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Shammas I, Alhammad R, Naddaf E. Filamin C-Associated Nemaline Myopathy. Neurology 2024; 102:e209477. [PMID: 38657199 DOI: 10.1212/wnl.0000000000209477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Affiliation(s)
- Ibrahim Shammas
- From the Department of Neurology (I.S., E.N.), Mayo Clinic, Rochester, MN; and Department of Internal Medicine (R.A.), College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Reem Alhammad
- From the Department of Neurology (I.S., E.N.), Mayo Clinic, Rochester, MN; and Department of Internal Medicine (R.A.), College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Elie Naddaf
- From the Department of Neurology (I.S., E.N.), Mayo Clinic, Rochester, MN; and Department of Internal Medicine (R.A.), College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Yavaş C, Doğan M, Eröz R, Türegün K. A rare TNNT1 gene variant causing creatine kinase elevation in nemaline myopathy: c.271_273del (p.Lys91del). Genes Genomics 2024; 46:613-620. [PMID: 38363456 DOI: 10.1007/s13258-024-01502-0] [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: 12/01/2023] [Accepted: 02/01/2024] [Indexed: 02/17/2024]
Abstract
BACKGROUND Nemaline Myopathy (NM) is a rare genetic disorder that affects muscle function and is characterized by the presence of nemaline rods in muscle fibers. These rods are abnormal structures that interfere with muscle contraction and can cause muscle weakness, respiratory distress, and other complications. NM is caused by variants in several genes, including TNNT1, which encodes the protein troponin T1. NM is inherited in an autosomal recessive pattern. The prevalence of heterozygous TNNT1 variants has been reported to be 1/152,000, indicating that the disease is relatively rare. OBJECTIVE Investigation of TNNT1 gene variants that may cause cretin kinase elevation. METHODS Detailed family histories and clinical data were recorded. Whole exome sequencing was performed and family segregation was done by Sanger sequencing. RESULTS In this study, we report a 5-year-old girl with a novel variant recessive congenital TNNT1 myopathy. The patient had a novel homozygous (c.271_273del) deletion in the TNNT1 gene that is associated with creatine kinase elevation, which is a marker of muscle damage. CONCLUSION This case expands the phenotypic spectrum of TNNT1 myopathy and highlights the importance of genetic testing and counseling for families affected by this rare disorder. In this study provides valuable insights into the genetic basis of NM and highlights the importance of early diagnosis and management for patients with this rare disorder. Further research is needed to better understand the pathophysiology of TNNT1 myopathy and to develop effective treatments for this debilitating condition.
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Affiliation(s)
- Cüneyd Yavaş
- Department of Molecular Biology and Genetics, Biruni University, Karanfil St. No:1H/12, Beylikduzu, Istanbul, 34100, Turkey.
| | - Mustafa Doğan
- Genetic Diseases Assessment Center, Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey
| | - Recep Eröz
- Department of Medical Genetics Medical Faculty, Aksaray University, Aksaray, Turkey
| | - Kübra Türegün
- Department of Biotechnology, Institute of Science and Technology, Yıldız Technical University, Istanbul, Turkey
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Karimi E, Gohlke J, van der Borgh M, Lindqvist J, Hourani Z, Kolb J, Cossette S, Lawlor MW, Ottenheijm C, Granzier H. Characterization of NEB pathogenic variants in patients reveals novel nemaline myopathy disease mechanisms and omecamtiv mecarbil force effects. Acta Neuropathol 2024; 147:72. [PMID: 38634969 PMCID: PMC11026289 DOI: 10.1007/s00401-024-02726-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/19/2024] [Accepted: 03/26/2024] [Indexed: 04/19/2024]
Abstract
Nebulin, a critical protein of the skeletal muscle thin filament, plays important roles in physiological processes such as regulating thin filament length (TFL), cross-bridge cycling, and myofibril alignment. Pathogenic variants in the nebulin gene (NEB) cause NEB-based nemaline myopathy (NEM2), a genetically heterogeneous disorder characterized by hypotonia and muscle weakness, currently lacking curative therapies. In this study, we examined a cohort of ten NEM2 patients, each with unique pathogenic variants, aiming to understand their impact on mRNA, protein, and functional levels. Results show that pathogenic truncation variants affect NEB mRNA stability and lead to nonsense-mediated decay of the mutated transcript. Moreover, a high incidence of cryptic splice site activation was found in patients with pathogenic splicing variants that are expected to disrupt the actin-binding sites of nebulin. Determination of protein levels revealed patients with either relatively normal or markedly reduced nebulin. We observed a positive relation between the reduction in nebulin and a reduction in TFL, or reduction in tension (both maximal and submaximal tension). Interestingly, our study revealed a pathogenic duplication variant in nebulin that resulted in a four-copy gain in the triplicate region of NEB and a much larger nebulin protein and longer TFL. Additionally, we investigated the effect of Omecamtiv mecarbil (OM), a small-molecule activator of cardiac myosin, on force production of type 1 muscle fibers of NEM2 patients. OM treatment substantially increased submaximal tension across all NEM2 patients ranging from 87 to 318%, with the largest effects in patients with the lowest level of nebulin. In summary, this study indicates that post-transcriptional or post-translational mechanisms regulate nebulin expression. Moreover, we propose that the pathomechanism of NEM2 involves not only shortened but also elongated thin filaments, along with the disruption of actin-binding sites resulting from pathogenic splicing variants. Significantly, our findings highlight the potential of OM treatment to improve skeletal muscle function in NEM2 patients, especially those with large reductions in nebulin levels.
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Affiliation(s)
- Esmat Karimi
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Jochen Gohlke
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Mila van der Borgh
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Johan Lindqvist
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Zaynab Hourani
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Justin Kolb
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Stacy Cossette
- Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Michael W Lawlor
- Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, USA
- Diverge Translational Science Laboratory, Milwaukee, WI, USA
| | - Coen Ottenheijm
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
- Department of Physiology, Amsterdam UMC (Location VUMC), Amsterdam, Netherlands
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA.
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Galli RA, Borsboom TC, Gineste C, Brocca L, Rossi M, Hwee DT, Malik FI, Bottinelli R, Gondin J, Pellegrino MA, de Winter JM, Ottenheijm CA. Tirasemtiv enhances submaximal muscle tension in an Acta1:p.Asp286Gly mouse model of nemaline myopathy. J Gen Physiol 2024; 156:e202313471. [PMID: 38376469 PMCID: PMC10876480 DOI: 10.1085/jgp.202313471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/01/2023] [Accepted: 01/30/2024] [Indexed: 02/21/2024] Open
Abstract
Nemaline myopathies are the most common form of congenital myopathies. Variants in ACTA1 (NEM3) comprise 15-25% of all nemaline myopathy cases. Patients harboring variants in ACTA1 present with a heterogeneous disease course characterized by stable or progressive muscle weakness and, in severe cases, respiratory failure and death. To date, no specific treatments are available. Since NEM3 is an actin-based thin filament disease, we tested the ability of tirasemtiv, a fast skeletal muscle troponin activator, to improve skeletal muscle function in a mouse model of NEM3, harboring the patient-based p.Asp286Gly variant in Acta1. Acute and long-term tirasemtiv treatment significantly increased muscle contractile capacity at submaximal stimulation frequencies in both fast-twitch extensor digitorum longus and gastrocnemius muscle, and intermediate-twitch diaphragm muscle in vitro and in vivo. Additionally, long-term tirasemtiv treatment in NEM3 mice resulted in a decreased respiratory rate with preserved minute volume, suggesting more efficient respiration. Altogether, our data support the therapeutic potential of fast skeletal muscle troponin activators in alleviating skeletal muscle weakness in a mouse model of NEM3 caused by the Acta1:p.Asp286Gly variant.
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Affiliation(s)
- Ricardo A. Galli
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Musculoskeletal Health and Tissue Function and Regeneration, Amsterdam, The Netherlands
| | - Tamara C. Borsboom
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
| | | | - Lorenza Brocca
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Maira Rossi
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Darren T. Hwee
- Research and Early Development, Cytokinetics Inc., South San Francisco, CA, USA
| | - Fady I. Malik
- Research and Early Development, Cytokinetics Inc., South San Francisco, CA, USA
| | - Roberto Bottinelli
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
- IRCCS Mondino Foundation, Pavia, Italy
| | - Julien Gondin
- Aix-Marseille University, CNRS, CRMBM, Marseille, France
- Institut NeuroMyoGène, Unité Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS UMR 5261, INSERM U1315, Université Lyon, Lyon, France
| | | | - Josine M. de Winter
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Musculoskeletal Health and Tissue Function and Regeneration, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands
| | - Coen A.C. Ottenheijm
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Pulmonary Hypertension and Atherosclerosis, Amsterdam, The Netherlands
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
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Nóbrega PR, de Brito de Souza JL, Maurício RB, de Paiva ARB, Dias DA, Camelo CG, Zanotelli E, Schlesinger D, Braga-Neto P, Moreno CAM. Marked neuropsychiatric involvement and dysmorphic features in nemaline myopathy. Neurol Sci 2024; 45:1225-1231. [PMID: 37851294 DOI: 10.1007/s10072-023-07128-6] [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: 04/23/2023] [Accepted: 10/08/2023] [Indexed: 10/19/2023]
Abstract
BACKGROUND Inherited nemaline myopathy is one of the most common congenital myopathies. This genetically heterogeneous disease is defined by the presence of nemaline bodies in muscle biopsy. The phenotypic spectrum is wide and cognitive involvement has been reported, although not extensively evaluated. METHODS We report two nemaline myopathy patients presenting pronounced central nervous system involvement leading to functional compromise and novel facial and skeletal dysmorphic findings, possibly expanding the disease phenotype. RESULTS One patient had two likely pathogenic NEB variants, c.2943G > A and c.8889 + 1G > A, and presented cognitive impairment and dysmorphic features, and the other had one pathogenic variant in ACTA1, c.169G > C (p.Gly57Arg), presenting autism spectrum disorder and corpus callosum atrophy. Both patients had severe cognitive involvement despite milder motor dysfunction. CONCLUSION We raise the need for further studies regarding the role of thin filament proteins in the central nervous system and for a systematic cognitive assessment of congenital myopathy patients.
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Affiliation(s)
- Paulo Ribeiro Nóbrega
- Department of Neurology, Faculdade de Medicina, Universidade Federal do Ceará, R. Alexandre Baraúna, 949, Rodolfo Teófilo, Fortaleza, CE, 60430-160, Brazil.
- Department of Neurology, Faculdade de Medicina, Universidade de São Paulo (FMUSP), Av. Dr. Arnaldo, 455, Cerqueira César, Pacaembu, São Paulo, 01246-903, Brazil.
- Faculty of Medicine, Unichristus University, Rua Vereador Paulo Mamede, 131, Fortaleza, CE, 60160-196, Brazil.
| | - Jorge Luiz de Brito de Souza
- Center of Health Sciences, Universidade Estadual do Ceará, Av. Dr. Silas Munguba, 1700, Itaperi, Fortaleza, CE, 60714-903, Brazil
| | - Rebeca Bessa Maurício
- Center of Health Sciences, Universidade Estadual do Ceará, Av. Dr. Silas Munguba, 1700, Itaperi, Fortaleza, CE, 60714-903, Brazil
| | - Anderson Rodrigues Brandão de Paiva
- Department of Neurology, Faculdade de Medicina, Universidade de São Paulo (FMUSP), Av. Dr. Arnaldo, 455, Cerqueira César, Pacaembu, São Paulo, 01246-903, Brazil
- Mendelics Genomic Analysis, Av. Braz Leme, 1631, Casa Verde, São Paulo, SP, 02511-000, Brazil
| | - Daniel Aguiar Dias
- Department of Radiology, Faculdade de Medicina da Universidade Federal do Ceará, R. Alexandre Baraúna, 949, Rodolfo Teófilo, Fortaleza, CE, 60430-160, Brazil
| | - Clara Gontijo Camelo
- Department of Neurology, Faculdade de Medicina, Universidade de São Paulo (FMUSP), Av. Dr. Arnaldo, 455, Cerqueira César, Pacaembu, São Paulo, 01246-903, Brazil
| | - Edmar Zanotelli
- Department of Neurology, Faculdade de Medicina, Universidade de São Paulo (FMUSP), Av. Dr. Arnaldo, 455, Cerqueira César, Pacaembu, São Paulo, 01246-903, Brazil
| | - David Schlesinger
- Mendelics Genomic Analysis, Av. Braz Leme, 1631, Casa Verde, São Paulo, SP, 02511-000, Brazil
| | - Pedro Braga-Neto
- Department of Neurology, Faculdade de Medicina, Universidade Federal do Ceará, R. Alexandre Baraúna, 949, Rodolfo Teófilo, Fortaleza, CE, 60430-160, Brazil
- Center of Health Sciences, Universidade Estadual do Ceará, Av. Dr. Silas Munguba, 1700, Itaperi, Fortaleza, CE, 60714-903, Brazil
| | - Cristiane Araujo Martins Moreno
- Department of Neurology, Faculdade de Medicina, Universidade de São Paulo (FMUSP), Av. Dr. Arnaldo, 455, Cerqueira César, Pacaembu, São Paulo, 01246-903, Brazil
- Mendelics Genomic Analysis, Av. Braz Leme, 1631, Casa Verde, São Paulo, SP, 02511-000, Brazil
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Buchignani B, Marinella G, Pasquariello R, Sgherri G, Frosini S, Santorelli FM, Orsini A, Battini R, Astrea G. KLHL40-Related Myopathy: A Systematic Review and Insight into a Follow-up Biomarker via a New Case Report. Genes (Basel) 2024; 15:208. [PMID: 38397198 PMCID: PMC10887776 DOI: 10.3390/genes15020208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND Mutations in the KLHL40 gene are a common cause of severe or even lethal nemaline myopathy. Some cases with mild forms have been described, although the cases are still anecdotal. The aim of this paper was to systematically review the cases described in the literature and to describe a 12-year clinical and imaging follow-up in an Italian patient with KLHL40- related myopathy in order to suggest possible follow-up measurements. METHODS Having searched through three electronic databases (PubMed, Scopus, and EBSCO), 18 articles describing 65 patients with homozygous or compound heterozygous KLHL40 mutations were selected. A patient with a KLHL40 homozygous mutation (c.1582G>A/p.E528K) was added and clinical and genetic data were collected. RESULTS The most common mutation identified in our systematic review was the (c.1516A>C) followed by the (c.1582G>A). In our review, 60% percent of the patients died within the first 4 years of life. Clinical features were similar across the sample. Unfortunately, however, there is no record of the natural history data in the surviving patients. The 12-year follow-up of our patient revealed a slow improvement in her clinical course, identifying muscle MRI as the only possible marker of disease progression. CONCLUSIONS Due to its clinical and genotype homogeneity, KLHL40-related myopathy may be a condition that would greatly benefit from the development of new gene therapies; muscle MRI could be a good biomarker to monitor disease progression.
