1
|
Valentino MR, Annunziata A, Atripaldi L, Fiorentino G. An unusual way to improve lung function in congenital myopathies: the power of singing. Acta Myol 2023; 42:86-88. [PMID: 38090546 PMCID: PMC10712659 DOI: 10.36185/2532-1900-357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 09/04/2023] [Indexed: 12/18/2023]
Abstract
Congenital myopathies (CMs) are a clinically and genetically heterogeneous group of disorders characterized by early onset weakness, hypotonia and characteristic structural abnormalities in muscle fibres. Hypotonia and weakness can be present at birth or appear in infancy, and a static or slowly progressive clinical course may present with muscle weakness, loss of spontaneous movement, involuntary muscle activity, and muscle atrophy. Often patients develop a restrictive syndrome and respiratory failure and require respiratory support In our case, we described lung improvement and respiratory muscle training due to singing in a young patient, affected by CMs with a poor adherence to non-invasive mechanical ventilation.
Collapse
Affiliation(s)
| | - Anna Annunziata
- UOC Malattie, Fisiopatologia e Riabilitazione dell’Apparato Respiratorio, Monaldi Hospital, Naples, Italy
| | | | | |
Collapse
|
2
|
Pons-Espinal M, Clotet-Caba J, Cesar-Díaz S, Yubero-Siles D. Arrhythmias in patients with X-linked myotubular myopathy. Rev Neurol 2023; 77:79-81. [PMID: 37466134 PMCID: PMC10662247 DOI: 10.33588/rn.7703.2022222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Indexed: 07/20/2023]
Abstract
INTRODUCTION Myotubular myopathy is a congenital muscle disease caused by a mutation in the myotubularin (MTM1) gene. The X-linked myotubular myopathy (XLMTM) affects males with early-onset symptoms such as muscle weakness, hypotonia, and respiratory distress. To our knowledge, cardiac involvement has not been previously described in this condition, in contrast to other types of congenital myopathies such as nemaline myopathy or core myopathy. CASE REPORTS We report two clinical cases of XLMTM that started with severe sinus bradycardia or auriculoventricular block from the first days of life, with pathologic 24-hours Holter monitoring in both cases. A primary cardiac affection was excluded by electrophysiological studies and normal heart rate was recovered with proper respiratory support. DISCUSSION These cases with sever bradyarrhythmia in a well know pathology such the XLMTM represents a nuance on the usual differential diagnostics of congenital myopathies.
Collapse
Affiliation(s)
- M Pons-Espinal
- Hospital Sant Joan de Déu-Hospital Clínic. Universitat de Barcelona, Barcelona, España
| | - J Clotet-Caba
- Hospital Sant Joan de Déu-Hospital Clínic. Universitat de Barcelona, Barcelona, España
| | - S Cesar-Díaz
- Instituto de Investigación Sant Joan de Déu, Barcelona, España
| | - D Yubero-Siles
- Hospital Sant Joan de Déu-Hospital Clínic. Universitat de Barcelona, Barcelona, España
| |
Collapse
|
3
|
Marinella G, Orsini A, Scacciati M, Costa E, Santangelo A, Astrea G, Frosini S, Pasquariello R, Rubegni A, Sgherri G, Corsi M, Bonuccelli A, Battini R. Congenital Myopathy as a Phenotypic Expression of CACNA1S Gene Mutation: Case Report and Systematic Review of the Literature. Genes (Basel) 2023; 14:1363. [PMID: 37510268 PMCID: PMC10379235 DOI: 10.3390/genes14071363] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/17/2023] [Accepted: 06/22/2023] [Indexed: 07/30/2023] Open
Abstract
BACKGROUND Congenital myopathies are a group of clinically, genetically, and histologically heterogeneous diseases caused by mutations in a large group of genes. One of these is CACNA1S, which is recognized as the cause of Dihydropyridine Receptor Congenital Myopathy. METHODS To better characterize the phenotypic spectrum of CACNA1S myopathy, we conducted a systematic review of cases in the literature through three electronic databases following the PRISMA guidelines. We selected nine articles describing 23 patients with heterozygous, homozygous, or compound heterozygous mutations in CACNA1S and we added one patient with a compound heterozygous mutation in CACNA1S (c.1394-2A>G; c.1724T>C, p.L575P) followed at our Institute. We collected clinical and genetic data, muscle biopsies, and muscle MRIs when available. RESULTS The phenotype of this myopathy is heterogeneous, ranging from more severe forms with a lethal early onset and mild-moderate forms with a better clinical course. CONCLUSIONS Our patient presented a phenotype compatible with the mild-moderate form, although she presented peculiar features such as a short stature, myopia, mild sensorineural hearing loss, psychiatric symptoms, and posterior-anterior impairment gradient on thigh muscle MRI.
Collapse
Affiliation(s)
- Gemma Marinella
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (G.M.); (G.A.); (S.F.); (R.P.); (A.R.); (G.S.)
| | - Alessandro Orsini
- Pediatric Neurology, Pediatric University Department, Azienda Ospedaliera Universitaria Pisana, University of Pisa, 56100 Pisa, Italy; (A.O.); (M.S.); (A.S.); (A.B.)
| | - Massimo Scacciati
- Pediatric Neurology, Pediatric University Department, Azienda Ospedaliera Universitaria Pisana, University of Pisa, 56100 Pisa, Italy; (A.O.); (M.S.); (A.S.); (A.B.)
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Elisa Costa
- Pediatric Neurology, Pediatric University Department, Azienda Ospedaliera Universitaria Pisana, University of Pisa, 56100 Pisa, Italy; (A.O.); (M.S.); (A.S.); (A.B.)
