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Granger A, Sorenson EJ, Selcen D, Liewluck T. Myopathy With Crescent of Nuclei: A Novel Histopathologic Finding in Desminopathy. J Clin Neuromuscul Dis 2024; 25:197-198. [PMID: 38771229 DOI: 10.1097/cnd.0000000000000493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Affiliation(s)
- Andre Granger
- Department of Neurology, Mayo Clinic, Jacksonville, FL; and
- Department of Neurology, Mayo Clinic, Rochester, MN
| | | | - Duygu Selcen
- Department of Neurology, Mayo Clinic, Rochester, MN
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de Fuenmayor-Fernández de la Hoz CP, Lupo V, Bermejo-Guerrero L, Martín-Jiménez P, Hernández-Laín A, Olivé M, Gallardo E, Esteban-Pérez J, Espinós C, Domínguez-González C. Distal hereditary motor neuronopathy as a new phenotype associated with variants in BAG3. J Neurol 2024; 271:986-994. [PMID: 37907725 DOI: 10.1007/s00415-023-12039-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 11/02/2023]
Abstract
OBJECTIVE To describe a new phenotype associated with a novel variant in BAG3: autosomal dominant adult-onset distal hereditary motor neuronopathy. METHODS This study enrolled eight affected individuals from a single family and included a comprehensive evaluation of the clinical phenotype, neurophysiologic testing, muscle MRI, muscle biopsy and western blot of BAG3 protein in skeletal muscle. Genetic workup included whole exome sequencing and segregation analysis of the detected variant in BAG3. RESULTS Seven patients developed slowly progressive and symmetric distal weakness and atrophy of lower limb muscles, along with absent Achilles reflexes. The mean age of onset was 46 years. The neurophysiological examination was consistent with the diagnosis of distal motor neuronopathy. One 57-year-old female patient was minimally symptomatic. The pattern of inheritance was autosomal dominant, with one caveat: one female patient who was an obligate carrier of the variant died at the age of 73 years without exhibiting any muscle weakness. The muscle biopsies revealed neurogenic changes. A novel heterozygous truncating variant c.1513_1514insGGAC (p.Val505GlyfsTer6) in the gene BAG3 was identified in all affected family members. CONCLUSIONS We report an autosomal dominant adult-onset distal hereditary motor neuronopathy with incomplete penetrance in women as a new phenotype related to a truncating variant in the BAG3 gene. Our findings expand the phenotypic spectrum of BAG3-related disorders, which previously included dilated cardiomyopathy, myofibrillar myopathy and adult-onset Charcot-Marie-Tooth type 2 neuropathy. Variants in BAG3 should be considered in the differential diagnosis of distal hereditary motor neuronopathies.
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Affiliation(s)
| | - Vincenzo Lupo
- Unit of Rare Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Laura Bermejo-Guerrero
- Neuromuscular Disorders Unit, Servicio de Neurología, Department of Neurology, Hospital Universitario 12 de Octubre, Avenida de Córdoba Sin Número, 28041, Madrid, Spain
| | - Paloma Martín-Jiménez
- Neuromuscular Disorders Unit, Servicio de Neurología, Department of Neurology, Hospital Universitario 12 de Octubre, Avenida de Córdoba Sin Número, 28041, Madrid, Spain
| | - Aurelio Hernández-Laín
- Neuromuscular Disorders Unit, Department of Pathology (Neuropathology), 12 de Octubre University Hospital, Madrid, Spain
| | - Montse Olivé
- Neuromuscular Disorders Unit, Department of Neurology and Laboratory of Neuromuscular Diseases, Institut de Recerca Hospital de la, Santa Creu I Sant Pau, Barcelona, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Eduard Gallardo
- Neuromuscular Disorders Unit, Department of Neurology and Laboratory of Neuromuscular Diseases, Institut de Recerca Hospital de la, Santa Creu I Sant Pau, Barcelona, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Esteban-Pérez
- Neuromuscular Disorders Unit, Servicio de Neurología, Department of Neurology, Hospital Universitario 12 de Octubre, Avenida de Córdoba Sin Número, 28041, Madrid, Spain
| | - Carmen Espinós
- Unit of Rare Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
- Biotechnology Department, Faculty of Veterinary and Experimental Sciences, Universidad Católica de Valencia, 46001, Valencia, Spain
| | - Cristina Domínguez-González
- Neuromuscular Disorders Unit, Servicio de Neurología, Department of Neurology, Hospital Universitario 12 de Octubre, Avenida de Córdoba Sin Número, 28041, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
- Mitochondrial and Neuromuscular Disorders Group, Hospital 12 de Octubre Health Research Institute (imas12), Madrid, Spain
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Claeyssen C, Bulangalire N, Bastide B, Agbulut O, Cieniewski-Bernard C. Desmin and its molecular chaperone, the αB-crystallin: How post-translational modifications modulate their functions in heart and skeletal muscles? Biochimie 2024; 216:137-159. [PMID: 37827485 DOI: 10.1016/j.biochi.2023.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/04/2023] [Accepted: 10/02/2023] [Indexed: 10/14/2023]
Abstract
Maintenance of the highly organized striated muscle tissue requires a cell-wide dynamic network through protein-protein interactions providing an effective mechanochemical integrator of morphology and function. Through a continuous and complex trans-cytoplasmic network, desmin intermediate filaments ensure this essential role in heart and in skeletal muscle. Besides their role in the maintenance of cell shape and architecture (permitting contractile activity efficiency and conferring resistance towards mechanical stress), desmin intermediate filaments are also key actors of cell and tissue homeostasis. Desmin participates to several cellular processes such as differentiation, apoptosis, intracellular signalisation, mechanotransduction, vesicle trafficking, organelle biogenesis and/or positioning, calcium homeostasis, protein homeostasis, cell adhesion, metabolism and gene expression. Desmin intermediate filaments assembly requires αB-crystallin, a small heat shock protein. Over its chaperone activity, αB-crystallin is involved in several cellular functions such as cell integrity, cytoskeleton stabilization, apoptosis, autophagy, differentiation, mitochondria function or aggresome formation. Importantly, both proteins are known to be strongly associated to the aetiology of several cardiac and skeletal muscles pathologies related to desmin filaments disorganization and a strong disturbance of desmin interactome. Note that these key proteins of cytoskeleton architecture are extensively modified by post-translational modifications that could affect their functional properties. Therefore, we reviewed in the herein paper the impact of post-translational modifications on the modulation of cellular functions of desmin and its molecular chaperone, the αB-crystallin.
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Affiliation(s)
- Charlotte Claeyssen
- University of Lille, University of Artois, University of Littoral Côte d'Opale, ULR 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, F-59000 Lille, France
| | - Nathan Bulangalire
- University of Lille, University of Artois, University of Littoral Côte d'Opale, ULR 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, F-59000 Lille, France; Université de Lille, CHU Lille, F-59000 Lille, France
| | - Bruno Bastide
- University of Lille, University of Artois, University of Littoral Côte d'Opale, ULR 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, F-59000 Lille, France
| | - Onnik Agbulut
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, 75005, Paris, France
| | - Caroline Cieniewski-Bernard
- University of Lille, University of Artois, University of Littoral Côte d'Opale, ULR 7369 - URePSSS - Unité de Recherche Pluridisciplinaire Sport Santé Société, F-59000 Lille, France.
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Bermejo-Guerrero L, de Fuenmayor Fernández-de la Hoz CP, González-Quereda L, Segarra-Casas A, Nedkova V, Gallano P, Martín-Jiménez P, Hernández-Laín A, Olivé M, Arteche-López A, Domínguez-González C. Distal myopathy due to digenic inheritance of TIA1 and SQSTM1 variants in two unrelated Spanish patients. Neuromuscul Disord 2023; 33:983-987. [PMID: 38016875 DOI: 10.1016/j.nmd.2023.10.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 09/28/2023] [Accepted: 10/26/2023] [Indexed: 11/30/2023]
Abstract
Welander distal myopathy typically manifests in late adulthood and is caused by the founder TIA1 c.1150G>A (p.Glu384Lys) variant in families of Swedish and Finnish descent. Recently, a similar phenotype has been attributed to the digenic inheritance of TIA1 c.1070A>G (p.Asn357Ser) and SQSTM1 c.1175C>T (p.Pro392Leu) variants. We describe two unrelated Spanish patients presenting with slowly progressive gait disturbance, distal-predominant weakness, and mildly elevated creatine kinase (CK) levels since their 6th decade. Electromyography revealed abnormal spontaneous activity and a myopathic pattern. Muscle magnetic resonance imaging (MRI) showed marked fatty replacement in distal leg muscles. A muscle biopsy, performed on one patient, revealed myopathic changes with rimmed vacuoles. Both patients carried the TIA1 p.Asn357Ser and SQSTM1 p.Pro392Leu variants. Digenic inheritance is supported by evidence from unrelated pedigrees and a plausible biological interaction between both proteins in protein quality control processes. Recent functional studies and additional case descriptions further support this. Clinical suspicion is necessary to seek both variants.
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Affiliation(s)
- Laura Bermejo-Guerrero
- Neuromuscular Disorders Unit, Department of Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain
| | | | - Lidia González-Quereda
- Genetics Department, Institut d'Investigació Biomèdica Sant Pau (IIB SANT PAU), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Genetics and Microbiology Department, Universitat Autonoma de Barcelona, Bellaterra, Spain
| | - Alba Segarra-Casas
- Genetics Department, Institut d'Investigació Biomèdica Sant Pau (IIB SANT PAU), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Genetics and Microbiology Department, Universitat Autonoma de Barcelona, Bellaterra, Spain
| | - Velina Nedkova
- Department of Neurology, Bellvitge Hospital, 08041 Barcelona, Spain
| | - Pia Gallano
- Genetics Department, Institut d'Investigació Biomèdica Sant Pau (IIB SANT PAU), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | | | | | - Montse Olivé
- Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Neuromuscular Diseases Unit, Neurology Department, Institut d'Investigació Biomèdica Sant Pau (IIB SANT PAU), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Ana Arteche-López
- Department of Genetics, 12 de Octubre University Hospital, 28041 Madrid, Spain
| | - Cristina Domínguez-González
- Neuromuscular Disorders Unit, Department of Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Mitochondrial and Neuromuscular Disorders Group, Hospital 12 de Octubre Health Research Institute (imas12), Madrid, Spain.
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Skolka MP, Naddaf E. Exploring challenges in the management and treatment of inclusion body myositis. Curr Opin Rheumatol 2023; 35:404-413. [PMID: 37503813 PMCID: PMC10552844 DOI: 10.1097/bor.0000000000000958] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
PURPOSE OF REVIEW This review provides an overview of the management and treatment landscape of inclusion body myositis (IBM), while highlighting the current challenges and future directions. RECENT FINDINGS IBM is a slowly progressive myopathy that predominantly affects patients over the age of 40, leading to increased morbidity and mortality. Unfortunately, a definitive cure for IBM remains elusive. Various clinical trials targeting inflammatory and some of the noninflammatory pathways have failed. The search for effective disease-modifying treatments faces numerous hurdles including variability in presentation, diagnostic challenges, poor understanding of pathogenesis, scarcity of disease models, a lack of validated outcome measures, and challenges related to clinical trial design. Close monitoring of swallowing and respiratory function, adapting an exercise routine, and addressing mobility issues are the mainstay of management at this time. SUMMARY Addressing the obstacles encountered by patients with IBM and the medical community presents a multitude of challenges. Effectively surmounting these hurdles requires embracing cutting-edge research strategies aimed at enhancing the management and treatment of IBM, while elevating the quality of life for those affected.
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Takegami N, Mitsutake A, Mano T, Shintani-Domoto Y, Unuma A, Yamaguchi-Takegami N, Ishiura H, Sakuishi K, Ando M, Yamauchi H, Ono M, Morishita S, Mitsui J, Shimizu J, Tsuji S, Toda T. The Myocardial Accumulation of Aggregated Desmin Protein in a Case of Desminopathy with a de novo DES p.R406W Mutation. Intern Med 2023; 62:2883-2887. [PMID: 36792195 PMCID: PMC10602824 DOI: 10.2169/internalmedicine.0992-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/04/2023] [Indexed: 02/16/2023] Open
Abstract
Desminopathy is a cardiac and skeletal myopathy caused by disease-causing variants in the desmin (DES) gene and represents a subgroup of myofibrillar myopathies, where cytoplasmic desmin-postive immunoreactivity is the pathological hallmark. We herein report a 28-year-old Japanese man who was initially diagnosed with sporadic hypertrophic cardiomyopathy with atrioventricular block at 9 years old and developed weakness in the soft palate and extremities. The myocardial tissue dissected during implantation of the ventricular-assisted device showed a dilated phase of hypertrophic cardiomyopathy and intracellular accumulation of proteinase K-resistant desmin aggregates. Genetic testing confirmed a de novo mutation of DES, which has already been linked to desminopathy. As the molecular diagnosis of desminopathy is challenging, particularly if patients show predominantly cardiac signs and a routine skeletal muscle biopsy is unavailable, these characteristic pathological findings of endomyocardial proteinase K-resistant desmin aggregates might aid in clinical practice.
