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Bang ML, Bogomolovas J, Chen J. Understanding the molecular basis of cardiomyopathy. Am J Physiol Heart Circ Physiol 2022; 322:H181-H233. [PMID: 34797172 PMCID: PMC8759964 DOI: 10.1152/ajpheart.00562.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/16/2021] [Accepted: 11/16/2021] [Indexed: 02/03/2023]
Abstract
Inherited cardiomyopathies are a major cause of mortality and morbidity worldwide and can be caused by mutations in a wide range of proteins located in different cellular compartments. The present review is based on Dr. Ju Chen's 2021 Robert M. Berne Distinguished Lectureship of the American Physiological Society Cardiovascular Section, in which he provided an overview of the current knowledge on the cardiomyopathy-associated proteins that have been studied in his laboratory. The review provides a general summary of the proteins in different compartments of cardiomyocytes associated with cardiomyopathies, with specific focus on the proteins that have been studied in Dr. Chen's laboratory.
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Affiliation(s)
- Marie-Louise Bang
- Institute of Genetic and Biomedical Research (IRGB), National Research Council (CNR), Milan Unit, Milan, Italy
- IRCCS Humanitas Research Hospital, Rozzano (Milan), Italy
| | - Julius Bogomolovas
- Division of Cardiovascular Medicine, Department of Medicine Cardiology, University of California, San Diego, La Jolla, California
| | - Ju Chen
- Division of Cardiovascular Medicine, Department of Medicine Cardiology, University of California, San Diego, La Jolla, California
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2
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Filomena MC, Yamamoto DL, Carullo P, Medvedev R, Ghisleni A, Piroddi N, Scellini B, Crispino R, D'Autilia F, Zhang J, Felicetta A, Nemska S, Serio S, Tesi C, Catalucci D, Linke WA, Polishchuk R, Poggesi C, Gautel M, Bang ML. Myopalladin knockout mice develop cardiac dilation and show a maladaptive response to mechanical pressure overload. eLife 2021; 10:e58313. [PMID: 34558411 PMCID: PMC8547954 DOI: 10.7554/elife.58313] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/23/2021] [Indexed: 12/13/2022] Open
Abstract
Myopalladin (MYPN) is a striated muscle-specific immunoglobulin domain-containing protein located in the sarcomeric Z-line and I-band. MYPN gene mutations are causative for dilated (DCM), hypertrophic, and restrictive cardiomyopathy. In a yeast two-hybrid screening, MYPN was found to bind to titin in the Z-line, which was confirmed by microscale thermophoresis. Cardiac analyses of MYPN knockout (MKO) mice showed the development of mild cardiac dilation and systolic dysfunction, associated with decreased myofibrillar isometric tension generation and increased resting tension at longer sarcomere lengths. MKO mice exhibited a normal hypertrophic response to transaortic constriction (TAC), but rapidly developed severe cardiac dilation and systolic dysfunction, associated with fibrosis, increased fetal gene expression, higher intercalated disc fold amplitude, decreased calsequestrin-2 protein levels, and increased desmoplakin and SORBS2 protein levels. Cardiomyocyte analyses showed delayed Ca2+ release and reuptake in unstressed MKO mice as well as reduced Ca2+ spark amplitude post-TAC, suggesting that altered Ca2+ handling may contribute to the development of DCM in MKO mice.
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Affiliation(s)
- Maria Carmela Filomena
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
| | - Daniel L Yamamoto
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
| | - Pierluigi Carullo
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
| | - Roman Medvedev
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Cardiac Surgery, University of VeronaVeronaItaly
| | - Andrea Ghisleni
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research ExcellenceLondonUnited Kingdom
| | - Nicoletta Piroddi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Beatrice Scellini
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Roberta Crispino
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | | | - Jianlin Zhang
- Department of Medicine, University of California, San DiegoLa JollaUnited States
| | - Arianna Felicetta
- IRCCS Humanitas Research HospitalMilanItaly
- Humanitas UniversityPieve EmanueleItaly
| | | | | | - Chiara Tesi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | | | - Wolfgang A Linke
- Institute of Physiology II, University of MuensterMuensterGermany
| | - Roman Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | - Corrado Poggesi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research ExcellenceLondonUnited Kingdom
| | - Marie-Louise Bang
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
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3
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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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4
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Polavarapu K, Bardhan M, Anjanappa RM, Vengalil S, Preethish-Kumar V, Shingavi L, Chawla T, Nashi S, Mohan D, Arunachal G, Geetha TS, Ramprasad V, Nalini A. Nemaline Rod/Cap Myopathy Due to Novel Homozygous MYPN Mutations: The First Report from South Asia and Comprehensive Literature Review. J Clin Neurol 2021; 17:409-418. [PMID: 34184449 PMCID: PMC8242322 DOI: 10.3988/jcn.2021.17.3.409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 02/16/2021] [Accepted: 02/16/2021] [Indexed: 11/17/2022] Open
Abstract
Background and Purpose Pathogenic variants in the myopalladin gene (MYPN) are known to cause mildly progressive nemaline/cap myopathy. Only nine cases have been reported in the English literature. Methods A detailed evaluation was conducted of the clinical, muscle magnetic resonance imaging (MRI), and genetic findings of two unrelated adults with MYPN-related cap myopathy. Genetic analysis was performed using whole-exome sequencing. MRI was performed on a 1.5-T device in patient 1. Results Two unrelated adults born to consanguineous parents, a 28-year-old male and a 23-year-old female, were diagnosed with pathogenic variants in MYPN that cause cap myopathy. Both patients presented with early-onset, insidiously progressive, and minimally disabling proximodistal weakness with mild ptosis, facial weakness, and bulbar symptoms. Patient 1 had a prominent foot drop from the onset. Both patients were followed up at age 30 years, at which point serum creatine kinase concentrations were minimally elevated. There were no cardiac symptoms; electrocardiograms and two-dimensional echocardiograms were normal in both patients. Muscle MRI revealed preferential involvement of the glutei, posterior thigh muscles, and anterior leg muscles. Whole-exome sequencing revealed significant homozygous splice-site variants in both of the probands, affecting intron 10 of MYPN: c.1973+1G>C (patient 1) and c.1974-2A>C (patient 2). Conclusions This study elaborates on two patients with homozygous MYPN pathogenic variants, presenting as slowly progressive congenital myopathy. These patients are only the tenth and eleventh cases reported in the English literature, and the first from South Asia. The clinical phenotype reiterates the mild form of nemaline rod/cap myopathy. A comprehensive literature review is presented.
