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Ibarra Moreno CA, Silva HCA, Voermans NC, Jungbluth H, van den Bersselaar LR, Rendu J, Cieniewicz A, Hopkins PM, Riazi S. Myopathic manifestations across the adult lifespan of patients with malignant hyperthermia susceptibility: a narrative review. Br J Anaesth 2024; 133:759-767. [PMID: 39107166 PMCID: PMC11443134 DOI: 10.1016/j.bja.2024.05.046] [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: 02/17/2024] [Revised: 05/27/2024] [Accepted: 05/29/2024] [Indexed: 08/09/2024] Open
Abstract
Malignant hyperthermia susceptibility (MHS) designates individuals at risk of developing a hypermetabolic reaction triggered by halogenated anaesthetics or the depolarising neuromuscular blocking agent suxamethonium. Over the past few decades, beyond the operating theatre, myopathic manifestations impacting daily life are increasingly recognised as a prevalent phenomenon in MHS patients. At the request of the European Malignant Hyperthermia Group, we reviewed the literature and gathered the opinion of experts to define MHS-related myopathy as a distinct phenotype expressed across the adult lifespan of MHS patients unrelated to anaesthetic exposure; this serves to raise awareness about non-anaesthetic manifestations, potential therapies, and management of MHS-related myopathy. We focused on the clinical presentation, biochemical and histopathological findings, and the impact on patient well-being. The spectrum of symptoms of MHS-related myopathy encompasses muscle cramps, stiffness, myalgias, rhabdomyolysis, and weakness, with a wide age range of onset mainly during adulthood. Histopathological analysis can reveal nonspecific abnormalities suggestive of RYR1 involvement, while metabolic profiling reflects altered energy metabolism in MHS muscle. Myopathic manifestations can significantly impact patient quality of life and lead to functional limitations and socio-economic burden. While currently available therapies can provide symptomatic relief, there is a need for further research into targeted treatments addressing the underlying pathophysiology. Counselling early after establishing the MHS diagnosis, followed by multidisciplinary management involving various medical specialties, is crucial to optimise patient care.
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Affiliation(s)
- Carlos A Ibarra Moreno
- Malignant Hyperthermia Investigation Unit, Department of Anesthesiology and Pain Management, University Health Network, Toronto, ON, Canada
| | - Helga C A Silva
- Malignant Hyperthermia Unit, Department of Anesthesiology, Pain and Intensive Care, Federal University of São Paulo, São Paulo, Brazil
| | - Nicol C Voermans
- Department of Neurology, Radboudumc Research Institute for Medical Innovation, Nijmegen, The Netherlands
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina London Children's Hospital, Guy's and St. Thomas' Hospital NHS Foundation Trust, London, UK; Randall Centre for Cell and Molecular Biophysics, Muscle Signalling Section, Faculty of Life Sciences and Medicine (FoLSM), King's College London, London, UK
| | - Luuk R van den Bersselaar
- Malignant Hyperthermia Investigation Unit, Department of Anesthesiology, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands; Department of Anesthesiology, Pain and Palliative Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - John Rendu
- Universite Grenoble Alpes, INSERM, Grenoble Institut Neurosciences, U1216, CHU Grenoble Alpes, Grenoble, France
| | - Agnieszka Cieniewicz
- Department of Anaesthesiology and Intensive Therapy, Institute of Tuberculosis and Lung Diseases, Warsaw, Poland
| | - Philip M Hopkins
- Leeds Institute of Medical Research at St James's, University of Leeds, Leeds, UK; Department of Anaesthesia, St James's University Hospital, Leeds Teaching Hospitals, NHS Trust, Leeds, UK
| | - Sheila Riazi
- Malignant Hyperthermia Investigation Unit, Department of Anesthesiology and Pain Management, University Health Network, Toronto, ON, Canada.
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Moreno CAI, Kraeva N, Zvaritch E, Jungbluth H, Voermans NC, Riazi S. Oral Dantrolene for Myopathic Symptoms in Malignant Hyperthermia-Susceptible Patients: A 25-Year Retrospective Cohort Study of Adverse Effects and Tolerability. Anesth Analg 2023; 136:569-577. [PMID: 36201369 PMCID: PMC9974786 DOI: 10.1213/ane.0000000000006207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND Patients susceptible to malignant hyperthermia (MH) may experience disabling manifestations of an unspecified myopathy outside the context of anesthesia, including myalgia, fatigue, or episodic rhabdomyolysis. Clinical observations suggest that oral dantrolene may relief myopathic symptoms in MH-susceptible (MHS) patients. However, high-dose oral dantrolene has been associated with severe hepatotoxicity. METHODS In a retrospective database review (1994-2018), we investigated a cohort of patients who were diagnosed as MHS by a positive caffeine-halothane contracture test (CHCT), had myopathic manifestations, and received oral dantrolene. Our aim was to investigate the occurrence of serious adverse effects and the adherence to oral dantrolene therapy. We also explored factors associated with self-reported clinical improvement, considering as nonresponders patients with intolerable adverse effects or who reported no improvement 8 weeks after starting treatment. RESULTS Among 476 MHS patients with positive CHCT, 193 had muscle symptoms, 164 started oral dantrolene, 27 refused treatment, and 2 were excluded due to abnormal liver function before starting therapy. There were no serious adverse effects reported. Forty-six of 164 patients (28%; 95% confidence interval [CI], 22%-35%) experienced mild to moderate adverse effects. Twenty-two patients (22/164, 13%; 95% CI, 9%-19%) discontinued treatment, among which 16 due to adverse effects and 6 due to lack of improvement. One hundred forty-two patients (87%; 95% CI, 80%-90%) adhered to therapy and reported improvement of myalgia (n = 78), fatigue (n = 32), or rhabdomyolysis/hiperCKemia (n = 32). The proportion of responders was larger among patients with MH history than among those referred due to a clinical myopathy with nonpertinent anesthetic history (97% vs 79%, respectively; 95% CI of the difference, 8.5-28; P < .001). Patients with a sarcoplasmic reticulum Ca2+ release channel ryanodine receptor gene ( RYR1 ) variant had higher odds of responding to dantrolene treatment (OR, 6.4; 95% CI, 1.3-30.9; P = .013). Dantrolene median dose was 50 (25-400) and 200 (25-400) mg·day -1 in responders and nonresponders, respectively. CONCLUSIONS We found that oral dantrolene produced no serious adverse effects within the reported dose range, and was well tolerated by most MH-susceptible patients presenting myopathic symptoms. Our study provides dosing and adverse effect data as a basis for further randomized controlled clinical trials to determine the efficacy of oral dantrolene for symptomatic relief in MHS-related myopathies.
