1
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
| |
Collapse
|
2
|
Rodríguez Cruz PM, Ravenscroft G, Natera D, Carr A, Manzur A, Liu WW, Vella NR, Jericó I, Gonzalez-Quereda L, Gallano P, Montalto SA, Davis MR, Lamont PJ, Laing NG, Bourque P, Nascimento A, Muntoni F, Polavarapu K, Lochmüller H, Palace J, Beeson D. A novel phenotype of AChR-deficiency syndrome with predominant facial and distal weakness resulting from the inclusion of an evolutionary alternatively-spliced exon in CHRNA1. Neuromuscul Disord 2023; 33:161-168. [PMID: 36634413 DOI: 10.1016/j.nmd.2022.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Primary acetylcholine receptor deficiency is the most common subtype of congenital myasthenic syndrome, resulting in reduced amount of acetylcholine receptors expressed at the muscle endplate and impaired neuromuscular transmission. AChR deficiency is caused mainly by pathogenic variants in the ε-subunit of the acetylcholine receptor encoded by CHRNE, although pathogenic variants in other subunits are also seen. We report the clinical and molecular features of 13 patients from nine unrelated kinships with acetylcholine receptor deficiency harbouring the CHRNA1 variant NM_001039523.3:c.257G>A (p.Arg86His) in homozygosity or compound heterozygosity. This variant results in the inclusion of an alternatively-spliced evolutionary exon (P3A) that causes expression of a non-functional acetylcholine receptor α-subunit. We compare the clinical findings of this group to the other cases of acetylcholine receptor deficiency within our cohort. We report differences in phenotype, highlighting a predominant pattern of facial and distal weakness in adulthood, predominantly in the upper limbs, which is unusual for acetylcholine receptor deficiency syndromes, and more in keeping with slow-channel syndrome or distal myopathy. Finally, we stress the importance of including alternative exons in variant analysis to increase the probability of achieving a molecular diagnosis.
Collapse
Affiliation(s)
- Pedro M Rodríguez Cruz
- CNAG-CRG, Centro Nacional de Análisis Genómico - Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.
| | - Gianina Ravenscroft
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia; Centre of Medical Research, University of Western Australia, Nedlands, WA, Australia
| | - Daniel Natera
- Neuromuscular Unit, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Aisling Carr
- Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Adnan Manzur
- Dubowitz Neuromuscular Centre, NIHR Biomedical Research Centre, UCL Great Ormond Street Institute of Child Health; Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Wei Wei Liu
- Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford, UK
| | - Norbert R Vella
- Department of Neuroscience, Mater Dei Hospital, Msida, Malta
| | - Ivonne Jericó
- Department of Neurology, Hospital Universitario de Navarra, IdisNa (Instituto Investigación Sanitaria Navarra), Pamplona, Spain
| | - Lidia Gonzalez-Quereda
- Center for the Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain; Department of Genetics, Hospital de Sant Pau, IIB Sant Pau, Barcelona, Spain
| | - Pia Gallano
- Center for the Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain; Department of Genetics, Hospital de Sant Pau, IIB Sant Pau, Barcelona, Spain
| | | | - Mark R Davis
- Neurogenetic Unit, Department of Diagnostic Genomics, PathWest Laboratory Medicine, Western Australian Department of Health, Nedlands, WA, Australia
| | - Phillipa J Lamont
- Department of Neurology, Royal Perth Hospital, Nedlands, WA, Australia
| | - Nigel G Laing
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia; Centre of Medical Research, University of Western Australia, Nedlands, WA, Australia; Neurogenetic Unit, Department of Diagnostic Genomics, PathWest Laboratory Medicine, Western Australian Department of Health, Nedlands, WA, Australia
| | - Pierre Bourque
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | | | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, NIHR Biomedical Research Centre, UCL Great Ormond Street Institute of Child Health; Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Kiran Polavarapu
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - Hanns Lochmüller
- CNAG-CRG, Centro Nacional de Análisis Genómico - Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain; Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada; Division of Neurology, Department of Medicine, The Ottawa Hospital; and 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.
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - David Beeson
- Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| |
Collapse
|
3
|
Ndondo AP, Eley B, Wilmshurst JM, Kakooza-Mwesige A, Giannoccaro MP, Willison HJ, Cruz PMR, Heckmann JM, Bateman K, Vincent A. Post-Infectious Autoimmunity in the Central (CNS) and Peripheral (PNS) Nervous Systems: An African Perspective. Front Immunol 2022; 13:833548. [PMID: 35356001 PMCID: PMC8959857 DOI: 10.3389/fimmu.2022.833548] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 02/10/2022] [Indexed: 11/13/2022] Open
Abstract
The direct impact and sequelae of infections in children and adults result in significant morbidity and mortality especially when they involve the central (CNS) or peripheral nervous system (PNS). The historical understanding of the pathophysiology has been mostly focused on the direct impact of the various pathogens through neural tissue invasion. However, with the better understanding of neuroimmunology, there is a rapidly growing realization of the contribution of the innate and adaptive host immune responses in the pathogenesis of many CNS and PNS diseases. The balance between the protective and pathologic sequelae of immunity is fragile and can easily be tipped towards harm for the host. The matter of immune privilege and surveillance of the CNS/PNS compartments and the role of the blood-brain barrier (BBB) and blood nerve barrier (BNB) makes this even more complex. Our understanding of the pathogenesis of many post-infectious manifestations of various microbial agents remains elusive, especially in the diverse African setting. Our exploration and better understanding of the neuroimmunology of some of the infectious diseases that we encounter in the continent will go a long way into helping us to improve their management and therefore lessen the burden. Africa is diverse and uniquely poised because of the mix of the classic, well described, autoimmune disease entities and the specifically "tropical" conditions. This review explores the current understanding of some of the para- and post-infectious autoimmune manifestations of CNS and PNS diseases in the African context. We highlight the clinical presentations, diagnosis and treatment of these neurological disorders and underscore the knowledge gaps and perspectives for future research using disease models of conditions that we see in the continent, some of which are not uniquely African and, where relevant, include discussion of the proposed mechanisms underlying pathogen-induced autoimmunity. This review covers the following conditions as models and highlight those in which a relationship with COVID-19 infection has been reported: a) Acute Necrotizing Encephalopathy; b) Measles-associated encephalopathies; c) Human Immunodeficiency Virus (HIV) neuroimmune disorders, and particularly the difficulties associated with classical post-infectious autoimmune disorders such as the Guillain-Barré syndrome in the context of HIV and other infections. Finally, we describe NMDA-R encephalitis, which can be post-HSV encephalitis, summarise other antibody-mediated CNS diseases and describe myasthenia gravis as the classic antibody-mediated disease but with special features in Africa.