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Affiliation(s)
- Kiran Polavarapu
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India.,Children's Hospital of Eastern Ontario Research Institute; Division of Neurology, Department of Medicine, The Ottawa Hospital; Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Mainak Bardhan
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Ram Murthy Anjanappa
- Department of Human Genetics, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | | | - Leena Shingavi
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Tanushree Chawla
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Saraswati Nashi
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Dhaarini Mohan
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Gautham Arunachal
- Department of Human Genetics, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | | | | | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India.
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5
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Zheng Y, Lv H, Zhang W, Wang Z, Yuan Y. Respiratory Failure as the Presenting Symptom in a Sporadic Case of Cap Myopathy. J Neuropathol Exp Neurol 2020; 79:1382-1384. [PMID: 33064836 DOI: 10.1093/jnen/nlaa117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Yiming Zheng
- Department of Neurology, Peking University First Hospital, Peking, China
| | - He Lv
- Department of Neurology, Peking University First Hospital, Peking, China
| | - Wei Zhang
- Department of Neurology, Peking University First Hospital, Peking, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Peking, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Peking, China
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6
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Papadimas GK, Xirou S, Kararizou E, Papadopoulos C. Update on Congenital Myopathies in Adulthood. Int J Mol Sci 2020; 21:ijms21103694. [PMID: 32456280 PMCID: PMC7279481 DOI: 10.3390/ijms21103694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/17/2020] [Accepted: 05/19/2020] [Indexed: 12/11/2022] Open
Abstract
Congenital myopathies (CMs) constitute a group of heterogenous rare inherited muscle diseases with different incidences. They are traditionally grouped based on characteristic histopathological findings revealed on muscle biopsy. In recent decades, the ever-increasing application of modern genetic technologies has not just improved our understanding of their pathophysiology, but also expanded their phenotypic spectrum and contributed to a more genetically based approach for their classification. Later onset forms of CMs are increasingly recognised. They are often considered milder with slower progression, variable clinical presentations and different modes of inheritance. We reviewed the key features and genetic basis of late onset CMs with a special emphasis on those forms that may first manifest in adulthood.
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7
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Pula S, Urankar K, Norman A, Pierre G, Langton-Hewer S, Selby V, Mason F, Vijayakumar K, McFarland R, Taylor RW, Majumdar A. A novel de novo ACTA1 variant in a patient with nemaline myopathy and mitochondrial Complex I deficiency. Neuromuscul Disord 2020; 30:159-164. [PMID: 32005493 DOI: 10.1016/j.nmd.2019.11.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 11/23/2019] [Accepted: 11/28/2019] [Indexed: 12/30/2022]
Abstract
We describe the presentation and follow-up of a three-year-old girl with nemaline myopathy due to a de-novo variant in ACTA1 (encoding skeletal alpha actin) and moderately low enzyme level of Complex I of the mitochondrial respiratory chain. She presented in the neonatal period with hypotonia, followed by weakness in the facial, bulbar, respiratory and neck flexors muscles. A biopsy of her quadriceps muscle at the age of one year showed nemaline rods. Based on her clinical presentation of a congenital myopathy and histopathological features on a muscle biopsy, ACTA1 was sequenced, and this revealed a novel sequence variant, c.760 A>C p. (Asn254His). In addition, mitochondrial respiratory chain enzymatic activity of skeletal muscle biopsy showed a moderately low activity of complex I (nicotinamide adenine dinucleotide (NADH): ubiquinone oxidoreductase). Disturbances of Complex I of the respiratory chain have been reported in patients with nemaline myopathy, although the mechanism remains unclear.
