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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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Palmio J, Kiviranta P, Hartikainen PH, Isohanni P, Auranen M, Videman K, Penttilä S, Lehtinen S, Kirjavainen J, Hintikka S, Paloviita K, Saarela J, Udd B. Homozygosity of a Founder Variant c.1508dupC in DOK7 Causes Congenital Myasthenia With Variable Severity. Neurol Genet 2024; 10:e200155. [PMID: 38725677 PMCID: PMC11081763 DOI: 10.1212/nxg.0000000000200155] [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: 10/02/2023] [Accepted: 03/14/2024] [Indexed: 05/12/2024]
Abstract
Background and Objectives Description of 15 patients with the same variant in DOK7 causing congenital myasthenic syndrome (CMS). Methods Nine adult and 6 pediatric patients were studied with molecular genetic and clinical investigations. Results All patients were identified with the c.1508dupC variant in DOK7, of whom 13 were homozygous and 2 patients compound heterozygous. Only 2 patients had limb girdle phenotype, while all adult patients also had ptosis, ophthalmoplegia, facial weakness, as well as inspiratory stridor. Pediatric patients had severe respiratory insufficiency and feeding difficulties at birth. Discussion The disease severity in our patients varied extensively from ventilator or wheelchair dependence to mild facial weakness, ptosis, and ophthalmoparesis. Most of the patients had normal transmission in conventional 3 Hz stimulation electrophysiologic studies, making the diagnosis of CMS challenging. Our cohort of adult and pediatric patients expands the phenotype of DOK7 CMS and shows the importance of correct and early diagnosis.
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Affiliation(s)
- Johanna Palmio
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Panu Kiviranta
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Päivi H Hartikainen
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Pirjo Isohanni
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Mari Auranen
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Karoliina Videman
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Sini Penttilä
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Sara Lehtinen
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Jarkko Kirjavainen
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Susanna Hintikka
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Katriina Paloviita
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Janna Saarela
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
| | - Bjarne Udd
- From the Neuromuscular Research Center (J.P., S.P., B.U.), Tampere University and University Hospital, Neurology; The Finnish Medical Society Duodecim (P.K.), Helsinki; Department of Pediatrics (P.K.), Kuopio University Hospital, and University of Eastern Finland Kuopio; Neurocenter (P.H.H.), Neurology, Kuopio University Hospital; Department of Child Neurology (P.I.), Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital; Research Programs Unit (P.I.), Stem Cells and Metabolism, University of Helsinki; Clinical Neurosciences (M.A.), Neurology, University of Helsinki and Helsinki University Hospital; Department of Pediatric Neurology (K.V.); Department of Genetics (S.L.), Fimlab Laboratories, Tampere University Hospital; Department of Pediatric Neurology (J.K.), Kuopio University Hospital; Department of Neurology (S.H., K.P.), Central Finland Central Hospital, Jyväskylä; Institute for Molecular Medicine Finland FIMM (J.S.), University Helsinki, Finland; Centre for Molecular Medicine Norway (J.S.), University of Oslo, Norway; Folkhälsan Institute of Genetics and the Department of Medical Genetics (B.U.), Haartman Institute, University of Helsinki; and Department of Neurology (B.U.), Vaasa Central Hospital, Finland
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Wiendl H, Abicht A, Chan A, Della Marina A, Hagenacker T, Hekmat K, Hoffmann S, Hoffmann HS, Jander S, Keller C, Marx A, Melms A, Melzer N, Müller-Felber W, Pawlitzki M, Rückert JC, Schneider-Gold C, Schoser B, Schreiner B, Schroeter M, Schubert B, Sieb JP, Zimprich F, Meisel A. Guideline for the management of myasthenic syndromes. Ther Adv Neurol Disord 2023; 16:17562864231213240. [PMID: 38152089 PMCID: PMC10752078 DOI: 10.1177/17562864231213240] [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] [Received: 05/26/2023] [Accepted: 10/23/2023] [Indexed: 12/29/2023] Open
Abstract
Myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS), and congenital myasthenic syndromes (CMS) represent an etiologically heterogeneous group of (very) rare chronic diseases. MG and LEMS have an autoimmune-mediated etiology, while CMS are genetic disorders. A (strain dependent) muscle weakness due to neuromuscular transmission disorder is a common feature. Generalized MG requires increasingly differentiated therapeutic strategies that consider the enormous therapeutic developments of recent years. To include the newest therapy recommendations, a comprehensive update of the available German-language guideline 'Diagnostics and therapy of myasthenic syndromes' has been published by the German Neurological society with the aid of an interdisciplinary expert panel. This paper is an adapted translation of the updated and partly newly developed treatment guideline. It defines the rapid achievement of complete disease control in myasthenic patients as a central treatment goal. The use of standard therapies, as well as modern immunotherapeutics, is subject to a staged regimen that takes into account autoantibody status and disease activity. With the advent of modern, fast-acting immunomodulators, disease activity assessment has become pivotal and requires evaluation of the clinical course, including severity and required therapies. Applying MG-specific scores and classifications such as Myasthenia Gravis Activities of Daily Living, Quantitative Myasthenia Gravis, and Myasthenia Gravis Foundation of America allows differentiation between mild/moderate and (highly) active (including refractory) disease. Therapy decisions must consider age, thymic pathology, antibody status, and disease activity. Glucocorticosteroids and the classical immunosuppressants (primarily azathioprine) are the basic immunotherapeutics to treat mild/moderate to (highly) active generalized MG/young MG and ocular MG. Thymectomy is indicated as a treatment for thymoma-associated MG and generalized MG with acetylcholine receptor antibody (AChR-Ab)-positive status. In (highly) active generalized MG, complement inhibitors (currently eculizumab and ravulizumab) or neonatal Fc receptor modulators (currently efgartigimod) are recommended for AChR-Ab-positive status and rituximab for muscle-specific receptor tyrosine kinase (MuSK)-Ab-positive status. Specific treatment for myasthenic crises requires plasmapheresis, immunoadsorption, or IVIG. Specific aspects of ocular, juvenile, and congenital myasthenia are highlighted. The guideline will be further developed based on new study results for other immunomodulators and biomarkers that aid the accurate measurement of disease activity.