Collapse
Affiliation(s)
- Alvin Pumelele Ndondo
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa
| | - Brian Eley
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa.,Paediatric Infectious Diseases Unit, Red Cross War Memorial Children's Hospital, Cape Town, South Africa
| | - Jo Madeleine Wilmshurst
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa.,Department of Paediatric Neurology, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Angelina Kakooza-Mwesige
- Department of Pediatrics and Child Health, School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Maria Pia Giannoccaro
- Laboratory of Neuromuscular Pathology and Neuroimmunology, Istituto di Ricovero e Cura a CarattereScientifico (IRCCS) Instiuto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica Bologna, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Hugh J Willison
- Institute of Infection, Immunity and Inflammation (3I), University of Glasgow, Glasgow, United Kingdom
| | - Pedro M Rodríguez Cruz
- Centro Nacional de Analisis Genomico - Centre for Genomic Regulation (CNAG-CRG ), Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Department of Neuromuscular Disease, University College London (UCL) Queen Square Institute of Neurology, London, United Kingdom.,Faculté de Médecine, de Pharmacie et d'Odontologie, Université Cheikh Anta Diop, Dakar, Senegal
| | - Jeannine M Heckmann
- Neurology Division, Department of Medicine, Groote Schuur Hospital, Cape Town, South Africa.,The University of Cape Town (UCT) Neurosciences Institute, University of Cape Town, Cape Town, South Africa
| | - Kathleen Bateman
- Neurology Division, Department of Medicine, Groote Schuur Hospital, Cape Town, South Africa
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
4
|
Rodríguez Cruz PM, Hughes I, Manzur A, Munot P, Ramdas S, Wright R, Breen C, Pitt M, Pagnamenta AT, Taylor JC, Palace J, Beeson D. Presynaptic congenital myasthenic syndrome due to three novel mutations in SLC5A7 encoding the sodium-dependant high-affinity choline transporter. Neuromuscul Disord 2021; 31:21-28. [DOI: 10.1016/j.nmd.2020.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 01/14/2023]
|
5
|
Rodríguez Cruz PM, Cossins J, Beeson D, Vincent A. The Neuromuscular Junction in Health and Disease: Molecular Mechanisms Governing Synaptic Formation and Homeostasis. Front Mol Neurosci 2020; 13:610964. [PMID: 33343299 PMCID: PMC7744297 DOI: 10.3389/fnmol.2020.610964] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 10/30/2020] [Indexed: 12/28/2022] Open
Abstract
The neuromuscular junction (NMJ) is a highly specialized synapse between a motor neuron nerve terminal and its muscle fiber that are responsible for converting electrical impulses generated by the motor neuron into electrical activity in the muscle fibers. On arrival of the motor nerve action potential, calcium enters the presynaptic terminal, which leads to the release of the neurotransmitter acetylcholine (ACh). ACh crosses the synaptic gap and binds to ACh receptors (AChRs) tightly clustered on the surface of the muscle fiber; this leads to the endplate potential which initiates the muscle action potential that results in muscle contraction. This is a simplified version of the events in neuromuscular transmission that take place within milliseconds, and are dependent on a tiny but highly structured NMJ. Much of this review is devoted to describing in more detail the development, maturation, maintenance and regeneration of the NMJ, but first we describe briefly the most important molecules involved and the conditions that affect their numbers and function. Most important clinically worldwide, are myasthenia gravis (MG), the Lambert-Eaton myasthenic syndrome (LEMS) and congenital myasthenic syndromes (CMS), each of which causes specific molecular defects. In addition, we mention the neurotoxins from bacteria, snakes and many other species that interfere with neuromuscular transmission and cause potentially fatal diseases, but have also provided useful probes for investigating neuromuscular transmission. There are also changes in NMJ structure and function in motor neuron disease, spinal muscle atrophy and sarcopenia that are likely to be secondary but might provide treatment targets. The NMJ is one of the best studied and most disease-prone synapses in the nervous system and it is amenable to in vivo and ex vivo investigation and to systemic therapies that can help restore normal function.