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Affiliation(s)
- Shpresa Pula
- Department of Paediatric Neurology, University Hospitals Bristol NHS Foundation Trust, 6th Floor Education Centre, Upper Maudlin St, Bristol BS2 8BJ, United Kingdom
| | - Kathryn Urankar
- Department of Neuropathology, North Bristol Hospital NHS Foundation Trust, Bristol, United Kingdom
| | - Andrew Norman
- Department of Clinical Genetics, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
| | - Germaine Pierre
- Department of Paediatric Neurology, University Hospitals Bristol NHS Foundation Trust, 6th Floor Education Centre, Upper Maudlin St, Bristol BS2 8BJ, United Kingdom
| | - Simon Langton-Hewer
- Department of Paediatric Respiratory Medicine, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
| | - Victoria Selby
- Department of Paediatric Neurology, University Hospitals Bristol NHS Foundation Trust, 6th Floor Education Centre, Upper Maudlin St, Bristol BS2 8BJ, United Kingdom
| | - Faye Mason
- Department of Paediatric Neurology, University Hospitals Bristol NHS Foundation Trust, 6th Floor Education Centre, Upper Maudlin St, Bristol BS2 8BJ, United Kingdom
| | - Kayal Vijayakumar
- Department of Paediatric Neurology, University Hospitals Bristol NHS Foundation Trust, 6th Floor Education Centre, Upper Maudlin St, Bristol BS2 8BJ, United Kingdom
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of Neurosciences, Newcastle University, Newcastle, United Kingdom
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neurosciences, Newcastle University, Newcastle, United Kingdom
| | - Anirban Majumdar
- Department of Paediatric Neurology, University Hospitals Bristol NHS Foundation Trust, 6th Floor Education Centre, Upper Maudlin St, Bristol BS2 8BJ, United Kingdom.
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8
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Filomena MC, Yamamoto DL, Caremani M, Kadarla VK, Mastrototaro G, Serio S, Vydyanath A, Mutarelli M, Garofalo A, Pertici I, Knöll R, Nigro V, Luther PK, Lieber RL, Beck MR, Linari M, Bang M. Myopalladin promotes muscle growth through modulation of the serum response factor pathway. J Cachexia Sarcopenia Muscle 2020; 11:169-194. [PMID: 31647200 PMCID: PMC7015241 DOI: 10.1002/jcsm.12486] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/01/2019] [Accepted: 07/22/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Myopalladin (MYPN) is a striated muscle-specific, immunoglobulin-containing protein located in the Z-line and I-band of the sarcomere as well as the nucleus. Heterozygous MYPN gene mutations are associated with hypertrophic, dilated, and restrictive cardiomyopathy, and homozygous loss-of-function truncating mutations have recently been identified in patients with cap myopathy, nemaline myopathy, and congenital myopathy with hanging big toe. METHODS Constitutive MYPN knockout (MKO) mice were generated, and the role of MYPN in skeletal muscle was studied through molecular, cellular, biochemical, structural, biomechanical, and physiological studies in vivo and in vitro. RESULTS MKO mice were 13% smaller compared with wild-type controls and exhibited a 48% reduction in myofibre cross-sectional area (CSA) and significantly increased fibre number. Similarly, reduced myotube width was observed in MKO primary myoblast cultures. Biomechanical studies showed reduced isometric force and power output in MKO mice as a result of the reduced CSA, whereas the force developed by each myosin molecular motor was unaffected. While the performance by treadmill running was similar in MKO and wild-type mice, MKO mice showed progressively decreased exercise capability, Z-line damage, and signs of muscle regeneration following consecutive days of downhill running. Additionally, MKO muscle exhibited progressive Z-line widening starting from 8 months of age. RNA-sequencing analysis revealed down-regulation of serum response factor (SRF)-target genes in muscles from postnatal MKO mice, important for muscle growth and differentiation. The SRF pathway is regulated by actin dynamics as binding of globular actin to the SRF-cofactor myocardin-related transcription factor A (MRTF-A) prevents its translocation to the nucleus where it binds and activates SRF. MYPN was found to bind and bundle filamentous actin as well as interact with MRTF-A. In particular, while MYPN reduced actin polymerization, it strongly inhibited actin depolymerization and consequently increased MRTF-A-mediated activation of SRF signalling in myogenic cells. Reduced myotube width in MKO primary myoblast cultures was rescued by transduction with constitutive active SRF, demonstrating that MYPN promotes skeletal muscle growth through activation of the SRF pathway. CONCLUSIONS Myopalladin plays a critical role in the control of skeletal muscle growth through its effect on actin dynamics and consequently the SRF pathway. In addition, MYPN is important for the maintenance of Z-line integrity during exercise and aging. These results suggest that muscle weakness in patients with biallelic MYPN mutations may be associated with reduced myofibre CSA and SRF signalling and that the disease phenotype may be aggravated by exercise.