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Affiliation(s)
- Bianca Buchignani
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (B.B.); (G.M.); (R.P.); (G.S.); (S.F.); (G.A.)
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, 56126 Pisa, Italy
| | - Gemma Marinella
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (B.B.); (G.M.); (R.P.); (G.S.); (S.F.); (G.A.)
| | - Rosa Pasquariello
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (B.B.); (G.M.); (R.P.); (G.S.); (S.F.); (G.A.)
| | - Giada Sgherri
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (B.B.); (G.M.); (R.P.); (G.S.); (S.F.); (G.A.)
| | - Silvia Frosini
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (B.B.); (G.M.); (R.P.); (G.S.); (S.F.); (G.A.)
| | | | - Alessandro Orsini
- Pediatric Neurology, Azienda Ospedaliera Universitaria Pisana, 56100 Pisa, Italy;
| | - Roberta Battini
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (B.B.); (G.M.); (R.P.); (G.S.); (S.F.); (G.A.)
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Guja Astrea
- Department of Neuroscience, IRCCS Stella Maris Foundation, 56128 Pisa, Italy; (B.B.); (G.M.); (R.P.); (G.S.); (S.F.); (G.A.)
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Haidong L, Yin L, Ping C, Xianzhao Z, Qi Q, Xiaoli M, Zheng L, Wenhao C, Yaguang Z, Qianqian Q. Clinico-pathological and gene features of 15 nemaline myopathy patients from a single Chinese neuromuscular center. Acta Neurol Belg 2024; 124:91-99. [PMID: 37525074 PMCID: PMC10874337 DOI: 10.1007/s13760-023-02333-8] [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: 04/17/2023] [Accepted: 07/12/2023] [Indexed: 08/02/2023]
Abstract
BACKGROUND Nemaline myopathy, the most common of the congenital myopathies, is caused by various genetic mutations. In this study, we attempted to investigate the clinical features, muscle pathology and genetic features of 15 patients with nemaline myopathy. RESULTS Among the 15 patients, there were 9 (60.00%) males and 6 (40.00%) females, and 9 (60.00%) of them came from three families respectively. The age of seeing a doctor ranged from 9 to 52 years old, the age of onset was from 5 to 23 years old, and the duration of disease ranged from 3 to 35 years. Ten out of the 15 patients had high arched palate and elongated face. Only one patient had mild respiratory muscle involvement and none had dysphagia. Muscle biopsies were performed in 9 out of the 15 patients. Pathologically, muscle fibers of different sizes, atrophic muscle fibers and compensatory hypertrophic fibers could be found, and occasionally degenerated and necrotic muscle fibers were observed. Different degrees of nemaline bodies aggregation could be seen in all 9 patients. The distribution of type I and type II muscle fibers were significantly abnormal in patients with nemaline myopathy caused by NEB gene, however, it was basically normal in patients with nemaline myopathy caused by TPM3 gene and ACTA1 gene. Electron microscopic analysis of 6 patients showed that nemaline bodies aggregated between myofibrils were found in 5(83.33%) cases, and most of them were located near the Z band, but no intranuclear rods were found. The gene analysis of 15 NM patients showed that three NM-related genes were harbored, including 11 (73.33%) patients with NEB, 3 (20.00%) patients with TPM3, and 1 (6.67%) patient with ACTA1, respectively. A total of 12 mutation sites were identified and included 10 (83.33%) mutations in exon and 2(16.67%) mutations in intron. CONCLUSIONS The clinical phenotype of nemaline myopathy is highly heterogeneous. Muscle pathology shows that nemaline bodies aggregation is an important feature for the diagnosis of NM. NEB is the most frequent causative gene in this cohort. The splicing mutation, c.21522 + 3A > G may be the hotspot mutation of the NEB gene in Chinese NM patients.
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Affiliation(s)
- Lv Haidong
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Liu Yin
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei Province, People's Republic of China
| | - Chen Ping
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Zheng Xianzhao
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Qian Qi
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Ma Xiaoli
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Lv Zheng
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Cui Wenhao
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Zhou Yaguang
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Qu Qianqian
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China.
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Wallgren-Pettersson C, Jokela M, Lehtokari VL, Tyynismaa H, Sainio MT, Ylikallio E, Tynninen O, Pelin K, Auranen M. Variants in tropomyosins TPM2 and TPM3 causing muscle hypertonia. Neuromuscul Disord 2024; 35:29-32. [PMID: 38219297 DOI: 10.1016/j.nmd.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/28/2023] [Accepted: 12/11/2023] [Indexed: 01/16/2024]
Abstract
Patients with myopathies caused by pathogenic variants in tropomyosin genes TPM2 and TPM3 usually have muscle hypotonia and weakness, their muscle biopsies often showing fibre size disproportion and nemaline bodies. Here, we describe a series of patients with hypercontractile molecular phenotypes, high muscle tone, and mostly non-specific myopathic biopsy findings without nemaline bodies. Three of the patients had trismus, whilst in one patient, the distal joints of her fingers flexed on extension of the wrists. In one biopsy from a patient with a rare TPM3 pathogenic variant, cores and minicores were observed, an unusual finding in TPM3-caused myopathy. The variants alter conserved contact sites between tropomyosin and actin.
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Affiliation(s)
- Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics, the Folkhälsan Research Center, Helsinki, Finland, and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland.
| | - Manu Jokela
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Vilma-Lotta Lehtokari
- The Folkhälsan Institute of Genetics, the Folkhälsan Research Center, Helsinki, Finland, and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Henna Tyynismaa
- Stem Cells and Metabolism Research Programme, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Markus T Sainio
- Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Emil Ylikallio
- Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Olli Tynninen
- Olli Tynninen, Department of Pathology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Katarina Pelin
- The Folkhälsan Institute of Genetics, the Folkhälsan Research Center, Helsinki, Finland, and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland; Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Mari Auranen
- Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Liu Y, Lin W. Morphological and functional alterations of neuromuscular synapses in a mouse model of ACTA1 congenital myopathy. Hum Mol Genet 2024; 33:233-244. [PMID: 37883471 PMCID: PMC10800017 DOI: 10.1093/hmg/ddad183] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 10/09/2023] [Accepted: 10/20/2023] [Indexed: 10/28/2023] Open
Abstract
Mutations in skeletal muscle α-actin (Acta1) cause myopathies. In a mouse model of congenital myopathy, heterozygous Acta1 (H40Y) knock-in (Acta1+/Ki) mice exhibit features of human nemaline myopathy, including premature lethality, severe muscle weakness, reduced mobility, and the presence of nemaline rods in muscle fibers. In this study, we investigated the impact of Acta1 (H40Y) mutation on the neuromuscular junction (NMJ). We found that the NMJs were markedly fragmented in Acta1+/Ki mice. Electrophysiological analysis revealed a decrease in amplitude but increase in frequency of miniature end-plate potential (mEPP) at the NMJs in Acta1+/Ki mice, compared with those in wild type (Acta1+/+) mice. Evoked end-plate potential (EPP) remained similar at the NMJs in Acta1+/Ki and Acta1+/+ mice, but quantal content was increased at the NMJs in Acta1+/Ki, compared with Acta1+/+ mice, suggesting a homeostatic compensation at the NMJs in Acta1+/Ki mice to maintain normal levels of neurotransmitter release. Furthermore, short-term synaptic plasticity of the NMJs was compromised in Acta1+/Ki mice. Together, these results demonstrate that skeletal Acta1 H40Y mutation, albeit muscle-origin, leads to both morphological and functional defects at the NMJ.
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Affiliation(s)
- Yun Liu
- Department of Neuroscience, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX 75390-9111, United States
| | - Weichun Lin
- Department of Neuroscience, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX 75390-9111, United States
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10
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Lehtokari VL, Sagath L, Davis M, Ho D, Kiiski K, Kettunen K, Demczko M, Stein R, Vatta M, Winder TL, Shohet A, Orenstein N, Krcho P, Bohuš P, Huovinen S, Udd B, Pelin K, Laing NG, Wallgren-Pettersson C. A recurrent ACTA1 amino acid change in mosaic form causes milder asymmetric myopathy. Neuromuscul Disord 2024; 34:32-40. [PMID: 38142473 DOI: 10.1016/j.nmd.2023.11.009] [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: 06/27/2023] [Revised: 10/25/2023] [Accepted: 11/26/2023] [Indexed: 12/26/2023]
Abstract
We describe three patients with asymmetric congenital myopathy without definite nemaline bodies and one patient with severe nemaline myopathy. In all four patients, the phenotype had been caused by pathogenic missense variants in ACTA1 leading to the same amino acid change, p.(Gly247Arg). The three patients with milder myopathy were mosaic for their variants. In contrast, in the severely affected patient, the missense variant was present in a de novo, constitutional form. The grade of mosaicism in the three mosaic patients ranged between 20 % and 40 %. We speculate that the milder clinical and histological manifestations of the same ACTA1 variant in the patients with mosaicism reflect the lower abundance of mutant actin in their muscle tissue. Similarly, the asymmetry of body growth and muscle weakness may be a consequence of the affected cells being unevenly distributed. The partial improvement in muscle strength with age in patients with mosaicism might be due to an increased proportion over time of nuclei carrying and expressing two normal alleles.
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Affiliation(s)
- Vilma-Lotta Lehtokari
- Folkhälsan Research Center, 00290 Helsinki, Finland; Department of Medical and Clinical Genetics, Medicum, 00014 University of Helsinki, Finland.
| | - Lydia Sagath
- Folkhälsan Research Center, 00290 Helsinki, Finland; Department of Medical and Clinical Genetics, Medicum, 00014 University of Helsinki, Finland
| | - Mark Davis
- Department of Diagnostic Genomics, PathWest Laboratory Medicine WA, Nedlands WA 6009, SA
| | - Desiree Ho
- Department of Diagnostic Genomics, PathWest Laboratory Medicine WA, Nedlands WA 6009, SA
| | - Kirsi Kiiski
- Folkhälsan Research Center, 00290 Helsinki, Finland; Laboratory of Genetics, Division of Genetics and Clinical Pharmacology, HUS Diagnostic Center, 00029 Helsinki University Hospital and 00014 University of Helsinki, Helsinki, Finland
| | - Kaisa Kettunen
- Laboratory of Genetics, Division of Genetics and Clinical Pharmacology, HUS Diagnostic Center, 00029 Helsinki University Hospital and 00014 University of Helsinki, Helsinki, Finland
| | - Matthew Demczko
- Division of Diagnostic Referral Services, Nemours Children's Hospital, Wilmington, DE 19803, United States
| | - Riki Stein
- Genetics Unit, Schneider Children's Medical Center, Petach Tikva 4920235, Israel
| | - Matteo Vatta
- Invitae Corporation, San Francisco, CA 94103, United States
| | | | - Adi Shohet
- Genetics Unit, Schneider Children's Medical Center, Petach Tikva 4920235, Israel
| | - Naama Orenstein
- Genetics Unit, Schneider Children's Medical Center, Petach Tikva 4920235, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Peter Krcho
- Department of Neonatology, Pavol Jozef Safarik University, 041 80 Košice, Slovakia
| | - Peter Bohuš
- Department of Pathology, L. Pasteur University Hospital, 040 11 Košice, Slovakia
| | - Sanna Huovinen
- Department of Pathology, Fimlab Laboratories, Tampere University Hospital, 33101 Tampere, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, 00290 Helsinki, Finland; Neuromuscular Research Center, Department of Neurology, Tampere University and University Hospital, 33520 Tampere, Finland; Department of Neurology, Vaasa Central Hospital, 65130 Vaasa, Finland
| | - Katarina Pelin
- Folkhälsan Research Center, 00290 Helsinki, Finland; Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, 00014 University of Helsinki, Finland
| | - Nigel G Laing
- Department of Diagnostic Genomics, PathWest Laboratory Medicine WA, Nedlands WA 6009, SA; Harry Perkins Institute of Medical Research, and University of Western Australia Centre for Medical Research, Nedlands Western Australia 6009, Australia
| | - Carina Wallgren-Pettersson
- Folkhälsan Research Center, 00290 Helsinki, Finland; Department of Medical and Clinical Genetics, Medicum, 00014 University of Helsinki, Finland
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11
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Yu QX, Zhen L, Lin XM, Wen YJ, Li DZ. Clinical and molecular analysis of nine fetal cases with clinically significant variants causing nemaline myopathy. Eur J Obstet Gynecol Reprod Biol 2024; 292:263-266. [PMID: 38071834 DOI: 10.1016/j.ejogrb.2023.12.005] [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: 07/05/2023] [Revised: 11/17/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE To present the prenatal features and postnatal outcomes of pregnancies with fetal nemaline myopathy (NM). STUDY DESIGN This was a retrospective study of nine cases with NM diagnosed by prenatal or postnatal clinical features and confirmed by genetic testing. Clinical and laboratory data were collected and reviewed for these cases, including maternal demographics, prenatal sonographic findings, exome sequencing (ES) results, and pregnancy outcomes. RESULTS All of the nine cases were detected to have NM-causing variants, involving NEB gene in 2 cases, ACTA1 in 3 cases, KLHL40 in 3 cases, and TPM2 in 1 case. Almost all (8/9) had normal first-trimester ultrasound scans except one who had an increased nuchal translucency. Seven (7/9) cases had second-trimester abnormal ultrasounds with fetal akinesia and/or extremity anomalies. Two (2/9) had only third-trimester abnormal ultrasounds with fetal akinesia and polyhydramnios, with one combined with fetal growth restriction. Four pregnancies with a positive prenatal ES were terminated, while five having not receiving prenatal ES continued to term. Only one infant survived 1 year old, and four passed away within 12 months. CONCLUSION Prenatal ultrasound can detect clues that lead to the diagnosis of NM, such as reduced or absent fetal movements, polyhydramnios and extremity anomalies.
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Affiliation(s)
- Qiu-Xia Yu
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center affiliated to Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Li Zhen
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center affiliated to Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Xiao-Mei Lin
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center affiliated to Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yun-Jing Wen
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center affiliated to Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Dong-Zhi Li
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center affiliated to Guangzhou Medical University, Guangzhou, Guangdong, China.