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Affiliation(s)
- Heinz Wiendl
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, Münster 48149, Germany
| | - Angela Abicht
- Friedrich-Baur-Institut an der Neurologischen Klinik und Poliklinik, LMU Munich, Munich, Germany
| | - Andrew Chan
- Universitätsklinik für Neurologie, Inselspital Bern, Bern, Switzerland
| | - Adela Della Marina
- Klinik für Kinderheilkunde I, Universitätsklinikum Essen, Essen, Germany
| | - Tim Hagenacker
- Klinik für Neurologie, Universitätsklinikum Essen, Essen, Germany
| | | | - Sarah Hoffmann
- Charité – Universitätsmedizin Berlin, Klinik für Neurologie mit Experimenteller Neurologie, Berlin, Germany
| | | | - Sebastian Jander
- Klinik für Neurologie, Marien Hospital Düsseldorf, Düsseldorf, Germany
| | - Christian Keller
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Alexander Marx
- Pathologisches Institut, Universitätsklinikum Mannheim, Mannheim, Germany
| | - Arthur Melms
- Facharztpraxis für Neurologie und Psychiatrie, Stuttgart, Germany
| | - Nico Melzer
- Klinik für Neurologie, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | - Wolfgang Müller-Felber
- Kinderklinik und Kinderpoliklinik im Dr. von Haunerschen Kinderspital, LMU Munich, Munich, Germany
| | - Marc Pawlitzki
- Klinik für Neurologie, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
| | | | | | - Benedikt Schoser
- Friedrich-Baur-Institut an der Neurologischen Klinik und Poliklinik, LMU Munich, Munich, Germany
| | - Bettina Schreiner
- Klinik für Neurologie, Universitätsspital Zürich, Zürich, Switzerland
| | - Michael Schroeter
- Klinik und Poliklinik für Neurologie, Uniklinik Cologne, Cologne, Germany
| | | | | | - Fritz Zimprich
- Universitätsklinik für Neurologie, AKH-Wien, Wien, Austria
| | - Andreas Meisel
- Charité – Universitätsmedizin Berlin, Klinik für Neurologie mit Experimenteller Neurologie, Berlin, 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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Poulos J, Samuels M, Palace J, Beeson D, Robb S, Ramdas S, Chan S, Munot P. Congenital myasthenic syndromes: a retrospective natural history study of respiratory outcomes in a single centre. Brain Commun 2023; 5:fcad299. [PMID: 38035366 PMCID: PMC10684295 DOI: 10.1093/braincomms/fcad299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 06/05/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023] Open
Abstract
Respiratory problems are a major cause of morbidity and mortality in patients with congenital myasthenic syndromes, a rare heterogeneous group of neuromuscular disorders caused by genetic defects impacting the structure and function of the neuromuscular junction. Recurrent, life-threatening episodic apnoea in early infancy and childhood and progressive respiratory failure requiring ventilation are features of certain genotypes of congenital myasthenic syndromes. Robb et al. published empirical guidance on respiratory management of the congenital myasthenic syndromes, but other than this workshop report, there are little published longitudinal natural history data on respiratory outcomes of these disorders. We report a retrospective, single-centre study on respiratory outcomes in a cohort of 40 well characterized genetically confirmed cases of congenital myasthenic syndromes, including 10 distinct subtypes (DOK7, COLQ, RAPSN, CHAT, CHRNA1, CHRNG, COL13A1, CHRNE, CHRNE fast channel syndrome and CHRNA1 slow channel syndrome), with many followed up over 20 years in our centre. A quantitative and longitudinal analysis of key spirometry and sleep study parameters, as well as a description of historical hospital admissions for respiratory decompensation, provides a snapshot of the respiratory trajectory of congenital myasthenic syndrome patients based on genotype.