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Andrea Santangelo
- Pediatric Neurology, Pediatric University Department, Azienda Ospedaliera Universitaria Pisana, University of Pisa, 56100 Pisa, Italy; (A.O.); (M.S.); (A.S.); (A.B.)
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Guja Astrea
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (G.M.); (G.A.); (S.F.); (R.P.); (A.R.); (G.S.)
| | - Silvia Frosini
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (G.M.); (G.A.); (S.F.); (R.P.); (A.R.); (G.S.)
| | - Rosa Pasquariello
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (G.M.); (G.A.); (S.F.); (R.P.); (A.R.); (G.S.)
| | - Anna Rubegni
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (G.M.); (G.A.); (S.F.); (R.P.); (A.R.); (G.S.)
| | - Giada Sgherri
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (G.M.); (G.A.); (S.F.); (R.P.); (A.R.); (G.S.)
| | - Martina Corsi
- Department of Preventive and Occupational Medicine, Azienda Ospedaliera Universitaria Pisana, University of Pisa, 56126 Pisa, Italy;
| | - Alice Bonuccelli
- Pediatric Neurology, Pediatric University Department, Azienda Ospedaliera Universitaria Pisana, University of Pisa, 56100 Pisa, Italy; (A.O.); (M.S.); (A.S.); (A.B.)
| | - Roberta Battini
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (G.M.); (G.A.); (S.F.); (R.P.); (A.R.); (G.S.)
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| |
Collapse
|
4
|
Saint-Gerons M, Rubio MA, Aznar G, Matheu A. Ophthalmological Manifestations of Hereditary Myopathies. J Binocul Vis Ocul Motil 2022; 72:4-17. [PMID: 35049410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
BACKGROUND Myopathies are neuromuscular disorders of the skeletal muscles, in which the main symptom is muscle weakness due to muscle fiber dysfunction. Myopathies may be classified into two main categories: inherited and acquired. Hereditary myopathies are a heterogeneous group of diseases that include congenital myopathies, mitochondrial myopathies, myotonic syndromes, muscular dystrophies, and other myopathies. PURPOSE The objective of this paper is to review the ophthalmological findings and genetic patterns of hereditary myopathies. METHODS This review is based on articles obtained by a relevant search of the PubMed database. CONCLUSION Ophthalmoplegia with or without ptosis and pupil sparing appeared to be the most frequent ophthalmological manifestation of myopathies. The identification of the main ophthalmological features can help in the diagnosis and treatment of these muscular diseases.
Collapse
Affiliation(s)
- Marta Saint-Gerons
- Unit of Neurophthalmology, Consorci Parc de Salut Mar de Barcelona, Barcelona, Spain
| | - Miguel Angel Rubio
- Unit of Neuromuscular Diseases, Consorci Parc de Salut Mar de Barcelona, Barcelona, Spain
| | - Gemma Aznar
- Unit of Paediatric Neurology, Consorci Parc de Salut Mar de Barcelona, Barcelona, Spain
| | - Ana Matheu
- Unit of Neurophthalmology, Consorci Parc de Salut Mar de Barcelona, Barcelona, Spain
| |
Collapse
|
5
|
Meunier J, Villar-Quiles RN, Duband-Goulet I, Ferreiro A. Inherited Defects of the ASC-1 Complex in Congenital Neuromuscular Diseases. Int J Mol Sci 2021; 22:ijms22116039. [PMID: 34204919 PMCID: PMC8199739 DOI: 10.3390/ijms22116039] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/19/2021] [Accepted: 05/27/2021] [Indexed: 12/12/2022] Open
Abstract
Defects in transcriptional and cell cycle regulation have emerged as novel pathophysiological mechanisms in congenital neuromuscular disease with the recent identification of mutations in the TRIP4 and ASCC1 genes, encoding, respectively, ASC-1 and ASCC1, two subunits of the ASC-1 (Activating Signal Cointegrator-1) complex. This complex is a poorly known transcriptional coregulator involved in transcriptional, post-transcriptional or translational activities. Inherited defects in components of the ASC-1 complex have been associated with several autosomal recessive phenotypes, including severe and mild forms of striated muscle disease (congenital myopathy with or without myocardial involvement), but also cases diagnosed of motor neuron disease (spinal muscular atrophy). Additionally, antenatal bone fractures were present in the reported patients with ASCC1 mutations. Functional studies revealed that the ASC-1 subunit is a novel regulator of cell cycle, proliferation and growth in muscle and non-muscular cells. In this review, we summarize and discuss the available data on the clinical and histopathological phenotypes associated with inherited defects of the ASC-1 complex proteins, the known genotype–phenotype correlations, the ASC-1 pathophysiological role, the puzzling question of motoneuron versus primary muscle involvement and potential future research avenues, illustrating the study of rare monogenic disorders as an interesting model paradigm to understand major physiological processes.
Collapse
Affiliation(s)
- Justine Meunier
- Basic and Translational Myology Laboratory, UMR8251, University of Paris/National Center for Scientific Research, 75013 Paris, France; (J.M.); (R.-N.V.-Q.)
| | - Rocio-Nur Villar-Quiles
- Basic and Translational Myology Laboratory, UMR8251, University of Paris/National Center for Scientific Research, 75013 Paris, France; (J.M.); (R.-N.V.-Q.)
- Reference Center for Neuromuscular Disorders, Pitié-Salpêtrière Hospital, APHP, Institute of Myology, 75013 Paris, France
| | - Isabelle Duband-Goulet
- Basic and Translational Myology Laboratory, UMR8251, University of Paris/National Center for Scientific Research, 75013 Paris, France; (J.M.); (R.-N.V.-Q.)