Collapse
Affiliation(s)
- Pedro M Rodríguez Cruz
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford, United Kingdom
| | - Judith Cossins
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford, United Kingdom
| | - David Beeson
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford, United Kingdom
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford, United Kingdom
| |
Collapse
|
6
|
Cossins J, Webster R, Maxwell S, Rodríguez Cruz PM, Knight R, Llewelyn JG, Shin JY, Palace J, Beeson D. Congenital myasthenic syndrome due to a TOR1AIP1 mutation: a new disease pathway for impaired synaptic transmission. Brain Commun 2020; 2:fcaa174. [PMID: 33215087 PMCID: PMC7660151 DOI: 10.1093/braincomms/fcaa174] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/24/2020] [Accepted: 08/12/2020] [Indexed: 02/06/2023] Open
Abstract
Congenital myasthenic syndromes are inherited disorders characterized by fatiguable muscle weakness resulting from impaired signal transmission at the neuromuscular junction. Causative mutations have been identified in genes that can affect the synaptic function or structure. We identified a homozygous frameshift deletion c.127delC, p. Pro43fs in TOR1AIP1 in two siblings with limb-girdle weakness and impaired transmission at the neuromuscular synapse. TOR1AIP1 encodes the inner nuclear membrane protein lamin-associated protein 1. On muscle biopsy from the index case, lamin-associated protein 1 was absent from myonuclei. A mouse model with lamin-associated protein 1 conditionally knocked out in striated muscle was used to analyse the role of lamin-associated protein 1 in synaptic dysfunction. Model mice develop fatiguable muscle weakness as demonstrated by using an inverted screen hang test. Electromyography on the mice revealed a decrement on repetitive nerve stimulation. Ex vivo analysis of hemi-diaphragm preparations showed both miniature and evoked end-plate potential half-widths were prolonged which was associated with upregulation of the foetal acetylcholine receptor γ subunit. Neuromuscular junctions on extensor digitorum longus muscles were enlarged and fragmented, and the number of subsynaptic nuclei was significantly increased. Following these findings, electromyography was performed on cases of other nuclear envelopathies caused by mutations in LaminA/C or emerin, but decrement on repetitive nerve stimulation or other indications of defective neuromuscular transmission were not seen. Thus, this report highlights the first nuclear membrane protein in which defective function can lead to impaired synaptic transmission.
Collapse
Affiliation(s)
- Judith Cossins
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Richard Webster
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Susan Maxwell
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Pedro M Rodríguez Cruz
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Ravi Knight
- Department of Clinical Neurology, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - John Gareth Llewelyn
- Neurology Department, University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK
| | - Ji-Yeon Shin
- Department of Medicine, Columbia University Medical Centre, New York, NY 10032, USA
| | - Jacqueline Palace
- Department of Clinical Neurology, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - David Beeson
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| |
Collapse
|
7
|
Rodríguez Cruz PM, Cossins J, Estephan EDP, Munell F, Selby K, Hirano M, Maroofin R, Mehrjardi MYV, Chow G, Carr A, Manzur A, Robb S, Munot P, Wei Liu W, Banka S, Fraser H, De Goede C, Zanoteli E, Conti Reed U, Sage A, Gratacos M, Macaya A, Dusl M, Senderek J, Töpf A, Hofer M, Knight R, Ramdas S, Jayawant S, Lochmüller H, Palace J, Beeson D. The clinical spectrum of the congenital myasthenic syndrome resulting from COL13A1 mutations. Brain 2020; 142:1547-1560. [PMID: 31081514 PMCID: PMC6752227 DOI: 10.1093/brain/awz107] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/08/2019] [Accepted: 02/22/2019] [Indexed: 02/02/2023] Open
Abstract
Next generation sequencing techniques were recently used to show mutations in COL13A1 cause synaptic basal lamina-associated congenital myasthenic syndrome type 19. Animal studies showed COL13A1, a synaptic extracellular-matrix protein, is involved in the formation and maintenance of the neuromuscular synapse that appears independent of the Agrin-LRP4-MuSK-DOK7 acetylcholine receptor clustering pathway. Here, we report the phenotypic spectrum of 16 patients from 11 kinships harbouring homozygous or heteroallelic mutations in COL13A1. Clinical presentation was mostly at birth with hypotonia and breathing and feeding difficulties often requiring ventilation and artificial feeding. Respiratory crisis related to recurrent apnoeas, sometimes triggered by chest infections, were common early in life but resolved over time. The predominant pattern of muscle weakness included bilateral ptosis (non-fatigable in adulthood), myopathic facies and marked axial weakness, especially of neck flexion, while limb muscles were less involved. Other features included facial dysmorphism, skeletal abnormalities and mild learning difficulties. All patients tested had results consistent with abnormal neuromuscular transmission. Muscle biopsies were within normal limits or showed non-specific changes. Muscle MRI and serum creatine kinase levels were normal. In keeping with COL13A1 mutations affecting both synaptic structure and presynaptic function, treatment with 3,4-diaminopyridine and salbutamol resulted in motor and respiratory function improvement. In non-treated cases, disease severity and muscle strength improved gradually over time and several adults recovered normal muscle strength in the limbs. In summary, patients with COL13A1 mutations present mostly with severe early-onset myasthenic syndrome with feeding and breathing difficulties. Axial weakness is greater than limb weakness. Disease course improves gradually over time, which could be consistent with the less prominent role of COL13A1 once the neuromuscular junction is mature. This report emphasizes the role of collagens at the human muscle endplate and should facilitate the recognition of this disorder, which can benefit from pharmacological treatment.