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Affiliation(s)
- Jordan Poulos
- Paediatrics, University College London Medical School, London WC1E 6BT, UK
| | - Martin Samuels
- Respiratory Medicine, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Jacqueline Palace
- University of Oxford and Department of Neurology, Oxford Radcliffe Hospitals, Oxford OX3 9DU, UK
| | - David Beeson
- Neurology, Nuffield Department of Clinical Neurosciences, Oxford OX3 7BN, UK
| | - Stephanie Robb
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Sithara Ramdas
- Neurology, MDUK Neuromuscular Centre, Oxford University Hospitals, Oxford OX3 9DU, UK
| | - Samantha Chan
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London WC1N 3JH, UK
- Neurosciences, University College London and Institute of Child Health, London WC1N 1EH, UK
| | - Pinki Munot
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London WC1N 3JH, UK
- Neurosciences, University College London and Institute of Child Health, London WC1N 1EH, UK
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6
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Almatrafi AM, Alluqmani MM, Basit S. Homozygous Duplication in the CHRNE in a Family with Congenital Myasthenic Syndrome 4C: 18-Year Follow Up. Biomedicines 2023; 11:2983. [PMID: 38001983 PMCID: PMC10668953 DOI: 10.3390/biomedicines11112983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/29/2023] [Accepted: 11/02/2023] [Indexed: 11/26/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Congenital myasthenic syndromes (CMSs) are rare inherited diseases characterized by muscle weakness and fatigability on exertion resulting from defects in the neuromuscular junctions. Mutations in 32 genes have been reported as the underlying causes of CMS, with mutations in the cholinergic receptor nicotinic epsilon subunit (CHRNE) being the most common cause of the disease. Methodology and Materials: This study investigated a large consanguineous family with multiple individuals suffering from abnormal fatigue and muscle weakness in the ocular and limb regions. Moreover, the affected individuals were followed up for 18 years to observe the clinical course of the disease. RESULTS High-quality exome sequencing followed by bidirectional Sanger sequencing revealed a homozygous duplication variant (NM_000080.4: c.1220-8_1227dup) in the splice acceptor site of exon 11 of the CHRNE gene. This variant is predicted to cause frameshift and premature termination (p.Cys410ProfsTer51). Both parents had heterozygous duplication variants with no clinical symptoms. The personalized treatment of the affected individuals resulted in a marked improvement in the clinical symptoms. More than 80% of the disease symptoms in the affected individuals subsided after the use of pyridostigmine and salbutamol (4 mg). CONCLUSIONS This is the first report of long-term follow up of cases with homozygous insertion (c.1220-8_1227dup) in the CHRNE gene. Furthermore, this report expands the phenotypic symptoms associated with the CHRNE mutation.
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Affiliation(s)
- Ahmad M. Almatrafi
- Department of Biology, College of Science, Taibah University, Medina 42353, Saudi Arabia;
| | - Majed M. Alluqmani
- Department of Neurology, College of Medicine, Taibah University, Medina 42353, Saudi Arabia;
| | - Sulman Basit
- Department of Biochemistry and Molecular Medicine, College of Medicine, Taibah University, Medina 42353, Saudi Arabia
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Yildiz EP, Kilic MA, Yalcin EU, Kurekci F, Avci R, Hacıfazlıoğlu NE, Ceylaner S, Gezdirici A, Çalışkan M. Genetic and clinical evaluation of congenital myasthenic syndromes with long-term follow-up: experience of a tertiary center in Turkey. Acta Neurol Belg 2023; 123:1841-1847. [PMID: 36094697 DOI: 10.1007/s13760-022-02090-0] [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: 05/09/2022] [Accepted: 09/01/2022] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Congenital myasthenic syndromes (CMS) are a heterogeneous group of genetic disorders affecting the safety factor which required for neuromuscular transmission. Here we reported our experience in children with CMS. METHODS We retrospectively collected the data of 18 patients with CMS who were examined in our outpatient clinic between January 2021 and January 2022. The diagnosis of CMS was based on the presence of clinical symptoms such as abnormal fatigability and weakness, absence of autoantibodies against acetylcholine receptor and muscle-specific kinase, electromyographic evidence of neuromuscular junction defect, molecular genetic confirmation, and response to treatment. RESULTS The most common mutations were in the acetylcholine receptor (CHRNE) gene (8/18) and choline acetyltransferase (ChAT) (2/18) gene. Despite targeted gene sequencing and whole exome sequencing (WES) were underwent, we couldn't detect a genetic mutation in three out of patients. The most commonly determined initial finding was eyelid ptosis, followed by fatigable weakness, and respiratory insufficiency. Although the most commonly used drug was pyridostigmine, we have experienced that caution should be exercised as it may worsen some types of CMS. DISCUSSION We reported in detail the phenotypic features of very rare gene mutations associated with CMS and our experience in the treatment of this disease. Although CMS are rare genetic disorder, the prognosis can be very promising with appropriate treatment in most CMS subtypes.