- Correspondence: (I.D.-G.); (A.F.); Tel.: +33-1-5727-7965 (I.D.-G.); +33-1-5727-7959 (A.F.)
| | - Ana Ferreiro
- Basic and Translational Myology Laboratory, UMR8251, University of Paris/National Center for Scientific Research, 75013 Paris, France; (J.M.); (R.-N.V.-Q.)
- Reference Center for Neuromuscular Disorders, Pitié-Salpêtrière Hospital, APHP, Institute of Myology, 75013 Paris, France
- Correspondence: (I.D.-G.); (A.F.); Tel.: +33-1-5727-7965 (I.D.-G.); +33-1-5727-7959 (A.F.)
| |
Collapse
|
6
|
Saat H, Sahin I. Mutation spectrum of hereditary myopathies in Turkish patients and novel variants. Ann Hum Genet 2021; 85:178-185. [PMID: 33963534 DOI: 10.1111/ahg.12429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 11/28/2022]
Abstract
Hereditary myopathies are a heterogeneous disorder known to be associated with more than 100 genes. Although hereditary myopathy subgroups can be partially described with traditional methods such as muscle biopsy, next-generation sequencing (NGS) is essential to reveal the disease's underlying genetic etiology and molecular mechanisms. In this study, we performed clinical exome sequencing or whole-exome sequencing (CES/WES) in 20 unrelated Turkish patients. Thirteen pathogenic or likely pathogenic variants, including five novel variantswere detected in the 16 known hereditary myopathy genes. We achieved a high rate of diagnosis (65%) compared to previous studies. The most common condition noticed was limb-girdle muscular dystrophy (LGMD), which should not be ignored in patients diagnosed with myopathy. CES or WES provides a certain molecular diagnosis from a broad perspective to demonstrate underlying genetic causes in heterogeneous disorders. Therefore, exome sequencing offers a higher and more complete diagnosis than the gene panel.
Collapse
Affiliation(s)
- Hanife Saat
- Department of Medical Genetics, University of Health Sciences, Dışkapı Yıldırım Beyazıt Research and Training Hospital, Ankara, Turkey
| | - Ibrahim Sahin
- Department of Medical Genetics, University of Health Sciences, Dışkapı Yıldırım Beyazıt Research and Training Hospital, Ankara, Turkey
| |
Collapse
|
7
|
Villalón-García I, Álvarez-Córdoba M, Suárez-Rivero JM, Povea-Cabello S, Talaverón-Rey M, Suárez-Carrillo A, Munuera-Cabeza M, Sánchez-Alcázar JA. Precision Medicine in Rare Diseases. Diseases 2020; 8:diseases8040042. [PMID: 33202892 PMCID: PMC7709101 DOI: 10.3390/diseases8040042] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/05/2020] [Accepted: 11/12/2020] [Indexed: 01/06/2023] Open
Abstract
Rare diseases are those that have a low prevalence in the population (less than 5 individuals per 10,000 inhabitants). However, infrequent pathologies affect a large number of people, since according to the World Health Organization (WHO), there are about 7000 rare diseases that affect 7% of the world’s population. Many patients with rare diseases have suffered the consequences of what is called the diagnostic odyssey, that is, extensive and prolonged serial tests and clinical visits, sometimes for many years, all with the hope of identifying the etiology of their disease. For patients with rare diseases, obtaining the genetic diagnosis can mean the end of the diagnostic odyssey, and the beginning of another, the therapeutic odyssey. This scenario is especially challenging for the scientific community, since more than 90% of rare diseases do not currently have an effective treatment. This therapeutic failure in rare diseases means that new approaches are necessary. Our research group proposes that the use of precision or personalized medicine techniques can be an alternative to find potential therapies in these diseases. To this end, we propose that patients’ own cells can be used to carry out personalized pharmacological screening for the identification of potential treatments.
Collapse
|
8
|
Massenet J, Gitiaux C, Magnan M, Cuvellier S, Hubas A, Nusbaum P, Dilworth FJ, Desguerre I, Chazaud B. Derivation and Characterization of Immortalized Human Muscle Satellite Cell Clones from Muscular Dystrophy Patients and Healthy Individuals. Cells 2020; 9:E1780. [PMID: 32722643 DOI: 10.3390/cells9081780] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 12/15/2022] Open
Abstract
In Duchenne muscular dystrophy (DMD) patients, absence of dystrophin causes muscle wasting by impacting both the myofiber integrity and the properties of muscle stem cells (MuSCs). Investigation of DMD encompasses the use of MuSCs issued from human skeletal muscle. However, DMD-derived MuSC usage is restricted by the limited number of divisions that human MuSCs can undertake in vitro before losing their myogenic characteristics and by the scarcity of human material available from DMD muscle. To overcome these limitations, immortalization of MuSCs appears as a strategy. Here, we used CDK4/hTERT expression in primary MuSCs and we derived MuSC clones from a series of clinically and genetically characterized patients, including eight DMD patients with various mutations, four congenital muscular dystrophies and three age-matched control muscles. Immortalized cultures were sorted into single cells and expanded as clones into homogeneous populations. Myogenic characteristics and differentiation potential were tested for each clone. Finally, we screened various promoters to identify the preferred gene regulatory unit that should be used to ensure stable expression in the human MuSC clones. The 38 clonal immortalized myogenic cell clones provide a large collection of controls and DMD clones with various genetic defects and are available to the academic community.