Collapse
Affiliation(s)
- Pedro M Rodríguez Cruz
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.,Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Judith Cossins
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Eduardo de Paula Estephan
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - Francina Munell
- Neuromuscular disorders Group, Child Neurology Unit, Hospital Universitari Vall d'Hebron, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Kathryn Selby
- University of British Columbia, Vancouver, British Columbia, Canada
| | - Michio Hirano
- Department of Neurology, H. Houston Merritt Neuromuscular Research Center, Columbia University Medical Center, New York, NY, USA
| | - Reza Maroofin
- Molecular and Clinical Sciences Institute, St. George's, University of London, Cranmer Terrace, London, UK
| | | | - Gabriel Chow
- Department of Paediatric Neurology, Nottingham City Hospital, Nottingham University Hospitals NHS Trust, Hucknall Road, Nottingham, UK
| | - Aisling Carr
- MRC Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, UK
| | - Adnan Manzur
- Dubowitz Neuromuscular Centre and MRC Centre for Neuromuscular Diseases, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Stephanie Robb
- Dubowitz Neuromuscular Centre and MRC Centre for Neuromuscular Diseases, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Pinki Munot
- Dubowitz Neuromuscular Centre and MRC Centre for Neuromuscular Diseases, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Wei Wei Liu
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Siddharth Banka
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester, UK
| | - Harry Fraser
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester, UK
| | | | - Edmar Zanoteli
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - Umbertina Conti Reed
- Departamento de Neurologia, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, Brazil
| | - Abigail Sage
- Department of Neurology, H. Houston Merritt Neuromuscular Research Center, Columbia University Medical Center, New York, NY, USA
| | - Margarida Gratacos
- Department of Clinical Neurophysiology, Hospital Universitari Vall d'Hebron, Barcelona Spain
| | - Alfons Macaya
- Neuromuscular disorders Group, Child Neurology Unit, Hospital Universitari Vall d'Hebron, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Marina Dusl
- Friedrich-Baur-Institute at the Department of Neurology, University Hospital LMU Munich, Munich, Germany
| | - Jan Senderek
- Friedrich-Baur-Institute at the Department of Neurology, University Hospital LMU Munich, Munich, Germany
| | - Ana Töpf
- Institute of Genetic Medicine, Central Parkway, Newcastle upon Tyne, UK
| | - Monika Hofer
- Department of Neuropathology, John Radcliffe Hospital NHS Foundation Trust, Oxford, UK
| | - Ravi Knight
- Department of Clinical Neurophysiology, John Radcliffe Hospital NHS Foundation Trust, Oxford, UK
| | - Sithara Ramdas
- Department of Paediatric Neurology, John Radcliffe Hospital NHS Foundation Trust, Oxford, UK
| | - Sandeep Jayawant
- Department of Paediatric Neurology, John Radcliffe Hospital NHS Foundation Trust, Oxford, UK
| | - Hans Lochmüller
- 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, Spain.,Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada.,Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Canada
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - David Beeson
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
8
|
Rodríguez Cruz PM, Cossins J, Cheung J, Maxwell S, Jayawant S, Herbst R, Waithe D, Kornev AP, Palace J, Beeson D. Congenital myasthenic syndrome due to mutations in MUSK suggests that the level of MuSK phosphorylation is crucial for governing synaptic structure. Hum Mutat 2019; 41:619-631. [PMID: 31765060 PMCID: PMC7028094 DOI: 10.1002/humu.23949] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/08/2019] [Accepted: 11/05/2019] [Indexed: 11/18/2022]
Abstract
MUSK encodes the muscle‐specific receptor tyrosine kinase (MuSK), a key component of the agrin‐LRP4‐MuSK‐DOK7 signaling pathway, which is essential for the formation and maintenance of highly specialized synapses between motor neurons and muscle fibers. We report a patient with severe early‐onset congenital myasthenic syndrome and two novel missense mutations in MUSK (p.C317R and p.A617V). Functional studies show that MUSK p.C317R, located at the frizzled‐like cysteine‐rich domain of MuSK, disrupts an integral part of MuSK architecture resulting in ablated MuSK phosphorylation and acetylcholine receptor (AChR) cluster formation. MUSK p.A617V, located at the kinase domain of MuSK, enhances MuSK phosphorylation resulting in anomalous AChR cluster formation. The identification and evidence for pathogenicity of MUSK mutations supported the initiation of treatment with β2‐adrenergic agonists with a dramatic improvement of muscle strength in the patient. This work suggests uncharacterized mechanisms in which control of the precise level of MuSK phosphorylation is crucial in governing synaptic structure.
Collapse
Affiliation(s)
- Pedro M Rodríguez Cruz
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Neurosciences Group, The John Radcliffe Hospital, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Judith Cossins
- Neurosciences Group, The John Radcliffe Hospital, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Jonathan Cheung
- Neurosciences Group, The John Radcliffe Hospital, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Susan Maxwell
- Neurosciences Group, The John Radcliffe Hospital, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Sandeep Jayawant
- Department of Paediatric Neurology, Children's Hospital, John Radcliffe Hospital, Oxford, UK
| | - Ruth Herbst
- Center for Pathophysiology, Infectiology and Immunology, Medical Science Divisions, Medical University of Vienna, Vienna, Austria
| | - Dominic Waithe
- MRC Centre for Computational Biology and Wolfson Imaging Centre, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Alexandr P Kornev
- Department of Pharmacology, University of California at San Diego, La Jolla, California
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - David Beeson
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Neurosciences Group, The John Radcliffe Hospital, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
9
|
Rodríguez Cruz PM, Palace J, Beeson D. The Neuromuscular Junction and Wide Heterogeneity of Congenital Myasthenic Syndromes. Int J Mol Sci 2018; 19:ijms19061677. [PMID: 29874875 PMCID: PMC6032286 DOI: 10.3390/ijms19061677] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/17/2018] [Accepted: 05/21/2018] [Indexed: 01/16/2023] Open
Abstract
Congenital myasthenic syndromes (CMS) are genetic disorders characterised by impaired neuromuscular transmission. This review provides an overview on CMS and highlights recent advances in the field, including novel CMS causative genes and improved therapeutic strategies. CMS due to mutations in SLC5A7 and SLC18A3, impairing the synthesis and recycling of acetylcholine, have recently been described. In addition, a novel group of CMS due to mutations in SNAP25B, SYT2, VAMP1, and UNC13A1 encoding molecules implicated in synaptic vesicles exocytosis has been characterised. The increasing number of presynaptic CMS exhibiting CNS manifestations along with neuromuscular weakness demonstrate that the myasthenia can be only a small part of a much more extensive disease phenotype. Moreover, the spectrum of glycosylation abnormalities has been increased with the report that GMPPB mutations can cause CMS, thus bridging myasthenic disorders with dystroglycanopathies. Finally, the discovery of COL13A1 mutations and laminin α5 deficiency has helped to draw attention to the role of extracellular matrix proteins for the formation and maintenance of muscle endplates. The benefit of β2-adrenergic agonists alone or combined with pyridostigmine or 3,4-Dyaminopiridine is increasingly being reported for different subtypes of CMS including AChR-deficiency and glycosylation abnormalities, thus expanding the therapeutic repertoire available.