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12
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Goebel HH, Stenzel W. A brief history of the congenital myopathies - the myopathological perspective. Neuromuscul Disord 2023; 33:990-995. [PMID: 37980206 DOI: 10.1016/j.nmd.2023.10.007] [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: 05/15/2023] [Revised: 09/23/2023] [Accepted: 10/13/2023] [Indexed: 11/20/2023]
Abstract
Congenital myopathies are defined by early clinical onset, slow progression, hereditary nature and disease-specific myopathological lesions - however, with exceptions - demanding special techniques in regard to morphological diagnostic and research work-up. To identify an index disease in a family requires a muscle biopsy - and no congenital myopathy has ever been first described at autopsy. The nosographic history commenced when - in addition to special histopathological techniques in the earliest classical triad of central core disease, 1956, nemaline myopathy, 1963, and centronuclear myopathy, 1966/67, within a decade - electron microscopy and enzyme histochemistry were applied to unfixed frozen muscle tissue and, thus, revolutionized diagnostic and research myopathology. During the following years, the list of structure-defined congenital myopathies grew to some 40 conditions. Then, the introduction of immunohistochemistry allowed myopathological documentation of proteins and their abnormalities in individual congenital myopathies. Together with the diagnostic evolution of molecular genetics, many more congenital myopathies were described, without new disease-specific lesions or only already known ones. These were nosographically defined by individual mutations in hitherto congenital myopathies-unrelated genes. This latter development may also affect the nomenclature of congenital myopathies in that the mutant gene needs to be attached to the individually identified congenital myopathies with or without the disease-specific lesion, such as CCD-RYR1 or CM-RYR1. This principle is similar to that of the nomenclature of Congenital Disorders of Glycosylation. Retroactive molecular characterization of originally and first described congenital myopathies has only rarely been achieved.
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Affiliation(s)
- Hans H Goebel
- Institute of Neuropathology, Charite Universitätsmedizin, Berlin, Germany; Department of Neuropathology, Universitätsmedizin, Mainz, Germany.
| | - Werner Stenzel
- Institute of Neuropathology, Charite Universitätsmedizin, Berlin, Germany
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13
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Schultz LE, Colpan M, Smith GE, Mayfield RM, Larrinaga TM, Kostyukova AS, Gregorio CC. A nemaline myopathy-linked mutation inhibits the actin-regulatory functions of tropomodulin and leiomodin. Proc Natl Acad Sci U S A 2023; 120:e2315820120. [PMID: 37956287 PMCID: PMC10665800 DOI: 10.1073/pnas.2315820120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 10/06/2023] [Indexed: 11/15/2023] Open
Abstract
Actin is a highly expressed protein in eukaryotic cells and is essential for numerous cellular processes. In particular, efficient striated muscle contraction is dependent upon the precise regulation of actin-based thin filament structure and function. Alterations in the lengths of actin-thin filaments can lead to the development of myopathies. Leiomodins and tropomodulins are members of an actin-binding protein family that fine-tune thin filament lengths, and their dysfunction is implicated in muscle diseases. An Lmod3 mutation [G326R] was previously identified in patients with nemaline myopathy (NM), a severe skeletal muscle disorder; this residue is conserved among Lmod and Tmod isoforms and resides within their homologous leucine-rich repeat (LRR) domain. We mutated this glycine to arginine in Lmod and Tmod to determine the physiological function of this residue and domain. This G-to-R substitution disrupts Lmod and Tmod's LRR domain structure, altering their binding interface with actin and destroying their abilities to regulate thin filament lengths. Additionally, this mutation renders Lmod3 nonfunctional in vivo. We found that one single amino acid is essential for folding of Lmod and Tmod LRR domains, and thus is essential for the opposing actin-regulatory functions of Lmod (filament elongation) and Tmod (filament shortening), revealing a mechanism underlying the development of NM.
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Affiliation(s)
- Lauren E. Schultz
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ85724
| | - Mert Colpan
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ85724
| | - Garry E. Smith
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA99164
| | - Rachel M. Mayfield
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ85724
| | - Tania M. Larrinaga
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ85724
| | - Alla S. Kostyukova
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA99164
| | - Carol C. Gregorio
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ85724
- Department of Medicine, Cardiovascular Research Institute, Icahn School of Medicine, New York, NY10029
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14
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Robaszkiewicz K, Siatkowska M, Wadman RI, Kamsteeg EJ, Chen Z, Merve A, Parton M, Bugiardini E, de Bie C, Moraczewska J. A Novel Variant in TPM3 Causing Muscle Weakness and Concomitant Hypercontractile Phenotype. Int J Mol Sci 2023; 24:16147. [PMID: 38003336 PMCID: PMC10671854 DOI: 10.3390/ijms242216147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 10/31/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
A novel variant of unknown significance c.8A > G (p.Glu3Gly) in TPM3 was detected in two unrelated families. TPM3 encodes the transcript variant Tpm3.12 (NM_152263.4), the tropomyosin isoform specifically expressed in slow skeletal muscle fibers. The patients presented with slowly progressive muscle weakness associated with Achilles tendon contractures of early childhood onset. Histopathology revealed features consistent with a nemaline rod myopathy. Biochemical in vitro assays performed with reconstituted thin filaments revealed defects in the assembly of the thin filament and regulation of actin-myosin interactions. The substitution p.Glu3Gly increased polymerization of Tpm3.12, but did not significantly change its affinity to actin alone. Affinity of Tpm3.12 to actin in the presence of troponin ± Ca2+ was decreased by the mutation, which was due to reduced interactions with troponin. Altered molecular interactions affected Ca2+-dependent regulation of the thin filament interactions with myosin, resulting in increased Ca2+ sensitivity and decreased relaxation of the actin-activated myosin ATPase activity. The hypercontractile molecular phenotype probably explains the distal joint contractions observed in the patients, but additional research is needed to explain the relatively mild severity of the contractures. The slowly progressive muscle weakness is most likely caused by the lack of relaxation and prolonged contractions which cause muscle wasting. This work provides evidence for the pathogenicity of the TPM3 c.8A > G variant, which allows for its classification as (likely) pathogenic.
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Affiliation(s)
- Katarzyna Robaszkiewicz
- Department of Biochemistry and Cell Biology, Kazimierz Wielki University, 85-671 Bydgoszcz, Poland; (K.R.); (M.S.)
| | - Małgorzata Siatkowska
- Department of Biochemistry and Cell Biology, Kazimierz Wielki University, 85-671 Bydgoszcz, Poland; (K.R.); (M.S.)
| | - Renske I. Wadman
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, 3584 CX Utrecht, The Netherlands;
| | - Erik-Jan Kamsteeg
- Department of Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Zhiyong Chen
- Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology, The National Hospital for Neurology, London WC1N 3BG, UK; (Z.C.); (M.P.); (E.B.)
- Department of Neurology, National Neuroscience Institute, Singapore 308433, Singapore
| | - Ashirwad Merve
- Department of Neuropathology, UCL Queen Square Institute of Neurology, The National Hospital for Neurology, London WC1N 3BG, UK;
| | - Matthew Parton
- Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology, The National Hospital for Neurology, London WC1N 3BG, UK; (Z.C.); (M.P.); (E.B.)
| | - Enrico Bugiardini
- Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology, The National Hospital for Neurology, London WC1N 3BG, UK; (Z.C.); (M.P.); (E.B.)
| | - Charlotte de Bie
- Department of Genetics, University Medical Utrecht, 3584 CX Utrecht, The Netherlands;
| | - Joanna Moraczewska
- Department of Biochemistry and Cell Biology, Kazimierz Wielki University, 85-671 Bydgoszcz, Poland; (K.R.); (M.S.)
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15
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Nicolau S, Milone M. Sporadic Late-Onset Nemaline Myopathy: Current Landscape. Curr Neurol Neurosci Rep 2023; 23:777-784. [PMID: 37856049 DOI: 10.1007/s11910-023-01311-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2023] [Indexed: 10/20/2023]
Abstract
PURPOSE OF REVIEW Sporadic late-onset nemaline myopathy (SLONM) is a rare adult-onset, acquired, muscle disease that can be associated with monoclonal gammopathy or HIV infection. The pathological hallmark of SLONM is the accumulation of nemaline rods in muscle fibers. We review here current knowledge about its presentation, pathophysiology, and management. RECENT FINDINGS SLONM usually manifests with subacutely progressive proximal and axial weakness, but it can also present with chronic progressive weakness mimicking muscular dystrophy. The pathophysiology of the disease remains poorly understood, with evidence pointing to both autoimmune mechanisms and hematological neoplasia. Recent studies have identified histological, proteomic, and transcriptomic alterations that shed light on disease mechanisms and distinguish SLONM from inherited nemaline myopathies. A majority of SLONM patients respond to intravenous immunoglobulins, chemotherapy, or hematopoietic stem cell transplant. SLONM is a treatable myopathy, although its underlying etiology and pathomechanisms remain unclear. A high degree of suspicion should be maintained for this disease to reduce diagnostic delay and treatment in SLONM and facilitate its distinction from inherited nemaline myopathies.
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Affiliation(s)
- Stefan Nicolau
- Center for Gene Therapy, Nationwide Children's Hospital, Columbus, OH, USA
| | - Margherita Milone
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
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16
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Haghighi A, Alvandi Z, Nilipour Y, Haghighi A, Kornreich R, Nafissi S, Desnick RJ. Nemaline myopathy: reclassification of previously reported variants according to ACMG guidelines, and report of novel genetic variants. Eur J Hum Genet 2023; 31:1237-1250. [PMID: 37460656 PMCID: PMC10620380 DOI: 10.1038/s41431-023-01378-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 12/11/2022] [Accepted: 04/26/2023] [Indexed: 11/03/2023] Open
Abstract
Nemaline myopathy (NM) is a heterogeneous genetic neuromuscular disorder characterized by rod bodies in muscle fibers resulting in multiple complications due to muscle weakness. NM patients and their families could benefit from genetic analysis for early diagnosis, carrier and prenatal testing; however, clinical classification of variants is subject to change as further information becomes available. Reclassification can significantly alter the clinical management of patients and their families. We used the newly published data and ACMG/AMP guidelines to reassess NM-associated variants previously reported by clinical laboratories (ClinVar). Our analyses on rare variants that were not canonical loss-of-function (LOF) resulted in the downgrading of ~29% (28/97) of variants from pathogenic or likely-pathogenic (P/LP) to variants of uncertain significance (VUS). In addition, we analyzed the splicing effect of variants identified in NM patients by clinical laboratories or research, using an accurate in silico prediction tool that applies a deep-learning network. We identified 55 rare variants that may impact splicing (cryptic splicing). We also analyzed six new NM families and identified eight variants in NEB and ACTA1, including three novel variants: homozygous pathogenic c.164A > G (p.Tyr55Cys), and homozygous likely pathogenic c.980T > C (p.Met327Thr) in ACTA1, and heterozygous VUS c.18694-3T > G in NEB. This study demonstrates the importance of reclassifying variants to facilitate more definitive "calls" on causality or no causality in clinical genetic testing of patients with NM. Reclassification of ~150 variants is now available for improved clinical management, risk counseling and screening of NM patients.
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Affiliation(s)
- Alireza Haghighi
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA.
- Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA, 02115, USA.
- The Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.
| | - Zahra Alvandi
- Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
- Vascular Biology Program, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Yalda Nilipour
- Pediatric Pathology Research Center, Research Institute for Children's Health, and Mofid Children Hospital, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amirreza Haghighi
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Ruth Kornreich
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Shahriar Nafissi
- Department of Neurology, Neuromuscular Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Robert J Desnick
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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17
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Lindqvist J, Granzier H. Pharmacological Inhibition of Myostatin in a Mouse Model of Typical Nemaline Myopathy Increases Muscle Size and Force. Int J Mol Sci 2023; 24:15124. [PMID: 37894805 PMCID: PMC10606666 DOI: 10.3390/ijms242015124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/27/2023] [Accepted: 10/03/2023] [Indexed: 10/29/2023] Open
Abstract
Nemaline myopathy is one of the most common non-dystrophic congenital myopathies. Individuals affected by this condition experience muscle weakness and muscle smallness, often requiring supportive measures like wheelchairs or respiratory support. A significant proportion of patients, approximately one-third, exhibit compound heterozygous nebulin mutations, which usually give rise to the typical form of the disease. Currently, there are no approved treatments available for nemaline myopathy. Our research explored the modulation of myostatin, a negative regulator of muscle mass, in combating the muscle smallness associated with the disease. To investigate the effect of myostatin inhibition, we employed a mouse model with compound heterozygous nebulin mutations that mimic the typical form of the disease. The mice were treated with mRK35, a myostatin antibody, through weekly intraperitoneal injections of 10 mg/kg mRK35, commencing at two weeks of age and continuing until the mice reached four months of age. The treatment resulted in an increase in body weight and an approximate 20% muscle weight gain across most skeletal muscles, without affecting the heart. The minimum Feret diameter of type IIA and IIB fibers exhibited an increase in compound heterozygous mice, while only type IIB fibers demonstrated an increase in wild-type mice. In vitro mechanical experiments conducted on intact extensor digitorum longus muscle revealed that mRK35 augmented the physiological cross-sectional area of muscle fibers and enhanced absolute tetanic force in both wild-type and compound heterozygous mice. Furthermore, mRK35 administration improved grip strength in treated mice. Collectively, these findings indicate that inhibiting myostatin can mitigate the muscle deficits in nebulin-based typical nemaline myopathy, potentially serving as a much-needed therapeutic option.
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Affiliation(s)
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, USA;
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18
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Tinklenberg JA, Slick RA, Sutton J, Zhang L, Meng H, Beatka MJ, Vanden Avond M, Prom MJ, Ott E, Montanaro F, Heisner J, Toro R, Hardeman EC, Geurts AM, Stowe DF, Hill RB, Lawlor MW. Different Mouse Models of Nemaline Myopathy Harboring Acta1 Mutations Display Differing Abnormalities Related to Mitochondrial Biology. Am J Pathol 2023; 193:1548-1567. [PMID: 37419385 PMCID: PMC10548277 DOI: 10.1016/j.ajpath.2023.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 06/20/2023] [Accepted: 06/23/2023] [Indexed: 07/09/2023]
Abstract
ACTA1 encodes skeletal muscle-specific α-actin, which polymerizes to form the thin filament of the sarcomere. Mutations in ACTA1 are responsible for approximately 30% of nemaline myopathy (NM) cases. Previous studies of weakness in NM have focused on muscle structure and contractility, but genetic issues alone do not explain the phenotypic heterogeneity observed in patients with NM or NM mouse models. To identify additional biological processes related to NM phenotypic severity, proteomic analysis was performed using muscle protein isolates from wild-type mice in comparison to moderately affected knock-in (KI) Acta1H40Y and the minimally affected transgenic (Tg) ACTA1D286G NM mice. This analysis revealed abnormalities in mitochondrial function and stress-related pathways in both mouse models, supporting an in-depth assessment of mitochondrial biology. Interestingly, evaluating each model in comparison to its wild-type counterpart identified different degrees of mitochondrial abnormality that correlated well with the phenotypic severity of the mouse model. Muscle histology, mitochondrial respiration, electron transport chain function, and mitochondrial transmembrane potential were all normal or minimally affected in the TgACTA1D286G mouse model. In contrast, the more severely affected KI.Acta1H40Y mice displayed significant abnormalities in relation to muscle histology, mitochondrial respirometry, ATP, ADP, and phosphate content, and mitochondrial transmembrane potential. These findings suggest that abnormal energy metabolism is related to symptomatic severity in NM and may constitute a contributor to phenotypic variability and a novel treatment target.