Collapse
|
9
|
Gonzalez-Quereda L, Rodriguez MJ, Diaz-Manera J, Alonso-Perez J, Gallardo E, Nascimento A, Ortez C, Natera-de Benito D, Olive M, Gonzalez-Mera L, Munain AL, Zulaica M, Poza JJ, Jerico I, Torne L, Riera P, Milisenda J, Sanchez A, Garrabou G, Llano I, Madruga-Garrido M, Gallano P. Targeted Next-Generation Sequencing in a Large Cohort of Genetically Undiagnosed Patients with Neuromuscular Disorders in Spain. Genes (Basel) 2020; 11:E539. [PMID: 32403337 DOI: 10.3390/genes11050539] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/06/2020] [Accepted: 05/06/2020] [Indexed: 12/12/2022] Open
Abstract
The term neuromuscular disorder (NMD) includes many genetic and acquired diseases and differential diagnosis can be challenging. Next-generation sequencing (NGS) is especially useful in this setting given the large number of possible candidate genes, the clinical, pathological, and genetic heterogeneity, the absence of an established genotype-phenotype correlation, and the exceptionally large size of some causative genes such as TTN, NEB and RYR1. We evaluated the diagnostic value of a custom targeted next-generation sequencing gene panel to study the mutational spectrum of a subset of NMD patients in Spain. In an NMD cohort of 207 patients with congenital myopathies, distal myopathies, congenital and adult-onset muscular dystrophies, and congenital myasthenic syndromes, we detected causative mutations in 102 patients (49.3%), involving 42 NMD-related genes. The most common causative genes, TTN and RYR1, accounted for almost 30% of cases. Thirty-two of the 207 patients (15.4%) carried variants of uncertain significance or had an unidentified second mutation to explain the genetic cause of the disease. In the remaining 73 patients (35.3%), no candidate variant was identified. In combination with patients’ clinical and myopathological data, the custom gene panel designed in our lab proved to be a powerful tool to diagnose patients with myopathies, muscular dystrophies and congenital myasthenic syndromes. Targeted NGS approaches enable a rapid and cost-effective analysis of NMD- related genes, offering reliable results in a short time and relegating invasive techniques to a second tier.
Collapse
|
10
|
Boncompagni S, Pozzer D, Viscomi C, Ferreiro A, Zito E. Physical and Functional Cross Talk Between Endo-Sarcoplasmic Reticulum and Mitochondria in Skeletal Muscle. Antioxid Redox Signal 2020; 32:873-883. [PMID: 31825235 DOI: 10.1089/ars.2019.7934] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Significance: The physiological relevance of contacts between the sarcoplasmic reticulum (SR), a specialized domain of the endoplasmic reticulum (ER) in skeletal muscle, and mitochondria is still not clear. Recent Advances: An extensive close proximity of these two organelles is a late developmental event, which suggests that it does not have an essential function. Critical Issues: The intimate association of SR/mitochondria develops during murine postnatal differentiation and the recovery of denervated atrophic muscle, which suggests that this is a highly regulated process with a specific function. Analyses of mouse models for muscle diseases suggest that impaired ER/SR-mitochondrial contacts may be due to ER stress and lead to defective bioenergetics and insulin signaling. Future Directions: Future studies are necessary to identify the molecular determinants weakening insulin signaling upon impairment of ER/mitochondrial contacts in skeletal muscles as well as to analyze the distance between SR/ER and mitochondria in muscle diseases associated with ER stress.
Collapse
Affiliation(s)
- Simona Boncompagni
- CeSI-Met-Center for Research on Ageing and Translational Medicine, University G. d' Annunzio, Chieti, Italy.,DNICS-Department of Neuroscience, Imaging and Clinical Sciences, University G. d' Annunzio, Chieti, Italy
| | - Diego Pozzer
- Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Milan, Italy
| | - Carlo Viscomi
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Ana Ferreiro
- Unit of Functional and Adaptive Biology, BFA, Pathophysiology of Striated Muscles Laboratory, University Paris Diderot/CNRS, Sorbonne Paris Cité, Paris, France.,AP-HP, Centre de Référence Maladies Neuromusculaires Paris-Est, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Ester Zito
- Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, Milan, Italy
| |
Collapse
|
11
|
Jang JY, Park Y, Jang DH, Jang JH, Ryu JS. Two novel mutations in TTN of a patient with congenital myopathy: A case report. Mol Genet Genomic Med 2019; 7:e866. [PMID: 31332964 PMCID: PMC6687639 DOI: 10.1002/mgg3.866] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 07/01/2019] [Accepted: 07/05/2019] [Indexed: 11/23/2022] Open
Abstract
Background Early‐onset myopathies show a wide spectrum of phenotypes and are composed of various types of inherited neuromuscular diseases, making it difficult to diagnose. TTN mutation‐related myopathy is a known cause of early‐onset myopathy. Since a next‐generation sequencing (NGS) has enabled sequencing of the vast amount of DNA, TTN, which is the longest coding sequence of any human gene, mutations can now be revealed. We report a 10‐year‐old female with severe congenital muscular weakness and delayed motor development since birth. Methods Next‐generation sequencing as well as electromyography and muscle biopsy were performed. Results To date, she is incapable of walking alone. Her younger sister had similar but more severe symptoms with respiratory failure. In electromyography, short‐duration, small‐amplitude motor unit action potential, and early recruitment patterns were observed in the involved proximal muscles, suggesting myopathy. Muscle histopathology showed a specific atrophy of increased fiber size variability, frequent nuclear internalization, as well as degeneration and regeneration of fibers with type I fiber predominance, consistent with the findings of a previous report about congenital titinopathy. A NGS study revealed two different possible pathogenic variants in TTN: (a) canonical splicing mutation in the intron 105 (c. 29963‐1G>C) and (b) frameshift and truncating mutation in the exon 339 (c.92812dup/p.Arg30938LysfsTer15). All variants were confirmed by conventional Sanger sequencing. Conclusion We propose that unbiased genomic sequencing can be helpful in screening patients with early‐onset myopathy.