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Affiliation(s)
- Carlos A. Ibarra Moreno
- Department of Anesthesiology and Pain Medicine, Malignant Hyperthermia Investigation Unit, Toronto General Hospital–University Health Network, Toronto, Ontario, Canada
| | - Natalia Kraeva
- Department of Anesthesiology and Pain Medicine, Malignant Hyperthermia Investigation Unit, Toronto General Hospital–University Health Network, Toronto, Ontario, Canada
| | - Elena Zvaritch
- Department of Anesthesiology and Pain Medicine, Malignant Hyperthermia Investigation Unit, Toronto General Hospital–University Health Network, Toronto, Ontario, Canada
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children’s Hospital, Guy’s and St Thomas’ Hospital NHS Foundation Trust, London, United Kingdom, Randall Centre for Cell and Molecular Biophysics, Muscle Signalling Section, Faculty of Life Sciences and Medicine, King’s College, London, United Kingdom
| | - Nicol C. Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Sheila Riazi
- Department of Anesthesiology and Pain Medicine, Malignant Hyperthermia Investigation Unit, Toronto General Hospital–University Health Network, Toronto, Ontario, Canada
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Fusto A, Cassandrini D, Fiorillo C, Codemo V, Astrea G, D’Amico A, Maggi L, Magri F, Pane M, Tasca G, Sabbatini D, Bello L, Battini R, Bernasconi P, Fattori F, Bertini ES, Comi G, Messina S, Mongini T, Moroni I, Panicucci C, Berardinelli A, Donati A, Nigro V, Pini A, Giannotta M, Dosi C, Ricci E, Mercuri E, Minervini G, Tosatto S, Santorelli F, Bruno C, Pegoraro E. Expanding the clinical-pathological and genetic spectrum of RYR1-related congenital myopathies with cores and minicores: an Italian population study. Acta Neuropathol Commun 2022; 10:54. [PMID: 35428369 PMCID: PMC9013059 DOI: 10.1186/s40478-022-01357-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 03/25/2022] [Indexed: 11/10/2022] Open
Abstract
Mutations in the RYR1 gene, encoding ryanodine receptor 1 (RyR1), are a well-known cause of Central Core Disease (CCD) and Multi-minicore Disease (MmD). We screened a cohort of 153 patients carrying an histopathological diagnosis of core myopathy (cores and minicores) for RYR1 mutation. At least one RYR1 mutation was identified in 69 of them and these patients were further studied. Clinical and histopathological features were collected. Clinical phenotype was highly heterogeneous ranging from asymptomatic or paucisymptomatic hyperCKemia to severe muscle weakness and skeletal deformity with loss of ambulation. Sixty-eight RYR1 mutations, generally missense, were identified, of which 16 were novel. The combined analysis of the clinical presentation, disease progression and the structural bioinformatic analyses of RYR1 allowed to associate some phenotypes to mutations in specific domains. In addition, this study highlighted the structural bioinformatics potential in the prediction of the pathogenicity of RYR1 mutations. Further improvement in the comprehension of genotype-phenotype relationship of core myopathies can be expected in the next future: the actual lack of the human RyR1 crystal structure paired with the presence of large intrinsically disordered regions in RyR1, and the frequent presence of more than one RYR1 mutation in core myopathy patients, require designing novel investigation strategies to completely address RyR1 mutation effect.
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Maggi L, Bonanno S, Altamura C, Desaphy JF. Ion Channel Gene Mutations Causing Skeletal Muscle Disorders: Pathomechanisms and Opportunities for Therapy. Cells 2021; 10:cells10061521. [PMID: 34208776 PMCID: PMC8234207 DOI: 10.3390/cells10061521] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/03/2021] [Accepted: 06/10/2021] [Indexed: 02/06/2023] Open
Abstract
Skeletal muscle ion channelopathies (SMICs) are a large heterogeneous group of rare genetic disorders caused by mutations in genes encoding ion channel subunits in the skeletal muscle mainly characterized by myotonia or periodic paralysis, potentially resulting in long-term disabilities. However, with the development of new molecular technologies, new genes and new phenotypes, including progressive myopathies, have been recently discovered, markedly increasing the complexity in the field. In this regard, new advances in SMICs show a less conventional role of ion channels in muscle cell division, proliferation, differentiation, and survival. Hence, SMICs represent an expanding and exciting field. Here, we review current knowledge of SMICs, with a description of their clinical phenotypes, cellular and molecular pathomechanisms, and available treatments.