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Affiliation(s)
- Naoki Takegami
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Akihiko Mitsutake
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Tatsuo Mano
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Japan
| | | | - Atsushi Unuma
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | | | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Kaori Sakuishi
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Masahiko Ando
- Department of Cardiovascular Surgery, Graduate School of Medicine, The University of Tokyo Hospital, Japan
| | - Haruo Yamauchi
- Department of Cardiovascular Surgery, Graduate School of Medicine, The University of Tokyo Hospital, Japan
| | - Minoru Ono
- Department of Cardiovascular Surgery, Graduate School of Medicine, The University of Tokyo Hospital, Japan
| | - Shinichi Morishita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Japan
| | - Jun Mitsui
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
- Department of Molecular Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Jun Shimizu
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Shoji Tsuji
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
- Department of Molecular Neurology, Graduate School of Medicine, The University of Tokyo, Japan
- Institute of Medical Genomics, International University of Health and Welfare, Japan
| | - Tatsushi Toda
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
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Stonadge A, Genzor AV, Russell A, Hamed MF, Romero N, Evans G, Pownall ME, Bekker-Jensen S, Blanco G. Myofibrillar myopathy hallmarks associated with ZAK deficiency. Hum Mol Genet 2023; 32:2751-2770. [PMID: 37427997 PMCID: PMC10789240 DOI: 10.1093/hmg/ddad113] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/04/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023] Open
Abstract
The ZAK gene encodes two functionally distinct kinases, ZAKα and ZAKβ. Homozygous loss of function mutations affecting both isoforms causes a congenital muscle disease. ZAKβ is the only isoform expressed in skeletal muscle and is activated by muscle contraction and cellular compression. The ZAKβ substrates in skeletal muscle or the mechanism whereby ZAKβ senses mechanical stress remains to be determined. To gain insights into the pathogenic mechanism, we exploited ZAK-deficient cell lines, zebrafish, mice and a human biopsy. ZAK-deficient mice and zebrafish show a mild phenotype. In mice, comparative histopathology data from regeneration, overloading, ageing and sex conditions indicate that while age and activity are drivers of the pathology, ZAKβ appears to have a marginal role in myoblast fusion in vitro or muscle regeneration in vivo. The presence of SYNPO2, BAG3 and Filamin C (FLNC) in a phosphoproteomics assay and extended analyses suggested a role for ZAKβ in the turnover of FLNC. Immunofluorescence analysis of muscle sections from mice and a human biopsy showed evidence of FLNC and BAG3 accumulations as well as other myofibrillar myopathy markers. Moreover, endogenous overloading of skeletal muscle exacerbated the presence of fibres with FLNC accumulations in mice, indicating that ZAKβ signalling is necessary for an adaptive turnover of FLNC that allows for the normal physiological response to sustained mechanical stress. We suggest that accumulation of mislocalized FLNC and BAG3 in highly immunoreactive fibres contributes to the pathogenic mechanism of ZAK deficiency.
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Affiliation(s)
- Amy Stonadge
- York Biomedical Research Institute, Department of Biology, University of York, York, YO10 5DD, UK
| | - Aitana V Genzor
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Alex Russell
- York Biomedical Research Institute, Department of Biology, University of York, York, YO10 5DD, UK
| | - Mohamed F Hamed
- Department of Pathology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | - Norma Romero
- Unité de Morphologie Neuromusculaire Institut de Myologie - Inserm Sorbonne Université - GHU Pitié-Salpêtrière 47- 83, boulevard de l’Hôpital F-75 651 Paris, Cedex 13, France
| | - Gareth Evans
- York Biomedical Research Institute, Department of Biology, University of York, York, YO10 5DD, UK
| | - Mary Elizabeth Pownall
- York Biomedical Research Institute, Department of Biology, University of York, York, YO10 5DD, UK
| | - Simon Bekker-Jensen
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Gonzalo Blanco
- York Biomedical Research Institute, Department of Biology, University of York, York, YO10 5DD, UK
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Gibertini S, Ruggieri A, Cheli M, Maggi L. Protein Aggregates and Aggrephagy in Myopathies. Int J Mol Sci 2023; 24:ijms24098456. [PMID: 37176163 PMCID: PMC10179229 DOI: 10.3390/ijms24098456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/02/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023] Open
Abstract
A number of muscular disorders are hallmarked by the aggregation of misfolded proteins within muscle fibers. A specialized form of macroautophagy, termed aggrephagy, is designated to remove and degrade protein aggregates. This review aims to summarize what has been studied so far about the direct involvement of aggrephagy and the activation of the key players, among others, p62, NBR1, Alfy, Tollip, Optineurin, TAX1BP1 and CCT2 in muscular diseases. In the first part of the review, we describe the aggrephagy pathway with the involved proteins; then, we illustrate the muscular disorder histologically characterized by protein aggregates, highlighting the role of aggrephagy pathway abnormalities in these muscular disorders.
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Affiliation(s)
- Sara Gibertini
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
| | - Alessandra Ruggieri
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
| | - Marta Cheli
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
| | - Lorenzo Maggi
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
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Chen PS, Chao CC, Tsai LK, Huang HY, Chien YH, Huang PH, Hwu WL, Hsieh ST, Lee NC, Hsueh HW, Yang CC. Diagnostic Challenges of Neuromuscular Disorders after Whole Exome Sequencing. J Neuromuscul Dis 2023:JND230013. [PMID: 37066920 DOI: 10.3233/jnd-230013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
BACKGROUND Whole-exome sequencing (WES) facilitates the diagnosis of hereditary neuromuscular disorders. To achieve an accurate diagnosis, physicians should interpret the genetic report carefully along with clinical information and examinations. We described our experience with (1) clinical validation in patients with variants found using WES and (2) a diagnostic approach for those with negative findings from WES. METHODS WES was performed on patients with the clinical impression of hereditary neuromuscular disorders. Information on clinical manifestations, neurological examination, electrodiagnostic studies, histopathology of muscle and nerve, and laboratory tests were collected. RESULTS Forty-one patients (Male/Female: 18/23, age of onset: 34.5±15.9) accepted WES and were categorized into four scenarios: (1) patients with a positive WES result, (2) patients with an inconclusive WES result but supporting clinical data, (3) negative findings from WES, but a final diagnosis after further work-up, and (4) undetermined etiology from WES and in further work-ups. The yield rate of the initial WES was 63.4% (26/41). Among these, seventeen patients had positive WES result, while the other nine patients had inconclusive WES result but supporting clinical data. Notably, in the fifteen patients with equivocal or negative findings from WES, four patients (26.7%) achieved a diagnosis after further workup: tumor-induced osteomalacia, metabolic myopathy with pathogenic variants in mitochondrial DNA, microsatellite expansion disease, and vasculitis-related neuropathy. The etiologies remained undetermined in eleven patients (myopathy: 7, neuropathy: 4) after WES and further workup. CONCLUSIONS It is essential to design genotype-guided molecular studies to correlate the identified variants with their clinical features. For patients who had negative findings from WES, acquired diseases, mitochondrial DNA disorders and microsatellite expansion diseases should be considered.
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Affiliation(s)
- Pin-Shiuan Chen
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chi-Chao Chao
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Li-Kai Tsai
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Hsin-Yi Huang
- Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yin-Hsiu Chien
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Pei-Hsin Huang
- Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan
| | - Wuh-Liang Hwu
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Sung-Tsang Hsieh
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Ni-Chung Lee
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Hsueh-Wen Hsueh
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
- Department of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chih-Chao Yang
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
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10
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Wu R, Shao S, Yin L, Deng J, Guo S, Lu L. Frameshift mutation in SQSTM1 causes proximal myopathy with rimmed vacuoles: A case report. Front Neurol 2023; 14:1043136. [PMID: 36998782 PMCID: PMC10043206 DOI: 10.3389/fneur.2023.1043136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 02/06/2023] [Indexed: 03/17/2023] Open
Abstract
p62/Sequestosome-1 (SQSTM1) is a stress-inducible scaffold protein involved in multiple cellular processes, including apoptosis, inflammation, cell survival, and selective autophagy. SQSTM1 mutations are associated with a spectrum of multisystem proteinopathy, including Paget disease of the bone, amyotrophic lateral sclerosis, frontotemporal dementia, and distal myopathy with rimmed vacuoles (MRV). Herein, we report a new phenotype of SQSTM1-associated proteinopathy, a novel frameshift mutation in SQSTM1 causing proximal MRV. A 44-year-old Chinese patient presented with progressive limb–girdle weakness. She had asymmetric proximal limb weakness and myopathic features on electromyography. The magnetic resonance images showed fatty infiltration into muscles, predominantly in the thighs and medial gastrocnemius, sparing the tibialis anterior. Muscle histopathology revealed abnormal protein deposition, p62/SQSTM1-positive inclusions, and rimmed vacuoles. Next-generation sequencing showed a novel pathogenic SQSTM1 frameshift mutation, c.542_549delACAGCCGC (p. H181Lfs*66). We expanded the pathogenic genotype of SQSTM1 to include a new, related phenotype: proximal MRV. We suggest that SQSTM1 variations should be screened in cases of proximal MRV.
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Affiliation(s)
- Rui Wu
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
- *Correspondence: Rui Wu
| | - Sai Shao
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Ling Yin
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Jianwen Deng
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Shougang Guo
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Lin Lu
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
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11
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Valberg SJ, Henry ML, Herrick KL, Velez-Irizarry D, Finno CJ, Petersen JL. Absence of myofibrillar myopathy in Quarter Horses with a histopathological diagnosis of type 2 polysaccharide storage myopathy and lack of association with commercial genetic tests. Equine Vet J 2023; 55:230-238. [PMID: 35288976 PMCID: PMC10084132 DOI: 10.1111/evj.13574] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 03/10/2022] [Indexed: 12/01/2022]
Abstract
BACKGROUND Genetic tests for variants in MYOT (P2; rs1138656462), FLNC (P3a; rs1139799323 or P3b; rs1142918816) and MYOZ3 (P4; rs1142544043) genes are offered commercially to diagnose myofibrillar myopathy (MFM) and type 2 polysaccharide storage myopathy (PSSM2) in Quarter Horses (QH). OBJECTIVES To determine if PSSM2-QH has histopathological features of MFM. To compare genotype and allele frequencies of variants P2, P3, P4 between control-QH and PSSM2-QH diagnosed by histopathology. STUDY DESIGN Retrospective cross-sectional. METHODS The study includes a total of 229 healthy control-QH, 163 PSSM2-QH GYS1 mutation negative. Desmin stains of gluteal/semimembranosus muscle were evaluated. Purported disease alleles P2, P3a, P3b, P4 were genotyped by pyrosequencing. Genotype, allele frequency and total number of variant alleles or loci were compared between phenotypes using additive/genotypic and dominant models and quantitative effects evaluated by multivariable logistic regression. RESULTS Histopathological features of MFM were absent in all QH. A P variant allele at any locus was not associated (P > .05) with a histopathological diagnosis of PSSM2 and one or more P variants were common in control-QH (57%) and PSSM2-QH (61%). Allele frequencies (control/PSSM2) were: 0.24/0.21 (P2), 0.07/0.12 (P3a), 0.07/0.11 (P3b) and 0.06/0.08 (P4). P3a and P3b loci were not independent (r2 = 0.894); and not associated with PSSM2 histopathology comparing the haplotype of both P3a and P3b variants to other haplotypes. A receiver operator curve did not accurately predict the PSSM2 phenotype (AUC = 0.67, 95% CI 0.62-0.72), and there was no difference in the total number of variant loci or total variant allele count between control-QH and PSSM2-QH. MAIN LIMITATIONS P3a and P3b were not in complete linkage disequilibrium. CONCLUSIONS The P2, P3 and P4 variants in genes associated with human MFM were not associated with PSSM2 in 392 QH. Their use would improperly diagnose PSSM2/MFM in 57% of healthy QH and fail to diagnose PSSM2 in 40% of QH with histopathological evidence of PSSM2.
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Affiliation(s)
- Stephanie J Valberg
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Marisa L Henry
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Keely L Herrick
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Deborah Velez-Irizarry
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Carrie J Finno
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - Jessica L Petersen
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
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12
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[Neuropathology I: muscular diseases]. PATHOLOGIE (HEIDELBERG, GERMANY) 2023; 44:104-112. [PMID: 36459202 PMCID: PMC9984347 DOI: 10.1007/s00292-022-01163-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 10/10/2022] [Indexed: 12/03/2022]
Abstract
Muscle diseases include hereditary and acquired diseases with clinical manifestation in both childhood and adulthood. The different muscle diseases may have ultrastructural alterations that help us further understand the pathology of the disease. Specific changes in sarcomere structure help to classify a congenital myopathy. The detection of cellular aggregates supports the classification of myositis. Pathologically altered mitochondria, on the other hand, can occur both in genetic mitochondriopathies but also secondarily in acquired muscle diseases like myositis. Ultrastructural analysis of the myocardium is also helpful in the diagnosis of hereditary cardiomyopathies in childhood. This review article highlights the ultrastructural features of different muscle diseases and pathognomonic findings in specific disease groups.
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13
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Distinctive chaperonopathy in skeletal muscle associated with the dominant variant in DNAJB4. Acta Neuropathol 2023; 145:235-255. [PMID: 36512060 DOI: 10.1007/s00401-022-02530-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/15/2022] [Accepted: 12/07/2022] [Indexed: 12/15/2022]
Abstract
DnaJ homolog, subfamily B, member 4, a member of the heat shock protein 40 chaperones encoded by DNAJB4, is highly expressed in myofibers. We identified a heterozygous c.270 T > A (p.F90L) variant in DNAJB4 in a family with a dominantly inherited distal myopathy, in which affected members have specific features on muscle pathology represented by the presence of cytoplasmic inclusions and the accumulation of desmin, p62, HSP70, and DNAJB4 predominantly in type 1 fibers. Both Dnajb4F90L knockin and knockout mice developed muscle weakness and recapitulated the patient muscle pathology in the soleus muscle, where DNAJB4 has the highest expression. These data indicate that the identified variant is causative, resulting in defective chaperone function and selective muscle degeneration in specific muscle fibers. This study demonstrates the importance of DNAJB4 in skeletal muscle proteostasis by identifying the associated chaperonopathy.