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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, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Clinical and Translational Science Institute, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Rebecca A Slick
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Clinical and Translational Science Institute, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jessica Sutton
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Liwen Zhang
- Mass Spectrometry and Proteomics Facility, Campus Chemical Instrument Center, The Ohio State University, Columbus, Ohio
| | - Hui Meng
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Margaret J Beatka
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Mark Vanden Avond
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Mariah J Prom
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Emily Ott
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Federica Montanaro
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neuroscience Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom; NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - James Heisner
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Rafael Toro
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Edna C Hardeman
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - David F Stowe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - R Blake Hill
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Michael W Lawlor
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.
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19
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Slick RA, Tinklenberg JA, Sutton J, Zhang L, Meng H, Beatka MJ, Vanden Avond M, Prom MJ, Ott E, Montanaro F, Heisner J, Toro R, Granzier H, Geurts AM, Stowe DF, Hill RB, Lawlor MW. Aberrations in Energetic Metabolism and Stress-Related Pathways Contribute to Pathophysiology in the Neb Conditional Knockout Mouse Model of Nemaline Myopathy. Am J Pathol 2023; 193:1528-1547. [PMID: 37422147 PMCID: PMC10548278 DOI: 10.1016/j.ajpath.2023.06.009] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 05/08/2023] [Accepted: 06/08/2023] [Indexed: 07/10/2023]
Abstract
Nemaline myopathy (NM) is a genetically and clinically heterogeneous disease that is diagnosed on the basis of the presence of nemaline rods on skeletal muscle biopsy. Although NM has typically been classified by causative genes, disease severity or prognosis cannot be predicted. The common pathologic end point of nemaline rods (despite diverse genetic causes) and an unexplained range of muscle weakness suggest that shared secondary processes contribute to the pathogenesis of NM. We speculated that these processes could be identified through a proteome-wide interrogation using a mouse model of severe NM in combination with pathway validation and structural/functional analyses. A proteomic analysis was performed using skeletal muscle tissue from the Neb conditional knockout mouse model compared with its wild-type counterpart to identify pathophysiologically relevant biological processes that might impact disease severity or provide new treatment targets. A differential expression analysis and Ingenuity Pathway Core Analysis predicted perturbations in several cellular processes, including mitochondrial dysfunction and changes in energetic metabolism and stress-related pathways. Subsequent structural and functional studies demonstrated abnormal mitochondrial distribution, decreased mitochondrial respiratory function, an increase in mitochondrial transmembrane potential, and extremely low ATP content in Neb conditional knockout muscles relative to wild type. Overall, the findings of these studies support a role for severe mitochondrial dysfunction as a novel contributor to muscle weakness in NM.
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Affiliation(s)
- Rebecca A Slick
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Clinical and Translational Science Institute, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jennifer A Tinklenberg
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Clinical and Translational Science Institute, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jessica Sutton
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Liwen Zhang
- Mass Spectrometry and Proteomics Facility, Campus Chemical Instrument Center, The Ohio State University, Columbus, Ohio
| | - Hui Meng
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Margaret J Beatka
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Mark Vanden Avond
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Mariah J Prom
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Emily Ott
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Federica Montanaro
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neuroscience Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom the NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom; NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
| | - James Heisner
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Rafael Toro
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Henk Granzier
- College of Medicine, University of Arizona, Tucson, Arizona
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - David F Stowe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin; Joint Department of Biomedical Engineering, Medical College of Wisconsin and Marquette University, Milwaukee, Wisconsin
| | - R Blake Hill
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Michael W Lawlor
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.
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20
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Dofash LNH, Monahan GV, Servián-Morilla E, Rivas E, Faiz F, Sullivan P, Oates E, Clayton J, Taylor RL, Davis MR, Beilharz T, Laing NG, Cabrera-Serrano M, Ravenscroft G. A KLHL40 3' UTR splice-altering variant causes milder NEM8, an under-appreciated disease mechanism. Hum Mol Genet 2023; 32:1127-1136. [PMID: 36322148 DOI: 10.1093/hmg/ddac272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 10/04/2022] [Accepted: 10/29/2022] [Indexed: 12/23/2022] Open
Abstract
Nemaline myopathy 8 (NEM8) is typically a severe autosomal recessive disorder associated with variants in the kelch-like family member 40 gene (KLHL40). Common features include fetal akinesia, fractures, contractures, dysphagia, respiratory failure and neonatal death. Here, we describe a 26-year-old man with relatively mild NEM8. He presented with hypotonia and bilateral femur fractures at birth, later developing bilateral Achilles' contractures, scoliosis, and elbow and knee contractures. He had walking difficulties throughout childhood and became wheelchair bound from age 13 after prolonged immobilization. Muscle magnetic resonance imaging at age 13 indicated prominent fat replacement in his pelvic girdle, posterior compartments of thighs and vastus intermedius. Muscle biopsy revealed nemaline bodies and intranuclear rods. RNA sequencing and western blotting of patient skeletal muscle indicated significant reduction in KLHL40 mRNA and protein, respectively. Using gene panel screening, exome sequencing and RNA sequencing, we identified compound heterozygous variants in KLHL40; a truncating 10.9 kb deletion in trans with a likely pathogenic variant (c.*152G > T) in the 3' untranslated region (UTR). Computational tools SpliceAI and Introme predicted the c.*152G > T variant created a cryptic donor splice site. RNA-seq and in vitro analyses indicated that the c.*152G > T variant induces multiple de novo splicing events that likely provoke nonsense mediated decay of KLHL40 mRNA explaining the loss of mRNA expression and protein abundance in the patient. Analysis of 3' UTR variants in ClinVar suggests variants that introduce aberrant 3' UTR splicing may be underrecognized in Mendelian disease. We encourage consideration of this mechanism during variant curation.
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Affiliation(s)
- Lein N H Dofash
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, WA 6009, Australia
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6102, Australia
| | - Gavin V Monahan
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, WA 6009, Australia
| | - Emilia Servián-Morilla
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, Sevilla 41013, Spain
| | - Eloy Rivas
- Department of Pathology, Hospital Universitario Virgen del Rocío Sevilla, Sevilla 41013, Spain
| | - Fathimath Faiz
- Diagnostic Genomics, PathWest, Nedlands, WA 6009, Australia
| | - Patricia Sullivan
- Children's Cancer Institute, Lowy Cancer Centre, UNSW Sydney, Kensington, NSW 2052, Australia
| | - Emily Oates
- School of Biotechnology & Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2033, Australia
| | - Joshua Clayton
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, WA 6009, Australia
| | - Rhonda L Taylor
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, WA 6009, Australia
| | - Mark R Davis
- Diagnostic Genomics, PathWest, Nedlands, WA 6009, Australia
| | - Traude Beilharz
- Development and Stem Cells Program, Department of Biochemistry & Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton 3800 Victoria, Australia
| | - Nigel G Laing
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, WA 6009, Australia
| | - Macarena Cabrera-Serrano
- Department of Neurology, Neuromuscular Unit and Instituto de Biomedicina de Sevilla/CSIC, Hospital Universitario Virgen del Rocío, Sevilla 41013, Spain
| | - Gianina Ravenscroft
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, WA 6009, Australia
- School of Biomedical Sciences, University of Western Australia, Nedlands, WA 6009, Australia
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21
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Gartz M, Haberman M, Sutton J, Slick RA, Luttrell SM, Mack DL, Lawlor MW. ACTA1 H40Y mutant iPSC-derived skeletal myocytes display mitochondrial defects in an in vitro model of nemaline myopathy. Exp Cell Res 2023; 424:113507. [PMID: 36796746 PMCID: PMC9993434 DOI: 10.1016/j.yexcr.2023.113507] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/16/2023]
Abstract
Nemaline myopathies (NM) are a group of congenital myopathies that lead to muscle weakness and dysfunction. While 13 genes have been identified to cause NM, over 50% of these genetic defects are due to mutations in nebulin (NEB) and skeletal muscle actin (ACTA1), which are genes required for normal assembly and function of the thin filament. NM can be distinguished on muscle biopsies due to the presence of nemaline rods, which are thought to be aggregates of the dysfunctional protein. Mutations in ACTA1 have been associated with more severe clinical disease and muscle weakness. However, the cellular pathogenesis linking ACTA1 gene mutations to muscle weakness are unclear To evaluate cellular disease phenotypes, iPSC-derived skeletal myocytes (iSkM) harboring an ACTA1 H40Y point mutation were used to model NM in skeletal muscle. These were generated by Crispr-Cas9, and include one non-affected healthy control (C) and 2 NM iPSC clone lines, therefore representing isogenic controls. Fully differentiated iSkM were characterized to confirm myogenic status and subject to assays to evaluate nemaline rod formation, mitochondrial membrane potential, mitochondrial permeability transition pore (mPTP) formation, superoxide production, ATP/ADP/phosphate levels and lactate dehydrogenase release. C- and NM-iSkM demonstrated myogenic commitment as evidenced by mRNA expression of Pax3, Pax7, MyoD, Myf5 and Myogenin; and protein expression of Pax4, Pax7, MyoD and MF20. No nemaline rods were observed with immunofluorescent staining of NM-iSkM for ACTA1 or ACTN2, and these mRNA transcript and protein levels were comparable to C-iSkM. Mitochondrial function was altered in NM, as evidenced by decreased cellular ATP levels and altered mitochondrial membrane potential. Oxidative stress induction revealed the mitochondrial phenotype, as evidenced by collapsed mitochondrial membrane potential, early formation of the mPTP and increased superoxide production. Early mPTP formation was rescued with the addition of ATP to media. Together, these findings suggest that mitochondrial dysfunction and oxidative stress are disease phenotypes in the in vitro model of ACTA1 nemaline myopathy, and that modulation of ATP levels was sufficient to protect NM-iSkM mitochondria from stress-induced injury. Importantly, the nemaline rod phenotype was absent in our in vitro model of NM. We conclude that this in vitro model has the potential to recapitulate human NM disease phenotypes, and warrants further study.
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Affiliation(s)
- Melanie Gartz
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA; Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, USA.
| | - Margaret Haberman
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, USA; Diverge Translational Science Laboratory, Milwaukee, WI, USA
| | - Jessica Sutton
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, USA; Diverge Translational Science Laboratory, Milwaukee, WI, USA
| | - Rebecca A Slick
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Shawn M Luttrell
- Curi Bio Inc., 3000 Western Avenue, Seattle, WA, 98121, USA; Institute for Stem Cell and Regenerative Medicine, UW Medicine, Seattle, WA, USA
| | - David L Mack
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA; Institute for Stem Cell and Regenerative Medicine, UW Medicine, Seattle, WA, USA
| | - Michael W Lawlor
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA; Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, USA; Diverge Translational Science Laboratory, Milwaukee, WI, USA
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22
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Pelin K, Sagath L, Lehtonen J, Kiiski K, Tynninen O, Paetau A, Johari M, Savarese M, Wallgren-Pettersson C, Lehtokari VL. Novel Compound Heterozygous Splice-Site Variants in TPM3 Revealed by RNA Sequencing in a Patient with an Unusual Form of Nemaline Myopathy: A Case Report. J Neuromuscul Dis 2023; 10:977-984. [PMID: 37393515 PMCID: PMC10578209 DOI: 10.3233/jnd-230026] [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] [Accepted: 06/08/2023] [Indexed: 07/03/2023]
Abstract
BACKGROUND Pathogenic variants in the TPM3 gene, encoding slow skeletal muscle α-tropomyosin account for less than 5% of nemaline myopathy cases. Dominantly inherited or de novo missense variants in TPM3 are more common than recessive loss-of-function variants. The recessive variants reported to date seem to affect either the 5' or the 3' end of the skeletal muscle-specific TPM3 transcript. OBJECTIVES The aim of the study was to identify the disease-causing gene and variants in a Finnish patient with an unusual form of nemaline myopathy. METHODS The genetic analyses included Sanger sequencing, whole-exome sequencing, targeted array-CGH, and linked-read whole genome sequencing. RNA sequencing was done on total RNA extracted from cultured myoblasts and myotubes of the patient and controls. TPM3 protein expression was assessed by Western blot analysis. The diagnostic muscle biopsy was analyzed by routine histopathological methods. RESULTS The patient had poor head control and failure to thrive, but no hypomimia, and his upper limbs were clearly weaker than his lower limbs, features which in combination with the histopathology suggested TPM3-caused nemaline myopathy. Muscle histopathology showed increased fiber size variation and numerous nemaline bodies predominantly in small type 1 fibers. The patient was found to be compound heterozygous for two splice-site variants in intron 1a of TPM3: NM_152263.4:c.117+2_5delTAGG, deleting the donor splice site of intron 1a, and NM_152263.4:c.117 + 164 C>T, which activates an acceptor splice site preceding a non-coding exon in intron 1a. RNA sequencing revealed inclusion of intron 1a and the non-coding exon in the transcripts, resulting in early premature stop codons. Western blot using patient myoblasts revealed markedly reduced levels of the TPM3 protein. CONCLUSIONS Novel biallelic splice-site variants were shown to markedly reduce TPM3 protein expression. The effects of the variants on splicing were readily revealed by RNA sequencing, demonstrating the power of the method.
