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Groh WJ, Bhakta D, Tomaselli GF, Aleong RG, Teixeira RA, Amato A, Asirvatham SJ, Cha YM, Corrado D, Duboc D, Goldberger ZD, Horie M, Hornyak JE, Jefferies JL, Kääb S, Kalman JM, Kertesz NJ, Lakdawala NK, Lambiase PD, Lubitz SA, McMillan HJ, McNally EM, Milone M, Namboodiri N, Nazarian S, Patton KK, Russo V, Sacher F, Santangeli P, Shen WK, Sobral Filho DC, Stambler BS, Stöllberger C, Wahbi K, Wehrens XHT, Weiner MM, Wheeler MT, Zeppenfeld K. 2022 HRS expert consensus statement on evaluation and management of arrhythmic risk in neuromuscular disorders. Heart Rhythm 2022; 19:e61-e120. [PMID: 35500790 DOI: 10.1016/j.hrthm.2022.04.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 04/21/2022] [Indexed: 11/04/2022]
Abstract
This international multidisciplinary document is intended to guide electrophysiologists, cardiologists, other clinicians, and health care professionals in caring for patients with arrhythmic complications of neuromuscular disorders (NMDs). The document presents an overview of arrhythmias in NMDs followed by detailed sections on specific disorders: Duchenne muscular dystrophy, Becker muscular dystrophy, and limb-girdle muscular dystrophy type 2; myotonic dystrophy type 1 and type 2; Emery-Dreifuss muscular dystrophy and limb-girdle muscular dystrophy type 1B; facioscapulohumeral muscular dystrophy; and mitochondrial myopathies, including Friedreich ataxia and Kearns-Sayre syndrome, with an emphasis on managing arrhythmic cardiac manifestations. End-of-life management of arrhythmias in patients with NMDs is also covered. The document sections were drafted by the writing committee members according to their area of expertise. The recommendations represent the consensus opinion of the expert writing group, graded by class of recommendation and level of evidence utilizing defined criteria. The recommendations were made available for public comment; the document underwent review by the Heart Rhythm Society Scientific and Clinical Documents Committee and external review and endorsement by the partner and collaborating societies. Changes were incorporated based on these reviews. By using a breadth of accumulated available evidence, the document is designed to provide practical and actionable clinical information and recommendations for the diagnosis and management of arrhythmias and thus improve the care of patients with NMDs.
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Affiliation(s)
- William J Groh
- Ralph H. Johnson VA Medical Center and Medical University of South Carolina, Charleston, South Carolina
| | - Deepak Bhakta
- Indiana University School of Medicine, Indianapolis, Indiana
| | | | | | | | - Anthony Amato
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | | | | | - Domenico Corrado
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Padova, Italy
| | - Denis Duboc
- Cardiology Department, Hôpital Cochin, AP-HP, Université de Paris, Paris, France
| | - Zachary D Goldberger
- University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Minoru Horie
- Shiga University of Medical Sciences, Otsu, Japan
| | | | | | - Stefan Kääb
- Department of Medicine I, University Hospital, LMU Munich, Munich, Germany
| | - Jonathan M Kalman
- Royal Melbourne Hospital and University of Melbourne, Melbourne, Victoria, Australia
| | | | - Neal K Lakdawala
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Pier D Lambiase
- Barts Heart Centre, St Bartholomew's Hospital, University College London, and St Bartholomew's Hospital London, London, United Kingdom
| | | | - Hugh J McMillan
- Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada
| | | | | | - Narayanan Namboodiri
- Sree Chitra Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | | | | | | | - Frederic Sacher
- Bordeaux University Hospital, LIRYC Institute, Bordeaux, France
| | | | | | | | | | - Claudia Stöllberger
- Second Medical Department with Cardiology and Intensive Care Medicine, Klinik Landstraße, Vienna, Austria
| | - Karim Wahbi
- Cardiology Department, Hôpital Cochin, AP-HP, Université de Paris, Paris, France
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Carson L, Merrick D. Genotype-phenotype correlations in alpha-sarcoglycanopathy: a systematic review. Ir J Med Sci 2022; 191:2743-2750. [PMID: 35040091 DOI: 10.1007/s11845-021-02855-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 10/27/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Mutations in the alpha-sarcoglycan gene cause limb-girdle muscular dystrophy 2D, an autosomal recessive muscle wasting disorder primarily affecting the muscles of the shoulder and pelvic girdles. To date, no previous study has collated all known mutations in alpha-sarcoglycan and mapped these to the associated phenotypes. AIMS To examine for correlations between mutation locations, or mutation type, and the phenotype caused in all reported mutations in alpha-sarcoglycan. METHODS We present a systematic literature review examining correlations between mutation locations, or mutation type, and the phenotype caused in all reported cases of limb-girdle muscular dystrophy 2D. RESULTS From 134 unique genotypes collated, a strong prevalence of missense mutations (64% of all unique mutations) was found in this gene. Mutation hotspots were noted in exon three and the extracellular domain, with mutation densities varying significantly between both exons and protein domains (p ≤ 0.01). All compound heterozygous limb-girdle muscular dystrophy 2D patients with cardiac involvement contained at least one mutation in exon three, a novel finding. All non-sense mutations in alpha-sarcoglycan give a severe phenotype, as do genotypes involving a combination of exons four and five. This study confirms on a large, diverse cohort the extremely high prevalence of the c.229C > T mutation. CONCLUSIONS This study demonstrates the vast variation in disease severity seen between patients possessing the same mutation, highlighting the difficulty identifying genotype-phenotype correlations in this condition. Novel findings including the involvement of exon three in all compound heterozygous patients who suffered from cardiomyopathy, and the severity of mutations involving exons four and five may help to guide investigations and therapeutic decisions in an era of personalised medicine.
