying by genetic defect, as treatment varies depending on the underlying cause. We assess the strength and quality of the evidence and create a dataset that provides the foundation for a computer-aided system to enable clinicians to gain easier access to information about treatable variants and the evidence they need to consider.
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