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Affiliation(s)
- Lorenzo Maggi
- Neuroimmunology and Neuromuscular Disorders Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy;
- Correspondence:
| | - Silvia Bonanno
- Neuroimmunology and Neuromuscular Disorders Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy;
| | - Concetta Altamura
- Department of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari Aldo Moro, 70124 Bari, Italy; (C.A.); (J.-F.D.)
| | - Jean-François Desaphy
- Department of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari Aldo Moro, 70124 Bari, Italy; (C.A.); (J.-F.D.)
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Lawal TA, Todd JJ, Witherspoon JW, Bönnemann CG, Dowling JJ, Hamilton SL, Meilleur KG, Dirksen RT. Ryanodine receptor 1-related disorders: an historical perspective and proposal for a unified nomenclature. Skelet Muscle 2020; 10:32. [PMID: 33190635 PMCID: PMC7667763 DOI: 10.1186/s13395-020-00243-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/18/2020] [Indexed: 12/14/2022] Open
Abstract
The RYR1 gene, which encodes the sarcoplasmic reticulum calcium release channel or type 1 ryanodine receptor (RyR1) of skeletal muscle, was sequenced in 1988 and RYR1 variations that impair calcium homeostasis and increase susceptibility to malignant hyperthermia were first identified in 1991. Since then, RYR1-related myopathies (RYR1-RM) have been described as rare, histopathologically and clinically heterogeneous, and slowly progressive neuromuscular disorders. RYR1 variants can lead to dysfunctional RyR1-mediated calcium release, malignant hyperthermia susceptibility, elevated oxidative stress, deleterious post-translational modifications, and decreased RyR1 expression. RYR1-RM-affected individuals can present with delayed motor milestones, contractures, scoliosis, ophthalmoplegia, and respiratory insufficiency. Historically, RYR1-RM-affected individuals were diagnosed based on morphologic features observed in muscle biopsies including central cores, cores and rods, central nuclei, fiber type disproportion, and multi-minicores. However, these histopathologic features are not always specific to RYR1-RM and often change over time. As additional phenotypes were associated with RYR1 variations (including King-Denborough syndrome, exercise-induced rhabdomyolysis, lethal multiple pterygium syndrome, adult-onset distal myopathy, atypical periodic paralysis with or without myalgia, mild calf-predominant myopathy, and dusty core disease) the overlap among diagnostic categories is ever increasing. With the continuing emergence of new clinical subtypes along the RYR1 disease spectrum and reports of adult-onset phenotypes, nuanced nomenclatures have been reported (RYR1- [related, related congenital, congenital] myopathies). In this narrative review, we provide historical highlights of RYR1 research, accounts of the main diagnostic disease subtypes and propose RYR1-related disorders (RYR1-RD) as a unified nomenclature to describe this complex and evolving disease spectrum.
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Affiliation(s)
- Tokunbor A Lawal
- Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA.
| | - Joshua J Todd
- Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Jessica W Witherspoon
- Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Carsten G Bönnemann
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - James J Dowling
- Departments of Paediatrics and Molecular Genetics, Hospital for Sick Children and University of Toronto, Toronto, Canada
| | - Susan L Hamilton
- Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Katherine G Meilleur
- Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA
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Chagovetz AA, Klatt Shaw D, Ritchie E, Hoshijima K, Grunwald DJ. Interactions among ryanodine receptor isotypes contribute to muscle fiber type development and function. Dis Model Mech 2019; 13:dmm.038844. [PMID: 31383689 PMCID: PMC6906632 DOI: 10.1242/dmm.038844] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 07/17/2019] [Indexed: 12/14/2022] Open
Abstract
Mutations affecting ryanodine receptor (RyR) calcium release channels commonly underlie congenital myopathies. Although these channels are known principally for their essential roles in muscle contractility, mutations in the human RYR1 gene result in a broad spectrum of phenotypes, including muscle weakness, altered proportions of fiber types, anomalous muscle fibers with cores or centrally placed nuclei, and dysmorphic craniofacial features. Currently, it is unknown which phenotypes directly reflect requirements for RyRs and which result secondarily to aberrant muscle function. To identify biological processes requiring RyR function, skeletal muscle development was analyzed in zebrafish embryos harboring protein-null mutations. RyR channels contribute to both muscle fiber development and function. Loss of some RyRs had modest effects, altering muscle fiber-type specification in the embryo without compromising viability. In addition, each RyR-encoding gene contributed to normal swimming behavior and muscle function. The RyR channels do not function in a simple additive manner. For example, although isoform RyR1a is sufficient for muscle contraction in the absence of RyR1b, RyR1a normally attenuates the activity of the co-expressed RyR1b channel in slow muscle. RyR3 also acts to modify the functions of other RyR channels. Furthermore, diminished RyR-dependent contractility affects both muscle fiber maturation and craniofacial development. These findings help to explain some of the heterogeneity of phenotypes that accompany RyR1 mutations in humans.
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Affiliation(s)
- Alexis A Chagovetz
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Dana Klatt Shaw
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Erin Ritchie
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Kazuyuki Hoshijima
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - David J Grunwald
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
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Abstract
The congenital myopathies are a genetically heterogeneous and diverse group of early-onset, nondystrophic neuromuscular disorders. While the originally reported "classical" entities within this group - Central Core Disease, Multiminicore Disease, Nemaline Myopathy, and Centronuclear Myopathy - were defined by the predominant finding on muscle biopsy, "novel" forms with multiple, subtle, and unusual histopathologic features have been described more recently, reflective of an expanding phenotypical spectrum. The main disease mechanisms concern excitation-contraction coupling, intracellular calcium homeostasis, and thin/thick filament interactions. Management to date has been mainly supportive. Therapeutic strategies currently at various stages of exploration include genetic interventions aimed at direct correction of the underlying genetic defect, enzyme replacement therapy, and pharmacologic approaches, either specifically targeting the principal effect of the underlying gene mutation, or addressing its downstream consequences more generally. Clinical trial development is accelerating but will require more robust natural history data and tailored outcome measures.