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Affiliation(s)
- Edibe Pembegul Yildiz
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey.
- Istanbul University Institute of Child Health, Istanbul, Turkey.
- Istanbul University Medical School. Millet Cd, 34000, Fatih-Istanbul, Turkey.
| | - Mehmet Akif Kilic
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey
| | - Emek Uyur Yalcin
- Department of Pediatric Neurology, Zeynep Kamil Maternity and Children's Diseases Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| | - Fulya Kurekci
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey
| | - Ridvan Avci
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey
| | - Nilüfer Eldeş Hacıfazlıoğlu
- Department of Pediatric Neurology, Zeynep Kamil Maternity and Children's Diseases Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| | | | - Alper Gezdirici
- Department of Medical Genetics, Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey
| | - Mine Çalışkan
- Department of Pediatric Neurology, Istanbul Medical Faculty, Istanbul, Turkey
- Istanbul University Institute of Child Health, Istanbul, Turkey
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8
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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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9
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Spendiff S, Dong Y, Maggi L, Rodríguez Cruz PM, Beeson D, Lochmüller H. 260th ENMC International Workshop: Congenital myasthenic syndromes 11-13 March 2022, Hoofddorp, The Netherlands. Neuromuscul Disord 2023; 33:111-118. [PMID: 36609117 DOI: 10.1016/j.nmd.2022.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/02/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Affiliation(s)
- Sally Spendiff
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Yin Dong
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Lorenzo Maggi
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Pedro M Rodríguez Cruz
- Centro Nacional de Análisis Genómico (CNAG-CRG), Centre for Genomic Regulation, Barcelona, Spain; Department of Human Genetics, Université Cheikh Anta Diop, Dakar, Senegal; Department of Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - David Beeson
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Hanns Lochmüller
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada; Department of Medicine, Division of Neurology, The Ottawa Hospital, Ottawa, Canada; Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada; Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany; Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain.
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10
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Ohno K, Ohkawara B, Shen XM, Selcen D, Engel AG. Clinical and Pathologic Features of Congenital Myasthenic Syndromes Caused by 35 Genes-A Comprehensive Review. Int J Mol Sci 2023; 24:ijms24043730. [PMID: 36835142 PMCID: PMC9961056 DOI: 10.3390/ijms24043730] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/09/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Congenital myasthenic syndromes (CMS) are a heterogeneous group of disorders characterized by impaired neuromuscular signal transmission due to germline pathogenic variants in genes expressed at the neuromuscular junction (NMJ). A total of 35 genes have been reported in CMS (AGRN, ALG14, ALG2, CHAT, CHD8, CHRNA1, CHRNB1, CHRND, CHRNE, CHRNG, COL13A1, COLQ, DOK7, DPAGT1, GFPT1, GMPPB, LAMA5, LAMB2, LRP4, MUSK, MYO9A, PLEC, PREPL, PURA, RAPSN, RPH3A, SCN4A, SLC18A3, SLC25A1, SLC5A7, SNAP25, SYT2, TOR1AIP1, UNC13A, VAMP1). The 35 genes can be classified into 14 groups according to the pathomechanical, clinical, and therapeutic features of CMS patients. Measurement of compound muscle action potentials elicited by repetitive nerve stimulation is required to diagnose CMS. Clinical and electrophysiological features are not sufficient to identify a defective molecule, and genetic studies are always required for accurate diagnosis. From a pharmacological point of view, cholinesterase inhibitors are effective in most groups of CMS, but are contraindicated in some groups of CMS. Similarly, ephedrine, salbutamol (albuterol), amifampridine are effective in most but not all groups of CMS. This review extensively covers pathomechanical and clinical features of CMS by citing 442 relevant articles.
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Affiliation(s)
- Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Correspondence: (K.O.); (A.G.E.)
| | - Bisei Ohkawara
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Xin-Ming Shen
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
| | - Duygu Selcen
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
| | - Andrew G. Engel
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
- Correspondence: (K.O.); (A.G.E.)
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11
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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: 0] [Impact Index Per Article: 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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12
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Shao S, Shi G, Bi FF, Huang K. Pharmacological Treatments for Congenital Myasthenic Syndromes Caused by COLQ Mutations. Curr Neuropharmacol 2023; 21:1594-1605. [PMID: 36703579 PMCID: PMC10472815 DOI: 10.2174/1570159x21666230126145652] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 09/30/2022] [Accepted: 11/18/2022] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Congenital myasthenic syndromes (CMS) refer to a series of inherited disorders caused by defects in various proteins. Mutation in the collagen-like tail subunit of asymmetric acetylcholinesterase (COLQ) is the second-most common cause of CMS. However, data on pharmacological treatments are limited. OBJECTIVE In this study, we reviewed related reports to determine the most appropriate pharmacological strategy for CMS caused by COLQ mutations. A literature review and meta-analysis were also performed. PubMed, MEDLINE, Web of Science, and Cochrane Library databases were searched to identify studies published in English before July 22, 2022. RESULTS A total of 42 studies including 164 patients with CMS due to 72 different COLQ mutations were selected for evaluation. Most studies were case reports, and none were randomized clinical trials. Our meta-analysis revealed evidence that β-adrenergic agonists, including salbutamol and ephedrine, can be used as first-line pharmacological treatments for CMS patients with COLQ mutations, as 98.7% of patients (74/75) treated with β-adrenergic agonists showed positive effects. In addition, AChEIs should be avoided in CMS patients with COLQ mutations, as 90.5% (105/116) of patients treated with AChEIs showed either no or negative effects. CONCLUSION (1) β-adrenergic agonist therapy is the first pharmacological strategy for treating CMS with COLQ mutations. (2) AChEIs should be avoided in patients with CMS with COLQ mutations.