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14
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Rauf A, Ahamed H, Shanil M, Sandal S. Desmin Myopathy-A Masquerader of Infantile-Onset Pompe Disease. Indian J Pediatr 2022; 89:925. [PMID: 35779230 DOI: 10.1007/s12098-022-04281-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 05/11/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Abdul Rauf
- Department of Pediatrics, Baby Memorial Hospital, Calicut, Kerala, 673004, India.
| | - Hisham Ahamed
- Department of Cardiology, Amrita Institute of Medical Sciences and Research, Kochi, Kerala, India
| | - Mohamed Shanil
- Department of Pediatrics, Baby Memorial Hospital, Calicut, Kerala, 673004, India
| | - Sapna Sandal
- Institute of Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
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15
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Claes L, Schil KV, Dewals W, Beysen D. A Severe Form of Familial Desminopathy Due to a Homozygous Nonsense DES Variant in Two Siblings. Neuropediatrics 2022. [PMID: 35675837 DOI: 10.1055/a-1871-3692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Familial primary desminopathies are usually autosomal dominantly inherited and present at the age of 20 to 40 years with progressive muscle weakness and atrophy, cardiomyopathy, and cardiac arrhythmias. Cardiac features may precede the muscular weakness. Here, we report the rare case of two siblings presenting with a desminopathy at pediatric age, due to homozygous nonsense variations (c.700G > T [p.Glu234Ter]) in DES, representing an autosomal recessive inheritance pattern. The homozygous state of these variants is expected to result in the complete absence of desmin production. Rare autosomal recessive DES variants are associated with an earlier clinical presentation (from childhood to early adulthood) and faster evolution compared with more common autosomal dominant variants. A normal resting electrocardiography (ECG) and cardiac ultrasound can be a pitfall, as seen in our patient who has extensive fibrotic scarring on cardiac magnetic resonance imaging (MRI). We recommend yearly cardiac ultrasound, yearly 24-hour Holter monitoring and 2 yearly cardiac MRI from the age of 10 years in all asymptomatic patients. Heterozygous patients usually have no or only mild complaints but, though not yet reported in autosomal recessive desminopathies, muscular complaints are possible, as seen in the father of our patients. The prognosis for these patients with desminopathy presenting in childhood is unpredictable but anticipated as poor.
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Affiliation(s)
- Laura Claes
- Department of Paediatric Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Kristof van Schil
- Department of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.,Department of Medical Genetics, Antwerp University Hospital, Antwerp, Belgium
| | - Wendy Dewals
- Department of Paediatric Cardiology, Antwerp University Hospital, Antwerp, Belgium
| | - Diane Beysen
- Department of Paediatric Neurology, Antwerp University Hospital, Antwerp, Belgium.,Department of Paediatrics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
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16
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Thaxton C, Goldstein J, DiStefano M, Wallace K, Witmer PD, Haendel MA, Hamosh A, Rehm HL, Berg JS. Lumping versus splitting: How to approach defining a disease to enable accurate genomic curation. CELL GENOMICS 2022; 2:100131. [PMID: 35754516 PMCID: PMC9221396 DOI: 10.1016/j.xgen.2022.100131] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The dilemma of how to categorize and classify diseases has been debated for centuries. The field of medical genetics has historically approached nosology based on clinical phenotypes observed in patients and families. Advances in genomic sequencing and understanding of genetic contributions to disease often provoke a need to reassess these classifications. The Clinical Genome Resource (ClinGen) has developed frameworks to classify the strength of evidence underlying monogenic gene-disease relationships, variant pathogenicity, and clinical actionability. It is therefore necessary to define the disease entity being evaluated, which can be challenging for genes associated with multiple conditions and/or a broad phenotypic spectrum. We therefore developed criteria to guide "lumping and splitting" decisions and improve consistency in defining monogenic gene-disease relationships. Here, we outline the precuration process, the lumping and splitting guidelines with examples, and describe the implications for clinical diagnosis, informatics, and care management.
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Affiliation(s)
- Courtney Thaxton
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA,Lead contact,Correspondence:
| | - Jennifer Goldstein
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | - Kathleen Wallace
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - P. Dane Witmer
- Johns Hopkins Genomics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Melissa A. Haendel
- Center for Health AI, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Ada Hamosh
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Heidi L. Rehm
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA,Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jonathan S. Berg
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
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17
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Shah F, Stål P. Myopathy of the upper airway in snoring and obstructive sleep apnea. Laryngoscope Investig Otolaryngol 2022; 7:636-645. [PMID: 35434344 PMCID: PMC9008167 DOI: 10.1002/lio2.782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 11/19/2022] Open
Abstract
Objective Previous reports of muscle changes in the upper airways of obstructive sleep apnea (OSA) patients have primarily been attributed to acquired nerve lesions due to snoring vibrations. The aim of this study was to investigate whether alterations reflecting muscle fiber injuries also occur in the upper respiratory tract of snoring and OSA patients and if these changes relate to upper airway dysfunction. Methods Muscle changes in biopsies from the soft palate of 20 patients suffering from snoring and OSA were investigated with enzyme, immunohistochemical, and morphometric techniques. Biopsies from eight healthy non‐snoring subjects were used as controls. Swallowing dysfunction was assessed with videoradiography. Results Fourteen patients had various degrees of swallowing dysfunction. The muscle samples from all the patients showed changes typical for both motor‐nerve lesions and muscle fiber injuries. The most common alterations reflecting myopathy were fibers having aggregates and disorganization of cytoskeletal proteins (15.5 ± 10.7%). Other changes were fibers with vacuole‐like structures (5.0 ± 4.4%), centrally positioned myonuclei (7.9 ± 4.8%), subsarcolemmal accumulations of nuclei, and various forms and sizes of ring fibers, that is, fibers where the myofilaments were disorganized peripherally (2.8 ± 2.8%). Conclusion The results show that muscle changes mirroring both myopathy and neuropathy co‐exist in the upper airway of snoring OSA patients. These findings suggest muscle weakness as a contributing factor to the upper airway dysfunction in OSA patients.
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Affiliation(s)
- Farhan Shah
- Laboratory of Muscle Biology, Department of Integrative Medical Biology Umeå University Umeå Sweden
| | - Per Stål
- Laboratory of Muscle Biology, Department of Integrative Medical Biology Umeå University Umeå Sweden
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18
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Zhan L, Lv L, Chen X, Xu X, Ni J. Ultrasound evaluation of diaphragm motion in BAG-3 myofibrillar myopathy: A case report. Medicine (Baltimore) 2022; 101:e28484. [PMID: 35029900 PMCID: PMC8735720 DOI: 10.1097/md.0000000000028484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 12/16/2021] [Indexed: 11/25/2022] Open
Abstract
RATIONALE Mutations in Bcl-2-associated athanogene-3 (BAG-3) can cause a rare subtype of myofibrillar myopathies (MFMs), characterized by progressive muscle weakness, cardiomyopathy, and severe respiratory insufficiency in childhood. Little is known about diaphragmatic function in BAG-3 MFM. To our knowledge, this is the first case report of detailed evaluation of diaphragmatic function with ultrasound in BAG-3 MFM. PATIENT CONCERN We describe the case of a 15-year-old girl who complained of fever and shortness of breath. Diaphragmatic sonography revealed bilateral diaphragmatic paralysis. Shortness of breath progressed to respiratory failure approximately 3 months later. DIAGNOSIS A neurologist was consulted and genetic sequencing identified a p.Pro209Leu mutation in BAG-3, yielding diagnosis of BAG-3 MFM leading to bilateral diaphragmatic paralysis. INTERVENTIONS Respiratory muscle training and long-term mechanical ventilation. OUTCOMES It is quite unfortunate for this patient to have a poor prognosis due to the lack of effective treatment for this genetic disorder. LESSONS This case provides more clinical information for this rare disease which may cause severe diaphragm pathological damage leading to respiratory failure in BAG3 MFM and a future study with a systematic evaluation of a greater number of patients will be necessary to characterize this population.
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Affiliation(s)
- Liqiong Zhan
- Department of Rehabilitation Medicine, First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Lan Lv
- Department of Rehabilitation Medicine, First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Xinyuan Chen
- Department of Rehabilitation Medicine, First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Xiang Xu
- Department of Ultrasound Medicine, First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Jun Ni
- Department of Rehabilitation Medicine, First Affiliated Hospital of Fujian Medical University, Fuzhou, China
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19
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Scarpini G, Valentino ML, Giannotta M, Ragni L, Torella A, Columbaro M, Nigro V, Pini A. BAG3-related myofibrillar myopathy: a further observation with cardiomyopathy at onset in pediatric age. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2021; 40:177-183. [PMID: 35047758 PMCID: PMC8744013 DOI: 10.36185/2532-1900-061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/13/2021] [Indexed: 11/18/2022]
Abstract
Myofibrillar myopathies are a heterogeneous group of neuromuscular disorders characterized by degeneration of Z-disk, causing the disintegration of myofibrils. They may be caused by mutations in different genes, among these, the BAG3 gene (Bcl-2 associed-athanogene-3) encodes a multidomain protein that plays an important role in many cellular processes. We report the case of a 16-year-old male who at 4 years of age presented with a hypertrophic obstructive cardiomyopathy, then developed axonal sensory motor polyneuropathy, muscle weakness, rigid spine, severe kyphoscoliosis and respiratory failure. Muscle biopsy showed the typical hallmark of myofibrillar myopathy with abnormal cytoplasmic expression of multiple proteins. Ade novo heterozygous common mutation in the BAG3 gene with a c.626C > T (p.Pro209Leu) was discovered on NGS genetic analysis. Mutations in the BAG3 gene are causes of a severe and progressive condition and natural history data are important to be collected. An early diagnosis is critical for prognostic implications in cardiomyopathy and respiratory failure treatment.
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Affiliation(s)
- Gaia Scarpini
- Neuromuscular Pediatric Unit, UOC di Neuropsichiatria dell’età pediatrica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Maria Lucia Valentino
- UOC di Clinica Neurologica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy, Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna, Italy
| | - Melania Giannotta
- Neuromuscular Pediatric Unit, UOC di Neuropsichiatria dell’età pediatrica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Luca Ragni
- Pediatric Cardiology, University of Bologna, Bologna, Italy
| | - Annalaura Torella
- Telethon Institute of Genetics and Medicine (TIGEM), Università della Campania “Luigi Vanvitelli”, Pozzuoli, Naples, Italy
| | - Marta Columbaro
- SC Musculoskeletal Cell Biology Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Bologna, Italy
| | - Vincenzo Nigro
- Telethon Institute of Genetics and Medicine (TIGEM), Università della Campania “Luigi Vanvitelli”, Pozzuoli, Naples, Italy
| | - Antonella Pini
- Neuromuscular Pediatric Unit, UOC di Neuropsichiatria dell’età pediatrica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy,Correspondence Antonella Pini UOC pediatric Neurology and Psychiatry, IRCCS – Istituto delle Scienze Neurologiche di Bologna, via Altura 3, 40139 Bologna, Italy. Tel.: +39 051 6225111 E-mail:
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20
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Harlaar L, Ciet P, van Tulder G, Brusse E, Timmermans RGM, Janssen WGM, de Bruijne M, van der Ploeg AT, Tiddens HAWM, van Doorn PA, van der Beek NAME. Diaphragmatic dysfunction in neuromuscular disease, an MRI study. Neuromuscul Disord 2021; 32:15-24. [PMID: 34973872 DOI: 10.1016/j.nmd.2021.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 09/03/2021] [Accepted: 11/02/2021] [Indexed: 11/19/2022]
Abstract
The aim of this exploratory study was to evaluate diaphragmatic function across various neuromuscular diseases using spirometry-controlled MRI. We measured motion of the diaphragm relative to that of the thoracic wall (cranial-caudal ratio vs. anterior posterior ratio; CC-AP ratio), and changes in the diaphragmatic curvature (diaphragm height and area ratio) during inspiration in 12 adults with a neuromuscular disease having signs of respiratory muscle weakness, 18 healthy controls, and 35 adult Pompe patients - a group with prominent diaphragmatic weakness. CC-AP ratio was lower in patients with myopathies (n=7, 1.25±0.30) and motor neuron diseases (n=5, 1.30±0.10) than in healthy controls (1.37±0.14; p=0.001 and p=0.008), but not as abnormal as in Pompe patients (1.12±0.18; p=0.011 and p=0.024). The mean diaphragm height ratio was 1.17±0.33 in patients with myopathies, pointing at an insufficient diaphragmatic contraction. This was also seen in patients with Pompe disease (1.28±0.36), but not in healthy controls (0.82±0.33) or patients with motor neuron disease (0.82±0.24). We conclude that spirometry-controlled MRI enables us to investigate respiratory dysfunction across neuromuscular diseases, suggesting that the diaphragm is affected in a different way in myopathies and motor neuron diseases. Whether MRI can also be used to evaluate progression of diaphragmatic dysfunction requires additional studies.
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Affiliation(s)
- Laurike Harlaar
- Erasmus MC, University Medical Center Rotterdam, Center for Lysosomal and Metabolic Diseases, Department of Neurology, Rotterdam, the Netherlands; Erasmus MC - Sophia Children's Hospital, University Medical Center Rotterdam, Center for Lysosomal and Metabolic Diseases, Department of Paediatrics, Rotterdam, the Netherlands
| | - Pierluigi Ciet
- Erasmus MC, University Medical Center Rotterdam, Department of Radiology and Nuclear Medicine, Rotterdam, the Netherlands; Erasmus MC - Sophia Children's Hospital, University Medical Center Rotterdam, Department of Respiratory Medicine and Allergology, Rotterdam, the Netherlands
| | - Gijs van Tulder
- Erasmus MC, University Medical Center Rotterdam, Department of Radiology and Nuclear Medicine, Rotterdam, the Netherlands
| | - Esther Brusse
- Erasmus MC, University Medical Center Rotterdam, Center for Lysosomal and Metabolic Diseases, Department of Neurology, Rotterdam, the Netherlands
| | - Remco G M Timmermans
- Rijndam Rehabilitation Centre Rotterdam, location Erasmus MC, Rotterdam, the Netherlands
| | - Wim G M Janssen
- Rijndam Rehabilitation Centre Rotterdam, location Erasmus MC, Rotterdam, the Netherlands
| | - Marleen de Bruijne
- Erasmus MC, University Medical Center Rotterdam, Department of Radiology and Nuclear Medicine, Rotterdam, the Netherlands; University of Copenhagen, Department of Computer Science, Copenhagen, Denmark
| | - Ans T van der Ploeg
- Erasmus MC - Sophia Children's Hospital, University Medical Center Rotterdam, Center for Lysosomal and Metabolic Diseases, Department of Paediatrics, Rotterdam, the Netherlands
| | - Harm A W M Tiddens
- Erasmus MC, University Medical Center Rotterdam, Department of Radiology and Nuclear Medicine, Rotterdam, the Netherlands; Erasmus MC - Sophia Children's Hospital, University Medical Center Rotterdam, Department of Respiratory Medicine and Allergology, Rotterdam, the Netherlands
| | - Pieter A van Doorn
- Erasmus MC, University Medical Center Rotterdam, Center for Lysosomal and Metabolic Diseases, Department of Neurology, Rotterdam, the Netherlands
| | - Nadine A M E van der Beek
- Erasmus MC, University Medical Center Rotterdam, Center for Lysosomal and Metabolic Diseases, Department of Neurology, Rotterdam, the Netherlands.