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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
- Folkhälsan Research Center, Helsinki, Finland
| | - Lydia Sagath
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Johanna Lehtonen
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- Centre for Molecular Medicine Norway (NCMM), University of Oslo, Oslo, Norway
| | - Kirsi Kiiski
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Laboratory of Genetics, HUS Diagnostic Centre, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Olli Tynninen
- Department of Pathology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Anders Paetau
- Department of Pathology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Mridul Johari
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, WA, Australia
| | - Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Carina Wallgren-Pettersson
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Vilma-Lotta Lehtokari
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
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23
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Abstract
The congenital myopathies are inherited muscle disorders characterized clinically by hypotonia and weakness, usually from birth, with a static or slowly progressive clinical course. Historically, the congenital myopathies have been classified according to major morphological features seen on muscle biopsy as nemaline myopathy, central core disease, centronuclear or myotubular myopathy, and congenital fiber type disproportion. However, in the past two decades, the genetic basis of these different forms of congenital myopathy has been further elucidated with the result being improved correlation with histological and genetic characteristics. However, these notions have been challenged for three reasons. First, many of the congenital myopathies can be caused by mutations in more than one gene that suggests an impact of genetic heterogeneity. Second, mutations in the same gene can cause different muscle pathologies. Third, the same genetic mutation may lead to different pathological features in members of the same family or in the same individual at different ages. This chapter provides a clinical overview of the congenital myopathies and a clinically useful guide to its genetic basis recognizing the increasing reliance of exome, subexome, and genome sequencing studies as first-line analysis in many patients.
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Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
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24
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Bevilacqua JA, Contreras JP, Trangulao A, Hernández Ú, Brochier G, Díaz J, Hughes R, Campero M, Romero NB. Novel autosomal dominant TPM3 mutation causes a combined congenital fibre type disproportion-cap disease histological pattern. Neuromuscul Disord 2022; 32:687-691. [PMID: 35688744 DOI: 10.1016/j.nmd.2022.05.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 12/09/2021] [Revised: 04/16/2022] [Accepted: 05/26/2022] [Indexed: 11/17/2022]
Abstract
Tropomyosin 3 (TPM3) gene mutations associate with autosomal dominant and recessive nemaline myopathy 1 (NEM1), congenital fiber type disproportion myopathy (CFTD) and cap myopathy (CAPM1), and a combination of caps and nemaline bodies. We report on a 47-year-old man with polyglobulia, restricted vital capacity and mild apnea hypopnea syndrome, requiring noninvasive ventilation. Physical assessment revealed bilateral ptosis and facial paresis, with high arched palate and retrognathia; global hypotonia and diffuse axial weakness, including neck and upper and lower limb girdle and foot dorsiflexion weakness. Whole body MRI showed a diffuse fatty replacement with an unspecific pattern. A 122 gene NGS neuromuscular disorders panel revealed the heterozygous VUS c.709G>A (p.Glu237Lys) on exon 8 of TMP3. A deltoid muscle biopsy showed a novel histological pattern combining fiber type disproportion and caps. Our findings support the pathogenicity of the novel TPM3 variant and widen the phenotypic gamut of TMP3-related congenital myopathy.
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Affiliation(s)
- Jorge A Bevilacqua
- Unidad Neuromuscular, Departamento Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Santiago, Chile; Departamento de Anatomía y Medicina Legal, Facultad de Medicina, Universidad de Chile. Santiago, Chile; Unidad de Patología Neuromuscular, Departamento de Neurología y Neurocirugía, Clínica Dávila, Santiago, Chile.
| | - Juan Pablo Contreras
- Unidad Neuromuscular, Departamento Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Santiago, Chile; Departamento de Especialidades, Facultad de Medicina, Universidad de Concepción, Concepción, Chile; Servicio Neurología, Hospital Clínico Regional de Concepción: "Dr. Guillermo Grant Benavente", Concepción, Chile
| | - Alejandra Trangulao
- Departamento de Anatomía y Medicina Legal, Facultad de Medicina, Universidad de Chile. Santiago, Chile; Unidad de Patología Neuromuscular, Departamento de Neurología y Neurocirugía, Clínica Dávila, Santiago, Chile
| | - Úrsula Hernández
- Unidad Neuromuscular, Departamento Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Santiago, Chile; Equipo de Neurología, Servicio de Medicina. Hospital San Juan de Dios La Serena, La Serena, Chile
| | - Guy Brochier
- Unité Morphologie Neuromusculaire, Institut de Myologie, GHU Pitié-Salpêtrière, Paris, France
| | - Jorge Díaz
- Centro de Imagenología, Hospital Clínico Universidad de Chile, Santiago, Chile
| | - Ricardo Hughes
- Unidad Neuromuscular, Departamento Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Santiago, Chile
| | - Mario Campero
- Unidad Neuromuscular, Departamento Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Santiago, Chile
| | - Norma B Romero
- Unité Morphologie Neuromusculaire, Institut de Myologie, GHU Pitié-Salpêtrière, Paris, France
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25
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Ito M, Shima S, Nagao R, Nakano S, Esaka K, Ueda A, Maeda S, Moriya R, Kondo M, Imaizumi K, Noda S, Katsuno M, Nishino I, Watanabe H. Nemaline Myopathy Initially Diagnosed as Right Heart Failure with Type 2 Respiratory Failure. Intern Med 2022; 61:1897-1901. [PMID: 34776486 PMCID: PMC9259818 DOI: 10.2169/internalmedicine.8314-21] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nemaline myopathy (NM) is a rare muscle disease with various clinical types. In some cases, NM can lead to type 2 respiratory failure and right heart failure. We herein report a patient with congenital NM with nebulin gene mutation who presented with acute right heart failure and type 2 respiratory failure due to respiratory muscle paralysis after upper respiratory tract infection, needing a permanent ventilator for assistance. However, the limb and trunk muscle strengths were within normal limits. This case showed that NM should be considered as a cause of right heart failure and type 2 respiratory failure.
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Affiliation(s)
- Mizuki Ito
- Department of Neurology, Fujita Health University School of Medicine, Japan
- Department of Neurology, Fujita Health University Bantane Hospital, Japan
| | - Sayuri Shima
- Department of Neurology, Fujita Health University School of Medicine, Japan
| | - Ryunosuke Nagao
- Department of Neurology, Fujita Health University School of Medicine, Japan
| | - Shoko Nakano
- Department of Neurology, Fujita Health University School of Medicine, Japan
| | - Konoka Esaka
- Department of Neurology, Fujita Health University School of Medicine, Japan
| | - Akihiro Ueda
- Department of Neurology, Fujita Health University School of Medicine, Japan
| | - Shingo Maeda
- Department of Respiratory Medicine, Fujita Health University School of Medicine, Japan
| | - Ryoma Moriya
- Department of Respiratory Medicine, Fujita Health University School of Medicine, Japan
| | - Masashi Kondo
- Department of Respiratory Medicine, Fujita Health University School of Medicine, Japan
| | - Kazuyoshi Imaizumi
- Department of Respiratory Medicine, Fujita Health University School of Medicine, Japan
| | - Seiya Noda
- Department of Neurology, Nagoya University Graduate School of Medicine, Japan
- Department of Neurology, National Hospital Organization Suzuka Hospital, Japan
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Japan
| | - Hirohisa Watanabe
- Department of Neurology, Fujita Health University School of Medicine, Japan
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26
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Sagath L, Lehtokari VL, Wallgren-Pettersson C, Pelin K, Kiiski K. A custom ddPCR method for the detection of copy number variations in the nebulin triplicate region. PLoS One 2022; 17:e0267793. [PMID: 35576196 PMCID: PMC9109913 DOI: 10.1371/journal.pone.0267793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 04/15/2022] [Indexed: 11/21/2022] Open
Abstract
The human genome contains repetitive regions, such as segmental duplications, known to be prone to copy number variation. Segmental duplications are highly identical and homologous sequences, posing a specific challenge for most mutation detection methods. The giant nebulin gene is expressed in skeletal muscle. It harbors a large segmental duplication region composed of eight exons repeated three times, the so-called triplicate region. Mutations in nebulin are known to cause nemaline myopathy and other congenital myopathies. Using our custom targeted Comparative Genomic Hybridization arrays, we have previously shown that copy number variations in the nebulin triplicate region are pathogenic when the copy number of the segmental duplication block deviates two or more copies from the normal number, which is three per allele. To complement our Comparative Genomic Hybridization arrays, we have established a custom Droplet Digital PCR method for the detection of copy number variations within the nebulin triplicate region. The custom Droplet Digital PCR assays allow sensitive, rapid, high-throughput, and cost-effective detection of copy number variations within this region and is ready for implementation a screening method for disease-causing copy number variations of the nebulin triplicate region. We suggest that Droplet Digital PCR may also be used in the study and diagnostics of other segmental duplication regions of the genome.
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Affiliation(s)
- Lydia Sagath
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- * E-mail: , (LS); (KK)
| | - Vilma-Lotta Lehtokari
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Carina Wallgren-Pettersson
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Katarina Pelin
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Kirsi Kiiski
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- * E-mail: , (LS); (KK)
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27
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Wang Z, Grange M, Pospich S, Wagner T, Kho AL, Gautel M, Raunser S. Structures from intact myofibrils reveal mechanism of thin filament regulation through nebulin. Science 2022; 375:eabn1934. [PMID: 35175800 DOI: 10.1126/science.abn1934] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In skeletal muscle, nebulin stabilizes and regulates the length of thin filaments, but the underlying mechanism remains nebulous. In this work, we used cryo-electron tomography and subtomogram averaging to reveal structures of native nebulin bound to thin filaments within intact sarcomeres. This in situ reconstruction provided high-resolution details of the interaction between nebulin and actin, demonstrating the stabilizing role of nebulin. Myosin bound to the thin filaments exhibited different conformations of the neck domain, highlighting its inherent structural variability in muscle. Unexpectedly, nebulin did not interact with myosin or tropomyosin, but it did interact with a troponin T linker through two potential binding motifs on nebulin, explaining its regulatory role. Our structures support the role of nebulin as a thin filament "molecular ruler" and provide a molecular basis for studying nemaline myopathies.
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Affiliation(s)
- Zhexin Wang
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Michael Grange
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Sabrina Pospich
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Thorsten Wagner
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Centre of Research Excellence, Guy's Campus, London SE1 1UL, UK
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, Kings College London BHF Centre of Research Excellence, Guy's Campus, London SE1 1UL, UK
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
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28
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Yang L, Mu X, Shen Q, Zhang D, Xu Y. Novel deletion in the ACTA1 gene associated with milder phenotype of nemaline myopathy in Chinese patient: a case report. Neurol Sci 2021; 42:5401-5405. [PMID: 34596777 DOI: 10.1007/s10072-021-05625-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/23/2021] [Indexed: 02/05/2023]
Affiliation(s)
- Li Yang
- Department of Neurology, West China Hospital, Sichuan University, Sichuan Province, Chengdu, 610041, China
| | - Xin Mu
- Department of Neurology, Chengdu First People's Hospital, NO. 18 Wanxiang North Road, Chengdu, 610041, China
| | - Qiuyan Shen
- Department of Neurology, West China Hospital, Sichuan University, Sichuan Province, Chengdu, 610041, China
| | - Dan Zhang
- Department of Neurology, West China Hospital, Sichuan University, Sichuan Province, Chengdu, 610041, China
| | - Yanming Xu
- Department of Neurology, West China Hospital, Sichuan University, Sichuan Province, Chengdu, 610041, China.
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29
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Abstract
The nemaline myopathies constitute a large proportion of the congenital or structural myopathies. Common to all patients is muscle weakness and the presence in the muscle biopsy of nemaline rods. The causative genes are at least twelve, encoding structural or regulatory proteins of the thin filament, and the clinical picture as well as the histological appearance on muscle biopsy vary widely. Here, we suggest a renewed clinical classification to replace the original one, summarise what is known about the pathogenesis from mutations in each causative gene to the forms of nemaline myopathy described to date, and provide perspectives on pathogenetic mechanisms possibly open to therapeutic modalities.
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Affiliation(s)
- Jenni Laitila
- The Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland; Department of Biomedical Sciences, University of Copenhagen, Denmark.
| | - Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland
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30
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de Winter JM, Gineste C, Minardi E, Brocca L, Rossi M, Borsboom T, Beggs AH, Bernard M, Bendahan D, Hwee DT, Malik FI, Pellegrino MA, Bottinelli R, Gondin J, Ottenheijm CAC. Acute and chronic tirasemtiv treatment improves in vivo and in vitro muscle performance in actin-based nemaline myopathy mice. Hum Mol Genet 2021; 30:1305-1320. [PMID: 33909041 PMCID: PMC8255131 DOI: 10.1093/hmg/ddab112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/09/2021] [Accepted: 04/07/2021] [Indexed: 12/13/2022] Open
Abstract
Nemaline myopathy, a disease of the actin-based thin filament, is one of the most frequent congenital myopathies. To date, no specific therapy is available to treat muscle weakness in nemaline myopathy. We tested the ability of tirasemtiv, a fast skeletal troponin activator that targets the thin filament, to augment muscle force—both in vivo and in vitro—in a nemaline myopathy mouse model with a mutation (H40Y) in Acta1. In Acta1H40Y mice, treatment with tirasemtiv increased the force response of muscles to submaximal stimulation frequencies. This resulted in a reduced energetic cost of force generation, which increases the force production during a fatigue protocol. The inotropic effects of tirasemtiv were present in locomotor muscles and, albeit to a lesser extent, in respiratory muscles, and they persisted during chronic treatment, an important finding as respiratory failure is the main cause of death in patients with congenital myopathy. Finally, translational studies on permeabilized muscle fibers isolated from a biopsy of a patient with the ACTA1H40Y mutation revealed that at physiological Ca2+ concentrations, tirasemtiv increased force generation to values that were close to those generated in muscle fibers of healthy subjects. These findings indicate the therapeutic potential of fast skeletal muscle troponin activators to improve muscle function in nemaline myopathy due to the ACTA1H40Y mutation, and future studies should assess their merit for other forms of nemaline myopathy and for other congenital myopathies.