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Affiliation(s)
- Shuai Shao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
- Xiangya School of Medicine, Central South University, Changsha, Hunan province, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Guanzhong Shi
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
- Xiangya School of Medicine, Central South University, Changsha, Hunan province, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Fang-Fang Bi
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Kun Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
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13
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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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14
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O'Connell K, Rooney T, Alabaf S, Ramdas S, Beeson D, Palace J. Pregnancy outcomes in patients with congenital myasthenic syndromes. Muscle Nerve 2022; 66:345-348. [PMID: 35661384 DOI: 10.1002/mus.27653] [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: 08/11/2021] [Revised: 05/22/2022] [Accepted: 05/28/2022] [Indexed: 11/08/2022]
Abstract
INTRODUCTION/AIMS The congenital myasthenic syndromes (CMS) are a heterogeneous group of inherited disorders that affect neuromuscular junction transmission. Data on pregnancy outcomes in women with CMS are limited due to their infrequency. In this study we explored pregnancy with CMS in a large cohort of women attending a national specialty clinic in England. METHODS All women with CMS who had a documented pregnancy were invited to complete a questionnaire assessing clinical status during pregnancy and postpartum, pregnancy outcomes, fetal outcomes, and medication use during pregnancy. RESULTS Among 16 women with CMS (acetylcholine receptor deficiency [CHRNE], slow channel syndrome [CHRNA1], DOK7, RAPSYN and glycosylation [DPAGT1 and GFPT1]), 27 pregnancies were recorded: 26 single pregnancies and 1 twin pregnancy. Symptom worsening was reported in 63% of pregnancies, but recovery to baseline function was seen in all but one patient. Miscarriage and cesarean section occurred in 31% and 33% of the women, respectively. Over half of the patients continued taking their medication during pregnancy, which included pyridostigmine (n = 10), 3,4-diaminopyridine (n = 9), ephedrine (n = 3), salbutamol (n = 3), and quinidine (n = 1). No fetal malformations were recorded. DISCUSSION Our results show that clinical worsening during pregnancy was common but rarely persistent. The majority of women with CMS can safely plan pregnancy, but close follow-up is required from their neurology and obstetric teams. Although we identified no safety concerns, continued medication use should be reviewed on a case-by-case basis.
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Affiliation(s)
- Karen O'Connell
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Tatiana Rooney
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Setareh Alabaf
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Sithara Ramdas
- Department of Paediatric Neurology, John Radcliffe Hospital, Oxford, UK
| | - David Beeson
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
- Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
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15
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Huang K, Duan HQ, Li QX, Luo YB, Bi FF, Yang H. Clinicopathological-genetic features of congenital myasthenic syndrome from a Chinese neuromuscular centre. J Cell Mol Med 2022; 26:3828-3836. [PMID: 35670010 PMCID: PMC9279597 DOI: 10.1111/jcmm.17417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 05/13/2022] [Accepted: 05/20/2022] [Indexed: 12/28/2022] Open
Abstract
Congenital myasthenic syndrome (CMS) encompasses a heterogeneous group of inherited disorders affecting nerve transmission across the neuromuscular junction. The aim of this study was to characterize the clinical, physiological, pathohistological and genetic features of nine unrelated Chinese patients with CMS from a single neuromuscular centre. A total of nine patients aged from neonates to 34 years were enrolled who exhibited initial symptoms. Physical examinations revealed that all patients exhibited muscle weakness. Muscle biopsies demonstrated multiple myopathological changes, including increased fibre size variation, myofibrillar network disarray, necrosis, myofiber grouping, regeneration, fibre atrophy and angular fibres. Genetic testing revealed six different mutated genes, including AGRN (2/9), CHRNE (1/9), GFPT1 (1/9), GMPPB (1/9), PLEC (3/9) and SCN4A (1/9). In addition, patients exhibited differential responses to pharmacological treatment. Prompt utilization of genetic testing will identify novel variants and expand our understanding of the phenotype of this rare syndrome. Our findings contribute to the clinical, pathohistological and genetic spectrum of congenital myasthenic syndrome in China.