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21
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Davalos L, Janecek J, Fudym Y, McKeever P, Callaghan BC. Clinical Reasoning: A 59-Year-Old Man With Progressive Proximal Weakness Since Childhood. Neurology 2021; 97:958-963. [PMID: 34261780 DOI: 10.1212/wnl.0000000000012488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Long Davalos
- Department of Neurology, Neuromuscular Division, University of Michigan, Ann Arbor, MI
| | - Jacqueline Janecek
- Department of Neurology, Neuromuscular Division, University of Michigan, Ann Arbor, MI
| | - Yelena Fudym
- Department of Pathology, University of Michigan, Ann Arbor, MI
| | - Paul McKeever
- Department of Pathology, University of Michigan, Ann Arbor, MI
| | - Brian C Callaghan
- Department of Neurology, Neuromuscular Division, University of Michigan, Ann Arbor, MI
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22
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Moloney PB, Lefter S, Ryan AM, Jansen M, Bermingham N, McNamara B. The Diagnostic Yield of Electromyography at Detecting Abnormalities on Muscle Biopsy: A Single Center Experience. Neurodiagn J 2021; 61:86-94. [PMID: 34120582 DOI: 10.1080/21646821.2021.1916730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Historically, electromyography (EMG) is utilized early in the diagnostic evaluation of neuromuscular disorders, but its importance may be diminishing with more sophisticated genetic, imaging and immunohistochemistry investigations now available. In the present study, the diagnostic yield of EMG at predicting pathological abnormalities confirmed by muscle biopsy was determined at our neuroscience center. A retrospective study of consecutive cases reviewed at neuromuscular multidisciplinary meetings between 2007 and 2016 identified patients who had EMG and muscle biopsy as part of their diagnostic evaluation. EMG and biopsy findings were categorized as myopathic, neurogenic or normal. The diagnostic accuracy was determined by calculating the concordance between EMG and pathological findings. Of the 175 cases included in the analysis, there was definite concordance between EMG and muscle biopsy findings in 134 cases (76.6%). Abnormal EMG produced sensitivity of 87% and specificity of 65% for abnormal muscle biopsy. Seventeen patients had a normal EMG and an abnormal muscle biopsy, of which 6 had histopathological findings consistent with mitochondrial myopathy, central core myopathy or glycogen storage disorder. Conflicting EMG and muscle biopsy findings were observed in 10 cases. Inclusion body myositis, chronic neuromuscular disorders and dual pathologies were associated with discordant findings. This study demonstrates that EMG has accurate predictive value in diagnosing neuromuscular disorders at our neuroscience center. EMG retains a vital role, particularly in initial diagnostic evaluations of neuromuscular disorders.
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Affiliation(s)
| | - Stela Lefter
- Department of Neurology, Cork University Hospital, Cork, Ireland.,Department of Clinical Neurophysiology, Cork University Hospital, Cork, Ireland
| | - Aisling M Ryan
- Department of Neurology, Cork University Hospital, Cork, Ireland
| | - Michael Jansen
- Department of Neuropathology, Cork University Hospital, Cork, Ireland
| | - Niamh Bermingham
- Department of Neuropathology, Cork University Hospital, Cork, Ireland
| | - Brian McNamara
- Department of Clinical Neurophysiology, Cork University Hospital, Cork, Ireland
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23
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Eggers B, Schork K, Turewicz M, Barkovits K, Eisenacher M, Schröder R, Clemen CS, Marcus K. Advanced Fiber Type-Specific Protein Profiles Derived from Adult Murine Skeletal Muscle. Proteomes 2021; 9:proteomes9020028. [PMID: 34201234 PMCID: PMC8293376 DOI: 10.3390/proteomes9020028] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 02/07/2023] Open
Abstract
Skeletal muscle is a heterogeneous tissue consisting of blood vessels, connective tissue, and muscle fibers. The last are highly adaptive and can change their molecular composition depending on external and internal factors, such as exercise, age, and disease. Thus, examination of the skeletal muscles at the fiber type level is essential to detect potential alterations. Therefore, we established a protocol in which myosin heavy chain isoform immunolabeled muscle fibers were laser microdissected and separately investigated by mass spectrometry to develop advanced proteomic profiles of all murine skeletal muscle fiber types. All data are available via ProteomeXchange with the identifier PXD025359. Our in-depth mass spectrometric analysis revealed unique fiber type protein profiles, confirming fiber type-specific metabolic properties and revealing a more versatile function of type IIx fibers. Furthermore, we found that multiple myopathy-associated proteins were enriched in type I and IIa fibers. To further optimize the assignment of fiber types based on the protein profile, we developed a hypothesis-free machine-learning approach, identified a discriminative peptide panel, and confirmed our panel using a public data set.
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Affiliation(s)
- Britta Eggers
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
- Correspondence: (B.E.); (K.M.)
| | - Karin Schork
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
| | - Michael Turewicz
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
| | - Katalin Barkovits
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
| | - Martin Eisenacher
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
| | - Rolf Schröder
- Institute of Neuropathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, 91054 Erlangen, Germany;
| | - Christoph S. Clemen
- German Aerospace Center, Institute of Aerospace Medicine, 51147 Cologne, Germany;
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Katrin Marcus
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
- Correspondence: (B.E.); (K.M.)
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BAG3 Myopathy Presenting With Prominent Neuropathic Phenotype and No Cardiac or Respiratory Involvement: A Case Report and Literature Review. J Clin Neuromuscul Dis 2021; 21:230-239. [PMID: 32453099 DOI: 10.1097/cnd.0000000000000300] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Bcl-2-associated athanogene 3 (BAG3) myopathy is a rare myofibrillar myopathy characterized by toe walking and clumsiness in the first decade with rapid progression to cardiomyopathy and restrictive lung disease in the second decade. Most patients (18 patients) have the c.626C >T (p.Pro209Leu) mutation. We describe BAG3 myopathy due to p.Pro209Leu in a 13-year-old girl with initial prominent neuropathic phenotype and no cardiac or respiratory involvement. Parents reported toe walking and clumsiness since 3 years old. Examination at the age of 13 years showed findings suggestive of Charcot-Marie-Tooth disease. Nerve conduction studies revealed demyelinating polyneuropathy. Next-generation sequencing panel for inherited neuropathies was unrevealing. Whole exome sequencing identified a de novo mutation in BAG3. Muscle biopsy confirmed myofibrillar myopathy. No cardiac involvement or symptoms of respiratory involvement at the age of 14 years. This case emphasizes the phenotypic variability of BAG3 myopathy and the importance of thorough electrophysiological examination and muscle pathology for establishing a precise diagnosis.
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25
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Sadeh M, Rahat D, Meiner V, Fellig Y, Arad M, Schueler-Furman O, Hu Y, Li Y, Bönnemann CG, Lossos A. Multi-system neurological disorder associated with a CRYAB variant. Neurogenetics 2021; 22:117-125. [PMID: 33811585 DOI: 10.1007/s10048-021-00640-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/18/2021] [Indexed: 10/21/2022]
Abstract
We report a multiplex family with extended multisystem neurological phenotype associated with a CRYAB variant. Two affected siblings were evaluated with whole exome sequencing, muscle biopsy, laser microdissection, and mass spectrometry-based proteomic analysis. Both patients and their mother manifested a combination of early-onset cataracts, cardiomyopathy, cerebellar ataxia, optic atrophy, cognitive impairment, and myopathy. Whole exome sequencing identified a heterozygous c.458C>T variant mapped to the C-terminal extension domain of the Alpha-crystallin B chain, disrupting its function as a molecular chaperone and its ability to suppress protein aggregation. In accordance with the molecular findings, muscle biopsies revealed subsarcolemmal deposits that appeared dark with H&E and trichrome staining were negative for the other routine histochemical staining and for amyloid with the Congo-red stain. Electron microscopy demonstrated that the deposits were composed of numerous parallel fibrils. Laser microdissection and mass spectrometry-based proteomic analysis revealed that the inclusions are almost exclusively composed of crystallized chaperones/heat shock proteins. Moreover, a structural model suggests that Ser153 could be involved in monomer stabilization, dimer association, and possible binding of partner proteins. We propose that our report potentially expands the complex phenotypic spectrum of alpha B-crystallinopathies with possible effect of a CRYAB variant on the central nervous system.
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Affiliation(s)
- Menachem Sadeh
- Department of Neurology, Wolfson Medical Center and Tel Aviv University, Holon, Israel.
| | - Dolev Rahat
- Department of Microbiology and Molecular Genetics, Faculty of Medicine, Institute for Biomedical Research Israel-Canada, Hebrew University, Jerusalem, Israel
| | - Vardiella Meiner
- Department of Genetics, Hadassah Medical Organization and Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Yakov Fellig
- Department of Pathology, Genetics, Hadassah Medical Organization and Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Michael Arad
- Leviev Heart Center, Sheba Medical Center, Tel Hashomer and Tel Aviv University, Tel Aviv, Israel
| | - Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, Faculty of Medicine, Institute for Biomedical Research Israel-Canada, Hebrew University, Jerusalem, Israel
| | - Ying Hu
- National Institute of Neurological Disorders and Stroke, Neurogenetics Branch, Bethesda, MD, USA
| | - Yan Li
- National Institute of Neurological Disorders and Stroke, Proteomics Core Facility, Bethesda, MD, USA
| | - Carsten G Bönnemann
- National Institute of Neurological Disorders and Stroke, Neurogenetics Branch, Bethesda, MD, USA
| | - Alexander Lossos
- Department of Neurology, Genetics, Hadassah Medical Organization and Faculty of Medicine, Hebrew University, Jerusalem, Israel
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26
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The Role of Z-disc Proteins in Myopathy and Cardiomyopathy. Int J Mol Sci 2021; 22:ijms22063058. [PMID: 33802723 PMCID: PMC8002584 DOI: 10.3390/ijms22063058] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/07/2021] [Accepted: 03/11/2021] [Indexed: 12/11/2022] Open
Abstract
The Z-disc acts as a protein-rich structure to tether thin filament in the contractile units, the sarcomeres, of striated muscle cells. Proteins found in the Z-disc are integral for maintaining the architecture of the sarcomere. They also enable it to function as a (bio-mechanical) signalling hub. Numerous proteins interact in the Z-disc to facilitate force transduction and intracellular signalling in both cardiac and skeletal muscle. This review will focus on six key Z-disc proteins: α-actinin 2, filamin C, myopalladin, myotilin, telethonin and Z-disc alternatively spliced PDZ-motif (ZASP), which have all been linked to myopathies and cardiomyopathies. We will summarise pathogenic variants identified in the six genes coding for these proteins and look at their involvement in myopathy and cardiomyopathy. Listing the Minor Allele Frequency (MAF) of these variants in the Genome Aggregation Database (GnomAD) version 3.1 will help to critically re-evaluate pathogenicity based on variant frequency in normal population cohorts.
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27
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Schänzer A, Schumann E, Zengeler D, Gulatz L, Maroli G, Ahting U, Sprengel A, Gräf S, Hahn A, Jux C, Acker T, Fürst DO, Rupp S, Schuld J, van der Ven PFM. The p.Ala2430Val mutation in filamin C causes a "hypertrophic myofibrillar cardiomyopathy". J Muscle Res Cell Motil 2021; 42:381-397. [PMID: 33710525 DOI: 10.1007/s10974-021-09601-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) often leads to heart failure. Mutations in sarcomeric proteins are most frequently the cause of HCM but in many patients the gene defect is not known. Here we report on a young man who was diagnosed with HCM shortly after birth. Whole exome sequencing revealed a mutation in the FLNC gene (c.7289C > T; p.Ala2430Val) that was previously shown to cause aggregation of the mutant protein in transfected cells. Myocardial tissue from patients with this mutation has not been analyzed before and thus, the underlying etiology is not well understood. Myocardial tissue of our patient obtained during myectomy at the age of 23 years was analyzed in detail by histochemistry, immunofluorescence staining, electron microscopy and western blot analysis. Cardiac histology showed a pathology typical for myofibrillar myopathy with myofibril disarray and abnormal protein aggregates containing BAG3, desmin, HSPB5 and filamin C. Analysis of sarcomeric and intercalated disc proteins showed focally reduced expression of the gap junction protein connexin43 and Xin-positive sarcomeric lesions in the cardiomyocytes of our patient. In addition, autophagy pathways were altered with upregulation of LC3-II, WIPI1 and HSPB5, 6, 7 and 8. We conclude that the p.Ala2430Val mutation in FLNC most probably is associated with HCM characterized by abnormal intercalated discs, disarray of myofibrils and aggregates containing Z-disc proteins similar to myofibrillar myopathy, which supports the pathological effect of the mutation.