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Affiliation(s)
- Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's and St. Thomas' Hospital NHS Foundation Trust, London, United Kingdom; Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section, London, United Kingdom; Department of Basic and Clinical Neuroscience, IoPPN, King's College, London, United Kingdom.
| | - Francesco Muntoni
- The Dubowitz Neuromuscular Centre, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health & Great Ormond Street Hospital for Children, London, United Kingdom; NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
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Abstract
Ryanodine receptor type 1-related myopathies (RYR1-RM) are the most common class of congenital myopathies. Historically, RYR1-RM classification and diagnosis have been guided by histopathologic findings on muscle biopsy. Main histological subtypes of RYR1-RM include central core disease, multiminicore disease, core-rod myopathy, centronuclear myopathy, and congenital fiber-type disproportion. A range of RYR1-RM clinical phenotypes has also emerged more recently and includes King Denborough syndrome, RYR1 rhabdomyolysis-myalgia syndrome, atypical periodic paralysis, congenital neuromuscular disease with uniform type 1 fibers, and late-onset axial myopathy. This expansion of the RYR1-RM disease spectrum is due, in part, to implementation of next-generation sequencing methods, which include the entire RYR1 coding sequence rather than being restricted to hotspot regions. These methods enhance diagnostic capabilities, especially given historic limitations of histopathologic and clinical overlap across RYR1-RM. Both dominant and recessive modes of inheritance have been documented, with the latter typically associated with a more severe clinical phenotype. As with all congenital myopathies, no FDA-approved treatments exist to date. Here, we review histopathologic, clinical, imaging, and genetic diagnostic features of the main RYR1-RM subtypes. We also discuss the current state of treatments and focus on disease-modulating (nongenetic) therapeutic strategies under development for RYR1-RM. Finally, perspectives for future approaches to treatment development are broached.
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Affiliation(s)
- Tokunbor A Lawal
- Neuromuscular Symptoms Unit, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Joshua J Todd
- Neuromuscular Symptoms Unit, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Katherine G Meilleur
- Neuromuscular Symptoms Unit, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA.
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Gonorazky HD, Bönnemann CG, Dowling JJ. The genetics of congenital myopathies. HANDBOOK OF CLINICAL NEUROLOGY 2018; 148:549-564. [PMID: 29478600 DOI: 10.1016/b978-0-444-64076-5.00036-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Congenital myopathies are a clinically and genetically heterogeneous group of conditions that most commonly present at or around the time of birth with hypotonia, muscle weakness, and (often) respiratory distress. Historically, this group of disorders has been subclassified based on muscle histopathologic characteristics. There has been an explosion of gene discovery, and there are now at least 32 different genetic causes of disease. With this increased understanding of the genetic basis of disease has come the knowledge that the mutations in congenital myopathy genes can present with a wide variety of clinical phenotypes and can result in a broad spectrum of histopathologic findings on muscle biopsy. In addition, mutations in several genes can share the same histopathologic features. The identification of new genes and interpretation of different pathomechanisms at a molecular level have helped us to understand the clinical and histopathologic similarities that this group of disorders share. In this review, we highlight the genetic understanding for each subtype, its pathogenesis, and the future key issues in congenital myopathies.
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Affiliation(s)
- Hernan D Gonorazky
- Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, United States
| | - James J Dowling
- Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada.
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Congenital myopathies: disorders of excitation-contraction coupling and muscle contraction. Nat Rev Neurol 2018; 14:151-167. [PMID: 29391587 DOI: 10.1038/nrneurol.2017.191] [Citation(s) in RCA: 178] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The congenital myopathies are a group of early-onset, non-dystrophic neuromuscular conditions with characteristic muscle biopsy findings, variable severity and a stable or slowly progressive course. Pronounced weakness in axial and proximal muscle groups is a common feature, and involvement of extraocular, cardiorespiratory and/or distal muscles can implicate specific genetic defects. Central core disease (CCD), multi-minicore disease (MmD), centronuclear myopathy (CNM) and nemaline myopathy were among the first congenital myopathies to be reported, and they still represent the main diagnostic categories. However, these entities seem to belong to a much wider phenotypic spectrum. To date, congenital myopathies have been attributed to mutations in over 20 genes, which encode proteins implicated in skeletal muscle Ca2+ homeostasis, excitation-contraction coupling, thin-thick filament assembly and interactions, and other mechanisms. RYR1 mutations are the most frequent genetic cause, and CCD and MmD are the most common subgroups. Next-generation sequencing has vastly improved mutation detection and has enabled the identification of novel genetic backgrounds. At present, management of congenital myopathies is largely supportive, although new therapeutic approaches are reaching the clinical trial stage.
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Abstract
This article reviews advancements in the genetics of malignant hyperthermia, new technologies and approaches for its diagnosis, and the existing limitations of genetic testing for malignant hyperthermia. It also reviews the various RYR1-related disorders and phenotypes, such as myopathies, exertional rhabdomyolysis, and bleeding disorders, and examines the connection between these disorders and malignant hyperthermia.