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Affiliation(s)
- Kun Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Institute of Molecular Precision Medicine and Hunan Key Laboratory of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Hui-Qian Duan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Qiu-Xiang Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yue-Bei Luo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Fang-Fang Bi
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
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16
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Rare slow channel congenital myasthenic syndromes without repetitive compound muscle action potential and dramatic response to low dose fluoxetine. Acta Neurol Belg 2021; 121:1755-1760. [PMID: 33030681 DOI: 10.1007/s13760-020-01505-0] [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: 08/07/2020] [Accepted: 09/15/2020] [Indexed: 10/23/2022]
Abstract
Congenital myasthenic syndromes are rare hereditary disorders caused by mutations associated with proteins of the neuromuscular junction. Abnormal ''gain of function'' mutations result in prolonged nicotinic acetylcholine receptor channel open state causing a rare subtype of CMS, slow-channel CMS (SCCMS). Mutations in the delta subunit encoding the gene, CHRND, resulting in SCCMS are extremely rare. An important clue to the diagnosis of SCCMS is repetitive CMAP's. Fluoxetine, usually at high doses, is used to treat SCCMS. The mutation, recently described in one patient, was identified by whole exome sequencing and validated, and its segregation with the disease was ascertained by Sanger sequencing. Here, we describe clinical and genetic findings of an early onset SCCMS patient carrying a very rare missense mutation c.880C > T in CHRND causing a highly conserved leucine to phenylalanine substitution in the M2 domain of CHRND. The patient had no repetitive CMAP. He had a dramatic response to fluoxetine at low-moderate doses (40 mg/day), increasing over months: Being wheelchair bound, he could walk independently after treatment. Rare cases may offer insight into the pathological gating mechanism leading to CMS. SCCMS should be suspected even without a repetitive CMAP. Fluoxetine at relatively low doses can be a very effective treatment.
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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: 1.7] [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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18
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Fernandes M, Caetano A, Pinto M, Medeiros E, Santos L. Diagnosis of DOK7 congenital myasthenic syndrome during pregnancy: A case report and literature review. Clin Neurol Neurosurg 2021; 203:106591. [PMID: 33714798 DOI: 10.1016/j.clineuro.2021.106591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/14/2021] [Accepted: 02/27/2021] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Pregnancy among patients with congenital myasthenic syndrome (CMS) is a rare occurrence. Since most of the patients with CMS reach adulthood, questions regarding clinical outcome with pregnancy arise. CASE REPORT We describe a 38-year-old Portuguese female who presented in the second trimester of pregnancy with proximal fluctuating limb-girdle weakness, hyperlordosis, waddling gait, dysphagia, dysphonia and ptosis, with no ophthalmoparesis. Initial diagnosis of seronegative myasthenia, supported by neurophysiology findings, led to unsuccessful treatment with intravenous immunoglobulin, pyridostigmine, prednisolone and plasmapheresis, and the patient slowly progressed to a severe tetraparesis with facial and bulbar involvement. Genetic testing for CMS identified a novel compound heterozygous mutation (c.1124_1127dupTGCC and c.935_936del) in the DOK7 gene. Subsequent treatment with salbutamol resulted in substantial clinical benefit. CONCLUSIONS This case underlines the importance of considering the diagnosis of CMS in patients with fluctuating weakness during pregnancy. Patients of child-bearing potential diagnosed with CMS, particularly due to DOK7 mutations, should be counseled in advance and closely followed during pregnancy.
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Affiliation(s)
- Marco Fernandes
- Department of Neurology, Hospital de Egas Moniz, Centro Hospitalar de Lisboa Ocidental, Rua da Junqueira 126, 1349-019, Lisbon, Portugal.
| | - André Caetano
- Department of Neurology, Hospital de Egas Moniz, Centro Hospitalar de Lisboa Ocidental, Rua da Junqueira 126, 1349-019, Lisbon, Portugal; CEDOC Chronic Diseases Research Centre, Nova Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Miguel Pinto
- Department of Neurology, Hospital de Egas Moniz, Centro Hospitalar de Lisboa Ocidental, Rua da Junqueira 126, 1349-019, Lisbon, Portugal
| | - Elmira Medeiros
- Department of Neurology, Hospital de Egas Moniz, Centro Hospitalar de Lisboa Ocidental, Rua da Junqueira 126, 1349-019, Lisbon, Portugal; CEDOC Chronic Diseases Research Centre, Nova Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Luís Santos
- Department of Neurology, Hospital de Egas Moniz, Centro Hospitalar de Lisboa Ocidental, Rua da Junqueira 126, 1349-019, Lisbon, Portugal; CEDOC Chronic Diseases Research Centre, Nova Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
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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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Della Marina A, Wibbeler E, Abicht A, Kölbel H, Lochmüller H, Roos A, Schara U. Long Term Follow-Up on Pediatric Cases With Congenital Myasthenic Syndromes-A Retrospective Single Centre Cohort Study. Front Hum Neurosci 2020; 14:560860. [PMID: 33364925 PMCID: PMC7750519 DOI: 10.3389/fnhum.2020.560860] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 11/16/2020] [Indexed: 02/01/2023] Open
Abstract