Collapse
Affiliation(s)
- Joon Young Jang
- Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Yulhyun Park
- Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Dae-Hyun Jang
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | | | - Ju Seok Ryu
- Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| |
Collapse
|
12
|
Bachmann C, Noreen F, Voermans NC, Schär PL, Vissing J, Fock JM, Bulk S, Kusters B, Moore SA, Beggs AH, Mathews KD, Meyer M, Genetti CA, Meola G, Cardani R, Mathews E, Jungbluth H, Muntoni F, Zorzato F, Treves S. Aberrant regulation of epigenetic modifiers contributes to the pathogenesis in patients with selenoprotein N-related myopathies. Hum Mutat 2019; 40:962-974. [PMID: 30932294 DOI: 10.1002/humu.23745] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/03/2019] [Accepted: 03/13/2019] [Indexed: 12/18/2022]
Abstract
Congenital myopathies are early onset, slowly progressive neuromuscular disorders of variable severity. They are genetically and phenotypically heterogeneous and caused by pathogenic variants in several genes. Multi-minicore Disease, one of the more common congenital myopathies, is frequently caused by recessive variants in either SELENON, encoding the endoplasmic reticulum glycoprotein selenoprotein N or RYR1, encoding a protein involved in calcium homeostasis and excitation-contraction coupling. The mechanism by which recessive SELENON variants cause Multiminicore disease (MmD) is unclear. Here, we extensively investigated muscle physiological, biochemical and epigenetic modifications, including DNA methylation, histone modification, and noncoding RNA expression, to understand the pathomechanism of MmD. We identified biochemical changes that are common in patients harboring recessive RYR1 and SELENON variants, including depletion of transcripts encoding proteins involved in skeletal muscle calcium homeostasis, increased levels of Class II histone deacetylases (HDACs) and DNA methyltransferases. CpG methylation analysis of genomic DNA of patients with RYR1 and SELENON variants identified >3,500 common aberrantly methylated genes, many of which are involved in calcium signaling. These results provide the proof of concept for the potential use of drugs targeting HDACs and DNA methyltransferases to treat patients with specific forms of congenital myopathies.
Collapse
Affiliation(s)
- Christoph Bachmann
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland.,Departments of Anesthesia, Basel University Hospital, Basel, Switzerland
| | - Faiza Noreen
- Genome Plasticity Group, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Nicol C Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Primo L Schär
- Genome Plasticity Group, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - John Vissing
- Department of Neurology, Copenhagen Neuromuscular Center, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Johanna M Fock
- Department of Neurology, University Hospital Groningen, Groningen, The Netherlands
| | - Saskia Bulk
- Department of Human Genetics, Service de Génétique, CHU de Liege, Liege, Belgium
| | - Benno Kusters
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Steven A Moore
- Department of Pathology, Carver College of Medicine, The University of Iowa, Iowa, Iowa
| | - Alan H Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Katherine D Mathews
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa, Iowa.,Department of Neurology, Carver College of Medicine, University of Iowa, Iowa, Iowa
| | - Megan Meyer
- Department of Pathology, Carver College of Medicine, The University of Iowa, Iowa, Iowa
| | - Casie A Genetti
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Giovanni Meola
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.,Department of Neurology, IRCCS Policlinico San Donato Milanese, Milan, Italy
| | - Rosanna Cardani
- Laboratory of Muscle Histopathology and Molecular Biology IRCCS-Policlinico San Donato, Milan, Italy
| | - Emma Mathews
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, St. Thomas' Hospital, London, UK.,Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, UK.,Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre and MRC Centre for Neuromuscular Diseases, UCL, Institute of Child Health, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - Francesco Zorzato
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland.,Departments of Anesthesia, Basel University Hospital, Basel, Switzerland.,Department of Life Sciences, Microbiology and Applied Pathology Section, University of Ferrara, Ferrara, Italy
| | - Susan Treves
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland.,Departments of Anesthesia, Basel University Hospital, Basel, Switzerland.,Department of Life Sciences, Microbiology and Applied Pathology Section, University of Ferrara, Ferrara, Italy
| |
Collapse
|
13
|
Qualls AE, Donkervoort S, Herkert JC, D'gama AM, Bharucha-Goebel D, Collins J, Chao KR, Foley AR, Schoots MH, Jongbloed JDH, Bönnemann CG, Agrawal PB. Novel SPEG mutations in congenital myopathies: Genotype-phenotype correlations. Muscle Nerve 2018; 59:357-362. [PMID: 30412272 DOI: 10.1002/mus.26378] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2018] [Indexed: 01/05/2023]
Abstract
INTRODUCTION Centronuclear myopathies (CNMs) are a subtype of congenital myopathies (CMs) characterized by muscle weakness, predominant type 1 fibers, and increased central nuclei. SPEG (striated preferentially expressed protein kinase) mutations have recently been identified in 7 CM patients (6 with CNMs). We report 2 additional patients with SPEG mutations expanding the phenotype and evaluate genotype-phenotype correlations associated with SPEG mutations. METHODS Using whole exome/genome sequencing in CM families, we identified novel recessive SPEG mutations in 2 patients. RESULTS Patient 1, with severe muscle weakness requiring respiratory support, dilated cardiomyopathy, ophthalmoplegia, and findings of nonspecific CM on muscle biopsy carried a homozygous SPEG mutation (p.Val3062del). Patient 2, with milder muscle weakness, ophthalmoplegia, and CNM carried compound heterozygous mutations (p.Leu728Argfs*82) and (p.Val2997Glyfs*52). CONCLUSIONS The 2 patients add insight into genotype-phenotype correlations of SPEG-associated CMs. Clinicians should consider evaluating a CM patient for SPEG mutations even in the absence of CNM features. Muscle Nerve 59:357-362, 2019.