Collapse
Affiliation(s)
- Pedro M Rodríguez Cruz
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
- Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford OX3 9DS, UK.
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
| | - David Beeson
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
- Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford OX3 9DS, UK.
| |
Collapse
|
10
|
Rodríguez Cruz PM, Belaya K, Basiri K, Sedghi M, Farrugia ME, Holton JL, Liu WW, Maxwell S, Petty R, Walls TJ, Kennett R, Pitt M, Sarkozy A, Parton M, Lochmüller H, Muntoni F, Palace J, Beeson D. Clinical features of the myasthenic syndrome arising from mutations in GMPPB. J Neurol Neurosurg Psychiatry 2016; 87:802-9. [PMID: 27147698 PMCID: PMC6047737 DOI: 10.1136/jnnp-2016-313163] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/31/2016] [Indexed: 11/04/2022]
Abstract
BACKGROUND Congenital myasthenic syndrome (CMS) due to mutations in GMPPB has recently been reported confirming the importance of glycosylation for the integrity of neuromuscular transmission. METHODS Review of case notes of patients with mutations in GMPPB to identify the associated clinical, neurophysiological, pathological and laboratory features. In addition, serum creatine kinase (CK) levels within the Oxford CMS cohort were retrospectively analysed to assess its usefulness in the differential diagnosis of this new entity. RESULTS All patients had prominent limb-girdle weakness with minimal or absent craniobulbar manifestations. Presentation was delayed beyond infancy with proximal muscle weakness and most patients recall poor performance in sports during childhood. Neurophysiology showed abnormal neuromuscular transmission only in the affected muscles and myopathic changes. Muscle biopsy showed dystrophic features and reduced α-dystroglycan glycosylation. In addition, myopathic changes were present on muscle MRI. CK was significantly increased in serum compared to other CMS subtypes. Patients were responsive to pyridostigimine alone or combined with 3,4-diaminopyridine and/or salbutamol. CONCLUSIONS Patients with GMPPB-CMS have phenotypic features aligned with CMS subtypes harbouring mutations within the early stages of the glycosylation pathway. Additional features shared with the dystroglycanopathies include myopathic features, raised CK levels and variable mild cognitive delay. This syndrome underlines that CMS can occur in the absence of classic myasthenic manifestations such as ptosis and ophthalmoplegia or facial weakness, and links myasthenic disorders with dystroglycanopathies. This report should facilitate the recognition of this disorder, which is likely to be underdiagnosed and can benefit from symptomatic treatment.
Collapse
Affiliation(s)
- Pedro M Rodríguez Cruz
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Katsiaryna Belaya
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Keivan Basiri
- Neurology Department, Neuroscience Research Centre, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Maryam Sedghi
- Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Maria Elena Farrugia
- Department of Neurology, Institute of Neurological Sciences, The Queen Elizabeth University Hospital, Glasgow, UK
| | - Janice L Holton
- Department of Molecular Neurosciences, UCL Institute of Neurology, London, UK MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Wei Wei Liu
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Susan Maxwell
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Richard Petty
- Department of Neurology, Institute of Neurological Sciences, The Queen Elizabeth University Hospital, Glasgow, UK
| | - Timothy J Walls
- Department of Neurology, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Robin Kennett
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Matthew Pitt
- Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Anna Sarkozy
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Matt Parton
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Hanns Lochmüller
- Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre & MRC Centre for Neuromuscular Diseases, UCL Institute of Child Health, London, UK
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - David Beeson
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
11
|
Rodríguez Cruz PM, Vargas A, Fernández-Carballal C, Garbizu J, De La Casa-Fages B, Grandas F. Long-term Thalamic Deep Brain Stimulation for Essential Tremor: Clinical Outcome and Stimulation Parameters. Mov Disord Clin Pract 2016; 3:567-572. [PMID: 30363558 DOI: 10.1002/mdc3.12337] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/25/2015] [Accepted: 01/04/2016] [Indexed: 11/09/2022] Open
Abstract
Background The reasons underlying the loss of efficacy of deep brain stimulation (DBS) of the thalamic nucleus ventralis intermedius (VIM-DBS) over time in patients with essential tremor are not well understood. Methods Long-term clinical outcome and stimulation parameters were evaluated in 14 patients with essential tremor who underwent VIM-DBS. The mean ± standard deviation postoperative follow-up was 7.7 ± 3.8 years. At each visit (every 3-6 months), tremor was assessed using the Fahn-Tolosa-Marin tremor rating scale (FTM-TRS) and stimulation parameters were recorded (contacts, voltage, frequency, pulse width, and total electrical energy delivered by the internal generator [TEED 1sec]). Results The mean reduction in FTM-TRS score was 73.4% at 6 months after VIM-DBS surgery (P < 0.001) and 50.1% at the last visit (P < 0.001). The gradual worsening of FTM-TRS scores over time fit a linear regression model (coefficient of determination [R2] = 0.887; P < 0.001). Stimulation adjustments to optimize tremor control required a statistically significant increase in voltage (P = 0.01), pulse width (P = 0.01), frequency (P = 0.02), and TEED 1sec (P = 0.008). TEED 1sec fit a third-order polynomial curve model throughout the follow-up period (R2 = 0.966; P < 0.001). The initial exponential increase (first 4 years of VIM-DBS) was followed by a plateau and a further increase from the seventh year onward. Conclusions The current findings suggest that the waning effect of VIM-DBS over time in patients with essential tremor may be the consequence of a combination of factors. Superimposed on the progression of the disease, tolerance can occur during the early years of stimulation.