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Affiliation(s)
| | | | | | - Lorenza Brocca
- Department of Molecular Medicine, University of Pavia, Pavia 27100, Italy
| | - Maira Rossi
- Department of Molecular Medicine, University of Pavia, Pavia 27100, Italy
| | - Tamara Borsboom
- Department of Physiology, Amsterdam UMC (location VUmc), Amsterdam 1081 HV, The Netherlands
| | - Alan H Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Monique Bernard
- Aix-Marseille Univ, CNRS, CRMBM, UMR 7339, 13005 Marseille, France
| | - David Bendahan
- Aix-Marseille Univ, CNRS, CRMBM, UMR 7339, 13005 Marseille, France
| | - Darren T Hwee
- Research and Early Development, Cytokinetics Inc., South San Francisco, CA 94080, USA
| | - Fady I Malik
- Research and Early Development, Cytokinetics Inc., South San Francisco, CA 94080, USA
| | - Maria Antonietta Pellegrino
- Department of Molecular Medicine, University of Pavia, Pavia 27100, Italy
- Interdipartimental Centre for Biology and Sport Medicine, University of Pavia, Pavia 27100, Italy
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31
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Clayton JS, Scriba CK, Romero NB, Malfatti E, Saker S, Larmonier T, Nowak KJ, Ravenscroft G, Laing NG, Taylor RL. Generation of two isogenic induced pluripotent stem cell lines from a 4-month-old severe nemaline myopathy patient with a heterozygous dominant c.553C > A (p.Arg183Ser) variant in the ACTA1 gene. Stem Cell Res 2021; 53:102273. [PMID: 33740643 DOI: 10.1016/j.scr.2021.102273] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 02/22/2021] [Indexed: 11/19/2022] Open
Abstract
Nemaline myopathy (NM) is a congenital myopathy typically characterized by skeletal muscle weakness and the presence of abnormal thread- or rod-like structures (nemaline bodies) in myofibres. Pathogenic variants in the skeletal muscle alpha actin gene, ACTA1, cause approximately 25% of all NM cases. We generated two induced pluripotent stem cell lines from lymphoblastoid cells of a 4-month-old female with severe NM harbouring a dominant variant in ACTA1 (c.553C > A). The isogenic lines displayed characteristic iPSC morphology, expressed pluripotency markers, differentiated into cells of all three germ layers, and possessed normal karyotypes. These lines could be useful models of human ACTA1 disease.
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Affiliation(s)
- Joshua S Clayton
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia; Centre for Medical Research, University of Western Australia, QEII Medical Centre, Nedlands, WA, Australia.
| | - Carolin K Scriba
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia; Centre for Medical Research, University of Western Australia, QEII Medical Centre, Nedlands, WA, Australia; Neurogenetics Laboratory, Department of Diagnostic Genomics, PP Block, QEII Medical Centre, Nedlands, WA, Australia
| | - Norma B Romero
- Sorbonne Université, Myology Institute, Neuromuscular Morphology Unit, Center for Research in Myology, GH Pitié-Salpêtrière, Paris, France; Centre de Référence de Pathologie Neuromusculaire Paris-Est, GHU Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Edoardo Malfatti
- Reference center for Neuromuscular disorders, Henri Mondor teaching hospital, University of Versailles-Paris Saclay, France
| | - Safaa Saker
- Genethon, DNA and Cell bank, 91000 Evry, France
| | | | - Kristen J Nowak
- Centre for Medical Research, University of Western Australia, QEII Medical Centre, Nedlands, WA, Australia; Office of Population Health Genomics, Public and Aboriginal Health Division, Western Australian Department of Health, East Perth, WA, Australia; Faculty of Health and Medical Sciences, School of Biomedical Sciences, University of Western Australia, QEII Medical Centre, Nedlands, WA, Australia
| | - Gianina Ravenscroft
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia; Centre for Medical Research, University of Western Australia, QEII Medical Centre, Nedlands, WA, Australia
| | - Nigel G Laing
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia; Centre for Medical Research, University of Western Australia, QEII Medical Centre, Nedlands, WA, Australia
| | - Rhonda L Taylor
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia; Centre for Medical Research, University of Western Australia, QEII Medical Centre, Nedlands, WA, Australia
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32
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Rocha ML, Dittmayer C, Uruha A, Korinth D, Chaoui R, Schlembach D, Rossi R, Pelin K, Suk EK, Schmid S, Goebel HH, Schuelke M, Stenzel W, Englert B. A novel mutation in NEB causing foetal nemaline myopathy with arthrogryposis during early gestation. Neuromuscul Disord 2020; 31:239-245. [PMID: 33376055 DOI: 10.1016/j.nmd.2020.11.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [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: 08/21/2020] [Revised: 11/27/2020] [Accepted: 11/30/2020] [Indexed: 12/24/2022]
Abstract
Nemaline myopathies are a clinically and genetically heterogeneous group of congenital myopathies, mainly characterized by muscle weakness, hypotonia and respiratory insufficiency. Here, we report a male foetus of consanguineous parents with a severe congenital syndrome characterized by arthrogryposis detected at 13 weeks of gestation. We describe severe complex dysmorphic facial and musculoskeletal features by post mortem fetal examination confirming the prenatal diagnosis. Histomorphological and ultrastructural studies of skeletal muscle reveal mini-rods in myotubes caused by a novel homozygous splice-site mutation in NEB (NM_001164508, chr2:g.152,417,623C>A GRCh37.p11 | c.19,102-1G>T ENST00000397345.3). No rods were seen in the myocardium. We discuss the relevance of this mutation in the context of nemaline myopathies associated with early developmental musculoskeletal disorders.
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Affiliation(s)
- Maria L Rocha
- Department of Pathology, Vivantes Friedrichshain Hospital, Vivantes Hospital Group, Charité Academic Teaching Hospital, Berlin, Germany
| | - Carsten Dittmayer
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Akinori Uruha
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Dirk Korinth
- Private practice of Human Genetics, Berlin, Germany and Private practice of Human Genetics and Molecular Pathology, Rostock, Germany
| | - Rabih Chaoui
- Center for Prenatal Diagnosis-Friedrichstrasse, Berlin, Germany
| | - Dietmar Schlembach
- Clinic for Obstetric Medicine and Center for Prenatal Medicine, Vivantes Neukölln Hospital, Vivantes Hospital Group, Charité Academic Teaching Hospital, Berlin, Germany
| | - Rainer Rossi
- Department of Paediatrics, Vivantes Neukölln Hospital, Vivantes Hospital Group, Charité Academic Teaching Hospital, Berlin, Germany
| | - Katarina Pelin
- Folkhälsan Research Center, Folkhälsan Institute of Genetics, Biomedicum, Helsinki, Finland; Department of Medical and Clinical Genetics, Biomedicum, University of Helsinki, Helsinki, Finland; Faculty of Biological and EnviroNEMental Sciences, Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Eun Kyung Suk
- Private practice of Human Genetics, Berlin, Germany and Private practice of Human Genetics and Molecular Pathology, Rostock, Germany
| | - Simone Schmid
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Hans H Goebel
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany; Department of Neuropathology, Universitätsmedizin Mainz, Germany
| | - Markus Schuelke
- Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Werner Stenzel
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany.
| | - Benjamin Englert
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany; Center for Neuropathology and Prion Research, Ludwig-Maximilians-Universität Munich, Munich, Germany
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33
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de Winter JM, Molenaar JP, Yuen M, van der Pijl R, Shen S, Conijn S, van de Locht M, Willigenburg M, Bogaards SJ, van Kleef ES, Lassche S, Persson M, Rassier DE, Sztal TE, Ruparelia AA, Oorschot V, Ramm G, Hall TE, Xiong Z, Johnson CN, Li F, Kiss B, Lozano-Vidal N, Boon RA, Marabita M, Nogara L, Blaauw B, Rodenburg RJ, Küsters B, Doorduin J, Beggs AH, Granzier H, Campbell K, Ma W, Irving T, Malfatti E, Romero NB, Bryson-Richardson RJ, van Engelen BG, Voermans NC, Ottenheijm CA. KBTBD13 is an actin-binding protein that modulates muscle kinetics. J Clin Invest 2020; 130:754-767. [PMID: 31671076 PMCID: PMC6994151 DOI: 10.1172/jci124000] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/24/2019] [Indexed: 11/17/2022] Open
Abstract
The mechanisms that modulate the kinetics of muscle relaxation are critically important for muscle function. A prime example of the impact of impaired relaxation kinetics is nemaline myopathy caused by mutations in KBTBD13 (NEM6). In addition to weakness, NEM6 patients have slow muscle relaxation, compromising contractility and daily life activities. The role of KBTBD13 in muscle is unknown, and the pathomechanism underlying NEM6 is undetermined. A combination of transcranial magnetic stimulation-induced muscle relaxation, muscle fiber- and sarcomere-contractility assays, low-angle x-ray diffraction, and superresolution microscopy revealed that the impaired muscle-relaxation kinetics in NEM6 patients are caused by structural changes in the thin filament, a sarcomeric microstructure. Using homology modeling and binding and contractility assays with recombinant KBTBD13, Kbtbd13-knockout and Kbtbd13R408C-knockin mouse models, and a GFP-labeled Kbtbd13-transgenic zebrafish model, we discovered that KBTBD13 binds to actin - a major constituent of the thin filament - and that mutations in KBTBD13 cause structural changes impairing muscle-relaxation kinetics. We propose that this actin-based impaired relaxation is central to NEM6 pathology.
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Affiliation(s)
| | - Joery P. Molenaar
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Neurology, Rijnstate Hospital, Arnhem, Netherlands
| | - Michaela Yuen
- Department of Physiology, Amsterdam University Medical Center, Netherlands
- Discipline of Paediatrics and Child Health, Faculty of Medicine, University of Sydney, Australia
| | - Robbert van der Pijl
- Department of Physiology, Amsterdam University Medical Center, Netherlands
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Shengyi Shen
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Stefan Conijn
- Department of Physiology, Amsterdam University Medical Center, Netherlands
| | | | - Menne Willigenburg
- Department of Physiology, Amsterdam University Medical Center, Netherlands
| | | | - Esmee S.B. van Kleef
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Saskia Lassche
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Malin Persson
- Department of Kinesiology and Physical Education, McGill University, Montreal, Canada
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Dilson E. Rassier
- Department of Kinesiology and Physical Education, McGill University, Montreal, Canada
| | - Tamar E. Sztal
- School of Biological Sciences, Monash University, Melbourne, Australia
| | | | - Viola Oorschot
- Monash Ramaciotti Centre for Structural Cryo-Electron Microscopy, Monash University, Melbourne, Australia
| | - Georg Ramm
- Monash Ramaciotti Centre for Structural Cryo-Electron Microscopy, Monash University, Melbourne, Australia
- Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Thomas E. Hall
- Institute for Molecular Bioscience, University of Queensland, Queensland, Australia
| | - Zherui Xiong
- Institute for Molecular Bioscience, University of Queensland, Queensland, Australia
| | - Christopher N. Johnson
- Division of Clinical Pharmacology, Center for Arrhythmia Research and Therapeutics and Center for Structural Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Frank Li
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Balazs Kiss
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | | | - Reinier A. Boon
- Department of Physiology, Amsterdam University Medical Center, Netherlands
| | - Manuela Marabita
- Venetian Institute of Molecular Medicine, Department of Biomedical Sciences, University of Padova, Italy
| | - Leonardo Nogara
- Venetian Institute of Molecular Medicine, Department of Biomedical Sciences, University of Padova, Italy
| | - Bert Blaauw
- Venetian Institute of Molecular Medicine, Department of Biomedical Sciences, University of Padova, Italy
| | - Richard J. Rodenburg
- Department of Pediatrics, Radboud University Medical Centre, Translational Metabolic Laboratory, Nijmegen, Netherlands
| | - Benno Küsters
- Department of Pathology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Jonne Doorduin
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Alan H. Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Ken Campbell
- Department of Physiology and Division of Cardiovascular Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Weikang Ma
- BioCAT, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Thomas Irving
- BioCAT, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Edoardo Malfatti
- Service Neurologie Médicale, Centre de Référence Maladies Neuromusculaire Paris-Nord CHU Raymond-Poincaré, U1179 UVSQ-INSERM Handicap Neuromusculaire: Physiologie, Biothérapie et Pharmacologie Appliquées, UFR des Sciences de la Santé Simone Veil, Université Versailles-Saint-Quentin-en-Yvelines, Garches, France
| | - Norma B. Romero
- Sorbonne Université, Myology Institute, Neuromuscular Morphology Unit, Center for Research in Myology, GH Pitié-Salpêtrière Paris, France
- Centre de Référence de Pathologie Neuromusculaire Paris-Est, GHU Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | | | - Baziel G.M. van Engelen
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Nicol C. Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Coen A.C. Ottenheijm
- Department of Physiology, Amsterdam University Medical Center, Netherlands
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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35
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Lindqvist J, Lee EJ, Karimi E, Kolb J, Granzier H. Omecamtiv mecarbil lowers the contractile deficit in a mouse model of nebulin-based nemaline myopathy. PLoS One 2019; 14:e0224467. [PMID: 31721788 PMCID: PMC6853306 DOI: 10.1371/journal.pone.0224467] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 10/14/2019] [Indexed: 01/10/2023] Open
Abstract
Nemaline myopathy (NEM) is a congenital neuromuscular disorder primarily caused by nebulin gene (NEB) mutations. NEM is characterized by muscle weakness for which currently no treatments exist. In NEM patients a predominance of type I fibers has been found. Thus, therapeutic options targeting type I fibers could be highly beneficial for NEM patients. Because type I muscle fibers express the same myosin isoform as cardiac muscle (Myh7), the effect of omecamtiv mecarbil (OM), a small molecule activator of Myh7, was studied in a nebulin-based NEM mouse model (Neb cKO). Skinned single fibers were activated by exogenous calcium and force was measured at a wide range of calcium concentrations. Maximal specific force of type I fibers was much less in fibers from Neb cKO animals and calcium sensitivity of permeabilized single fibers was reduced (pCa50 6.12 ±0.08 (cKO) vs 6.36 ±0.08 (CON)). OM increased the calcium sensitivity of type I single muscle fibers. The greatest effect occurred in type I fibers from Neb cKO muscle where OM restored the calcium sensitivity to that of the control type I fibers. Forces at submaximal activation levels (pCa 6.0–6.5) were significantly increased in Neb cKO fibers (~50%) but remained below that of control fibers. OM also increased isometric force and power during isotonic shortening of intact whole soleus muscle of Neb cKO mice, with the largest effects at physiological stimulation frequencies. We conclude that OM has the potential to improve the quality of life of NEM patients by increasing the force of type I fibers at submaximal activation levels.