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Affiliation(s)
- Luke Carson
- School of Life Sciences, University of Nottingham, Nottingham, UK.
| | - Deborah Merrick
- School of Life Sciences, University of Nottingham, Nottingham, UK
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Georganopoulou DG, Moisiadis VG, Malik FA, Mohajer A, Dashevsky TM, Wuu ST, Hu CK. A Journey with LGMD: From Protein Abnormalities to Patient Impact. Protein J 2021; 40:466-88. [PMID: 34110586 DOI: 10.1007/s10930-021-10006-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2021] [Indexed: 12/16/2022]
Abstract
The limb-girdle muscular dystrophies (LGMD) are a collection of genetic diseases united in their phenotypical expression of pelvic and shoulder area weakness and wasting. More than 30 subtypes have been identified, five dominant and 26 recessive. The increase in the characterization of new genotypes in the family of LGMDs further adds to the heterogeneity of the disease. Meanwhile, better understanding of the phenotype led to the reconsideration of the disease definition, which resulted in eight old subtypes to be no longer recognized officially as LGMD and five new diseases to be added to the LGMD family. The unique variabilities of LGMD stem from genetic mutations, which then lead to protein and ultimately muscle dysfunction. Herein, we review the LGMD pathway, starting with the genetic mutations that encode proteins involved in muscle maintenance and repair, and including the genotype–phenotype relationship of the disease, the epidemiology, disease progression, burden of illness, and emerging treatments.
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Bazrafshan S, Kushlaf H, Kakroo M, Quinlan J, Becker RC, Sadayappan S. Genetic Modifiers of Hereditary Neuromuscular Disorders and Cardiomyopathy. Cells 2021; 10:cells10020349. [PMID: 33567613 PMCID: PMC7915259 DOI: 10.3390/cells10020349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/26/2021] [Accepted: 02/03/2021] [Indexed: 12/18/2022] Open
Abstract
Novel genetic variants exist in patients with hereditary neuromuscular disorders (NMD), including muscular dystrophy. These patients also develop cardiac manifestations. However, the association between these gene variants and cardiac abnormalities is understudied. To determine genetic modifiers and features of cardiac disease in NMD patients, we have reviewed electronic medical records of 651 patients referred to the Muscular Dystrophy Association Care Center at the University of Cincinnati and characterized the clinical phenotype of 14 patients correlating with their next-generation sequencing data. The data were retrieved from the electronic medical records of the 14 patients included in the current study and comprised neurologic and cardiac phenotype and genetic reports which included comparative genomic hybridization array and NGS. Novel associations were uncovered in the following eight patients diagnosed with Limb-girdle Muscular Dystrophy, Bethlem Myopathy, Necrotizing Myopathy, Charcot-Marie-Tooth Disease, Peripheral Polyneuropathy, and Valosin-containing Protein-related Myopathy. Mutations in COL6A1, COL6A3, SGCA, SYNE1, FKTN, PLEKHG5, ANO5, and SMCHD1 genes were the most common, and the associated cardiac features included bundle branch blocks, ventricular chamber dilation, septal thickening, and increased outflow track gradients. Our observations suggest that features of cardiac disease and modifying gene mutations in patients with NMD require further investigation to better characterize genotype–phenotype relationships.