Collapse
Affiliation(s)
- Pedro M Rodríguez Cruz
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Antonio Vargas
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Carlos Fernández-Carballal
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Jose Garbizu
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Beatriz De La Casa-Fages
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| | - Francisco Grandas
- Movement Disorders Deep Brain Stimulation Group Hospital General Universitario Gregorio Marañón Madrid Spain
| |
Collapse
|
12
|
Rodríguez Cruz PM, Palace J, Ramjattan H, Jayawant S, Robb SA, Beeson D. Salbutamol and ephedrine in the treatment of severe AChR deficiency syndromes. Neurology 2015; 85:1043-7. [PMID: 26296515 DOI: 10.1212/wnl.0000000000001952] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To evaluate the response to salbutamol and ephedrine in the treatment of congenital myasthenic syndromes due to CHRNE mutations causing severe acetylcholine receptor (AChR)deficiency. METHODS A cohort study of 6 patients with severe AChR deficiency, symptomatic despite optimal therapy with anticholinesterase and 3,4-diaminopyridine, were analyzed for their response to the addition of salbutamol or ephedrine to their medication. Baseline quantitative myasthenia gravis (QMG) (severity) scores were worse than 15 of 39. Patients were assessed in clinic with QMG and mobility scores. Pretreatment and 6- to 8-month follow-up scores were evaluated. RESULTS All 6 patients tolerated treatment well and reported no side effects. There was a strong positive response to treatment over the 6- to 8-month assessment period with significant improvement in QMG (p = 0.027) and mobility scores. The analysis of subcomponents of the QMG score revealed marked improvement in upper (p = 0.028) and lower (p = 0.028) limb raise times. All patients reported enhanced activities of daily living at 6 to 8 months. CONCLUSIONS Oral salbutamol and ephedrine appear to be effective treatments in severe cases ofAChR deficiency on pyridostigmine. They are well tolerated and improvement in strength can be dramatic. Classification of evidence: This study provides Class IV evidence that salbutamol or ephedrine improves muscle strength in patients with congenital myasthenia from severe AChR deficiency.
Collapse
|
13
|
Logan CV, Cossins J, Rodríguez Cruz PM, Parry DA, Maxwell S, Martínez-Martínez P, Riepsaame J, Abdelhamed ZA, Lake AVR, Moran M, Robb S, Chow G, Sewry C, Hopkins PM, Sheridan E, Jayawant S, Palace J, Johnson CA, Beeson D. Congenital Myasthenic Syndrome Type 19 Is Caused by Mutations in COL13A1, Encoding the Atypical Non-fibrillar Collagen Type XIII α1 Chain. Am J Hum Genet 2015; 97:878-85. [PMID: 26626625 PMCID: PMC4678414 DOI: 10.1016/j.ajhg.2015.10.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/28/2015] [Indexed: 12/30/2022] Open
Abstract
The neuromuscular junction (NMJ) consists of a tripartite synapse with a presynaptic nerve terminal, Schwann cells that ensheathe the terminal bouton, and a highly specialized postsynaptic membrane. Synaptic structural integrity is crucial for efficient signal transmission. Congenital myasthenic syndromes (CMSs) are a heterogeneous group of inherited disorders that result from impaired neuromuscular transmission, caused by mutations in genes encoding proteins that are involved in synaptic transmission and in forming and maintaining the structural integrity of NMJs. To identify further causes of CMSs, we performed whole-exome sequencing (WES) in families without an identified mutation in known CMS-associated genes. In two families affected by a previously undefined CMS, we identified homozygous loss-of-function mutations in COL13A1, which encodes the alpha chain of an atypical non-fibrillar collagen with a single transmembrane domain. COL13A1 localized to the human muscle motor endplate. Using CRISPR-Cas9 genome editing, modeling of the COL13A1 c.1171delG (p.Leu392Sfs∗71) frameshift mutation in the C2C12 cell line reduced acetylcholine receptor (AChR) clustering during myotube differentiation. This highlights the crucial role of collagen XIII in the formation and maintenance of the NMJ. Our results therefore delineate a myasthenic disorder that is caused by loss-of-function mutations in COL13A1, encoding a protein involved in organization of the NMJ, and emphasize the importance of appropriate symptomatic treatment for these individuals.
Collapse
Affiliation(s)
- Clare V Logan
- Section of Ophthalmology & Neurosciences, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds LS9 7TF, UK
| | - Judith Cossins
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Pedro M Rodríguez Cruz
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - David A Parry
- Section of Genetics, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds LS9 7TF, UK
| | - Susan Maxwell
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Pilar Martínez-Martínez
- Neuroimmunology Group, Division of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, PO box 616, 6200 MD Maastricht, the Netherlands
| | - Joey Riepsaame
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Zakia A Abdelhamed
- Section of Ophthalmology & Neurosciences, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds LS9 7TF, UK
| | - Alice V R Lake
- Section of Ophthalmology & Neurosciences, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds LS9 7TF, UK
| | - Maria Moran
- Department of Paediatric Neurology, Nottingham City Hospital, Nottingham University Hospitals NHS Trust, Hucknall Road, Nottingham NG5 1PB, UK
| | - Stephanie Robb
- Dubowitz Neuromuscular Centre, Institute of Child Health and Great Ormond Street Hospital, 30 Guilford Street, London WC1N 1EH, UK
| | - Gabriel Chow
- Department of Paediatric Neurology, Nottingham City Hospital, Nottingham University Hospitals NHS Trust, Hucknall Road, Nottingham NG5 1PB, UK
| | - Caroline Sewry
- Dubowitz Neuromuscular Centre, Institute of Child Health and Great Ormond Street Hospital, 30 Guilford Street, London WC1N 1EH, UK
| | - Philip M Hopkins
- Section of Translational Anaesthesia and Surgical Sciences, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds LS9 7TF, UK
| | - Eamonn Sheridan
- Section of Genetics, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds LS9 7TF, UK
| | - Sandeep Jayawant
- Department of Paediatric Neurology, John Radcliffe Hospital, Oxford Radcliffe Hospitals NHS Trust, Oxford OX3 9DU, UK
| | - Jacqueline Palace
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK; Department of Clinical Neurology, John Radcliffe Hospital, Oxford Radcliffe Hospitals NHS Trust, Oxford OX3 9DU, UK
| | - Colin A Johnson
- Section of Ophthalmology & Neurosciences, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds LS9 7TF, UK.