Collapse
Affiliation(s)
- Anita E Qualls
- Division of Newborn Medicine, Division of Genetics and Genomics, and The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood, National Institutes of Health, Bethesda, Maryland, USA
| | - Johanna C Herkert
- University of Groningen, University Medical Centre Groningen, Department of Genetics, Groningen, the Netherlands
| | - Alissa M D'gama
- Division of Newborn Medicine, Division of Genetics and Genomics, and The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| | - Diana Bharucha-Goebel
- Neuromuscular and Neurogenetic Disorders of Childhood, National Institutes of Health, Bethesda, Maryland, USA.,Division of Neurology, Children's National Health System, Washington, DC, USA
| | - James Collins
- Mercy Clinic Pediatric Neurology, Springfield, Missouri, USA
| | - Katherine R Chao
- Center for Mendelian Genomics at the Broad Institute of MIT and Harvard, Boston, Massachusetts, USA
| | - A Reghan Foley
- Neuromuscular and Neurogenetic Disorders of Childhood, National Institutes of Health, Bethesda, Maryland, USA
| | - Mirthe H Schoots
- Department of Pathology, University of Groningen, University Medical Centre Groningen, Groningen, the Netherlands
| | - Jan D H Jongbloed
- University of Groningen, University Medical Centre Groningen, Department of Genetics, Groningen, the Netherlands
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood, National Institutes of Health, Bethesda, Maryland, USA
| | - Pankaj B Agrawal
- Division of Newborn Medicine, Division of Genetics and Genomics, and The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| |
Collapse
|
14
|
Abstract
Congenital myopathies are clinically and genetically a heterogeneous group of early onset neuromuscular disorders, characterized by hypotonia and muscle weakness. Clinical severity and age of onset are variable. Many patients are severely affected at birth while others have a milder, moderately progressive or nonprogressive phenotype. Respiratory weakness is a major clinical aspect that requires regular monitoring. Causative mutations in several genes have been identified that are inherited in a dominant, recessive or X-linked manner, or arise de novo. Muscle biopsies show characteristic pathological features such as nemaline rods/bodies, cores, central nuclei or caps. Small type 1 fibres expressing slow myosin are a common feature and may sometimes be the only abnormality. Small cores (minicores) devoid of mitochondria and areas showing variable myofibrillar disruption occur in several neuromuscular disorders including several forms of congenital myopathy. Muscle biopsies can also show more than one structural defect. There is considerable clinical, pathological and genetic overlap with mutations in one gene resulting in more than one pathological feature, and the same pathological feature being associated with defects in more than one gene. Increasing application of whole exome sequencing is broadening the clinical and pathological spectra in congenital myopathies, but pathology still has a role in clarifying the pathogenicity of gene variants as well as directing molecular analysis.
Collapse
Affiliation(s)
- C A Sewry
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health and Great Ormond Street Hospital for Children, London, UK.,Wolfson Centre for Inherited Neuromuscular Diseases, RJAH Orthopaedic Hospital, Oswestry, UK
| | - C Wallgren-Pettersson
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
| |
Collapse
|
15
|
Abstract
Pediatric neuromuscular diseases encompass all disorders with onset in childhood and where the primary area of pathology is in the peripheral nervous system. These conditions are largely genetic in etiology, and only those with a genetic underpinning will be presented in this review. This includes disorders of the anterior horn cell (e.g., spinal muscular atrophy), peripheral nerve (e.g., Charcot-Marie-Tooth disease), the neuromuscular junction (e.g., congenital myasthenic syndrome), and the muscle (myopathies and muscular dystrophies). Historically, pediatric neuromuscular disorders have uniformly been considered to be without treatment possibilities and to have dire prognoses. This perception has gradually changed, starting in part with the discovery and widespread application of corticosteroids for Duchenne muscular dystrophy. At present, several exciting therapeutic avenues are under investigation for a range of conditions, offering the potential for significant improvements in patient morbidities and mortality and, in some cases, curative intervention. In this review, we will present the current state of treatment for the most common pediatric neuromuscular conditions, and detail the treatment strategies with the greatest potential for helping with these devastating diseases.