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Affiliation(s)
- Anne Schänzer
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany.
| | - Elisabeth Schumann
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Diana Zengeler
- Center for Genomics and Transcriptomics (CeGat) GmbH, Tübingen, Germany
| | - Lisann Gulatz
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Giovanni Maroli
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Uwe Ahting
- Institute of Human Genetics, Technical University of Munich (TUM), Munich, Germany
| | - Anke Sprengel
- Pediatric Heart Center, Justus Liebig University, Giessen, Germany
| | - Sabine Gräf
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Andreas Hahn
- Department of Child Neurology, Justus Liebig University, Giessen, Germany
| | - Christian Jux
- Pediatric Heart Center, Justus Liebig University, Giessen, Germany
| | - Till Acker
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Dieter O Fürst
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Stefan Rupp
- Pediatric Heart Center, Justus Liebig University, Giessen, Germany
| | - Julia Schuld
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Peter F M van der Ven
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
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28
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Williams ZJ, Velez-Irizarry D, Petersen JL, Ochala J, Finno CJ, Valberg SJ. Candidate gene expression and coding sequence variants in Warmblood horses with myofibrillar myopathy. Equine Vet J 2021; 53:306-315. [PMID: 32453872 PMCID: PMC7864122 DOI: 10.1111/evj.13286] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/18/2020] [Accepted: 05/02/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Myofibrillar myopathy (MFM) of unknown aetiology has recently been identified in Warmblood (WB) horses. In humans, 16 genes have been implicated in various MFM-like disorders. OBJECTIVES To identify variants in 16 MFM candidate genes and compare allele frequencies of all variants between MFM WB and non-MFM WB and coding variants with moderate or severe predicted effects in MFM WB with publicly available data of other breeds. To compare differential gene expression and muscle fibre contractile force between MFM and non-MFM WB. STUDY DESIGN Case-control. ANIMALS 8 MFM WB, 8 non-MFM WB, 33 other WB, 32 Thoroughbreds, 80 Quarter Horses and 77 horses of other breeds in public databases. METHODS Variants were called within transcripts of 16 candidate genes using gluteal muscle mRNA sequences aligned to EquCab3.0 and allele frequencies compared by Fisher's exact test among MFM WB, non-MFM WB and public sequences across breeds. Candidate gene differential expression was determined between MFM and non-MFM WB by fitting a negative binomial generalised log-linear model per gene (false discovery rate <0.05). The maximal isometric force/cross-sectional area generated by isolated membrane-permeabilised muscle fibres was determined. RESULTS None of the 426 variants identified in 16 candidate genes were associated with MFM including 26 missense variants. Breed-specific differences existed in allele frequencies. Candidate gene differential expression and muscle fibre-specific force did not differ between MFM WB (143.1 ± 34.7 kPa) and non-MFM WB (140.2 ± 43.7 kPa) (P = .8). MAIN LIMITATIONS RNA-seq-only assays transcripts expressed in skeletal muscle. Other possible candidate genes were not evaluated. CONCLUSIONS Evidence for association of variants with a disease is essential because coding sequence variants are common in the equine genome. Variants identified in MFM candidate genes, including two coding variants offered as commercial MFM equine genetic tests, did not associate with the WB MFM phenotype.
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Affiliation(s)
- Zoë J. Williams
- Large Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, MI, USA
| | - Deborah Velez-Irizarry
- Large Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, MI, USA
| | - Jessica L. Petersen
- Department of Animal Science, University of Nebraska Lincoln, Lincoln, NE, USA
| | - Julien Ochala
- Faculty of Life Sciences and Medicine, King’s College London, London, UK
| | - Carrie J. Finno
- University of California at Davis, School of Veterinary Medicine, Davis, CA, USA
| | - Stephanie J. Valberg
- Large Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, MI, USA
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29
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Potulska-Chromik A, Jędrzejowska M, Gos M, Rosiak E, Kierdaszuk B, Maruszak A, Opuchlik A, Zekanowski C, Fichna JP. Pathogenic Mutations and Putative Phenotype-Affecting Variants in Polish Myofibrillar Myopathy Patients. J Clin Med 2021; 10:jcm10050914. [PMID: 33652732 PMCID: PMC7956316 DOI: 10.3390/jcm10050914] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/06/2021] [Accepted: 02/17/2021] [Indexed: 02/07/2023] Open
Abstract
Myofibrillar myopathies (MFM) are heterogeneous hereditary muscle diseases with characteristic myopathological features of Z-disk dissolution and aggregates of its degradation products. The onset and progression of the disease are variable, with an elusive genetic background, and around half of the cases lacking molecular diagnosis. Here, we attempted to establish possible genetic foundations of MFM by performing whole exome sequencing (WES) in eleven unrelated families of 13 patients clinically diagnosed as MFM spectrum. A filtering strategy aimed at identification of variants related to the disease was used and included integrative analysis of WES data and human phenotype ontology (HPO) terms, analysis of muscle-expressed genes, and analysis of the disease-associated interactome. Genetic diagnosis was possible in eight out of eleven cases. Putative causative mutations were found in the DES (two cases), CRYAB, TPM3, and SELENON (four cases) genes, the latter typically presenting with a rigid spine syndrome. Moreover, a variety of additional, possibly phenotype-affecting variants were found. These findings indicate a markedly heterogeneous genetic background of MFM and show the usefulness of next generation sequencing in the identification of disease-associated mutations. Finally, we discuss the emerging concept of variant load as the basis of phenotypic heterogeneity.
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Affiliation(s)
- Anna Potulska-Chromik
- Department of Neurology, Medical University of Warsaw, 1a Banacha St., 02-097 Warsaw, Poland; (A.P.-C.); (B.K.); (A.O.)
| | - Maria Jędrzejowska
- Neuromuscular Unit, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawinskiego St., 02-106 Warsaw, Poland;
| | - Monika Gos
- Department of Medical Genetics, Institute of Mother and Child, 17a Kasprzaka St, 01-211 Warsaw, Poland;
| | - Edyta Rosiak
- II Department of Radiology, Medical University of Warsaw, 1a Banacha St., 02-097 Warsaw, Poland;
| | - Biruta Kierdaszuk
- Department of Neurology, Medical University of Warsaw, 1a Banacha St., 02-097 Warsaw, Poland; (A.P.-C.); (B.K.); (A.O.)
| | - Aleksandra Maruszak
- Department of Neurodegenerative Disorders, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawinskiego St., 02-106 Warsaw, Poland; (A.M.); (C.Z.)
| | - Andrzej Opuchlik
- Department of Neurology, Medical University of Warsaw, 1a Banacha St., 02-097 Warsaw, Poland; (A.P.-C.); (B.K.); (A.O.)
| | - Cezary Zekanowski
- Department of Neurodegenerative Disorders, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawinskiego St., 02-106 Warsaw, Poland; (A.M.); (C.Z.)
| | - Jakub P. Fichna
- Department of Neurodegenerative Disorders, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawinskiego St., 02-106 Warsaw, Poland; (A.M.); (C.Z.)
- Correspondence: ; Tel.: +48-226-086-485
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30
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Qian FY, Guo YD, Zu J, Zhang JH, Zheng YM, Abdoulaye IA, Pan ZH, Xie CM, Gao HC, Zhang ZJ. A novel recessive mutation affecting DNAJB6a causes myofibrillar myopathy. Acta Neuropathol Commun 2021; 9:23. [PMID: 33557929 PMCID: PMC7869515 DOI: 10.1186/s40478-020-01046-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/02/2020] [Indexed: 11/10/2022] Open
Abstract
Mutations in the DNAJB6 gene have been identified as rare causes of myofibrillar myopathies. However, the underlying pathophysiologica mechanisms remain elusive. DNAJB6 has two known isoforms, including the nuclear isoform DNAJB6a and the cytoplasmic isoform DNAJB6b, which was thought to be the pathogenic isoform. Here, we report a novel recessive mutation c.695_699del (p. Val 232 Gly fs*7) in the DNAJB6 gene, associated with an apparently recessively inherited late onset distal myofibrillar myopathy in a Chinese family. Notably, the novel mutation localizes to exon 9 and uniquely encodes DNAJB6a. We further identified that this mutation decreases the mRNA and protein levels of DNAJB6a and results in an age-dependent recessive toxic effect on skeletal muscle in knock-in mice. Moreover, the mutant DNAJB6a showed a dose-dependent anti-aggregation effect on polyglutamine-containing proteins in vitro. Taking together, these findings reveal the pathogenic role of DNAJB6a insufficiency in myofibrillar myopathies and expand upon the molecular spectrum of DNAJB6 mutations.
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31
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Carroll LS, Walker M, Allen D, Marini-Bettolo C, Ditchfield A, Pinto AA, Hammans SR. Desminopathy presenting as late onset bilateral facial weakness, with diagnosis supported by lower limb MRI. Neuromuscul Disord 2021; 31:249-252. [PMID: 33546848 DOI: 10.1016/j.nmd.2020.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/12/2020] [Accepted: 12/30/2020] [Indexed: 11/29/2022]
Abstract
A 63 year old male presented with a 20 year history of facial weakness and several years of nasal regurgitation and dysphonia. Examination revealed bilateral facial weakness with nasal speech. Serum creatine kinase was 918 U/L. Neurophysiological studies suggested a myopathy and biopsy of the left vastus lateralis showed serpentine basophilic inclusions in the sarcoplasm and strong oxidative enzyme activity suggesting mitochondria accumulation. The muscle MRI showed selective fatty replacement within semitendinosus, gastrocnemius and soleus indicative of a desminopathy. A heterozygous missense variant c.17C>G (p.Ser6Trp) was identified within DES, predicted to be pathogenic in silico and previously described in a family with distal limb weakness. There are no previous case reports of desminopathy presenting with facial weakness, to our knowledge. Diagnosis was suggested following myoimaging of clinically unaffected muscles. Our study highlights the importance of muscle MRI in the diagnostic evaluation of muscle disease and further expands the known phenotypic heterogeneity of desminopathies.
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Affiliation(s)
- Liam S Carroll
- Wessex Neurological Centre, Southampton General Hospital, Southampton SO16 6YD, UK.
| | - Mark Walker
- Wessex Neurological Centre, Southampton General Hospital, Southampton SO16 6YD, UK
| | - David Allen
- Wessex Neurological Centre, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Ciara Marini-Bettolo
- John Walton Muscular Dystrophy Research Centre, Newcastle University and The Newcastle Hospitals NHS Foundation Trust, NE1 3BZ, UK
| | - Adam Ditchfield
- Wessex Neurological Centre, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Ashwin A Pinto
- Wessex Neurological Centre, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Simon R Hammans
- Wessex Neurological Centre, Southampton General Hospital, Southampton SO16 6YD, UK
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32
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Argov Z, de Visser M. Dysphagia in adult myopathies. Neuromuscul Disord 2020; 31:5-20. [PMID: 33334661 DOI: 10.1016/j.nmd.2020.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 12/11/2022]
Abstract
Dysphagia (impaired swallowing) is not a rare problem in various neuromuscular disorders, both in the pediatric and the adult patient population. On many occasions such patients are first presented to other medical specialists or health professionals. Disorders of deglutition are probably underrecognized in patients with a neuromuscular disease as a result of patient's and doctor's delay. This review will focus on dysphagia in adults suffering from a myopathy. Dysphagia in myopathies usually affects the oropharyngeal phases which rely mostly on voluntary muscle activity of the mouth, pharynx and upper esophageal sphincter. Dysphagia is known to contribute to a reduction of quality of life and may also lead to increased morbidity and mortality. The review includes an overview on symptomatology and tools of assessments, and elaborates on dysphagia in specific hereditary and acquired myopathies.
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Affiliation(s)
- Zohar Argov
- Department of Neurology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Marianne de Visser
- Department of Neurology, Amsterdam University Medical Centres, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, the Netherlands.
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33
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Cassandrini D, Merlini L, Pilla F, Cenni V, Santi S, Faldini C, Santorelli FM, Sabatelli P. Protein aggregates and autophagy involvement in a family with a mutation in Z-band alternatively spliced PDZ-motif protein. Neuromuscul Disord 2020; 31:44-51. [PMID: 33308939 DOI: 10.1016/j.nmd.2020.11.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/20/2022]
Abstract
Z-band alternatively spliced PDZ-motif protein (ZASP) is a sarcomeric component expressed both in cardiac and skeletal muscles. Mutations in the LDB3/ZASP gene cause cardiomyopathy and myofibrillar myopathy. We describe a c.76C>T / p.[Pro26Ser] mutation in the PDZ motif of LDB3/ZASP in two siblings exhibiting late-onset myopathy with axial, proximal and distal muscles involvement and marked variability in clinical severity in the absence of a significant family history for neuromuscular disorders. Notably, we identified involvement of the psoas muscle on MRI and muscle CT, a feature not previously documented. Proband's muscle biopsy showed an increase of ZASP expression by western blotting. Muscle fibres morphological features included peculiar sarcolemmal invaginations, pathological aggregates positive to ZASP, ubiquitin, p62 and LC3 antibodies, and the accumulation of autophagic vacuoles, suggesting that protein aggregate formation and autophagy are involved in this additional case of zaspopathy.
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Affiliation(s)
- Denise Cassandrini
- Molecular Medicine- IRCCS Fondazione Stella Maris- via dei Giacinti 2, 56128 Pisa, Italy
| | - Luciano Merlini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Ugo Foscolo 7, 40123 Bologna, Italy
| | - Federico Pilla
- 1st Orthopaedic and Traumatologic Clinic, IRCCS Istituto Ortopedico Rizzoli, via Pupilli 1, 40139 Bologna, Italy
| | - Vittoria Cenni
- CNR-Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza"-Unit of Bologna, via di Barbiano 1/10, 40136 Bologna, Italy; IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136 Bologna, Italy
| | - Spartaco Santi
- CNR-Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza"-Unit of Bologna, via di Barbiano 1/10, 40136 Bologna, Italy; IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136 Bologna, Italy
| | - Cesare Faldini
- 1st Orthopaedic and Traumatologic Clinic, IRCCS Istituto Ortopedico Rizzoli, via Pupilli 1, 40139 Bologna, Italy
| | - Filippo M Santorelli
- Molecular Medicine- IRCCS Fondazione Stella Maris- via dei Giacinti 2, 56128 Pisa, Italy
| | - Patrizia Sabatelli
- CNR-Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza"-Unit of Bologna, via di Barbiano 1/10, 40136 Bologna, Italy; IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136 Bologna, Italy.