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Walmsley GL, Blot S, Venner K, Sewry C, Laporte J, Blondelle J, Barthélémy I, Maurer M, Blanchard-Gutton N, Pilot-Storck F, Tiret L, Piercy RJ. Progressive Structural Defects in Canine Centronuclear Myopathy Indicate a Role for HACD1 in Maintaining Skeletal Muscle Membrane Systems. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 187:441-456. [PMID: 27939133 DOI: 10.1016/j.ajpath.2016.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/12/2016] [Accepted: 10/17/2016] [Indexed: 11/16/2022]
Abstract
Mutations in HACD1/PTPLA cause recessive congenital myopathies in humans and dogs. Hydroxyacyl-coA dehydratases are required for elongation of very long chain fatty acids, and HACD1 has a role in early myogenesis, but the functions of this striated muscle-specific enzyme in more differentiated skeletal muscle remain unknown. Canine HACD1 deficiency is histopathologically classified as a centronuclear myopathy (CNM). We investigated the hypothesis that muscle from HACD1-deficient dogs has membrane abnormalities in common with CNMs with different genetic causes. We found progressive changes in tubuloreticular and sarcolemmal membranes and mislocalized triads and mitochondria in skeletal muscle from animals deficient in HACD1. Furthermore, comparable membranous abnormalities in cultured HACD1-deficient myotubes provide additional evidence that these defects are a primary consequence of altered HACD1 expression. Our novel findings, including T-tubule dilatation and disorganization, associated with defects in this additional CNM-associated gene provide a definitive pathophysiologic link with these disorders, confirm that dogs deficient in HACD1 are relevant models, and strengthen the evidence for a unifying pathogenesis in CNMs via defective membrane trafficking and excitation-contraction coupling in muscle. These results build on previous work by determining further functional roles of HACD1 in muscle and provide new insight into the pathology and pathogenetic mechanisms of HACD1 CNM. Consequently, alterations in membrane properties associated with HACD1 mutations should be investigated in humans with related phenotypes.
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Affiliation(s)
- Gemma L Walmsley
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, United Kingdom.
| | - Stéphane Blot
- French National Institute of Health and Medical Research (Inserm), Mondor Institute of Biomedical Research (IMRB) U955-E10 Biology of the Neuromuscular System, Créteil, France; University of Paris East, Alfort School of Veterinary Medicine (EnvA), Maisons-Alfort, France
| | - Kerrie Venner
- Electron Microscopy Unit, Institute of Neurology, London, United Kingdom
| | - Caroline Sewry
- Dubowitz Neuromuscular Centre, University College London Institute of Child Health and Great Ormond Street Hospital, London, United Kingdom
| | - Jocelyn Laporte
- Department of Translational Medicine and Neurogenetics, Institute of Genetics and Cellular and Molecular Biology (IGBMC), Inserm U964, CNRS UMR7104, Strasbourg University, Illkirch, France
| | - Jordan Blondelle
- French National Institute of Health and Medical Research (Inserm), Mondor Institute of Biomedical Research (IMRB) U955-E10 Biology of the Neuromuscular System, Créteil, France; University of Paris East, Alfort School of Veterinary Medicine (EnvA), Maisons-Alfort, France
| | - Inès Barthélémy
- French National Institute of Health and Medical Research (Inserm), Mondor Institute of Biomedical Research (IMRB) U955-E10 Biology of the Neuromuscular System, Créteil, France; University of Paris East, Alfort School of Veterinary Medicine (EnvA), Maisons-Alfort, France
| | - Marie Maurer
- French National Institute of Health and Medical Research (Inserm), Mondor Institute of Biomedical Research (IMRB) U955-E10 Biology of the Neuromuscular System, Créteil, France; University of Paris East, Alfort School of Veterinary Medicine (EnvA), Maisons-Alfort, France
| | - Nicolas Blanchard-Gutton
- French National Institute of Health and Medical Research (Inserm), Mondor Institute of Biomedical Research (IMRB) U955-E10 Biology of the Neuromuscular System, Créteil, France; University of Paris East, Alfort School of Veterinary Medicine (EnvA), Maisons-Alfort, France
| | - Fanny Pilot-Storck
- French National Institute of Health and Medical Research (Inserm), Mondor Institute of Biomedical Research (IMRB) U955-E10 Biology of the Neuromuscular System, Créteil, France; University of Paris East, Alfort School of Veterinary Medicine (EnvA), Maisons-Alfort, France
| | - Laurent Tiret
- French National Institute of Health and Medical Research (Inserm), Mondor Institute of Biomedical Research (IMRB) U955-E10 Biology of the Neuromuscular System, Créteil, France; University of Paris East, Alfort School of Veterinary Medicine (EnvA), Maisons-Alfort, France
| | - Richard J Piercy
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, United Kingdom
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Jungbluth H, Dowling JJ, Ferreiro A, Muntoni F, Bönnemann C, Dirksen R, Faure J, Hamilton S, Hopkins P, Marks A, Marty I, Meilleur K, Riazi S, Sewry C, Treves S, Voermans N, Zorzato F. 217th ENMC International Workshop: RYR1-related myopathies, Naarden, The Netherlands, 29–31 January 2016. Neuromuscul Disord 2016; 26:624-33. [DOI: 10.1016/j.nmd.2016.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Accepted: 06/02/2016] [Indexed: 12/22/2022]
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Jungbluth H, Ochala J, Treves S, Gautel M. Current and future therapeutic approaches to the congenital myopathies. Semin Cell Dev Biol 2016; 64:191-200. [PMID: 27515125 DOI: 10.1016/j.semcdb.2016.08.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 08/04/2016] [Accepted: 08/08/2016] [Indexed: 12/14/2022]
Abstract
The congenital myopathies - including Central Core Disease (CCD), Multi-minicore Disease (MmD), Centronuclear Myopathy (CNM), Nemaline Myopathy (NM) and Congenital Fibre Type Disproportion (CFTD) - are a genetically heterogeneous group of early-onset neuromuscular conditions characterized by distinct histopathological features, and associated with a substantial individual and societal disease burden. Appropriate supportive management has substantially improved patient morbidity and mortality but there is currently no cure. Recent years have seen an exponential increase in the genetic and molecular understanding of these conditions, leading to the identification of underlying defects in proteins involved in calcium homeostasis and excitation-contraction coupling, thick/thin filament assembly and function, redox regulation, membrane trafficking and/or autophagic pathways. Based on these findings, specific therapies are currently being developed, or are already approaching the clinical trial stage. Despite undeniable progress, therapy development faces considerable challenges, considering the rarity and diversity of specific conditions, and the size and complexity of some of the genes and proteins involved. The present review will summarize the key genetic, histopathological and clinical features of specific congenital myopathies, and outline therapies already available or currently being developed in the context of known pathogenic mechanisms. The relevance of newly discovered molecular mechanisms and novel gene editing strategies for future therapy development will be discussed.