| | - David Beeson
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK.
| |
Collapse
|
14
|
Rodríguez Cruz PM, Al-Hajjar M, Huda S, Jacobson L, Woodhall M, Jayawant S, Buckley C, Hilton-Jones D, Beeson D, Vincent A, Leite MI, Palace J. Clinical Features and Diagnostic Usefulness of Antibodies to Clustered Acetylcholine Receptors in the Diagnosis of Seronegative Myasthenia Gravis. JAMA Neurol 2015; 72:642-9. [PMID: 25894002 DOI: 10.1001/jamaneurol.2015.0203] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Cell-based assays (CBAs) were shown to improve detection of acetylcholine receptor (AChR) antibodies in patients with myasthenia gravis (MG). Herein, we asked whether these assays were able to help determine the diagnosis in patients studied in routine clinical practice. OBJECTIVES To determine the diagnostic usefulness of CBAs in the diagnosis of MG and to compare the clinical features of patients with antibodies only to clustered AChRs with those of patients with seronegative MG (SNMG). DESIGN, SETTING, AND PARTICIPANTS All patients with clinical suspicion of MG who were seen within the Division of Clinical Neurology at the John Radcliffe Hospital in Oxford, England, between November 1, 2009, and November 30, 2013. Their serum antibodies and clinical features were studied. EXPOSURES Radioimmunoprecipitation assay (RIPA) and CBA were used to test for standard AChR antibodies and antibodies to clustered AChRs in 138 patients. All available samples from patients with SNMG were retrospectively tested for lipoprotein receptor-related protein 4 (LRP4) antibodies. MAIN OUTCOMES AND MEASURES Demographic, clinical, neurophysiological, and laboratory data. RESULTS In total, 138 patients were tested for antibodies to clustered AChRs, and 42 had a final diagnosis of MG. The clustered AChR CBA detected antibodies in 38.1% (16 of 42) of RIPA-negative patients with MG with 100% specificity. All patients with SNMG who were tested for LRP4 antibodies (21 of 26) were negative by CBA. Compared with patients with SNMG, patients with antibodies only to clustered AChRs had frequent prepubertal onset (62.5% [median age, 6 years; age range, 1-52 years] vs 11.5% [median age, 38 years; age range, 2-72 years], P ≤ .05), high prevalence of ocular MG (62.5% vs 42.3%), milder disease severity with less bulbar involvement (25.0% vs 46.2%), and absence of respiratory symptoms (0% vs 23.1%). Response to treatment and prognosis was good, with a reduced need for thymectomy (6.3% vs 19.2%) and a high proportion of patients going into remission (50.0% vs 8.3%, P ≤ .05). These observations also apply to the classic AChR MG phenotype seen in large series. CONCLUSIONS AND RELEVANCE Cell-based assay is a useful procedure in the routine diagnosis of RIPA-negative MG, particularly in children. Patients with antibodies only to clustered AChRs appear to be younger and have milder disease than other patients with MG. These observations will have implications in planning treatment.
Collapse
Affiliation(s)
- Pedro M Rodríguez Cruz
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England2Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - Michal Al-Hajjar
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - Saif Huda
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - Leslie Jacobson
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - Mark Woodhall
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - Sandeep Jayawant
- Department of Paediatric Neurology, Children's Hospital, John Radcliffe Hospital, Oxford, England
| | - Camilla Buckley
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - David Hilton-Jones
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - David Beeson
- Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - Maria Isabel Leite
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, England
| |
Collapse
|
15
|
Belaya K, Rodríguez Cruz PM, Liu WW, Maxwell S, McGowan S, Farrugia ME, Petty R, Walls TJ, Sedghi M, Basiri K, Yue WW, Sarkozy A, Bertoli M, Pitt M, Kennett R, Schaefer A, Bushby K, Parton M, Lochmüller H, Palace J, Muntoni F, Beeson D. Mutations in GMPPB cause congenital myasthenic syndrome and bridge myasthenic disorders with dystroglycanopathies. Brain 2015; 138:2493-504. [PMID: 26133662 PMCID: PMC4547052 DOI: 10.1093/brain/awv185] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 05/04/2015] [Indexed: 01/10/2023] Open
Abstract
Congenital myasthenic syndromes are associated with impairments in neuromuscular transmission. Belaya et al. show that mutations of the glycosylation pathway enzyme GMPPB, which has previously been implicated in muscular dystrophy dystroglycanopathy, also cause a congenital myasthenic syndrome. This differential diagnosis is important to ensure that affected individuals receive appropriate medication. Congenital myasthenic syndromes are inherited disorders that arise from impaired signal transmission at the neuromuscular junction. Mutations in at least 20 genes are known to lead to the onset of these conditions. Four of these, ALG2, ALG14, DPAGT1 and GFPT1, are involved in glycosylation. Here we identify a fifth glycosylation gene, GMPPB, where mutations cause congenital myasthenic syndrome. First, we identified recessive mutations in seven cases from five kinships defined as congenital myasthenic syndrome using decrement of compound muscle action potentials on repetitive nerve stimulation on electromyography. The mutations were present through the length of the GMPPB, and segregation, in silico analysis, exon trapping, cell transfection followed by western blots and immunostaining were used to determine pathogenicity. GMPPB congenital myasthenic syndrome cases show clinical features characteristic of congenital myasthenic syndrome subtypes that are due to defective glycosylation, with variable weakness of proximal limb muscle groups while facial and eye muscles are largely spared. However, patients with GMPPB congenital myasthenic syndrome had more prominent myopathic features that were detectable on muscle biopsies, electromyography, muscle magnetic resonance imaging, and through elevated serum creatine kinase levels. Mutations in GMPPB have recently been reported to lead to the onset of muscular dystrophy dystroglycanopathy. Analysis of four additional GMPPB-associated muscular dystrophy dystroglycanopathy cases by electromyography found that a defective neuromuscular junction component is not always present. Thus, we find mutations in GMPPB can lead to a wide spectrum of clinical features where deficit in neuromuscular transmission is the major component in a subset of cases. Clinical recognition of GMPPB-associated congenital myasthenic syndrome may be complicated by the presence of myopathic features, but correct diagnosis is important because affected individuals can respond to appropriate treatments.