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34
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Vikhorev PG, Vikhoreva NN, Yeung W, Li A, Lal S, dos Remedios CG, Blair CA, Guglin M, Campbell KS, Yacoub MH, de Tombe P, Marston SB. Titin-truncating mutations associated with dilated cardiomyopathy alter length-dependent activation and its modulation via phosphorylation. Cardiovasc Res 2020; 118:241-253. [PMID: 33135063 PMCID: PMC8752363 DOI: 10.1093/cvr/cvaa316] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 10/20/2020] [Indexed: 12/18/2022] Open
Abstract
Abstract
Aims
Dilated cardiomyopathy (DCM) is associated with mutations in many genes encoding sarcomere proteins. Truncating mutations in the titin gene TTN are the most frequent. Proteomic and functional characterizations are required to elucidate the origin of the disease and the pathogenic mechanisms of TTN-truncating variants.
Methods and results
We isolated myofibrils from DCM hearts carrying truncating TTN mutations and measured the Ca2+ sensitivity of force and its length dependence. Simultaneous measurement of force and adenosine triphosphate (ATP) consumption in skinned cardiomyocytes was also performed. Phosphorylation levels of troponin I (TnI) and myosin binding protein-C (MyBP-C) were manipulated using protein kinase A and λ phosphatase. mRNA sequencing was employed to overview gene expression profiles. We found that Ca2+ sensitivity of myofibrils carrying TTN mutations was significantly higher than in myofibrils from donor hearts. The length dependence of the Ca2+ sensitivity was absent in DCM myofibrils with TTN-truncating variants. No significant difference was found in the expression level of TTN mRNA between the DCM and donor groups. TTN exon usage and splicing were also similar. However, we identified down-regulation of genes encoding Z-disk proteins, while the atrial-specific regulatory myosin light chain gene, MYL7, was up-regulated in DCM patients with TTN-truncating variants.
Conclusion
Titin-truncating mutations lead to decreased length-dependent activation and increased elasticity of myofibrils. Phosphorylation levels of TnI and MyBP-C seen in the left ventricles are essential for the length-dependent changes in Ca2+ sensitivity in healthy donors, but they are reduced in DCM patients with TTN-truncating variants. A decrease in expression of Z-disk proteins may explain the observed decrease in myofibril passive stiffness and length-dependent activation.
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Affiliation(s)
- Petr G Vikhorev
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Natalia N Vikhoreva
- Heart Science Centre, Magdi Yacoub Institute, Harefield Hospital, London UB9 6JH, UK
| | - WaiChun Yeung
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Amy Li
- Department of Pharmacy and Biomedical Sciences, La Trobe University, Bendigo, VIC 3550, Australia
| | - Sean Lal
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW 2006, Australia
| | - Cristobal G dos Remedios
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Cheavar A Blair
- Division of Cardiovascular Medicine, Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Maya Guglin
- Division of Cardiovascular Medicine, Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Kenneth S Campbell
- Division of Cardiovascular Medicine, Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Magdi H Yacoub
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Pieter de Tombe
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
- Heart Science Centre, Magdi Yacoub Institute, Harefield Hospital, London UB9 6JH, UK
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
| | - Steven B Marston
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
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Valberg SJ, Finno CJ, Henry ML, Schott M, Velez-Irizarry D, Peng S, McKenzie EC, Petersen JL. Commercial genetic testing for type 2 polysaccharide storage myopathy and myofibrillar myopathy does not correspond to a histopathological diagnosis. Equine Vet J 2020; 53:690-700. [PMID: 32896939 PMCID: PMC7937766 DOI: 10.1111/evj.13345] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/18/2020] [Accepted: 08/27/2020] [Indexed: 02/04/2023]
Abstract
Background Commercial genetic tests for type 2 polysaccharide storage myopathy (PSSM2) and myofibrillar myopathy (MFM) have not been validated by peer‐review, and formal regulation of veterinary genetic testing is lacking. Objectives To compare genotype and allele frequencies of commercial test variants (P variants) in MYOT (P2; rs1138656462), FLNC (P3a; rs1139799323), FLNC (P3b; rs1142918816) and MYOZ3 (P4; rs1142544043) between Warmblood (WB) and Arabian (AR) horses diagnosed with PSSM2/MFM by muscle histopathology, and phenotyped breed‐matched controls. To quantify variant frequency in public repositories of ancient and modern horse breeds. Study design Cross sectional using archived clinical material and publicly available data. Methods We studied 54 control‐WB, 68 PSSM2/MFM‐WB, 30 control‐AR, 30 PSSM2/MFM‐AR and 205 public genotypes. Variants were genotyped by pyrosequencing archived DNA. Genotype and allele frequency, and number of variant alleles or loci were compared within breed between controls, PSSM2/MFM combined and MFM or PSSM2 horses considered separately using additive/genotypic and dominant models (Fisher's exact tests). Variant frequencies in modern, early domestic and Przewalski horses were determined from a public data repository. Results There was no significant association between any P locus and a histopathological diagnosis of PSSM2/MFM, and no difference between control and myopathic horses in total loci with alternative alleles, or total alternate alleles when PSSM2/MFM was considered combined or separately as PSSM2 or MFM. For all tests, sensitivity was <0.33. Allele frequencies in WB (controls/cases) were: 8%/15% (P2), 5%/6% (P3a/b) and 9%/13% (P4); in AR, frequencies were: 12%/17% (P2), 2%/2% (P3a/b) and 7%/12% (P4). All P variants were present in early domestic (400‐ to 5500‐year‐old) horses and P2 present in the Przewalski. Conclusions Because of the lack of significant association between a histopathological diagnosis of PSSM2 or MFM and the commercial genetic test variants P2, P3 and P4 in WB and AR, we cannot recommend the use of these variant genotypes for selection and breeding, prepurchase examination or diagnosis of a myopathy.
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Affiliation(s)
- Stephanie J Valberg
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Carrie J Finno
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
| | - Marisa L Henry
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Melissa Schott
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Deborah Velez-Irizarry
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Sichong Peng
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
| | - Erica C McKenzie
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - Jessica L Petersen
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE, USA
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36
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McMacken G, Whittaker RG, Charlton R, Barresi R, Lochmüller H, Horvath R. Inherited neuropathies with predominant upper limb involvement: genetic heterogeneity and overlapping pathologies. Eur J Neurol 2020; 28:297-304. [PMID: 32909314 DOI: 10.1111/ene.14514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 08/26/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE In a subset of patients with inherited peripheral neuropathies the first symptom is atrophy and weakness of the intrinsic muscles of the hands, without involvement of lower limbs until later in the disease course. The exact pathomechanisms of this phenotype are currently unknown. The aim of this study was to characterize the clinical, neurophysiological and genetic features of a group of patients with a clinical diagnosis of upper limb predominant Charcot-Marie-Tooth disease (CMT). METHODS The clinical, electrophysiology and genetic data of 11 patients with upper limb predominant peripheral neuropathy selected from a single-centre cohort of 461 patients diagnosed with inherited neuropathy were analysed and the clinical, electrophysiological and genetic characteristics of these patients reported. RESULTS An overlapping phenotype of neuropathy and myopathy was detected in two patients. Four patients carry autosomal dominant mutations in GARS and a single patient had a homozygous mutation in SH3TC2. However, the underlying genetic diagnosis could not be confirmed in six patients by gene panel sequencing. CONCLUSIONS Upper limb-onset inherited neuropathies are genetically heterogeneous and, in some cases, there is an overlapping myopathy. Autosomal dominant GARS mutations are the most common genetic cause; however, mutations in other CMT genes may also result in this phenotype in individual patients. The majority of these patients cannot be genetically diagnosed by gene panel testing of known CMT and myopathy genes, suggesting further genetic heterogeneity and highlighting the importance of further genetic investigations in these patients and families.
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Affiliation(s)
- G McMacken
- Department of Neurosciences, Royal Victoria Hospital, Belfast, UK
| | - R G Whittaker
- Department of Clinical Neurophysiology, Royal Victoria Infirmary, Newcastle upon Tyne, UK.,Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - R Charlton
- John Walton Muscular Dystrophy Research Centre, Newcastle University, Newcastle upon Tyne, UK
| | - R Barresi
- John Walton Muscular Dystrophy Research Centre, Newcastle University, Newcastle upon Tyne, UK
| | - H Lochmüller
- Division of Neurology, Department of Medicine, Children's Hospital of Eastern Ontario Research Institute, The Ottawa Hospital and Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - R Horvath
- Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge School of Clinical Medicine, Cambridge, UK
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37
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Huser S, Loavenbruck A, Manousakis G. Wild-type Transthyretin Amyloid Myopathy With an Inclusion Body Myositis Phenotype. J Clin Neuromuscul Dis 2020; 22:53-57. [PMID: 32833725 DOI: 10.1097/cnd.0000000000000288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Senile systemic amyloidosis (SSA), or wild-type transthyretin (wtATTR) amyloidosis, is associated most commonly with cardiomyopathy and carpal tunnel syndrome. SSA-associated skeletal myopathy is rare. We describe the case of a patient with SSA who exhibited asymmetric quadriceps and finger flexor weakness, a phenotype usually seen in inclusion body myositis.
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Affiliation(s)
- Sara Huser
- Department of Neurology, University of Minnesota, Minnesota, MN; and
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38
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Kölbel H, Roos A, van der Ven PFM, Evangelista T, Nolte K, Johnson K, Töpf A, Wilson M, Kress W, Sickmann A, Straub V, Kollipara L, Weis J, Fürst DO, Schara U. First clinical and myopathological description of a myofibrillar myopathy with congenital onset and homozygous mutation in FLNC. Hum Mutat 2020; 41:1600-1614. [PMID: 32516863 DOI: 10.1002/humu.24062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 05/17/2020] [Accepted: 06/07/2020] [Indexed: 02/06/2023]
Abstract
Filamin C (encoded by the FLNC gene) is a large actin-cross-linking protein involved in shaping the actin cytoskeleton in response to signaling events both at the sarcolemma and at myofibrillar Z-discs of cross-striated muscle cells. Multiple mutations in FLNC are associated with myofibrillar myopathies of autosomal-dominant inheritance. Here, we describe for the first time a boy with congenital onset of generalized muscular hypotonia and muscular weakness, delayed motor development but no cardiac involvement associated with a homozygous FLNC mutation c.1325C>G (p.Pro442Arg). We performed ultramorphological, proteomic, and functional investigations as well as immunological studies of known marker proteins for dominant filaminopathies. We show that the mutant protein is expressed in similar quantities as the wild-type variant in control skeletal muscle fibers. The proteomic signature of quadriceps muscle is altered and ultrastructural perturbations are evident. Moreover, filaminopathy marker proteins are comparable both in our homozygous and a dominant control case (c.5161delG). Biochemical investigations demonstrate that the recombinant mutant protein is less stable and more prone to degradation by proteolytic enzymes than the wild-type variant. The unusual congenital presentation of the disease clearly demonstrates that homozygosity for mutations in FLNC severely aggravates the phenotype.
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Affiliation(s)
- Heike Kölbel
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children's Hospital University of Essen, Essen, Germany
| | - Andreas Roos
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children's Hospital University of Essen, Essen, Germany
| | - Peter F M van der Ven
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Teresinha Evangelista
- Neuromuscular Morphology Unit, Myology Institute, GHU Pitié-Salpêtrière, Paris, France
| | - Kay Nolte
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Katherine Johnson
- The John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University, Newcastle upon Tyne, UK
| | - Ana Töpf
- The John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University, Newcastle upon Tyne, UK
| | - Michael Wilson
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts.,Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, Massachusetts
| | - Wolfram Kress
- Department of Human Genetics, University of Würzburg, Würzburg, Germany
| | - Albert Sickmann
- Department of Bioanalytics, Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany.,Department of Chemistry, College of Physical Sciences, University of Aberdeen, Aberdeen, Scotland, UK.,Medizinische Proteom-Center (MPC), Medizinische Fakultät, Ruhr-Universität Bochum, Bochum, Germany
| | - Volker Straub
- The John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University, Newcastle upon Tyne, UK
| | - Laxmikanth Kollipara
- Department of Bioanalytics, Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Dieter O Fürst
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Ulrike Schara
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children's Hospital University of Essen, Essen, Germany
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39
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Structure and Function of Filamin C in the Muscle Z-Disc. Int J Mol Sci 2020; 21:ijms21082696. [PMID: 32295012 PMCID: PMC7216277 DOI: 10.3390/ijms21082696] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 12/22/2022] Open
Abstract
Filamin C (FLNC) is one of three filamin proteins (Filamin A (FLNA), Filamin B (FLNB), and FLNC) that cross-link actin filaments and interact with numerous binding partners. FLNC consists of a N-terminal actin-binding domain followed by 24 immunoglobulin-like repeats with two intervening calpain-sensitive hinges separating R15 and R16 (hinge 1) and R23 and R24 (hinge-2). The FLNC subunit is dimerized through R24 and calpain cleaves off the dimerization domain to regulate mobility of the FLNC subunit. FLNC is localized in the Z-disc due to the unique insertion of 82 amino acid residues in repeat 20 and necessary for normal Z-disc formation that connect sarcomeres. Since phosphorylation of FLNC by PKC diminishes the calpain sensitivity, assembly, and disassembly of the Z-disc may be regulated by phosphorylation of FLNC. Mutations of FLNC result in cardiomyopathy and muscle weakness. Although this review will focus on the current understanding of FLNC structure and functions in muscle, we will also discuss other filamins because they share high sequence similarity and are better characterized. We will also discuss a possible role of FLNC as a mechanosensor during muscle contraction.