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Affiliation(s)
- Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, United Kingdom; Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section Biophysics and Cardiovascular Division, King's College BHF Centre of Research Excellence, United Kingdom; Department of Basic and Clinical Neuroscience, IoPPN, King's College, London, United Kingdom.
| | - Julien Ochala
- Centre of Human and Aerospace Physiological Sciences, King's College London, United Kingdom
| | - Susan Treves
- Departments of Biomedicine and Anaesthesia, Basel University Hospital, 4031 Basel, Switzerland
| | - Mathias Gautel
- Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section Biophysics and Cardiovascular Division, King's College BHF Centre of Research Excellence, United Kingdom
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15
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Scalco RS, Voermans NC, Piercy RJ, Jungbluth H, Quinlivan R. Dantrolene as a possible prophylactic treatment for RYR1-related rhabdomyolysis. Eur J Neurol 2016; 23:e56-7. [PMID: 27431030 DOI: 10.1111/ene.13051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 04/21/2016] [Indexed: 11/28/2022]
Affiliation(s)
- R S Scalco
- MRC Centre for Neuromuscular Diseases, UCL, London, UK
| | - N C Voermans
- Department of Neurology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - R J Piercy
- Comparative Neuromuscular Diseases Laboratory, Royal Veterinary College, London
| | - H Jungbluth
- Department of Clinical and Basic Neuroscience, IoPPN, King's College, UK
| | - R Quinlivan
- MRC Centre for Neuromuscular Diseases, UCL, London, UK
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16
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Davignon L, Chauveau C, Julien C, Dill C, Duband-Goulet I, Cabet E, Buendia B, Lilienbaum A, Rendu J, Minot MC, Guichet A, Allamand V, Vadrot N, Fauré J, Odent S, Lazaro L, Leroy JP, Marcorelles P, Dubourg O, Ferreiro A. The transcription coactivator ASC-1 is a regulator of skeletal myogenesis, and its deficiency causes a novel form of congenital muscle disease. Hum Mol Genet 2016; 25:1559-73. [PMID: 27008887 DOI: 10.1093/hmg/ddw033] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 02/04/2016] [Indexed: 01/17/2023] Open
Abstract
Despite recent progress in the genetic characterization of congenital muscle diseases, the genes responsible for a significant proportion of cases remain unknown. We analysed two branches of a large consanguineous family in which four patients presented with a severe new phenotype, clinically marked by neonatal-onset muscle weakness predominantly involving axial muscles, life-threatening respiratory failure, skin abnormalities and joint hyperlaxity without contractures. Muscle biopsies showed the unreported association of multi-minicores, caps and dystrophic lesions. Genome-wide linkage analysis followed by gene and exome sequencing in patients identified a homozygous nonsense mutation in TRIP4 encoding Activating Signal Cointegrator-1 (ASC-1), a poorly characterized transcription coactivator never associated with muscle or with human inherited disease. This mutation resulted in TRIP4 mRNA decay to around 10% of control levels and absence of detectable protein in patient cells. ASC-1 levels were higher in axial than in limb muscles in mouse, and increased during differentiation in C2C12 myogenic cells. Depletion of ASC-1 in cultured muscle cells from a patient and in Trip4 knocked-down C2C12 led to a significant reduction in myotube diameter ex vivo and in vitro, without changes in fusion index or markers of initial myogenic differentiation. This work reports the first TRIP4 mutation and defines a novel form of congenital muscle disease, expanding their histological, clinical and molecular spectrum. We establish the importance of ASC-1 in human skeletal muscle, identify transcriptional co-regulation as novel pathophysiological pathway, define ASC-1 as a regulator of late myogenic differentiation and suggest defects in myotube growth as a novel myopathic mechanism.