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Affiliation(s)
- Maria Carmela Filomena
- Institute of Genetic and Biomedical Research (IRGB), Milan UnitNational Research CouncilMilanItaly
- Humanitas Clinical and Research CenterRozzanoMilanItaly
| | - Daniel L. Yamamoto
- Institute of Genetic and Biomedical Research (IRGB), Milan UnitNational Research CouncilMilanItaly
| | - Marco Caremani
- Department of BiologyUniversity of FlorenceSesto FiorentinoFlorenceItaly
| | | | | | - Simone Serio
- Humanitas Clinical and Research CenterRozzanoMilanItaly
| | | | | | - Arcamaria Garofalo
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
- Department of Precision MedicineUniversity of Campania “Luigi Vanvitelli”NaplesItaly
| | - Irene Pertici
- Department of BiologyUniversity of FlorenceSesto FiorentinoFlorenceItaly
| | - Ralph Knöll
- Integrated Cardio Metabolic Centre (ICMC), Myocardial GeneticsKarolinska Institutet, University Hospital, Heart and Vascular ThemeSweden
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases (CVRM), Biopharmaceuticals R&DAstraZenecaMölndalSweden
| | - Vincenzo Nigro
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
- Department of Precision MedicineUniversity of Campania “Luigi Vanvitelli”NaplesItaly
| | | | - Richard L. Lieber
- Shirley Ryan AbilityLab and Hines V.A. Medical Center ChicagoChicagoILUSA
- Department of Physical Medicine and RehabilitationNorthwestern UniversityChicagoILUSA
- Department of Orthopaedic SurgeryUniversity of California San DiegoLa JollaCAUSA
| | - Moriah R. Beck
- Department of ChemistryWichita State UniversityWichitaKSUSA
| | - Marco Linari
- Department of BiologyUniversity of FlorenceSesto FiorentinoFlorenceItaly
| | - Marie‐Louise Bang
- Institute of Genetic and Biomedical Research (IRGB), Milan UnitNational Research CouncilMilanItaly
- Humanitas Clinical and Research CenterRozzanoMilanItaly
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9
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Tinklenberg JA, Siebers EM, Beatka MJ, Fickau BA, Ayres S, Meng H, Yang L, Simpson P, Granzier HL, Lawlor MW. Myostatin Inhibition Using ActRIIB-mFc Does Not Produce Weight Gain or Strength in the Nebulin Conditional KO Mouse. J Neuropathol Exp Neurol 2019; 78:130-139. [PMID: 30597051 DOI: 10.1093/jnen/nly120] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mutations in at least 12 genes are responsible for a group of congenital skeletal muscle diseases known as nemaline myopathies (NMs). NMs are associated with a range of clinical symptoms and pathological changes often including the presence of cytoplasmic rod-like structures (nemaline bodies) and myofiber hypotrophy. Our recent work has identified a variable degree of behavioral benefit when treating 2 NM mouse models due to mutations in Acta1 with myostatin inhibition. This study is focused on the effects of delivering ActRIIB-mFc (Acceleron; a myostatin inhibitor) to the nebulin conditional knockout KO (Neb cKO) mouse model of NM. Treatment of Neb cKO mice with ActRIIB-mFc did not produce increases in weight gain, strength, myofiber size, or hypertrophic pathway signaling. Overall, our studies demonstrate a lack of response in Neb cKO mice to myostatin inhibition, which differs from the response observed when treating other NM models.
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Affiliation(s)
- Jennifer A Tinklenberg
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Emily M Siebers
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Margaret J Beatka
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Brittany A Fickau
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Samuel Ayres
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Hui Meng
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine
| | - Lin Yang
- Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Pippa Simpson
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine
| | - Henk L Granzier
- Division of Quantitative Health Sciences, Department of Pediatrics Medical College of Wisconsin, Milwaukee, Wisconsin (PS); and College of Medicine, University of Arizona, Tucson, Arizona
| | - Michael W Lawlor
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine.,Neuroscience Research Center Medical College of Wisconsin, Milwaukee, Wisconsin
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10
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Malfatti E. Miopatie congenite. Neurologia 2019. [DOI: 10.1016/s1634-7072(19)42494-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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11
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Merlini L, Sabatelli P, Antoniel M, Carinci V, Niro F, Monetti G, Torella A, Giugliano T, Faldini C, Nigro V. Congenital myopathy with hanging big toe due to homozygous myopalladin (MYPN) mutation. Skelet Muscle 2019; 9:14. [PMID: 31133047 PMCID: PMC6535860 DOI: 10.1186/s13395-019-0199-9] [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: 10/31/2018] [Accepted: 04/25/2019] [Indexed: 12/11/2022] Open
Abstract
Background Myopalladin (MYPN) is a component of the sarcomere that tethers nebulin in skeletal muscle and nebulette in cardiac muscle to alpha-actinin at the Z lines. Autosomal dominant MYPN mutations cause hypertrophic, dilated, or restrictive cardiomyopathy. Autosomal recessive MYPN mutations have been reported in only six families showing a mildly progressive nemaline or cap myopathy with cardiomyopathy in some patients. Case presentation A consanguineous family with congenital to adult-onset muscle weakness and hanging big toe was reported. Muscle biopsy showed minimal changes with internal nuclei, type 1 fiber predominance, and ultrastructural defects of Z line. Muscle CT imaging showed marked hypodensity of the sartorius bilaterally and MRI scattered abnormal high-intensity areas in the internal tongue muscle and in the posterior cervical muscles. Cardiac involvement was demonstrated by magnetic resonance imaging and late gadolinium enhancement. Whole exome sequencing analysis identified a homozygous loss of function single nucleotide deletion in the exon 11 of the MYPN gene in two siblings. Full-length MYPN protein was undetectable on immunoblotting, and on immunofluorescence, its localization at the Z line was missed. Conclusions This report extends the phenotypic spectrum of recessive MYPN-related myopathies showing: (1) the two patients had hanging big toe and the oldest one developed spine and hand contractures, none of these signs observed in the previously reported patients, (2) specific ultrastructural changes consisting in Z line fragmentation, but (3) no nemaline or caps on muscle pathology.