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40
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Lee HCH, Wong S, Sheng B, Pan NYK, Leung YKF, Lau KKD, Cheng YS, Ho LC, Li R, Lee CN, Tsoi TH, Cheung YFN, Fu YPM, Kan NCA, Chu YP, Au WCL, Yeung HMJ, Li SH, Cheung CFM, Tong HF, Hung LYE, Chan TYC, Li CT, Tong TYT, Tong TWC, Leung HYC, Lee KH, Yeung SYS, Lee SYB, Lau TCG, Lam CW, Mak CM, Chan AYW. Clinical and pathological characterization of FLNC-related myofibrillar myopathy caused by founder variant c.8129G>A in Hong Kong Chinese. Clin Genet 2020; 97:747-757. [PMID: 32022900 DOI: 10.1111/cge.13715] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/17/2020] [Accepted: 01/28/2020] [Indexed: 12/18/2022]
Abstract
FLNC-related myofibrillar myopathy could manifest as autosomal dominant late-onset slowly progressive proximal muscle weakness; involvements of cardiac and/or respiratory functions are common. We describe 34 patients in nine families of FLNC-related myofibrillar myopathy in Hong Kong ethnic Chinese diagnosed over the last 12 years, in whom the same pathogenic variant c.8129G>A (p.Trp2710*) was detected. Twenty-six patients were symptomatic when diagnosed; four patients died of pneumonia and/or respiratory failure. Abnormal amorphous material or granulofilamentous masses were detected in half of the cases, with mitochondrial abnormalities noted in two-thirds. We also show by haplotype analysis the founder effect associated with this Hong Kong variant, which might have occurred 42 to 71 generations ago or around Tang and Song dynasties, and underlain a higher incidence of myofibrillar myopathy among Hong Kong Chinese. The late-onset nature and slowly progressive course of the highly penetrant condition could have significant impact on the family members, and an early diagnosis could benefit the whole family. Considering another neighboring founder variant in FLNC in German patients, we advocate development of specific therapies such as chaperone-based or antisense oligonucleotide strategies for this particular type of myopathy.
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Affiliation(s)
| | - Shun Wong
- Department of Pathology, Princess Margaret Hospital, Hong Kong.,Pathology Department, St. Paul's Hospital, Hong Kong
| | - Bun Sheng
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong
| | - Nin-Yuan Keith Pan
- Department of Diagnostic Radiology, Princess Margaret Hospital, Hong Kong
| | | | | | - Yue Sandy Cheng
- Department of Clinical Pathology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.,Department of Clinical Laboratory, Gleneagles Hong Kong Hospital, Hong Kong
| | - Luen-Cheung Ho
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong
| | - Richard Li
- Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | - Chi-Nam Lee
- Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | - Tak-Hong Tsoi
- Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | | | | | | | - Yim-Pui Chu
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong
| | - Wing-Chi Lisa Au
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | | | - Siu-Hung Li
- Department of Medicine, North District Hospital, Hong Kong
| | | | - Hok-Fung Tong
- Department of Pathology, Princess Margaret Hospital, Hong Kong
| | | | | | - Chi Terence Li
- Department of Pathology, Princess Margaret Hospital, Hong Kong
| | | | | | | | - Ka-Ho Lee
- Department of Pathology, Princess Margaret Hospital, Hong Kong
| | | | | | | | - Ching-Wan Lam
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Chloe Miu Mak
- Department of Pathology, Princess Margaret Hospital, Hong Kong
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41
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Mukund K, Subramaniam S. Skeletal muscle: A review of molecular structure and function, in health and disease. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2020; 12:e1462. [PMID: 31407867 PMCID: PMC6916202 DOI: 10.1002/wsbm.1462] [Citation(s) in RCA: 199] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/03/2019] [Accepted: 07/03/2019] [Indexed: 12/11/2022]
Abstract
Decades of research in skeletal muscle physiology have provided multiscale insights into the structural and functional complexity of this important anatomical tissue, designed to accomplish the task of generating contraction, force and movement. Skeletal muscle can be viewed as a biomechanical device with various interacting components including the autonomic nerves for impulse transmission, vasculature for efficient oxygenation, and embedded regulatory and metabolic machinery for maintaining cellular homeostasis. The "omics" revolution has propelled a new era in muscle research, allowing us to discern minute details of molecular cross-talk required for effective coordination between the myriad interacting components for efficient muscle function. The objective of this review is to provide a systems-level, comprehensive mapping the molecular mechanisms underlying skeletal muscle structure and function, in health and disease. We begin this review with a focus on molecular mechanisms underlying muscle tissue development (myogenesis), with an emphasis on satellite cells and muscle regeneration. We next review the molecular structure and mechanisms underlying the many structural components of the muscle: neuromuscular junction, sarcomere, cytoskeleton, extracellular matrix, and vasculature surrounding muscle. We highlight aberrant molecular mechanisms and their possible clinical or pathophysiological relevance. We particularly emphasize the impact of environmental stressors (inflammation and oxidative stress) in contributing to muscle pathophysiology including atrophy, hypertrophy, and fibrosis. This article is categorized under: Physiology > Mammalian Physiology in Health and Disease Developmental Biology > Developmental Processes in Health and Disease Models of Systems Properties and Processes > Cellular Models.
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Affiliation(s)
- Kavitha Mukund
- Department of BioengineeringUniversity of CaliforniaSan DiegoCalifornia
| | - Shankar Subramaniam
- Department of Bioengineering, Bioinformatics & Systems BiologyUniversity of CaliforniaSan DiegoCalifornia
- Department of Computer Science and EngineeringUniversity of CaliforniaSan DiegoCalifornia
- Department of Cellular and Molecular Medicine and NanoengineeringUniversity of CaliforniaSan DiegoCalifornia
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Ma K, Luo D, Tian T, Li N, He X, Rao C, Zhong B, Lu X. A novel homozygous initiation codon variant associated with infantile alpha-Bcrystallinopathy in a Chinese family. Mol Genet Genomic Med 2019; 7:e825. [PMID: 31215171 PMCID: PMC6687638 DOI: 10.1002/mgg3.825] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/22/2019] [Accepted: 05/29/2019] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Due to inconsistencies with reported myofibrillar myopathy (MFM), including autosomal dominant inheritance, late onset and a slowly progressive course, the severe, recessively inherited form of CRYAB (alpha-B crystallin) gene-related infantile MFM has been suggested. Here, we report an infant in a Chinese family with fatal neonatal-onset hypertonic MFM with a novel CRYAB homozygous variant (c.3G > A (p.Met1?)). METHODS Muscle biopsy indicated that muscle fibers showed a uniformly small diameter, cell atrophy, and visible focal muscle fiber degeneration and necrosis consistent with myogenic myopathy. We performed the whole exome sequencing of pathogenic genes and identified it as MFM. RESULTS The proband presented with profound muscle stiffness, progressive respiratory distress and a concurrent abnormal increase in myocardial enzymogram, and the patient died in the 17th month of life. Muscle biopsy and electron microscopy results were consistent with ultramicroscopic myogenic damage and pathological changes. Mutation analysis of the proband identified a novel rare homozygous mutation in the initiation codon of the CRYAB gene, which was inherited from currently asymptomatic, heterozygous carrier parents, and his heterozygous biological brother is unaffected. CONCLUSIONS This article reports one infant with CRYAB-related neonatal onset MFM with a novel homozygous variant in CRYAB. To our knowledge, this is the first reported case of infantile alpha-Bcrystallinopathy in the Chinese population.
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Affiliation(s)
- Keze Ma
- Department of Neonates, Dongguan Children's Hospital, Dongguan, China.,Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China
| | - Dong Luo
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China.,Medical Laboratory, Dongguan Children's Hospital, Dongguan, China
| | - Tian Tian
- Department of Pathology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ning Li
- Department of Neonates, Dongguan Children's Hospital, Dongguan, China.,Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China
| | - Xiaoguang He
- Department of Neonates, Dongguan Children's Hospital, Dongguan, China.,Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China
| | - Chunbao Rao
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China.,Medical Laboratory, Dongguan Children's Hospital, Dongguan, China
| | - Baimao Zhong
- Department of Neonates, Dongguan Children's Hospital, Dongguan, China.,Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China
| | - Xiaomei Lu
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China.,Medical Laboratory, Dongguan Children's Hospital, Dongguan, China
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43
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Vihola A, Palmio J, Danielsson O, Penttilä S, Louiselle D, Pittman S, Weihl C, Udd B. Novel mutation in TNPO3 causes congenital limb-girdle myopathy with slow progression. NEUROLOGY-GENETICS 2019; 5:e337. [PMID: 31192305 PMCID: PMC6515942 DOI: 10.1212/nxg.0000000000000337] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 03/27/2019] [Indexed: 12/03/2022]
Abstract
Objective We report a second family with autosomal dominant transportinopathy presenting with congenital or early-onset myopathy and slow progression, causing proximal and less pronounced distal muscle weakness. Methods Patients had clinical examinations, muscle MRI, EMG, and muscle biopsy studies. The MYOcap gene panel was used to identify the gene defect in the family. Muscle biopsies were used for histopathologic and protein expression studies, and TNPO3 constructs were used to study the effect of the mutations in transfected cells. Results We identified a novel heterozygous mutation, c.2757delC, in the last part of the transportin-3 (TNPO3) gene in the affected family members. The mutation causes an almost identical frameshift affecting the stop codon and elongating the C-term protein product of the TNPO3 transcript, as was previously reported in the first large Spanish-Italian LGMD1F kindred. TNPO3 protein was increased in the patient muscle and accumulated in the subsarcolemmal and perinuclear areas. At least one of the cargo proteins, the splicing factor SRRM2 was normally located in the nucleus. Transiently transfected mutant TNPO3 constructs failed to localize to cytoplasmic annulate lamellae pore complexes in cells. Conclusions We report the clinical, molecular genetic, and histopathologic features of the second transportinopathy family. The variability of the clinical phenotype together with histopathologic findings suggests that several molecular pathways may be involved in the disease pathomechanism, such as nucleocytoplasmic shuttling, protein aggregation, and defective protein turnover.
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Affiliation(s)
- Anna Vihola
- Folkhälsan Institute of Genetics and Department of Medical Genetics (A.V.), Medicum, University of Helsinki; Neuromuscular Research Center (J.P.), Tampere University and University Hospital of Tampere, Finland; Neuromuscular Unit (O.D.), Division of Neurology, Department of Clinical and Experimental Medicine, Linköping University, Sweden; Neuromuscular Research Center (S. Penttilä), Tampere University and University Hospital of Tampere, Finland; Department of Neurology (D.L.), Department of Neurology (S. Pittman), Department of Neurology (C.W.), Washington University School of Medicine, Saint Louis, MO; Folkhälsan Institute of Genetics and Department of Medical Genetics (B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (B.U.), Tampere University and University Hospital of Tampere; and Department of Neurology (B.U.), Vaasa Central Hospital, Vaasa, Finland
| | - Johanna Palmio
- Folkhälsan Institute of Genetics and Department of Medical Genetics (A.V.), Medicum, University of Helsinki; Neuromuscular Research Center (J.P.), Tampere University and University Hospital of Tampere, Finland; Neuromuscular Unit (O.D.), Division of Neurology, Department of Clinical and Experimental Medicine, Linköping University, Sweden; Neuromuscular Research Center (S. Penttilä), Tampere University and University Hospital of Tampere, Finland; Department of Neurology (D.L.), Department of Neurology (S. Pittman), Department of Neurology (C.W.), Washington University School of Medicine, Saint Louis, MO; Folkhälsan Institute of Genetics and Department of Medical Genetics (B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (B.U.), Tampere University and University Hospital of Tampere; and Department of Neurology (B.U.), Vaasa Central Hospital, Vaasa, Finland
| | - Olof Danielsson
- Folkhälsan Institute of Genetics and Department of Medical Genetics (A.V.), Medicum, University of Helsinki; Neuromuscular Research Center (J.P.), Tampere University and University Hospital of Tampere, Finland; Neuromuscular Unit (O.D.), Division of Neurology, Department of Clinical and Experimental Medicine, Linköping University, Sweden; Neuromuscular Research Center (S. Penttilä), Tampere University and University Hospital of Tampere, Finland; Department of Neurology (D.L.), Department of Neurology (S. Pittman), Department of Neurology (C.W.), Washington University School of Medicine, Saint Louis, MO; Folkhälsan Institute of Genetics and Department of Medical Genetics (B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (B.U.), Tampere University and University Hospital of Tampere; and Department of Neurology (B.U.), Vaasa Central Hospital, Vaasa, Finland
| | - Sini Penttilä
- Folkhälsan Institute of Genetics and Department of Medical Genetics (A.V.), Medicum, University of Helsinki; Neuromuscular Research Center (J.P.), Tampere University and University Hospital of Tampere, Finland; Neuromuscular Unit (O.D.), Division of Neurology, Department of Clinical and Experimental Medicine, Linköping University, Sweden; Neuromuscular Research Center (S. Penttilä), Tampere University and University Hospital of Tampere, Finland; Department of Neurology (D.L.), Department of Neurology (S. Pittman), Department of Neurology (C.W.), Washington University School of Medicine, Saint Louis, MO; Folkhälsan Institute of Genetics and Department of Medical Genetics (B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (B.U.), Tampere University and University Hospital of Tampere; and Department of Neurology (B.U.), Vaasa Central Hospital, Vaasa, Finland
| | - Daniel Louiselle
- Folkhälsan Institute of Genetics and Department of Medical Genetics (A.V.), Medicum, University of Helsinki; Neuromuscular Research Center (J.P.), Tampere University and University Hospital of Tampere, Finland; Neuromuscular Unit (O.D.), Division of Neurology, Department of Clinical and Experimental Medicine, Linköping University, Sweden; Neuromuscular Research Center (S. Penttilä), Tampere University and University Hospital of Tampere, Finland; Department of Neurology (D.L.), Department of Neurology (S. Pittman), Department of Neurology (C.W.), Washington University School of Medicine, Saint Louis, MO; Folkhälsan Institute of Genetics and Department of Medical Genetics (B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (B.U.), Tampere University and University Hospital of Tampere; and Department of Neurology (B.U.), Vaasa Central Hospital, Vaasa, Finland
| | - Sara Pittman
- Folkhälsan Institute of Genetics and Department of Medical Genetics (A.V.), Medicum, University of Helsinki; Neuromuscular Research Center (J.P.), Tampere University and University Hospital of Tampere, Finland; Neuromuscular Unit (O.D.), Division of Neurology, Department of Clinical and Experimental Medicine, Linköping University, Sweden; Neuromuscular Research Center (S. Penttilä), Tampere University and University Hospital of Tampere, Finland; Department of Neurology (D.L.), Department of Neurology (S. Pittman), Department of Neurology (C.W.), Washington University School of Medicine, Saint Louis, MO; Folkhälsan Institute of Genetics and Department of Medical Genetics (B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (B.U.), Tampere University and University Hospital of Tampere; and Department of Neurology (B.U.), Vaasa Central Hospital, Vaasa, Finland
| | - Conrad Weihl
- Folkhälsan Institute of Genetics and Department of Medical Genetics (A.V.), Medicum, University of Helsinki; Neuromuscular Research Center (J.P.), Tampere University and University Hospital of Tampere, Finland; Neuromuscular Unit (O.D.), Division of Neurology, Department of Clinical and Experimental Medicine, Linköping University, Sweden; Neuromuscular Research Center (S. Penttilä), Tampere University and University Hospital of Tampere, Finland; Department of Neurology (D.L.), Department of Neurology (S. Pittman), Department of Neurology (C.W.), Washington University School of Medicine, Saint Louis, MO; Folkhälsan Institute of Genetics and Department of Medical Genetics (B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (B.U.), Tampere University and University Hospital of Tampere; and Department of Neurology (B.U.), Vaasa Central Hospital, Vaasa, Finland
| | - Bjarne Udd
- Folkhälsan Institute of Genetics and Department of Medical Genetics (A.V.), Medicum, University of Helsinki; Neuromuscular Research Center (J.P.), Tampere University and University Hospital of Tampere, Finland; Neuromuscular Unit (O.D.), Division of Neurology, Department of Clinical and Experimental Medicine, Linköping University, Sweden; Neuromuscular Research Center (S. Penttilä), Tampere University and University Hospital of Tampere, Finland; Department of Neurology (D.L.), Department of Neurology (S. Pittman), Department of Neurology (C.W.), Washington University School of Medicine, Saint Louis, MO; Folkhälsan Institute of Genetics and Department of Medical Genetics (B.U.), Medicum, University of Helsinki; Neuromuscular Research Center (B.U.), Tampere University and University Hospital of Tampere; and Department of Neurology (B.U.), Vaasa Central Hospital, Vaasa, Finland
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Cai C, Anthony DC, Pytel P. A pattern-based approach to the interpretation of skeletal muscle biopsies. Mod Pathol 2019; 32:462-483. [PMID: 30401945 DOI: 10.1038/s41379-018-0164-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 09/24/2018] [Accepted: 09/25/2018] [Indexed: 12/19/2022]
Abstract
The interpretation of muscle biopsies is complex and provides the most useful information when integrated with the clinical presentation of the patient. These biopsies are performed for workup of a wide range of diseases including dystrophies, metabolic diseases, and inflammatory processes. Recent insights have led to changes in the classification of inflammatory myopathies and have changed the role that muscle biopsies have in the workup of inherited diseases. These changes will be reviewed. This review follows a morphology-driven approach by discussing diseases of skeletal muscle based on a few basic patterns that include cases with (1) active myopathic damage and inflammation, (2) active myopathic damage without associated inflammation, (3) chronic myopathic changes, (4) myopathies with distinctive inclusions or vacuoles, (5) biopsies mainly showing atrophic changes, and (6) biopsies that appear normal on routine preparations. Each of these categories goes along with certain diagnostic considerations and pitfalls. Individual biopsy features are only rarely pathognomonic. Establishing a firm diagnosis therefore typically requires integration of all of the biopsy findings and relevant clinical information. With this approach, a muscle biopsy can often provide helpful information in the diagnostic workup of patients presenting with neuromuscular problems.