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Affiliation(s)
- Laurianne Davignon
- Pathophysiology of Striated Muscles Laboratory, Unit of Functional and Adaptive Biology (BFA), University Paris Diderot, Sorbonne Paris Cité, BFA, UMR CNRS 8251, 75250 Paris Cedex 13, France, Inserm U787, Myology Group, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, 75013 Paris, France, UPMC, UMR787, 75013 Paris, France
| | - Claire Chauveau
- Inserm U787, Myology Group, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, 75013 Paris, France, UPMC, UMR787, 75013 Paris, France
| | - Cédric Julien
- Inserm U787, Myology Group, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, 75013 Paris, France, UPMC, UMR787, 75013 Paris, France
| | - Corinne Dill
- Pathophysiology of Striated Muscles Laboratory, Unit of Functional and Adaptive Biology (BFA), University Paris Diderot, Sorbonne Paris Cité, BFA, UMR CNRS 8251, 75250 Paris Cedex 13, France
| | - Isabelle Duband-Goulet
- Pathophysiology of Striated Muscles Laboratory, Unit of Functional and Adaptive Biology (BFA), University Paris Diderot, Sorbonne Paris Cité, BFA, UMR CNRS 8251, 75250 Paris Cedex 13, France
| | - Eva Cabet
- Pathophysiology of Striated Muscles Laboratory, Unit of Functional and Adaptive Biology (BFA), University Paris Diderot, Sorbonne Paris Cité, BFA, UMR CNRS 8251, 75250 Paris Cedex 13, France
| | - Brigitte Buendia
- Pathophysiology of Striated Muscles Laboratory, Unit of Functional and Adaptive Biology (BFA), University Paris Diderot, Sorbonne Paris Cité, BFA, UMR CNRS 8251, 75250 Paris Cedex 13, France
| | - Alain Lilienbaum
- Pathophysiology of Striated Muscles Laboratory, Unit of Functional and Adaptive Biology (BFA), University Paris Diderot, Sorbonne Paris Cité, BFA, UMR CNRS 8251, 75250 Paris Cedex 13, France
| | - John Rendu
- Université Grenoble Alpes, Université Joseph Fourier, 38041 Grenoble, France, Biochimie Génétique et Moléculaire, CHRU de Grenoble, 38700 Grenoble, France, INSERM U386, Equipe Muscle et Pathologies, Grenoble Institut des Neurosciences, 38700 Grenoble, France
| | | | - Agnès Guichet
- CHU Angers, Service de génétique médicale, 49100 Angers, France
| | - Valérie Allamand
- UPMC, Inserm UMRS974, CNRS FRE3617, Center for Research in Myology, 75013 Paris, France
| | - Nathalie Vadrot
- Pathophysiology of Striated Muscles Laboratory, Unit of Functional and Adaptive Biology (BFA), University Paris Diderot, Sorbonne Paris Cité, BFA, UMR CNRS 8251, 75250 Paris Cedex 13, France
| | - Julien Fauré
- Université Grenoble Alpes, Université Joseph Fourier, 38041 Grenoble, France, Biochimie Génétique et Moléculaire, CHRU de Grenoble, 38700 Grenoble, France, INSERM U386, Equipe Muscle et Pathologies, Grenoble Institut des Neurosciences, 38700 Grenoble, France
| | - Sylvie Odent
- Pôle Neurosciences, Service de Neurologie, CHU de Rennes, 35033 Rennes, France
| | - Leïla Lazaro
- Service de Pédiatrie, Centre Hospitalier de la Côte Basque, 64109 Bayonne, France
| | - Jean Paul Leroy
- Laboratoire d'Anatomo-Pathologie, CHU de Brest, 29609 Brest, France
| | - Pascale Marcorelles
- Laboratoire d'Anatomo-Pathologie, CHU de Brest, 29609 Brest, France, EA 4685 Laboratoire de Neuroscience de Brest, Université Bretagne Occidentale, 29200 Brest, France
| | - Odile Dubourg
- Inserm U787, Myology Group, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, 75013 Paris, France, UPMC, UMR787, 75013 Paris, France, AP-HP, Laboratoire de Neuropathologie, Groupe Hospitalier Pitié-Salpêtrière, 75013 Paris, France and
| | - Ana Ferreiro
- Pathophysiology of Striated Muscles Laboratory, Unit of Functional and Adaptive Biology (BFA), University Paris Diderot, Sorbonne Paris Cité, BFA, UMR CNRS 8251, 75250 Paris Cedex 13, France, Inserm U787, Myology Group, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, 75013 Paris, France, UPMC, UMR787, 75013 Paris, France, AP-HP, Centre de Référence Maladies Neuromusculaires Paris-Est, Groupe Hospitalier Pitié-Salpêtrière, 75013 Paris, France
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Abstract
The triad is a skeletal muscle substructure responsible for the regulation of excitation-contraction coupling. It is formed by the close apposition of the T-tubule and the terminal sarcoplasmic reticulum. A rapidly growing list of skeletal myopathies, here referred to as triadopathies, are caused by gene mutations in components of the triad. These disorders, at their root, are caused by defects in excitation contraction coupling and intracellular calcium homeostasis. Secondary abnormalities in triad structure and/or function are also reported in several muscle diseases, most notably certain muscular dystrophies. This review highlights the current understanding of both primary and secondary triadopathies, and identifies important concepts yet to be fully addressed in the field. The emphasis of the review is both on the pathogenesis of triadopathies and their potential treatment.