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Affiliation(s)
- Luciano Merlini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Patrizia Sabatelli
- IRCCS-Istituto Ortopedico Rizzoli, Bologna, Italy.,Institute of Molecular Genetics, National Research Council of Italy, Bologna, Italy
| | - Manuela Antoniel
- Institute of Molecular Genetics, National Research Council of Italy, Bologna, Italy
| | | | - Fabio Niro
- Division of Cardiology, Hospital St. Orsola, Bologna, Italy
| | | | - Annalaura Torella
- Dipartimento di Medicina di Precisione, Università della Campania "Luigi Vanvitelli", Naples, Italy.,Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Teresa Giugliano
- Dipartimento di Medicina di Precisione, Università della Campania "Luigi Vanvitelli", Naples, Italy
| | - Cesare Faldini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Clinic of Orthopaedic and Traumatology, Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Vincenzo Nigro
- Dipartimento di Medicina di Precisione, Università della Campania "Luigi Vanvitelli", Naples, Italy. .,Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.
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12
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Abstract
The congenital myopathies form a large clinically and genetically heterogeneous group of disorders. Currently mutations in at least 27 different genes have been reported to cause a congenital myopathy, but the number is expected to increase due to the accelerated use of next-generation sequencing methods. There is substantial overlap between the causative genes and the clinical and histopathologic features of the congenital myopathies. The mode of inheritance can be autosomal recessive, autosomal dominant or X-linked. Both dominant and recessive mutations in the same gene can cause a similar disease phenotype, and the same clinical phenotype can also be caused by mutations in different genes. Clear genotype-phenotype correlations are few and far between.
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Affiliation(s)
- Katarina Pelin
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland; The Folkhälsan Institute of Genetics, Folkhälsan Research Center, and Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland.
| | - Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics, Folkhälsan Research Center, and Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
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13
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Gonorazky HD, Dowling JJ, Volpatti JR, Vajsar J. Signs and Symptoms in Congenital Myopathies. Semin Pediatr Neurol 2019; 29:3-11. [PMID: 31060723 DOI: 10.1016/j.spen.2019.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Congenital myopathies (CM) represent a continuously growing group of disorders with a wide range of clinical and histopathologic presentations. The refinement and application of new technologies for genetic diagnosis have broadened our understanding of the genetic causes of CM. Our growing knowledge has revealed that there are no clear limits between each subgroup of CM, and thus the clinical overlap between genes has become more evident. The implementation of next generation sequencing has produced vast amounts of genomic data that may be difficult to interpret. With an increasing number of reports revealing variants of unknown significance, it is essential to support the genetic diagnosis with a well characterized clinical description of the patient. Phenotype-genotype correlation should be a priority at the moment of disclosing the genetic results. Thus, a detailed physical examination can provide us with subtle differences that are not only key in order to arrive at a correct diagnosis, but also in the characterization of new myopathies and candidate genes.
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Affiliation(s)
- Hernan D Gonorazky
- Division of Neurology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - James J Dowling
- Division of Neurology, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Molecular Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jonathan R Volpatti
- Department of Molecular Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jiri Vajsar
- Division of Neurology, The Hospital for Sick Children, Toronto, Ontario, Canada.
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Tinklenberg JA, Siebers EM, Beatka MJ, Meng H, Yang L, Zhang Z, Ross JA, Ochala J, Morris C, Owens JM, Laing NG, Nowak KJ, Lawlor MW. Myostatin inhibition using mRK35 produces skeletal muscle growth and tubular aggregate formation in wild type and TgACTA1D286G nemaline myopathy mice. Hum Mol Genet 2019; 27:638-648. [PMID: 29293963 DOI: 10.1093/hmg/ddx431] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/15/2017] [Indexed: 12/27/2022] Open
Abstract
Nemaline myopathy (NM) is a heterogeneous congenital skeletal muscle disease with cytoplasmic rod-like structures (nemaline bodies) in muscle tissue. While weakness in NM is related to contractile abnormalities, myofiber smallness is an additional abnormality in NM that may be treatable. We evaluated the effects of mRK35 (a myostatin inhibitor developed by Pfizer) treatment in the TgACTA1D286G mouse model of NM. mRK35 induced skeletal muscle growth that led to significant increases in animal bodyweight, forelimb grip strength and muscle fiber force, although it should be noted that animal weight and forelimb grip strength in untreated TgACTA1D286G mice was not different from controls. Treatment was also associated with an increase in the number of tubular aggregates found in skeletal muscle. These findings suggest that myostatin inhibition may be useful in promoting muscle growth and strength in Acta1-mutant muscle, while also further establishing the relationship between low levels of myostatin and tubular aggregate formation.