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Affiliation(s)
- Chunyu Cai
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Douglas C Anthony
- Departments of Pathology and Laboratory Medicine, and Neurology, Alpert Medical School of Brown University, Providence, RI, USA
| | - Peter Pytel
- Department of Pathology, University of Chicago, Chicago, IL, USA.
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Damian MS, Wijdicks EFM. The clinical management of neuromuscular disorders in intensive care. Neuromuscul Disord 2018; 29:85-96. [PMID: 30639065 DOI: 10.1016/j.nmd.2018.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 11/30/2018] [Accepted: 12/13/2018] [Indexed: 12/11/2022]
Abstract
Life-threatening neuromuscular disorders affect a small, but growing group of patients in the intensive care unit who present special management problems, as well as great therapeutic opportunities. In inflammatory conditions, a cure is often possible, and for chronic, genetic or degenerative conditions, achieving the previous level of function is the target. Neuromuscular experts and intensivists need to cooperate closely to achieve the best possible outcomes. They need to acquire a very specific set of skills, including both a thorough understanding of the mechanics of ventilation as well as familiarity with the diagnostic categories of genetic and of autoimmune diseases. This review of the clinical management of adult neuromuscular disease in the ICU aims to provide an overview of the most important conditions encountered in the ICU and a practical approach to their diagnosis, monitoring, and treatment.
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Affiliation(s)
- Maxwell S Damian
- Neurology and Neurointensive Care, Cambridge University Hospitals and Ipswich Hospital, Hills Road, Cambridge CB2 0QQ, UK.
| | - Eelco F M Wijdicks
- Neurology Division of Critical Care Neurology, Mayo Clinic, Rochester, MN, USA
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46
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Sterzyńska K, Klejewski A, Wojtowicz K, Świerczewska M, Nowicki M, Brązert J, Januchowski R. Myotilin, a New Topotecan Resistant Protein in Ovarian Cancer Cell Lines. J Cancer 2018; 9:4413-4421. [PMID: 30519347 PMCID: PMC6277650 DOI: 10.7150/jca.27342] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 08/24/2018] [Indexed: 11/17/2022] Open
Abstract
Background: Low effectiveness of chemotherapy in ovarian cancer results from development of drug resistance during treatment. Topotecan (TOP) is a chemotherapeutic drug used in second-line chemotherapy of this cancer. Unfortunately, during treatment cancer can develop diverse cellular and tissue specific mechanisms of resistance to cytotoxic drugs. Methods: We analyzed development of TOP resistance in ovarian cancer cell lines (A2780 and W1). On the base of our previous results where a set of “new genes” with different functions that can be related to TOP-resistance was described hereby we performed detailed analysis of MYOT expression. MYOT mRNA level (real time PCR analysis), protein expression in cell lysates and cell culture medium (western blot analysis) and protein expression in cancer cells (immunofluorescence analysis) were determined in this study. Results: We observed increased expression of MYOT in TOP resistant cell lines at both mRNA and protein level. MYOT, together with extracellular matrix molecules like COL1A2 and COL15A1 were also secreted to corresponding cell culture media. Conclusion: Our results suggest that upregulation of MYOT can be related to TOP resistance in ovarian cancer cell lines.
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Affiliation(s)
- Karolina Sterzyńska
- Department of Histology and Embryology, Poznan University of Medical Sciences, Poznań, Poland
| | - Andrzej Klejewski
- Department of Nursing, Poznan University of Medical Sciences, Poznań, Poland.,Department of Obstetrics and Women's Diseases, Poznan University of Medical Sciences, Poznań, Poland
| | - Karolina Wojtowicz
- Department of Histology and Embryology, Poznan University of Medical Sciences, Poznań, Poland
| | - Monika Świerczewska
- Department of Histology and Embryology, Poznan University of Medical Sciences, Poznań, Poland
| | - Michał Nowicki
- Department of Histology and Embryology, Poznan University of Medical Sciences, Poznań, Poland
| | - Jacek Brązert
- Department of Obstetrics and Women's Diseases, Poznan University of Medical Sciences, Poznań, Poland
| | - Radosław Januchowski
- Department of Histology and Embryology, Poznan University of Medical Sciences, Poznań, Poland
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47
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Wackerhage H, Schoenfeld BJ, Hamilton DL, Lehti M, Hulmi JJ. Stimuli and sensors that initiate skeletal muscle hypertrophy following resistance exercise. J Appl Physiol (1985) 2018; 126:30-43. [PMID: 30335577 DOI: 10.1152/japplphysiol.00685.2018] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
One of the most striking adaptations to exercise is the skeletal muscle hypertrophy that occurs in response to resistance exercise. A large body of work shows that a mammalian target of rapamycin complex 1 (mTORC1)-mediated increase of muscle protein synthesis is the key, but not sole, mechanism by which resistance exercise causes muscle hypertrophy. While much of the hypertrophy signaling cascade has been identified, the initiating, resistance exercise-induced and hypertrophy-stimulating stimuli have remained elusive. For the purpose of this review, we define an initiating, resistance exercise-induced and hypertrophy-stimulating signal as "hypertrophy stimulus," and the sensor of such a signal as "hypertrophy sensor." In this review we discuss our current knowledge of specific mechanical stimuli, damage/injury-associated and metabolic stress-associated triggers, as potential hypertrophy stimuli. Mechanical signals are the prime hypertrophy stimuli candidates, and a filamin-C-BAG3-dependent regulation of mTORC1, Hippo, and autophagy signaling is a plausible albeit still incompletely characterized hypertrophy sensor. Other candidate mechanosensing mechanisms are nuclear deformation-initiated signaling or several mechanisms related to costameres, which are the functional equivalents of focal adhesions in other cells. While exercise-induced muscle damage is probably not essential for hypertrophy, it is still unclear whether and how such muscle damage could augment a hypertrophic response. Interventions that combine blood flow restriction and especially low load resistance exercise suggest that resistance exercise-regulated metabolites could be hypertrophy stimuli, but this is based on indirect evidence and metabolite candidates are poorly characterized.
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Affiliation(s)
- Henning Wackerhage
- Department of Sport and Exercise Sciences, Technical University of Munich , Munich , Germany
| | | | - D Lee Hamilton
- Faculty of Health, School of Exercise and Nutrition Sciences, Deakin University , Victoria , Australia
| | - Maarit Lehti
- LIKES Research Centre for Physical Activity and Health , Jyväskylä , Finland
| | - Juha J Hulmi
- Neuromuscular Research Center, Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä , Jyväskylä , Finland
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48
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Identification of a novel nonsense mutation in kyphoscoliosis peptidase gene in an Iranian patient with myofibrillar myopathy. Genes Dis 2018; 5:331-334. [PMID: 30591934 PMCID: PMC6303478 DOI: 10.1016/j.gendis.2018.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 09/28/2018] [Indexed: 12/28/2022] Open
Abstract
Myofibrillar myopathies (MFMs) are rare genetic and slowly progressive neuromuscular disorders. Several pathogenic mutations have been reported in MFM-related genes including DES, CRYAB, MYOT, LDB3 or ZASP, FLNC, BAG3, FHL1 and DNAJB6. Although MFMs is commonly inherited in an autosomal dominant manner, the inheritance pattern and novel mutated genes are not thoroughly elucidated in some cases. Here, we report discovery of a novel nonsense mutation in a 29-year-old Iranian male patient with motor disorders and deformity in his lower limbs. His parents are second cousins. Hereditary Motor Sensory Neuropathy as initial genetic diagnosis was ruled out. Whole exome sequencing using NGS on Illumina HiSeq4000 platform was performed to identify the disease and possible mutated gene(s). Our data analysis identified a homozygous nonsense unreported c.C415T (p.R139X) variant on kyphoscoliosis peptidase (KY) gene (NM_178554: exon4). Sanger sequencing of this mutation has been performed for his other related family members. Sequencing and segregation analysis was confirmed the NGS results and autosomal recessive inheritance pattern of the disease.
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Fichna JP, Maruszak A, Żekanowski C. Myofibrillar myopathy in the genomic context. J Appl Genet 2018; 59:431-439. [PMID: 30203143 DOI: 10.1007/s13353-018-0463-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 08/30/2018] [Indexed: 12/31/2022]
Abstract
Myofibrillar myopathy (MFM) is a group of inherited muscular disorders characterized by myofibril dissolution and abnormal accumulation of degradation products. The diagnosis of muscular disorders based on clinical presentation is difficult due to phenotypic heterogeneity and overlapping symptoms. In addition, precise diagnosis does not always explain the disease etiopathology or the highly variable clinical course even among patients diagnosed with the same type of myopathy. The advent of high-throughput next-generation sequencing (NGS) has provided a successful and cost-effective strategy for identification of novel causative genes in myopathies, including MFM. So far, pathogenic mutations associated with MFM phenotype, including atypical MFM-like cases, have been identified in 17 genes: DES, CRYAB, MYOT, ZASP, FLNC, BAG3, FHL1, TTN, DNAJB6, PLEC, LMNA, ACTA1, HSPB8, KY, PYROXD1, and SQSTM + TIA1 (digenic). Most of these genes are also associated with other forms of muscle diseases. In addition, in many MFM patients, numerous genomic variants in muscle-related genes have been identified. The various myopathies and muscular dystrophies seem to form a single disease continuum; therefore, gene identification in one disease impacts the genetic etiology of the others. In this review, we describe the heterogeneity of the MFM genetic background focusing on the role of rare variants, the importance of whole genome sequencing in the identification of novel disease-associated mutations, and the emerging concept of variant load as the basis of the phenotypic heterogeneity.
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Affiliation(s)
- Jakub Piotr Fichna
- Department of Neurodegenerative Disorders, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego St., 02-106, Warsaw, Poland.
| | - Aleksandra Maruszak
- Department of Neurodegenerative Disorders, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego St., 02-106, Warsaw, Poland
| | - Cezary Żekanowski
- Department of Neurodegenerative Disorders, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego St., 02-106, Warsaw, Poland
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50
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Andersen AG, Fornander F, Schrøder HD, Krag T, Straub V, Duno M, Vissing J. BAG3 myopathy is not always associated with cardiomyopathy. Neuromuscul Disord 2018; 28:798-801. [DOI: 10.1016/j.nmd.2018.06.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 05/03/2018] [Accepted: 06/30/2018] [Indexed: 02/05/2023]
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