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Affiliation(s)
- James J Dowling
- Division of Neurology and Genetics and Genome Biology Program, Hospital for Sick Children, Toronto, ON, Canada,
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Brislin RP, Theroux MC. Core myopathies and malignant hyperthermia susceptibility: a review. Paediatr Anaesth 2013; 23:834-41. [PMID: 23617272 DOI: 10.1111/pan.12175] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/09/2013] [Indexed: 11/30/2022]
Abstract
The core myopathies are a subset of myopathies that present in infancy with hypotonia and muscle weakness. They were formerly considered a rare type of congenital myopathy but are now recognized as being more prevalent. Due to their genetic linkage to mutations in the ryanodine receptor gene (RYR1), core myopathies (in particular, central core disease) carry a high risk of malignant hyperthermia susceptibility. In this review article, we describe the phenotypical, genetic, and histopathological characteristics of core myopathies and further describe the currently understood nature of their risk of malignant hyperthermia. We also review the level of suspicion a clinician should exhibit with a child who has a possible core myopathy or other congenital myopathy presenting for an anesthetic prior to a definitive genetic analysis. For this review article, we performed literature searches using the key words anesthesiology, core myopathies, pediatric neurology, malignant hyperthermia, genetics, ryanodine receptor, and molecular biology. We also relied on literature accumulated by the two authors, who served as hotline consultants for the Malignant Hyperthermia Hotline of the Malignant Hyperthermia Association of the United States (MHAUS) for the past 12 years.
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Affiliation(s)
- Robert P Brislin
- Department of Anesthesiology and Critical Care Medicine, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE 19899, USA.
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19
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Kraeva N, Zvaritch E, Rossi AE, Goonasekera SA, Zaid H, Frodis W, Kraev A, Dirksen RT, Maclennan DH, Riazi S. Novel excitation-contraction uncoupled RYR1 mutations in patients with central core disease. Neuromuscul Disord 2012. [PMID: 23183335 DOI: 10.1016/j.nmd.2012.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Central core disease, one of the most common congenital myopathies in humans, has been linked to mutations in the RYR1 gene encoding the Ca(2+) release channel of the sarcoplasmic reticulum (RyR1). Functional analyses showed that disease-associated RYR1 mutations led to impairment of skeletal muscle Ca(2+) homeostasis; however, thorough understanding of the molecular mechanisms underlying central core disease and other RyR1-related conditions is still lacking. We screened by sequencing the complete RYR1 transcripts in ten unrelated patients with central core disease and identified five novel, p.M4640R, p.L4647P, p.F4808L, p.D4918N and p.F4941C, and four recurrent mutations. Four of the novel mutations involved amino acid residues that were positioned within putative transmembrane segments of the RyR1. The pathogenic character of the identified mutations was demonstrated by bioinformatic analyses and by the in vitro functional studies in HEK293 cells and RYR1-null (dyspedic) myotubes. Characterization of Ca(2+) channel properties of RyR1s carrying one recurrent and two novel mutations upholds the view that diminished intracellular Ca(2+) release caused by impaired Ca(2+) channel gating and/or Ca(2+) permeability is an important component of central core disease etiology. This study expands the list of functionally characterized disease-associated RyR1 mutations, increasing the value of genetic diagnosis for RyR1-related disorders.
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Affiliation(s)
- Natalia Kraeva
- Malignant Hyperthermia Investigation Unit, Toronto General Hospital, University Health Network, Toronto, ON, Canada M5G 2C4
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20
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Majczenko K, Davidson A, Camelo-Piragua S, Agrawal P, Manfready R, Li X, Joshi S, Xu J, Peng W, Beggs A, Li J, Burmeister M, Dowling J. Dominant mutation of CCDC78 in a unique congenital myopathy with prominent internal nuclei and atypical cores. Am J Hum Genet 2012; 91:365-71. [PMID: 22818856 DOI: 10.1016/j.ajhg.2012.06.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 05/21/2012] [Accepted: 06/05/2012] [Indexed: 10/28/2022] Open
Abstract
Congenital myopathies are clinically and genetically heterogeneous diseases that typically present in childhood with hypotonia and weakness and are most commonly defined by changes observed in muscle biopsy. Approximately 40% of congenital myopathies are currently genetically unresolved. We identified a family with dominantly inherited congenital myopathy characterized by distal weakness and biopsy changes that included core-like areas and increased internalized nuclei. To identify the causative genetic abnormality in this family, we performed linkage analysis followed by whole-exome capture and next-generation sequencing. A splice-acceptor variant in previously uncharacterized CCDC78 was detected in affected individuals and absent in unaffected family members and > 10,000 controls. This variant alters RNA-transcript processing and results in a 222 bp in-frame insertion. CCDC78 is expressed in skeletal muscle, enriched in the perinuclear region and the triad, and found in intracellular aggregates in patient muscle. Modeling of the CCDC78 mutation in zebrafish resulted in changes mirroring the human disease that included altered motor function and abnormal muscle ultrastructure. Using a combination of linkage analysis, next-generation sequencing, and modeling in the zebrafish, we have identified a CCDC78 mutation associated with a unique myopathy with prominent internal nuclei and atypical cores.
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21
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Nance JR, Dowling JJ, Gibbs EM, Bönnemann CG. Congenital myopathies: an update. Curr Neurol Neurosci Rep 2012; 12:165-74. [PMID: 22392505 DOI: 10.1007/s11910-012-0255-x] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Congenital myopathy is a clinicopathological concept of characteristic histopathological findings on muscle biopsy in a patient with early-onset weakness. Three main categories are recognized within the classical congenital myopathies: nemaline myopathy, core myopathy, and centronuclear myopathy. Recent evidence of overlapping clinical and histological features between the classical forms and their different genetic entities suggests that there may be shared pathomechanisms between the congenital myopathies. Animal models, especially mouse and zebrafish, have been especially helpful in elucidating such pathomechanisms associated with the congenital myopathies and provide models in which future therapies can be investigated.
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Affiliation(s)
- Jessica R Nance
- Department of Neurology, Children's National Medical Center, Washington, DC 20010, USA
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