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Affiliation(s)
- Jennifer A Tinklenberg
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee 53226, WI, USA
| | - Emily M Siebers
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee 53226, WI, USA
| | - Margaret J Beatka
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee 53226, WI, USA
| | - Hui Meng
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee 53226, WI, USA
| | - Lin Yang
- Department of Biomedical Engineering, University of Florida, Gainesville 32607, FL, USA
| | - Zizhao Zhang
- Department of Biomedical Engineering, University of Florida, Gainesville 32607, FL, USA
| | - Jacob A Ross
- School of Basic and Medical Biosciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Julien Ochala
- School of Basic and Medical Biosciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | | | | | - Nigel G Laing
- Centre for Medical Research, The University of Western Australia, Perth, WA, Australia.,Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
| | - Kristen J Nowak
- Harry Perkins Institute of Medical Research, Nedlands, WA, Australia.,Faculty of Health and Medical Sciences, School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
| | - Michael W Lawlor
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee 53226, WI, USA
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15
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Dominantly inherited distal nemaline/cap myopathy caused by a large deletion in the nebulin gene. Neuromuscul Disord 2018; 29:97-107. [PMID: 30679003 DOI: 10.1016/j.nmd.2018.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/29/2018] [Accepted: 12/16/2018] [Indexed: 11/20/2022]
Abstract
We report the first family with a dominantly inherited mutation of the nebulin gene (NEB). This ∼100 kb in-frame deletion encompasses NEB exons 14-89, causing distal nemaline/cap myopathy in a three-generation family. It is the largest deletion characterized in NEB hitherto. The mutated allele was shown to be expressed at the mRNA level and furthermore, for the first time, a deletion was shown to cause the production of a smaller mutant nebulin protein. Thus, we suggest that this novel mutant nebulin protein has a dominant-negative effect, explaining the first documented dominant inheritance of nebulin-caused myopathy. The index patient, a young man, was more severely affected than his mother and grandmother. His first symptom was foot drop at the age of three, followed by distal muscle atrophy, slight hypomimia, high-arched palate, and weakness of the neck and elbow flexors, hands, tibialis anterior and toe extensors. Muscle biopsies showed myopathic features with type 1 fibre predominance in the index patient and nemaline bodies and cap-like structures in biopsies from his mother and grandmother. The muscle biopsy findings constitute a further example of nemaline bodies and cap-like structures being part of the same spectrum of pathological changes.
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16
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Ravenscroft G, Bryson-Richardson RJ, Nowak KJ, Laing NG. Recent advances in understanding congenital myopathies. F1000Res 2018; 7. [PMID: 30631434 PMCID: PMC6290972 DOI: 10.12688/f1000research.16422.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/29/2018] [Indexed: 12/18/2022] Open
Abstract
By definition, congenital myopathy typically presents with skeletal muscle weakness and hypotonia at birth. Traditionally, congenital myopathy subtypes have been predominantly distinguished on the basis of the pathological hallmarks present on skeletal muscle biopsies. Many genes cause congenital myopathies when mutated, and a burst of new causative genes have been identified because of advances in gene sequencing technology. Recent discoveries include extending the disease phenotypes associated with previously identified genes and determining that genes formerly known to cause only dominant disease can also cause recessive disease. The more recently identified congenital myopathy genes account for only a small proportion of patients. Thus, the congenital myopathy genes remaining to be discovered are predicted to be extremely rare causes of disease, which greatly hampers their identification. Significant progress in the provision of molecular diagnoses brings important information and value to patients and their families, such as possible disease prognosis, better disease management, and informed reproductive choice, including carrier screening of parents. Additionally, from accurate genetic knowledge, rational treatment options can be hypothesised and subsequently evaluated
in vitro and in animal models. A wide range of potential congenital myopathy therapies have been investigated on the basis of improved understanding of disease pathomechanisms, and some therapies are in clinical trials. Although large hurdles remain, promise exists for translating treatment benefits from preclinical models to patients with congenital myopathy, including harnessing proven successes for other genetic diseases.
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Affiliation(s)
- Gianina Ravenscroft
- Centre for Medical Research, The University of Western Australia, Perth, WA, Australia.,Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia
| | | | - Kristen J Nowak
- Centre for Medical Research, The University of Western Australia, Perth, WA, Australia.,Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,School of Biological Sciences, Faculty of Health and Medical Sciences, The University of Western Australia, QEII Medical Centre, Nedlands, WA, Australia.,Office of Population Health Genomics, Western Australian Department of Health, East Perth, WA, Australia
| | - Nigel G Laing
- Centre for Medical Research, The University of Western Australia, Perth, WA, Australia.,Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,Department of Diagnostic Genomics, PathWest Laboratory Medicine, QEII Medical Centre, Nedlands, WA, Australia
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Moreau-Le Lan S, Aller E, Calabria I, Gonzalez-Tarancon L, Cardona-Gay C, Martinez-Matilla M, Aparisi MJ, Selles J, Sagath L, Pitarch I, Muelas N, Cervera JV, Millan JM, Pedrola L. New mutations found by Next-Generation Sequencing screening of Spanish patients with Nemaline Myopathy. PLoS One 2018; 13:e0207296. [PMID: 30517146 PMCID: PMC6281284 DOI: 10.1371/journal.pone.0207296] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 10/29/2018] [Indexed: 02/03/2023] Open
Abstract
Nemaline Myopathy (NM) is a rare genetic disorder that encompasses a large spectrum of myopathies characterized by hypotonia and generalized muscle weakness. To date, mutations in thirteen different genes have been associated with NM. The most frequently responsible genes are NEB (50% of cases) and ACTA1 (15–25% of cases). In this report all known NM related genes were screened by Next Generation Sequencing in five Spanish patients in order to genetically confirm the clinical and histological diagnosis of NM. Four mutations in NEB (c.17779_17780delTA, c.11086A>C, c.21076C>T and c.2310+5G>A) and one mutation in ACTA1 (c.871A>T) were found in four patients. Three of the four mutations in NEB were novel. A cDNA sequencing assay of the novel variants c.17779_17780delTA, c.11086A>C and c.2310+5G>A revealed that the intronic variant c.2310+5G>A affected the splicing process. Mutations reported here could help clinicians and geneticists in NM diagnosis.