Collapse
Affiliation(s)
- James J. Dowling
- Division of NeurologyHospital for Sick ChildrenTorontoOntarioCanada
- Program for Genetics and Genome BiologyHospital for Sick ChildrenTorontoOntarioCanada
- Departments of Paediatrics and Molecular GeneticsUniversity of TorontoTorontoOntarioCanada
| | | | - Ronald D. Cohn
- Program for Genetics and Genome BiologyHospital for Sick ChildrenTorontoOntarioCanada
- Departments of Paediatrics and Molecular GeneticsUniversity of TorontoTorontoOntarioCanada
| | - Craig Campbell
- Department of PediatricsClinical Neurological SciencesEpidemiologyWestern UniversityLondonOntarioCanada
| |
Collapse
|
16
|
Samões R, Oliveira J, Taipa R, Coelho T, Cardoso M, Gonçalves A, Santos R, Melo Pires M, Santos M. RYR1-Related Myopathies: Clinical, Histopathologic and Genetic Heterogeneity Among 17 Patients from a Portuguese Tertiary Centre. J Neuromuscul Dis 2018; 4:67-76. [PMID: 28269792 DOI: 10.3233/jnd-160199] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Pathogenic variants in ryanodine receptor type 1 (RYR1) gene are an important cause of congenital myopathy. The clinical, histopathologic and genetic spectrum is wide. OBJECTIVE Review a group of the patients diagnosed with ryanodinopathy in a tertiary centre from North Portugal, as an attempt to define some phenotypical patterns that may help guiding future diagnosis. METHODS Patients were identified from the database of the reference centre for Neuromuscular Disorders in North Portugal. Their data (clinical, histological and genetic) was retrospectively accessed. RESULTS Seventeen RYR1-related patients (including 4 familial cases) were identified. They were divided in groups according to three distinctive clinical characteristics: extraocular muscle (EOM) weakness (N = 6), disproportionate axial muscle weakness (N = 2) and joint laxity (N = 5). The fourth phenotype includes patients with mild tetraparesis and no distinctive clinical features (N = 4). Four different histopathological patterns were found: centronuclear (N = 5), central core (N = 4), type 1 fibres predominance (N = 4) and congenital fibre type disproportion (N = 1) myopathies. Each index case, except two patients, had a different RYR1 variant. Four new genetic variants were identified. All centronuclear myopathies were associated with autosomal recessive inheritance and EOM weakness. All central core myopathies were caused by pathogenic variants in hotspot 3 with autosomal dominant inheritance. Three genetic variants were reported to be associated to malignant hyperthermia susceptibility. CONCLUSIONS Distinctive clinical features were recognized as diagnostically relevant: extraocular muscle weakness (and centronuclear pattern on muscle biopsy), severe axial weakness disproportionate to the ambulatory state and mild tetraparesis associated with (proximal) joint laxity. There was a striking genetic heterogeneity, including four new RYR1 variants.
Collapse
Affiliation(s)
- Raquel Samões
- Department of Neurology, Centro Hospitalar do Porto, Porto, Portugal
| | - Jorge Oliveira
- Unidade de Genética Molecular, Centro de Genética Médica, Centro Hospitalar do Porto, Porto, Portugal.,Unidade Multidisciplinar de Investigação Biomédica (UMIB), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Ricardo Taipa
- Neuropathology Unit, Centro Hospitalar do Porto, Porto, Portugal
| | - Teresa Coelho
- Department of Neurophysiology and Neuromuscular Disorders Outpatient Clinic, Centro Hospitalar do Porto, Porto, Portugal
| | - Márcio Cardoso
- Department of Neurophysiology and Neuromuscular Disorders Outpatient Clinic, Centro Hospitalar do Porto, Porto, Portugal
| | - Ana Gonçalves
- Unidade de Genética Molecular, Centro de Genética Médica, Centro Hospitalar do Porto, Porto, Portugal.,Unidade Multidisciplinar de Investigação Biomédica (UMIB), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Rosário Santos
- Unidade de Genética Molecular, Centro de Genética Médica, Centro Hospitalar do Porto, Porto, Portugal.,Unidade Multidisciplinar de Investigação Biomédica (UMIB), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,UCIBIO/REQUIMTE, Departamento de Ciências Biológicas, Laboratório de Bioquímica, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | | | - Manuela Santos
- Neuromuscular Disorders Outpatient Clinic and Department of Neuropaediatrics, Centro Hospitalar do Porto, Porto, Portugal
| |
Collapse
|
17
|
Abstract
During the complex series of events leading to muscle contraction, the initial electric signal coming from motor neurons is transformed into an increase in calcium concentration that triggers sliding of myofibrils. This process, referred to as excitation-contraction coupling, is reliant upon the calcium-release complex, which is restricted spatially to a sub-compartment of muscle cells ("the triad") and regulated precisely. Any dysfunction in the calcium-release complex leads to muscle impairment and myopathy. Various causes can lead to alterations in excitation-contraction coupling and to muscle diseases. The latter are reviewed and classified into four categories: (i) mutation in a protein of the calcium-release complex; (ii) alteration in triad structure; (iii) modification of regulation of channels; (iv) modification in calcium stores within the muscle. Current knowledge of the pathophysiologic mechanisms in each category is described and discussed.
Collapse
Affiliation(s)
- Isabelle Marty
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, F-38000 Grenoble, France.,INSERM, U1216, F-38000 Grenoble, France
| | - Julien Fauré
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, F-38000 Grenoble, France.,INSERM, U1216, F-38000 Grenoble, France.,CHU de Grenoble, F-38000 Grenoble, France
| |
Collapse
|
18
|
Abstract
The triad is a skeletal muscle substructure responsible for the regulation of excitation-contraction coupling. It is formed by the close apposition of the T-tubule and the terminal sarcoplasmic reticulum. A rapidly growing list of skeletal myopathies, here referred to as triadopathies, are caused by gene mutations in components of the triad. These disorders, at their root, are caused by defects in excitation contraction coupling and intracellular calcium homeostasis. Secondary abnormalities in triad structure and/or function are also reported in several muscle diseases, most notably certain muscular dystrophies. This review highlights the current understanding of both primary and secondary triadopathies, and identifies important concepts yet to be fully addressed in the field. The emphasis of the review is both on the pathogenesis of triadopathies and their potential treatment.