Introduction: Congenital myasthenic syndromes (CMS) refer to a heterogenic group of neuromuscular transmission disorders. CMS-subtypes are diverse regarding exercise intolerance and muscular weakness, varying from mild symptoms to life-limiting forms with neonatal onset. Long-term follow-up studies on disease progression and treatment-response in pediatric patients are rare. Patients and Methods: We analyzed retrospective clinical and medication data in a cohort of 32 CMS-patients including the application of a standardized, not yet validated test (CMS-ST) to examine muscular strength and endurance in 21 patients at the last follow-up. Findings obtained in our cohort were compared with long-term follow-up studies of (adult) CMS-cohorts from the literature by considering the underlying molecular mechanisms. Outcomes of CMS-ST were compared to results of normal clinical assessment. Results: Thirty-two pediatric patients with defects in eight different CMS-genes were followed by a median time of 12.8 years. Fifty-nine percentage of patients manifested with first symptoms as neonates, 35% as infants. While 53% of patients presented a reduced walking distance, 34% were wheelchair-bound. Even under adequate therapy with pyridostigmine (PS) and 3,4-diaminopyridine, CHAT-mutations led to the progression of muscular weakness partly in combination with persistent respiratory and bulbar symptoms. RAPSN, CHRND, and CHRNB1 patients with neonatal manifestation, early respiratory problems, and bulbar symptoms showed a good and maintained treatment response. CHAT and CHRNE patients required higher PS dosages, whereas RAPSN patients needed a lower mean dosage at the last follow-up. The benefits of short-term medication and long-term progression of symptoms were highly dependent on the specific genetic defect. CMS-ST was carried out in 17/21 patients, determined affected muscle groups including bulbar and ocular symptoms, some of which were not reported by the patients. Conclusions: Our findings and comparison with the literature- suggest a better treatment-response and less severe progression of symptoms present in patients suffering from mutations in CMS-genes directly associated with receptor deficiency, while patients with defects leading to synaptopathy and presynaptic defects tend to have worse outcomes. Assessment of affected muscular groups and clinical symptoms by CMS-ST may be a useful tool for optimal therapeutic management of the patients, especially for future clinical studies.
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Affiliation(s)
- Adela Della Marina
- Department of Neuropediatrics, Developmental Neurology and Social Pediatrics, University Children's Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Eva Wibbeler
- Children's Hospital, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Angela Abicht
- Medical Genetic Center Munich, Munich, Germany.,Friedrich-Baur Institute, Ludwig Maximilian University, Munich, Germany
| | - Heike Kölbel
- Department of Neuropediatrics, Developmental Neurology and Social Pediatrics, University Children's Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Hanns Lochmüller
- Children's Hospital of Eastern Ontario Research Institute, Division of Neurology, Department of Medicine, The Ottawa Hospital, Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada.,Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany.,Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Andreas Roos
- Department of Neuropediatrics, Developmental Neurology and Social Pediatrics, University Children's Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Ulrike Schara
- Department of Neuropediatrics, Developmental Neurology and Social Pediatrics, University Children's Hospital Essen, University Duisburg-Essen, Essen, Germany
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21
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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: 4] [Impact Index Per Article: 1.0] [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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22
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Di L, Chen H, Lu Y, Selcen D, Engel AG, Da Y, Shen XM. Determinants of the repetitive-CMAP occurrence and therapy efficacy in slow-channel myasthenia. Neurology 2020; 95:e2781-e2793. [PMID: 32907971 DOI: 10.1212/wnl.0000000000010734] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 06/22/2020] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To find determinants of the occurrence of repetitive compound muscle action potential (R-CMAP) and to assess the efficacy of channel blocker therapy in slow-channel congenital myasthenic syndrome (SCCMS). METHODS Neurologic examination, EMG study, laboratory test, muscle biopsy, and next-generation and Sanger sequencing; literature review of reported patients with SCCMS, including EMG, kinetics of mutant acetylcholine receptors (AChRs), and response to therapy; and simulation of the decay phase of endplate potential (EPP) were performed. RESULTS Three newly characterized and 57 reported patients with SCCMS with mutations of AChR subunits were included. In patients with R-CMAP, the length of channel opening bursts of mutant AChR was increased 8.68 ± 2.82 (mean ± SD)-fold compared to wild-type; in patients without R-CMAP, the length was increased 3.84 ± 0.65-fold (95% confidence interval 3.18-6.50, p = 0.000014). The EPP amplitude after refractory period of action potential in muscle fiber is above the threshold in patients with R-CMAP but below the threshold in patients without R-CMAP. In patients with good results from channel blocker therapy, treatment was initiated 11.60 ± 5.17 years after onset of symptoms; in patients with no to moderate benefit from channel blocker therapy, treatment was initiated 30.70 ± 12.72 years after onset (95% confidence interval -28.57 to -9.63, p = 0.00089). CONCLUSIONS In SCCMS, the R-CMAP occurrence is related to the extent of prolongation of the opening episodes of mutant AChR channel. Channel blocker treatment is more effective the sooner it is started after the onset of symptoms. CLASSIFICATION OF EVIDENCE This study provides Class IV evidence that channel blocker therapy in patients with SCCMS improves symptoms.