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Affiliation(s)
- Johan Lindqvist
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, United States of America
| | - Eun-Jeong Lee
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, United States of America
| | - Esmat Karimi
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, United States of America
| | - Justin Kolb
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, United States of America
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, United States of America
- * E-mail:
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Oki K, Wei B, Feng HZ, Jin JP. The loss of slow skeletal muscle isoform of troponin T in spindle intrafusal fibres explains the pathophysiology of Amish nemaline myopathy. J Physiol 2019; 597:3999-4012. [PMID: 31148174 PMCID: PMC6675633 DOI: 10.1113/jp278119] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/29/2019] [Indexed: 01/17/2023] Open
Abstract
KEY POINTS The pathogenic mechanism and the neuromuscular reflex-related phenotype (e.g. tremors accompanied by clonus) of Amish nemaline myopathy, as well as of other recessively inherited TNNT1 myopathies, remain to be clarified. The truncated slow skeletal muscle isoform of troponin T (ssTnT) encoded by the mutant TNNT1 gene is unable to incorporate into myofilaments and is degraded in muscle cells. By contrast to extrafusal muscle fibres, spindle intrafusal fibres of normal mice contain a significant level of cardiac TnT and a low molecular weight splice form of ssTnT. Intrafusal fibres of ssTnT-knockout mice have significantly increased cardiac TnT. Rotarod and balance beam tests have revealed abnormal neuromuscular co-ordination in ssTnT-knockout mice and a blunted response to a spindle sensitizer, succinylcholine. The loss of ssTnT and a compensatory increase of cardiac TnT in intrafusal nuclear bag fibres may increase myofilament Ca2+ -sensitivity and tension, impairing spindle function, thus identifying a novel mechanism for the development of targeted treatment. ABSTRACT A nonsense mutation at codon Glu180 of TNNT1 gene causes Amish nemaline myopathy (ANM), a recessively inherited disease with infantile lethality. TNNT1 encodes the slow skeletal muscle isoform of troponin T (ssTnT). The truncated ssTnT is unable to incorporate into myofilament and is degraded in muscle cells. The symptoms of ANM include muscle weakness, atrophy, contracture and tremors accompanied by clonus. An ssTnT-knockout (KO) mouse model recapitulates key features of ANM such as atrophy of extrafusal slow muscle fibres and increased fatigability. However, the neuromuscular reflex-related symptoms of ANM have not been explained. By isolating muscle spindles from ssTnT-KO and control mice aiming to examine the composition of myofilament proteins, we found that, in contrast to extrafusal fibres, intrafusal fibres contain a significant level of cardiac TnT and the low molecular weight splice form of ssTnT. Intrafusal fibres from ssTnT-KO mice have significantly increased cardiac TnT. Rotarod and balance beam tests revealed impaired neuromuscular co-ordination in ssTnT-KO mice, indicating abnormality in spindle functions. Unlike the wild-type control, the beam running ability of ssTnT-KO mice had a blunted response to a spindle sensitizer, succinylcholine. Immunohistochemistry detected ssTnT and cardiac TnT in nuclear bag fibres, whereas fast skeletal muscle TnT was detected in nuclear chain fibres, and cardiac α-myosin was present in one of the two nuclear bag fibres. The loss of ssTnT and a compensatory increase of cardiac TnT in nuclear bag fibres would increase myofilament Ca2+ -sensitivity and tension, thus affecting spindle activities. This mechanism provides an explanation for the pathophysiology of ANM, as well as a novel target for treatment.
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Affiliation(s)
| | | | - Han-Zhong Feng
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - J.-P. Jin
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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37
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Abstract
Nemaline myopathy (NM) is among the most common non-dystrophic congenital myopathies (incidence 1:50.000). Hallmark features of NM are skeletal muscle weakness and the presence of nemaline bodies in the muscle fiber. The clinical phenotype of NM patients is quite diverse, ranging from neonatal death to normal lifespan with almost normal motor function. As the respiratory muscles are involved as well, severely affected patients are ventilator-dependent. The mechanisms underlying muscle weakness in NM are currently poorly understood. Therefore, no therapeutic treatment is available yet. Eleven implicated genes have been identified: ten genes encode proteins that are either components of thin filament, or are thought to contribute to stability or turnover of thin filament proteins. The thin filament is a major constituent of the sarcomere, the smallest contractile unit in muscle. It is at this level of contraction – thin-thick filament interaction – where muscle weakness originates in NM patients. This review focusses on how sarcomeric gene mutations directly compromise sarcomere function in NM. Insight into the contribution of sarcomeric dysfunction to muscle weakness in NM, across the genes involved, will direct towards the development of targeted therapeutic strategies.
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Affiliation(s)
| | - Coen A.C. Ottenheijm
- Correspondence to: Coen Ottenheijm, PhD, Department of Physiology, VU University Medical Center, O|2 building, 12W-51, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands. Tel.: +31 20 4448123; Fax: +31 20 4448124; E-mail:
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Blondelle J, Tallapaka K, Seto JT, Ghassemian M, Clark M, Laitila JM, Bournazos A, Singer JD, Lange S. Cullin-3 dependent deregulation of ACTN1 represents a new pathogenic mechanism in nemaline myopathy. JCI Insight 2019; 5:125665. [PMID: 30990797 PMCID: PMC6542616 DOI: 10.1172/jci.insight.125665] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 04/11/2019] [Indexed: 12/11/2022] Open
Abstract
Nemaline myopathy is a congenital neuromuscular disorder characterized by muscle weakness, fiber atrophy and presence of nemaline bodies within myofibers. However, the understanding of underlying pathomechanisms is lacking. Recently, mutations in KBTBD13, KLHL40 and KLHL41, three substrate adaptors for the E3-ubiquitin ligase Cullin-3, have been associated with early-onset nemaline myopathies. We hypothesized that deregulation of Cullin-3 and its muscle protein substrates may be responsible for the disease development. Using Cullin-3 knockout mice, we identified accumulation of non-muscle alpha-Actinins (ACTN1 and ACTN4) in muscles of these mice, which we also observed in KBTBD13 patients. Our data reveal that proper regulation of Cullin-3 activity and ACTN1 levels is essential for normal muscle and neuromuscular junction development. While ACTN1 is naturally downregulated during myogenesis, its overexpression in C2C12 myoblasts triggered defects in fusion, myogenesis and acetylcholine receptor clustering; features that we characterized in Cullin-3 deficient mice. Taken together, our data highlight the importance for Cullin-3 mediated degradation of ACTN1 for muscle development, and indicate a new pathomechanism for the etiology of myopathies seen in Cullin-3 knockout mice and nemaline myopathy patients.
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Affiliation(s)
- Jordan Blondelle
- Division of Cardiology, School of Medicine, UCSD, La Jolla, California, USA
| | - Kavya Tallapaka
- Division of Cardiology, School of Medicine, UCSD, La Jolla, California, USA
| | - Jane T. Seto
- Neuromuscular Research, Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Majid Ghassemian
- Department of Chemistry and Biochemistry. UCSD, La Jolla, California, USA
| | - Madison Clark
- Division of Cardiology, School of Medicine, UCSD, La Jolla, California, USA
| | - Jenni M. Laitila
- Folkhälsan Research Center and Medicum, University of Helsinki, Helsinki, Finland
| | - Adam Bournazos
- Kids Neuroscience Centre, Kids Research, Children’s Hospital at Westmead, Sydney, New South Wales, Australia
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Jeffrey D. Singer
- Department of Biology, Portland State University, Portland, Oregon, USA
| | - Stephan Lange
- Division of Cardiology, School of Medicine, UCSD, La Jolla, California, USA
- Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
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Fox MD, Carson VJ, Feng HZ, Lawlor MW, Gray JT, Brigatti KW, Jin JP, Strauss KA. TNNT1 nemaline myopathy: natural history and therapeutic frontier. Hum Mol Genet 2019; 27:3272-3282. [PMID: 29931346 DOI: 10.1093/hmg/ddy233] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/06/2018] [Indexed: 02/03/2023] Open
Abstract
We describe the natural history of 'Amish' nemaline myopathy (ANM), an infantile-onset, lethal disease linked to a pathogenic c.505G>T nonsense mutation of TNNT1, which encodes the slow fiber isoform of troponin T (TNNT1; a.k.a. TnT). The TNNT1 c.505G>T allele has a carrier frequency of 6.5% within Old Order Amish settlements of North America. We collected natural history data for 106 ANM patients born between 1923 and 2017. Over the last two decades, mean age of molecular diagnosis was 16 ± 27 days. TNNT1 c.505G>T homozygotes were normal weight at birth but failed to thrive by age 9 months. Presenting neonatal signs were axial hypotonia, hip and shoulder stiffness, and tremors, followed by progressive muscle weakness, atrophy and contractures. Affected children developed thoracic rigidity, pectus carinatum and restrictive lung disease during infancy, and all succumbed to respiratory failure by 6 years of age (median survival 18 months, range 0.2-66 months). Muscle histology from two affected children showed marked fiber size variation owing to both Type 1 myofiber smallness (hypotrophy) and Type 2 fiber hypertrophy, with evidence of nemaline rods, myofibrillar disarray and vacuolar pathology in both fiber types. The truncated slow TNNT1 (TnT) fragment (p.Glu180Ter) was undetectable in ANM muscle, reflecting its rapid proteolysis and clearance from sarcoplasm. Similar functional and histological phenotypes were observed in other human cohorts and two transgenic murine models (Tnnt1-/- and Tnnt1 c.505G>T). These findings have implications for emerging molecular therapies, including the suitably of TNNT1 gene replacement for newborns with ANM or other TNNT1-associated myopathies.
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Affiliation(s)
- Michael D Fox
- Clinic for Special Children, Strasburg, PA, USA
- Department of Pediatrics, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
- Diagnostic Referral Division, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | | | - Han-Zhong Feng
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Michael W Lawlor
- Department of Pathology and Laboratory Medicine and Neuroscience Research Center, The Medical College of Wisconsin, Milwaukee, WI, USA
| | - John T Gray
- Audentes Therapeutics, San Francisco, CA, USA
| | | | - J-P Jin
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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Sagath L, Lehtokari VL, Välipakka S, Udd B, Wallgren-Pettersson C, Pelin K, Kiiski K. An Extended Targeted Copy Number Variation Detection Array Including 187 Genes for the Diagnostics of Neuromuscular Disorders. J Neuromuscul Dis 2018; 5:307-314. [PMID: 30040739 PMCID: PMC6087456 DOI: 10.3233/jnd-170298] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Our previous array, the Comparative Genomic Hybridisation design (CGH-array) for nemaline myopathy (NM), named the NM-CGH array, revealed pathogenic copy number variation (CNV) in the genes for nebulin (NEB) and tropomyosin 3 (TPM3), as well as recurrent CNVs in the segmental duplication (SD), i.e. triplicate, region of NEB (TRI, exons 82-89, 90-97, 98-105). In the light of this knowledge, we have designed and validated an extended CGH array, which includes a selection of 187 genes known to cause neuromuscular disorders (NMDs). OBJECTIVE Our aim was to develop a reliable method for CNV detection in genes related to neuromuscular disorders for routine mutation detection and analysis, as a much-needed complement to sequencing methods. METHODS We have developed a novel custom-made 4×180 k CGH array for the diagnostics of NMDs. It includes the same tiled ultra-high density coverage of the 12 known or putative NM genes as our 8×60 k NM-CGH-array but also comprises a selection of 175 additional genes associated with NMDs, including titin (TTN), at a high to very high coverage. The genes were divided into three coverage groups according to known and potential pathogenicity in neuromuscular disorders. RESULTS The array detected known and putative CNVs in all three gene coverage groups, including the repetitive regions of NEB and TTN. CONCLUSIONS The targeted neuromuscular disorder 4×180 k array-CGH (NMD-CGH-array v1.0) design allows CNV detection for a broader spectrum of neuromuscular disorders at a high resolution.
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Affiliation(s)
- Lydia Sagath
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Finland
| | - Vilma-Lotta Lehtokari
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Finland
| | - Salla Välipakka
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Finland
| | - Bjarne Udd
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Finland
- Neuromuscular Research Center, Tampere University and University Hospital, Finland
- Department of Neurology, Vaasa Central Hospital, Finland
| | - Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Finland
| | - Katarina Pelin
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Finland
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Programme, University of Helsinki, Finland
| | - Kirsi Kiiski
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Finland
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Abstract
Congenital myopathy is an uncommon neonatal disorder that can manifest in the neonatal period with severe features. Presentation with signs of global hypotonia and respiratory insufficiency are among the classic findings. Rapid diagnosis is essential for medical management and family support. This case study reviews the presentation of hypotonia in the newborn, followed by a path to a diagnosis of nemaline myopathy in the form of an ACTA-1 mutation. This review can aid the clinician in the diagnosis of patients in whom hypotonia is present at birth. Included is a discussion of the incidence, pathophysiology, diagnosis, and management of this devastating disease.
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Berkenstadt M, Pode-Shakked B, Barel O, Barash H, Achiron R, Gilboa Y, Kidron D, Raas-Rothschild A. LMOD3-Associated Nemaline Myopathy: Prenatal Ultrasonographic, Pathologic, and Molecular Findings. J Ultrasound Med 2018; 37:1827-1833. [PMID: 29331079 DOI: 10.1002/jum.14520] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/29/2017] [Accepted: 10/08/2017] [Indexed: 06/07/2023]
Abstract
To describe the prenatal presentation, including ultrasonographic, histologic, and molecular findings, in 2 fetuses affected with LMOD3-related nemaline myopathy. Prenatal ultrasonographic examinations and histopathologic studies were performed on 2 fetuses with evidence of nemaline myopathy. To establish a molecular diagnosis, whole-exome sequencing was pursued for the affected fetuses. Nemaline myopathy is a common form of congenital myopathy manifesting with nonprogressive generalized muscle weakness, hypotonia, and electron-dense protein inclusions in skeletal myofibers. Although clinically, nemaline myopathy can be viewed as a common pathway phenotype, its molecular basis is heterogeneous, with mutations in 11 identified genes implicated in its pathogenesis so far. Whole-exome sequencing revealed that the affected fetuses were compound heterozygous for 2 newly reported pathogenic variants in the LMOD3 gene, which encodes leiomodin 3. To our knowledge, this article is the first report of LMOD3-related nemaline myopathy since the original reported cohort. We provide a detailed description of the prenatal imaging of these affected fetuses, which we hope, in combination with next-generation sequencing, may contribute to further diagnosis in additional families.