Collapse
Affiliation(s)
- James J Dowling
- Division of Neurology and Genetics and Genome Biology Program, Hospital for Sick Children, Toronto, ON, Canada,
| | | | | |
Collapse
|
19
|
Reifler A, Lenk GM, Li X, Groom L, Brooks SV, Wilson D, Bowerson M, Dirksen RT, Meisler MH, Dowling JJ. Murine Fig4 is dispensable for muscle development but required for muscle function. Skelet Muscle 2013; 3:21. [PMID: 24004519 PMCID: PMC3844516 DOI: 10.1186/2044-5040-3-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 07/29/2013] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Phosphatidylinositol phosphates (PIPs) are low-abundance phospholipids that participate in a range of cellular processes, including cell migration and membrane traffic. PIP levels and subcellular distribution are regulated by a series of lipid kinases and phosphatases. In skeletal muscle, PIPs and their enzymatic regulators serve critically important functions exemplified by mutations of the PIP phosphatase MTM1 in myotubular myopathy (MTM), a severe muscle disease characterized by impaired muscle structure and abnormal excitation-contraction coupling. FIG4 functions as a PIP phosphatase that participates in both the synthesis and breakdown of phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2). Mutation of FIG4 results in a severe neurodegenerative disorder in mice and a progressive peripheral polyneuropathy in humans. The effect of FIG4 mutation on skeletal muscle has yet to be examined. METHODS Herein we characterize the impact of FIG4 on skeletal muscle development and function using the spontaneously occurring mouse mutant pale tremor (plt), a mouse line with a loss of function mutation in Fig4. RESULTS In plt mice, we characterized abnormalities in skeletal muscle, including reduced muscle size and specific force generation. We also uncovered ultrastructural abnormalities and increased programmed cell death. Conversely, we detected no structural or functional abnormalities to suggest impairment of excitation-contraction coupling, a process previously shown to be influenced by PI(3,5)P2 levels. Conditional rescue of Fig4 mutation in neurons prevented overt muscle weakness and the development of obvious muscle abnormalities, suggesting that the changes observed in the plt mice were primarily related to denervation of skeletal muscle. On the basis of the ability of reduced FIG4 levels to rescue aspects of Mtmr2-dependent neuropathy, we evaluated the effect of Fig4 haploinsufficiency on the myopathy of Mtm1-knockout mice. Male mice with a compound Fig4+/-/Mtm1-/Y genotype displayed no improvements in muscle histology, muscle size or overall survival, indicating that FIG4 reduction does not ameliorate the Mtm1-knockout phenotype. CONCLUSIONS Overall, these data indicate that loss of Fig4 impairs skeletal muscle function but does not significantly affect its structural development.
Collapse
Affiliation(s)
- Aaron Reifler
- Department of Pediatrics, University of Michigan Medical Center, Ann Arbor, MI 48109-2200, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109-2200, USA
| | - Guy M Lenk
- Department of Human Genetics, University of Michigan Medical Center, Ann Arbor, MI 48109-2200, USA
| | - Xingli Li
- Department of Pediatrics, University of Michigan Medical Center, Ann Arbor, MI 48109-2200, USA
| | - Linda Groom
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Susan V Brooks
- Molecular and Integrative Physiology, University of Michigan Medical Center, Ann Arbor, MI 48109-2200, USA
| | - Desmond Wilson
- Department of Pediatrics, University of Michigan Medical Center, Ann Arbor, MI 48109-2200, USA
| | - Michyla Bowerson
- Department of Pediatrics, University of Michigan Medical Center, Ann Arbor, MI 48109-2200, USA
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Miriam H Meisler
- Department of Human Genetics, University of Michigan Medical Center, Ann Arbor, MI 48109-2200, USA
| | - James J Dowling
- Department of Pediatrics, University of Michigan Medical Center, Ann Arbor, MI 48109-2200, USA
| |
Collapse
|
20
|
Laing NG, Dye DE, Wallgren-Pettersson C, Richard G, Monnier N, Lillis S, Winder TL, Lochmüller H, Graziano C, Mitrani-Rosenbaum S, Twomey D, Sparrow JC, Beggs AH, Nowak KJ. Mutations and polymorphisms of the skeletal muscle alpha-actin gene (ACTA1). Hum Mutat 2009; 30:1267-77. [PMID: 19562689 PMCID: PMC2784950 DOI: 10.1002/humu.21059] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The ACTA1 gene encodes skeletal muscle alpha-actin, which is the predominant actin isoform in the sarcomeric thin filaments of adult skeletal muscle, and essential, along with myosin, for muscle contraction. ACTA1 disease-causing mutations were first described in 1999, when a total of 15 mutations were known. In this article we describe 177 different disease-causing ACTA1 mutations, including 85 that have not been described before. ACTA1 mutations result in five overlapping congenital myopathies: nemaline myopathy; intranuclear rod myopathy; actin filament aggregate myopathy; congenital fiber type disproportion; and myopathy with core-like areas. Mixtures of these histopathological phenotypes may be seen in a single biopsy from one patient. Irrespective of the histopathology, the disease is frequently clinically severe, with many patients dying within the first year of life. Most mutations are dominant and most patients have de novo mutations not present in the peripheral blood DNA of either parent. Only 10% of mutations are recessive and they are genetic or functional null mutations. To aid molecular diagnosis and establishing genotype-phenotype correlations, we have developed a locus-specific database for ACTA1 variations (http://waimr.uwa.edu.au).
Collapse
Affiliation(s)
- Nigel G Laing
- Centre for Medical Research, University of Western Australia, Western Australian Institute for Medical Research, QEII Medical Centre, Western Australia, Australia.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|