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Affiliation(s)
- Li Di
- From the Department of Neurology (L.D., H.C., Y.L., Y.D.), Xuanwu Hospital, Capital Medical University, Beijing, China; and Department of Neurology and Neuromuscular Research Laboratory (L.D., D.S., A.G.E., X.-M.S.), Mayo Clinic, Rochester, MN
| | - Hai Chen
- From the Department of Neurology (L.D., H.C., Y.L., Y.D.), Xuanwu Hospital, Capital Medical University, Beijing, China; and Department of Neurology and Neuromuscular Research Laboratory (L.D., D.S., A.G.E., X.-M.S.), Mayo Clinic, Rochester, MN
| | - Yan Lu
- From the Department of Neurology (L.D., H.C., Y.L., Y.D.), Xuanwu Hospital, Capital Medical University, Beijing, China; and Department of Neurology and Neuromuscular Research Laboratory (L.D., D.S., A.G.E., X.-M.S.), Mayo Clinic, Rochester, MN
| | - Duygu Selcen
- From the Department of Neurology (L.D., H.C., Y.L., Y.D.), Xuanwu Hospital, Capital Medical University, Beijing, China; and Department of Neurology and Neuromuscular Research Laboratory (L.D., D.S., A.G.E., X.-M.S.), Mayo Clinic, Rochester, MN
| | - Andrew G Engel
- From the Department of Neurology (L.D., H.C., Y.L., Y.D.), Xuanwu Hospital, Capital Medical University, Beijing, China; and Department of Neurology and Neuromuscular Research Laboratory (L.D., D.S., A.G.E., X.-M.S.), Mayo Clinic, Rochester, MN
| | - Yuwei Da
- From the Department of Neurology (L.D., H.C., Y.L., Y.D.), Xuanwu Hospital, Capital Medical University, Beijing, China; and Department of Neurology and Neuromuscular Research Laboratory (L.D., D.S., A.G.E., X.-M.S.), Mayo Clinic, Rochester, MN.
| | - Xin-Ming Shen
- From the Department of Neurology (L.D., H.C., Y.L., Y.D.), Xuanwu Hospital, Capital Medical University, Beijing, China; and Department of Neurology and Neuromuscular Research Laboratory (L.D., D.S., A.G.E., X.-M.S.), Mayo Clinic, Rochester, MN.
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23
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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: 0.8] [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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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: 1.0] [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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25
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Shen XM, Milone M, Wang HL, Banwell B, Selcen D, Sine SM, Engel AG. Slow-channel myasthenia due to novel mutation in M2 domain of AChR delta subunit. Ann Clin Transl Neurol 2019; 6:2066-2078. [PMID: 31560172 PMCID: PMC6801167 DOI: 10.1002/acn3.50902] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 09/01/2019] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE To characterize the molecular and phenotypic basis of a severe slow-channel congenital myasthenic syndrome (SCCMS). METHODS Intracellular and single-channel recordings from patient endplates; alpha-bungarotoxin binding studies; direct sequencing of AChR genes; microsatellite analysis; kinetic analysis of AChR activation; homology modeling of adult human AChR structure. RESULTS Among 24 variants reported to cause SCCMS only two appear in the AChR δ-subunit. We here report a 16-year-old patient harboring a novel δL273F mutation (δL294F in HGVS nomenclature) in the second transmembrane domain (M2) of the AChR δ subunit. Kinetic analyses with ACh and the weak agonist choline indicate that δL273F prolongs the channel opening bursts 9.4-fold due to a 75-fold increase in channel gating efficiency, whereas a previously identified εL269F mutation (εL289F in HGVS nomenclature) at an equivalent location in the AChR ε-subunit prolongs channel opening bursts 4.4-fold due to a 30-fold increase in gating efficiency. Structural modeling of AChR predicts that inter-helical hydrophobic interactions between the mutant residue in the δ and ε subunit and nearby M2 domain residues in neighboring α subunits contribute to structural stability of the open relative to the closed channel states. INTERPRETATION The greater increase in gating efficiency by δL273F than by εL269F explains why δL273F has more severe clinical effects. Both δL273F and εL269F impair channel gating by disrupting hydrophobic interactions with neighboring α-subunits. Differences in the extent of impairment of channel gating in δ and ε mutant receptors suggest unequal contributions of ε/α and δ/α subunit pairs to gating efficiency.
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Affiliation(s)
- Xin-Ming Shen
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Margherita Milone
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Hang-Long Wang
- Department of Neurology and Vesicular Biology Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Brenda Banwell
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Duygu Selcen
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Steven M Sine
- Department of Physiology and Biomedical Engineering and Receptor Biology Laboratory, Mayo Clinic, Rochester, Minnesota.,Department of Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,Department of Neurology, Mayo Clinic, Rochester, Minnesota
| | - Andrew G Engel
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, Minnesota
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26
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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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