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Affiliation(s)
- Sarah Moreau-Le Lan
- Genomic Unit, Health Research Institute Hospital La Fe (IIS La Fe), Valencia, Spain
| | - Elena Aller
- Genetics Unit, La Fe University Hospital, Valencia, Spain
- Research Group on Molecular, Cellular and Genomic Biomedicine, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
- Biomedical Network Research Center for Rare Diseases (CIBERER), Madrid, Spain
| | - Ines Calabria
- Genomic Unit, Health Research Institute Hospital La Fe (IIS La Fe), Valencia, Spain
| | | | - Cristina Cardona-Gay
- Genomic Unit, Health Research Institute Hospital La Fe (IIS La Fe), Valencia, Spain
| | | | - Maria J. Aparisi
- Genomic Unit, Health Research Institute Hospital La Fe (IIS La Fe), Valencia, Spain
| | - Jorge Selles
- Genomic Unit, Health Research Institute Hospital La Fe (IIS La Fe), Valencia, Spain
| | - Lydia Sagath
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Finland
| | - Inmaculada Pitarch
- Unit of Rare Neuromuscular Diseases, La Fe University Hospital, Valencia, Spain
| | - Nuria Muelas
- Biomedical Network Research Center in Oncology (CIBERONC), Madrid, Spain
- Neuromuscular Diseases Unit, Neurology Department, La Fe University Hospital, Valencia, Spain, and Neuromuscular & Ataxias Research Group, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | - Jose V. Cervera
- Genetics Unit, La Fe University Hospital, Valencia, Spain
- Biomedical Network Research Center in Oncology (CIBERONC), Madrid, Spain
| | - Jose M. Millan
- Genomic Unit, Health Research Institute Hospital La Fe (IIS La Fe), Valencia, Spain
- Research Group on Molecular, Cellular and Genomic Biomedicine, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
- Biomedical Network Research Center for Rare Diseases (CIBERER), Madrid, Spain
| | - Laia Pedrola
- Genomic Unit, Health Research Institute Hospital La Fe (IIS La Fe), Valencia, Spain
- * E-mail:
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18
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Malfatti E. Miopatías congénitas. REVISTA MÉDICA CLÍNICA LAS CONDES 2018. [DOI: 10.1016/j.rmclc.2018.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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19
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Copy Number Variants Account for a Tiny Fraction of Undiagnosed Myopathic Patients. Genes (Basel) 2018; 9:genes9110524. [PMID: 30373198 PMCID: PMC6267442 DOI: 10.3390/genes9110524] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/19/2018] [Accepted: 10/23/2018] [Indexed: 12/26/2022] Open
Abstract
Next-generation sequencing (NGS) technologies have led to an increase in the diagnosis of heterogeneous genetic conditions. However, over 50% of patients with a genetically inherited disease are still without a diagnosis. In these cases, different hypotheses are usually postulated, including variants in novel genes or elusive mutations. Although the impact of copy number variants (CNVs) in neuromuscular disorders has been largely ignored to date, missed CNVs are predicted to have a major role in disease causation as some very large genes, such as the dystrophin gene, have prone-to-deletion regions. Since muscle tissues express several large disease genes, the presence of elusive CNVs needs to be comprehensively assessed following an accurate and systematic approach. In this multicenter cohort study, we analyzed 234 undiagnosed myopathy patients using a custom array comparative genomic hybridization (CGH) that covers all muscle disease genes at high resolution. Twenty-two patients (9.4%) showed non-polymorphic CNVs. In 12 patients (5.1%), the identified CNVs were considered responsible for the observed phenotype. An additional ten patients (4.3%) presented candidate CNVs not yet proven to be causative. Our study indicates that deletions and duplications may account for 5⁻9% of genetically unsolved patients. This strongly suggests that other mechanisms of disease are yet to be discovered.
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Gonorazky HD, Bönnemann CG, Dowling JJ. The genetics of congenital myopathies. HANDBOOK OF CLINICAL NEUROLOGY 2018; 148:549-564. [PMID: 29478600 DOI: 10.1016/b978-0-444-64076-5.00036-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Congenital myopathies are a clinically and genetically heterogeneous group of conditions that most commonly present at or around the time of birth with hypotonia, muscle weakness, and (often) respiratory distress. Historically, this group of disorders has been subclassified based on muscle histopathologic characteristics. There has been an explosion of gene discovery, and there are now at least 32 different genetic causes of disease. With this increased understanding of the genetic basis of disease has come the knowledge that the mutations in congenital myopathy genes can present with a wide variety of clinical phenotypes and can result in a broad spectrum of histopathologic findings on muscle biopsy. In addition, mutations in several genes can share the same histopathologic features. The identification of new genes and interpretation of different pathomechanisms at a molecular level have helped us to understand the clinical and histopathologic similarities that this group of disorders share. In this review, we highlight the genetic understanding for each subtype, its pathogenesis, and the future key issues in congenital myopathies.
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Affiliation(s)
- Hernan D Gonorazky
- Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, United States
| | - James J Dowling
- Division of Neurology and Program of Genetics and Genome Biology, Hospital for Sick Children, Toronto, ON, Canada.