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Affiliation(s)
- Michal Berkenstadt
- Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Ben Pode-Shakked
- Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel-Hashomer, Israel
- Institute for Rare Diseases, Sheba Medical Center, Tel-Hashomer, Israel
- Dr Pinchas Borenstein Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Ortal Barel
- Sheba Cancer Research Center, Sheba Medical Center, Tel-Hashomer, Israel
| | - Hila Barash
- Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel-Hashomer, Israel
- Institute for Rare Diseases, Sheba Medical Center, Tel-Hashomer, Israel
| | - Reuven Achiron
- Department of Obstetrics and Gynecology, Sheba Medical Center, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Yinon Gilboa
- Department of Obstetrics and Gynecology, Sheba Medical Center, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Dvora Kidron
- Department of Pathology, Meir Medical Center, Kfar Saba, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Annick Raas-Rothschild
- Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel-Hashomer, Israel
- Institute for Rare Diseases, Sheba Medical Center, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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Wunderlich G, Brunn A, Daimagüler HS, Bozoglu T, Fink GR, Lehmann HC, Weis J, Cirak S. Long term history of a congenital core-rod myopathy with compound heterozygous mutations in the Nebulin gene. Acta Myol 2018; 37:121-127. [PMID: 30057997 PMCID: PMC6060425] [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] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Mutations in the Nebulin gene (NEB) may cause core-rod myopathy. The large size of the gene so far prevented inclusion of its routine analysis by didesoxy resequencing methodology in the diagnostic regime for muscular dystrophy cases. Here we report a 54-year-old female with a rare histological myopathy presentation of co-occurring cores and rods. The patient reported early childhood onset weakness. Muscle-MRI showed mainly proximal muscle involvement. We identified two compound heterozygous non-sense mutations in NEB (c.19653G > A, p.W6551* exon 127 and c.25441C > T, p.R8481* exon 182) using a comprehensive next generation sequencing (NGS)-based approach named Mendeliome Sequencing. The p.W6551* mutation has not been reported elsewhere. Early diagnosis by NGS shall be chased since even a scoliosis surgery at the age of 18 years had failed to initiate a neurological workup. Rather, cosmetic surgery for facial weakness had been performed recently, albeit with an unsatisfactory outcome.
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Affiliation(s)
- Gilbert Wunderlich
- Department of Neurology, University Hospital Cologne, 50937 Cologne, Germany
| | - Anna Brunn
- Institute for Neuropathology, University of Cologne, 50937 Cologne, Germany
| | - Hülya-Sevcan Daimagüler
- Department of Pediatrics, University Hospital Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Tarik Bozoglu
- Department of Pediatrics, University Hospital Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Gereon R. Fink
- Department of Neurology, University Hospital Cologne, 50937 Cologne, Germany
- Cognitive Neuroscience, Institute of Neuroscience and Medicine, Research Centre Jülich, 52428 Jülich, Germany
| | - Helmar C. Lehmann
- Department of Neurology, University Hospital Cologne, 50937 Cologne, Germany
| | - Joachim Weis
- Institute for Neuropathology, RWTH University Hospital Aachen, 52074 Aachen, Germany
| | - Sebahattin Cirak
- Department of Pediatrics, University Hospital Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
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45
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Sztal TE, McKaige EA, Williams C, Oorschot V, Ramm G, Bryson-Richardson RJ. Testing of therapies in a novel nebulin nemaline myopathy model demonstrate a lack of efficacy. Acta Neuropathol Commun 2018; 6:40. [PMID: 29848386 PMCID: PMC5977763 DOI: 10.1186/s40478-018-0546-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 05/12/2018] [Indexed: 12/19/2022] Open
Abstract
Nemaline myopathies are heterogeneous congenital muscle disorders causing skeletal muscle weakness and, in some cases, death soon after birth. Mutations in nebulin, encoding a large sarcomeric protein required for thin filament function, are responsible for approximately 50% of nemaline myopathy cases. Despite the severity of the disease there is no effective treatment for nemaline myopathy with limited research to develop potential therapies. Several supplements, including L-tyrosine, have been suggested to be beneficial and consequently self-administered by nemaline myopathy patients without any knowledge of their efficacy. We have characterized a zebrafish model for nemaline myopathy caused by a mutation in nebulin. These fish form electron-dense nemaline bodies and display reduced muscle function akin to the phenotypes observed in nemaline myopathy patients. We have utilized our zebrafish model to test and evaluate four treatments currently self-administered by nemaline myopathy patients to determine their ability to increase skeletal muscle function. Analysis of muscle pathology and locomotion following treatment with L-tyrosine, L-carnitine, taurine, or creatine revealed no significant improvement in skeletal muscle function emphasizing the urgency to develop effective therapies for nemaline myopathy.
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MESH Headings
- Actins/metabolism
- Animals
- Animals, Genetically Modified
- Dose-Response Relationship, Drug
- Embryo, Nonmammalian
- Gene Expression Regulation/genetics
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Microfilament Proteins/genetics
- Microfilament Proteins/metabolism
- Microscopy, Electron
- Muscle Proteins/genetics
- Muscle Proteins/metabolism
- Muscle Proteins/therapeutic use
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscle, Skeletal/ultrastructure
- Mutation/genetics
- Myopathies, Nemaline/genetics
- Myopathies, Nemaline/pathology
- Myopathies, Nemaline/therapy
- RNA, Messenger/metabolism
- Zebrafish
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Affiliation(s)
- Tamar E Sztal
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Emily A McKaige
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Caitlin Williams
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Viola Oorschot
- Monash Ramaciotti Centre for Cryo Electron Microscopy, Monash University, Melbourne, VIC, 3800, Australia
| | - Georg Ramm
- Monash Ramaciotti Centre for Cryo Electron Microscopy, Monash University, Melbourne, VIC, 3800, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia
- Biomedicine Discovery Institute, Monash University, Melbourne, Australia
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46
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Abstract
PURPOSE OF REVIEW This article uses a case-based approach to highlight the clinical features as well as recent advances in molecular genetics, muscle imaging, and pathophysiology of the congenital myopathies. RECENT FINDINGS Congenital myopathies refer to a heterogeneous group of genetic neuromuscular disorders characterized by early-onset muscle weakness, hypotonia, and developmental delay. Congenital myopathies are further classified into core myopathies, centronuclear myopathies, nemaline myopathies, and congenital fiber-type disproportion based on the key pathologic features found in muscle biopsies. Genotype and phenotype correlations are hampered by the diverse clinical variability of the genes responsible for congenital myopathies, ranging from a severe neonatal course with early death to mildly affected adults with late-onset disease. An increasing number of genes have been identified, which, in turn, are associated with overlapping morphologic changes in the myofibers. Precise genetic diagnosis has important implications for disease management, including family counseling; avoidance of anesthetic-related muscle injury for at-risk individuals; monitoring for potential cardiac, respiratory, or orthopedic complications; as well as for participation in clinical trials or potential genetic therapies. SUMMARY Collaboration with neuromuscular experts, geneticists, neuroradiologists, neuropathologists, and other specialists is needed to ensure accurate and timely diagnosis based on clinical and pathologic features. An integrated multidisciplinary model of care based on expert-guided standards will improve quality of care and optimize outcomes for patients and families with congenital myopathies.
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MESH Headings
- Adult
- Child
- Child, Preschool
- Female
- Genetic Therapy/trends
- Humans
- Infant
- Infant, Newborn
- Male
- Mutation/genetics
- Myopathies, Nemaline/genetics
- Myopathies, Nemaline/pathology
- Myopathies, Nemaline/therapy
- Myopathies, Structural, Congenital/genetics
- Myopathies, Structural, Congenital/pathology
- Myopathies, Structural, Congenital/therapy
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Lee JM, Lim JG, Shin JH, Park YE, Kim DS. Clinical and genetic diversity of nemaline myopathy from a single neuromuscular center in Korea. J Neurol Sci 2017; 383:61-68. [PMID: 29246625 DOI: 10.1016/j.jns.2017.10.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [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: 07/05/2017] [Revised: 09/19/2017] [Accepted: 10/09/2017] [Indexed: 11/17/2022]
Abstract
Nemaline myopathy (NM), the most common of the congenital myopathies, is caused by various genetic mutations. In this study, we attempted to identify the causative mutations of NM and to reveal any specific genotype-phenotype relationship in Korean patients with this disease. We investigated the clinical features and genotypes in 15 pathologically diagnosed NM patients, using whole exome sequencing (WES) combined with targeted sequencing and array-based comparative genomic hybridization. This strategy revealed pathogenic causative mutations in seven patients (46.7%), among whom mutations in the nebulin gene (NEB) were the most frequent (5 patients, 33.3%). Copy number variation (CNV) abnormality in NEB was not observed in any of our patients. In those with NEB-associated NM, the clinical spectrum was highly variable regardless of the mutation type. However, the majority of patients showing anterior lower leg weakness were associated with mutations located between NEB exons 166 and 177. We concluded that the combination of WES and targeted Sanger sequencing is an effective strategy for analyzing genotypes in patients with NM, and that CNV in NEB may not be a frequent cause of this disease among Koreans.
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Affiliation(s)
- Jong-Mok Lee
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Republic of Korea
| | - Jeong Geun Lim
- Department of Neurology, Keimyung University School of Medicine, Republic of Korea
| | - Jin-Hong Shin
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Republic of Korea
| | - Young-Eun Park
- Department of Neurology, Pusan National University School of Medicine, Republic of Korea
| | - Dae-Seong Kim
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Republic of Korea; Department of Neurology, Pusan National University School of Medicine, Republic of Korea.
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Cenik BK, Garg A, McAnally JR, Shelton JM, Richardson JA, Bassel-Duby R, Olson EN, Liu N. Severe myopathy in mice lacking the MEF2/SRF-dependent gene leiomodin-3. J Clin Invest 2015; 125:1569-78. [PMID: 25774500 DOI: 10.1172/jci80115] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 01/29/2015] [Indexed: 01/18/2023] Open
Abstract
Maintenance of skeletal muscle structure and function requires a precise stoichiometry of sarcomeric proteins for proper assembly of the contractile apparatus. Absence of components of the sarcomeric thin filaments causes nemaline myopathy, a lethal congenital muscle disorder associated with aberrant myofiber structure and contractility. Previously, we reported that deficiency of the kelch-like family member 40 (KLHL40) in mice results in nemaline myopathy and destabilization of leiomodin-3 (LMOD3). LMOD3 belongs to a family of tropomodulin-related proteins that promote actin nucleation. Here, we show that deficiency of LMOD3 in mice causes nemaline myopathy. In skeletal muscle, transcription of Lmod3 was controlled by the transcription factors SRF and MEF2. Myocardin-related transcription factors (MRTFs), which function as SRF coactivators, serve as sensors of actin polymerization and are sequestered in the cytoplasm by actin monomers. Conversely, conditions that favor actin polymerization de-repress MRTFs and activate SRF-dependent genes. We demonstrated that the actin nucleator LMOD3, together with its stabilizing partner KLHL40, enhances MRTF-SRF activity. In turn, SRF cooperated with MEF2 to sustain the expression of LMOD3 and other components of the contractile apparatus, thereby establishing a regulatory circuit to maintain skeletal muscle function. These findings provide insight into the molecular basis of the sarcomere assembly and muscle dysfunction associated with nemaline myopathy.
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Yuen M, Sandaradura SA, Dowling JJ, Kostyukova AS, Moroz N, Quinlan KG, Lehtokari VL, Ravenscroft G, Todd EJ, Ceyhan-Birsoy O, Gokhin DS, Maluenda J, Lek M, Nolent F, Pappas CT, Novak SM, D'Amico A, Malfatti E, Thomas BP, Gabriel SB, Gupta N, Daly MJ, Ilkovski B, Houweling PJ, Davidson AE, Swanson LC, Brownstein CA, Gupta VA, Medne L, Shannon P, Martin N, Bick DP, Flisberg A, Holmberg E, Van den Bergh P, Lapunzina P, Waddell LB, Sloboda DD, Bertini E, Chitayat D, Telfer WR, Laquerrière A, Gregorio CC, Ottenheijm CAC, Bönnemann CG, Pelin K, Beggs AH, Hayashi YK, Romero NB, Laing NG, Nishino I, Wallgren-Pettersson C, Melki J, Fowler VM, MacArthur DG, North KN, Clarke NF. Leiomodin-3 dysfunction results in thin filament disorganization and nemaline myopathy. J Clin Invest 2014; 124:4693-708. [PMID: 25250574 DOI: 10.1172/jci75199] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 08/19/2014] [Indexed: 01/02/2023] Open
Abstract
Nemaline myopathy (NM) is a genetic muscle disorder characterized by muscle dysfunction and electron-dense protein accumulations (nemaline bodies) in myofibers. Pathogenic mutations have been described in 9 genes to date, but the genetic basis remains unknown in many cases. Here, using an approach that combined whole-exome sequencing (WES) and Sanger sequencing, we identified homozygous or compound heterozygous variants in LMOD3 in 21 patients from 14 families with severe, usually lethal, NM. LMOD3 encodes leiomodin-3 (LMOD3), a 65-kDa protein expressed in skeletal and cardiac muscle. LMOD3 was expressed from early stages of muscle differentiation; localized to actin thin filaments, with enrichment near the pointed ends; and had strong actin filament-nucleating activity. Loss of LMOD3 in patient muscle resulted in shortening and disorganization of thin filaments. Knockdown of lmod3 in zebrafish replicated NM-associated functional and pathological phenotypes. Together, these findings indicate that mutations in the gene encoding LMOD3 underlie congenital myopathy and demonstrate that LMOD3 is essential for the organization of sarcomeric thin filaments in skeletal muscle.
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50
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Sudo A, Hayashi Y, Sano H, Kawamura N, Nishino I, Nonaka I. [Sibling cases of severe infantile form of nemaline myopathy with ACTA1-gene mutation]. No To Hattatsu 2013; 45:452-456. [PMID: 24313005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Severe infantile form of nemaline myopathy is clinically characterized by marked muscle hypotonia and weakness with respiratory and feeding difficulties since infancy. Recently, mutations in the skeletal muscle alpha-actine gene (ACTA1) have been identified in many patients with the nemaline myopathy. We experienced two cases of severe infantile form of nemaline myopathy with ACTA1 mutation (missence heterozygous mutation;c.553C>T, p.R185C) in siblings presenting with different clinical symptoms and courses. The elder brother was a typical "floppy infant" at birth. Because he could not suck and swallow at all, he was fed completely through a nasogastric tube. At 2 months of age, he developed respiratory insufficiency and was placed on a respirator all day. He was diagnosed with having nemaline myopathy from his muscle biopsy, which revealed marked variation in muscle fiber size with large numbers of nemaline bodies on Gomori-trichrome stain. In contrast, the younger brother presented with mild muscular hypotonia and feeding difficulty during the neonatal stage;therefore, he was partly fed through a nasogastric tube. At 2 months of age, he was admitted to our hospital because of respiratory distress, and he required nasal continuous positive airway pressure with oxygen followed by noninvasive positive pressure ventilation intermittently, mainly at night. He was followed at his home by parents with no serious problems;however he unexpectedly died at the age of 15 months. Although most cases of severe infantile form of nemaline myopathy caused by ACTA1 mutations are sporadic and have no family history, we emphasize that clinical symptoms are variable in siblings with the same mutation.
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Affiliation(s)
- Akira Sudo
- Department of Pediatrics, Sapporo City General Hospital, Sapporo, Hokkaido.
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