Collapse
Affiliation(s)
- Katsiaryna Belaya
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Pedro M Rodríguez Cruz
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK 2 Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Wei Wei Liu
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Susan Maxwell
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Simon McGowan
- 3 Computational Biology Research Group, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Maria E Farrugia
- 4 Department of Neurology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, UK
| | - Richard Petty
- 4 Department of Neurology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, UK
| | - Timothy J Walls
- 5 Department of Neurology, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - Maryam Sedghi
- 6 Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Keivan Basiri
- 7 Neurology Department, Neuroscience Research Centre, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Wyatt W Yue
- 8 Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ, UK
| | - Anna Sarkozy
- 9 Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK 10 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Marta Bertoli
- 9 Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - Matthew Pitt
- 11 Department of Clinical Neurophysiology, Great Ormond Street Hospital for children NHS foundation trust, London WC1N 3JH
| | - Robin Kennett
- 2 Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Andrew Schaefer
- 5 Department of Neurology, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - Kate Bushby
- 9 Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - Matt Parton
- 10 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Hanns Lochmüller
- 9 Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - Jacqueline Palace
- 2 Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Francesco Muntoni
- 12 Dubowitz Neuromuscular Centre and MRC Centre for Neuromuscular Diseases, UCL Institute of Child Health, London, WC1N 1EH, UK
| | - David Beeson
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| |
Collapse
|
16
|
Rodríguez Cruz PM, Sewry C, Beeson D, Jayawant S, Squier W, McWilliam R, Palace J. Congenital myopathies with secondary neuromuscular transmission defects; A case report and review of the literature. Neuromuscul Disord 2014; 24:1103-10. [DOI: 10.1016/j.nmd.2014.07.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 06/27/2014] [Accepted: 07/18/2014] [Indexed: 01/14/2023]
|
17
|
Rodríguez Cruz PM, Needham M, Hollingsworth P, Mastaglia FL, Hillman DR. Sleep disordered breathing and subclinical impairment of respiratory function are common in sporadic inclusion body myositis. Neuromuscul Disord 2014; 24:1036-41. [DOI: 10.1016/j.nmd.2014.08.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/15/2014] [Accepted: 08/10/2014] [Indexed: 10/24/2022]
|
18
|
Rodríguez Cruz PM, Luo YB, Miller J, Junckerstorff RC, Mastaglia FL, Fabian V. An analysis of the sensitivity and specificity of MHC-I and MHC-II immunohistochemical staining in muscle biopsies for the diagnosis of inflammatory myopathies. Neuromuscul Disord 2014; 24:1025-35. [PMID: 25153265 DOI: 10.1016/j.nmd.2014.06.436] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 06/17/2014] [Accepted: 06/20/2014] [Indexed: 01/09/2023]
Abstract
Although there have been several previous reports of immunohistochemical staining for MHC antigens in muscle biopsies, there appears to be a lack of consensus about its routine use in the diagnostic evaluation of biopsies from patients with suspected inflammatory myopathy. Positive MHC-I staining is nonspecific but is widely used as a marker for inflammatory myopathy, whilst the role of MHC-II staining is not clearly defined. We investigated the sensitivity and specificity of MHC-I and MHC-II immunostaining for the diagnosis of inflammatory myopathy in a large group of biopsies from a single reference laboratory. Positive staining for MHC-I was found to have a high sensitivity in biopsies from patients with inflammatory myopathy but a very low specificity, as it was also common in other non-inflammatory myopathies and neurogenic disorders. On the other hand, MHC-II positivity had a much higher specificity in all major subgroups of inflammatory myopathy, especially inclusion body myositis. The findings indicate that the combination of MHC-I and MHC-II staining results in a higher degree of specificity for the diagnosis of inflammatory myopathy and that in biopsies with inflammation, positive MHC-II staining strongly supports the diagnosis of an immune-mediated myopathy. We recommend that immunohistochemical staining for both MHC-I and MHC-II should be included routinely in the diagnostic evaluation of muscle biopsies from patients with suspected inflammatory myopathy. However, as the sensitivity and interpretation of MHC staining may depend on the technique used, further studies are needed to compare procedures in different centres and develop standardised protocols.
Collapse
Affiliation(s)
- Pedro M Rodríguez Cruz
- Centre for Neuromuscular and Neurological Disorders, Western Australian Neuroscience Research Institute, Perth, Australia; Department of Neurology, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Yue-Bei Luo
- Centre for Neuromuscular and Neurological Disorders, Western Australian Neuroscience Research Institute, Perth, Australia; Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - James Miller
- Department of Neurology, Royal Victoria Infirmary, Newcastle-upon-Tyne, United Kingdom
| | - Reimar C Junckerstorff
- Section of Neuropathology, Department of Anatomical Pathology, PathWest Laboratory Medicine WA, Royal Perth Hospital, Perth, Western Australia, Australia; School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands, Western Australia, Australia
| | - Frank L Mastaglia
- Centre for Neuromuscular and Neurological Disorders, Western Australian Neuroscience Research Institute, Perth, Australia; Institute for Immunology & Infectious Diseases, Murdoch University, Perth, Australia.
| | - Victoria Fabian
- Section of Neuropathology, Department of Anatomical Pathology, PathWest Laboratory Medicine WA, Royal Perth Hospital, Perth, Western Australia, Australia; School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands, Western Australia, Australia
| |
Collapse
|