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21
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Finsterer J, Stollberger C. Mutations in genes associated with either myopathy or noncompaction. Herz 2018; 44:756-758. [DOI: 10.1007/s00059-018-4705-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 04/03/2018] [Indexed: 12/26/2022]
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22
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Nilipour Y, Nafissi S, Tjust AE, Ravenscroft G, Hossein Nejad Nedai H, Taylor RL, Varasteh V, Pedrosa Domellöf F, Zangi M, Tonekaboni SH, Olivé M, Kiiski K, Sagath L, Davis MR, Laing NG, Tajsharghi H. Ryanodine receptor type 3 (RYR3) as a novel gene associated with a myopathy with nemaline bodies. Eur J Neurol 2018; 25:841-847. [PMID: 29498452 DOI: 10.1111/ene.13607] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 02/26/2018] [Indexed: 12/01/2022]
Abstract
BACKGROUND AND PURPOSE Nemaline myopathy (NEM) has been associated with mutations in 12 genes to date. However, for some patients diagnosed with NEM, definitive mutations are not identified in the known genes, suggesting that there are other genes involved. This study describes compound heterozygosity for rare variants in ryanodine receptor type 3 (RYR3) gene in one such patient. METHODS AND RESULTS Clinical examination of the patient at 22 years of age revealed a long narrow face, high arched palate and bilateral facial weakness. She had proximal weakness in all four limbs, mild scapular winging but no scoliosis. Muscle biopsy revealed wide variation in fibre size with type 1 fibre predominance and atrophy. Abundant nemaline bodies were located in perinuclear and subsarcolemmal areas, and within the cytoplasm. No likely pathogenic mutations in known NEM genes were identified. Copy number variation in known NEM genes was excluded by NEM-targeted comparative genomic hybridization array. Next-generation sequencing revealed compound heterozygous missense variants in the RYR3 gene. RYR3 transcripts are expressed in human fetal and adult skeletal muscle as well as in human brain and cauda equina samples. Immunofluorescence of human skeletal muscle revealed a 'single-row' appearance of RYR3, interspersed between the 'double rows' of ryanodine receptor type 1 (RYR1) at each A-I junction. CONCLUSION The results suggest that variants in RYR3 may cause a recessive muscle disease with pathological features including nemaline bodies. We characterize the expression pattern of RYR3 in human skeletal muscle and brain, and the subcellular localization of RYR1 and RYR3 in human skeletal muscle.
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Affiliation(s)
- Y Nilipour
- Pediatric Pathology Research Centre, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran
| | - S Nafissi
- Department of Neurology, Tehran University of Medical Sciences, Tehran, Iran
| | - A E Tjust
- Department of Integrative Medical Biology, Umeå University, Umeå.,Department of Clinical Sciences, Umeå University, Umeå, Sweden
| | - G Ravenscroft
- Centre for Medical Research, University of Western Australia and Harry Perkins Institute for Medical Research, Nedlands, WA, Australia
| | | | - R L Taylor
- Centre for Medical Research, University of Western Australia and Harry Perkins Institute for Medical Research, Nedlands, WA, Australia
| | - V Varasteh
- Department of Pathology, Shahid Beheshti University of Medical Sciences, Tehran
| | - F Pedrosa Domellöf
- Department of Integrative Medical Biology, Umeå University, Umeå.,Department of Clinical Sciences, Umeå University, Umeå, Sweden
| | - M Zangi
- Tracheal Diseases Research Center (TDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - S H Tonekaboni
- Pediatric Pathology Research Centre, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran
| | - M Olivé
- Department of Pathology and Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Barcelona, Spain
| | - K Kiiski
- Department of Medical and Clinical Genetics, Folkhälsan Institute of Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - L Sagath
- Department of Medical and Clinical Genetics, Folkhälsan Institute of Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - M R Davis
- Department of Diagnostic Genomics, Pathwest, QEII Medical Centre, Nedlands, WA, Australia
| | - N G Laing
- Centre for Medical Research, University of Western Australia and Harry Perkins Institute for Medical Research, Nedlands, WA, Australia
| | - H Tajsharghi
- Centre for Medical Research, University of Western Australia and Harry Perkins Institute for Medical Research, Nedlands, WA, Australia.,Division of Biomedicine, School of Health and Education, University of Skövde, Skövde, Sweden
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Congenital myopathies: disorders of excitation-contraction coupling and muscle contraction. Nat Rev Neurol 2018; 14:151-167. [PMID: 29391587 DOI: 10.1038/nrneurol.2017.191] [Citation(s) in RCA: 177] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The congenital myopathies are a group of early-onset, non-dystrophic neuromuscular conditions with characteristic muscle biopsy findings, variable severity and a stable or slowly progressive course. Pronounced weakness in axial and proximal muscle groups is a common feature, and involvement of extraocular, cardiorespiratory and/or distal muscles can implicate specific genetic defects. Central core disease (CCD), multi-minicore disease (MmD), centronuclear myopathy (CNM) and nemaline myopathy were among the first congenital myopathies to be reported, and they still represent the main diagnostic categories. However, these entities seem to belong to a much wider phenotypic spectrum. To date, congenital myopathies have been attributed to mutations in over 20 genes, which encode proteins implicated in skeletal muscle Ca2+ homeostasis, excitation-contraction coupling, thin-thick filament assembly and interactions, and other mechanisms. RYR1 mutations are the most frequent genetic cause, and CCD and MmD are the most common subgroups. Next-generation sequencing has vastly improved mutation detection and has enabled the identification of novel genetic backgrounds. At present, management of congenital myopathies is largely supportive, although new therapeutic approaches are reaching the clinical trial stage.
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