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Affiliation(s)
- Sholeh Bazrafshan
- Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.B.); (M.K.); (R.C.B.)
| | - Hani Kushlaf
- Department of Neurology and Rehabilitation Medicine, Neuromuscular Center, University of Cincinnati Gardner Neuroscience Institute, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (H.K.); (J.Q.)
| | - Mashhood Kakroo
- Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.B.); (M.K.); (R.C.B.)
| | - John Quinlan
- Department of Neurology and Rehabilitation Medicine, Neuromuscular Center, University of Cincinnati Gardner Neuroscience Institute, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (H.K.); (J.Q.)
| | - Richard C. Becker
- Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.B.); (M.K.); (R.C.B.)
| | - Sakthivel Sadayappan
- Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.B.); (M.K.); (R.C.B.)
- Correspondence: ; Tel.: +1-513-558-7498
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Dosi C, Rubegni A, Cassandrini D, Malandrini A, Maggi L, Donati MA, Santorelli FM. Alpha-sarcoglycanopathy presenting as myalgia and hyperCKemia in two adults with a long-term follow-up. Case reports. Acta Myol 2020; 39:218-221. [PMID: 33458577 PMCID: PMC7783442 DOI: 10.36185/2532-1900-025] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 11/16/2020] [Indexed: 11/08/2022]
Abstract
Two patients with a paucisymptomatic hyperckemia underwent a skeletal muscle biopsy and massive gene panel to investigate mutations associated with inherited muscle disorders. In the SGCA gene, sequence analyses revealed a homozygous c.850C > T/p.Arg284Cys in patient 1 and two heterozygous variants (c.739G > A/p.Val247Met and c.850C > T/p.Arg284Cys) in patient 2. Combination of histology and immunofluorence studies showed minimal changes for muscular proteins including the α-sarcoglycan. These two cases highlight the advantages of next-generation sequencing in the differential diagnosis of mild myopathic conditions before considering the more invasive muscle biopsy in sarcoglycanopathies.
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Affiliation(s)
| | | | | | | | - Lorenzo Maggi
- Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | - M Alice Donati
- Metabolic Disease Unit, AOU Meyer Children Hospital, Florence, Italy
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Zaganas I, Mastorodemos V, Spilioti M, Mathioudakis L, Latsoudis H, Michaelidou K, Kotzamani D, Notas K, Dimitrakopoulos K, Skoula I, Ioannidis S, Klothaki E, Erimaki S, Stavropoulos G, Vassilikos V, Amoiridis G, Efthimiadis G, Evangeliou A, Mitsias P. Genetic cause of heterogeneous inherited myopathies in a cohort of Greek patients. Mol Genet Metab Rep 2020; 25:100682. [PMID: 33304817 PMCID: PMC7711282 DOI: 10.1016/j.ymgmr.2020.100682] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 11/13/2020] [Accepted: 11/13/2020] [Indexed: 02/07/2023] Open
Abstract
Inherited muscle disorders are caused by pathogenic changes in numerous genes. Herein, we aimed to investigate the etiology of muscle disease in 24 consecutive Greek patients with myopathy suspected to be genetic in origin, based on clinical presentation and laboratory and electrophysiological findings and absence of known acquired causes of myopathy. Of these, 16 patients (8 females, median 24 years-old, range 7 to 67 years-old) were diagnosed by Whole Exome Sequencing as suffering from a specific type of inherited muscle disorder. Specifically, we have identified causative variants in 6 limb-girdle muscular dystrophy genes (6 patients; ANO5, CAPN3, DYSF, ISPD, LAMA2, SGCA), 3 metabolic myopathy genes (4 patients; CPT2, ETFDH, GAA), 1 congenital myotonia gene (1 patient; CLCN1), 1 mitochondrial myopathy gene (1 patient; MT-TE) and 3 other myopathy-associated genes (4 patients; CAV3, LMNA, MYOT). In 6 additional family members affected by myopathy, we reached genetic diagnosis following identification of a causative variant in an index patient. In our patients, genetic diagnosis ended a lengthy diagnostic process and, in the case of Multiple acyl-CoA dehydrogenase deficiency and Pompe's disease, it enabled specific treatment to be initiated. These results further expand the genotypic and phenotypic spectrum of inherited myopathies.
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Affiliation(s)
- Ioannis Zaganas
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece.,Neurology Department, University Hospital of Crete, Heraklion, Crete, Greece
| | | | - Martha Spilioti
- AHEPA General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Lambros Mathioudakis
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Helen Latsoudis
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Kleita Michaelidou
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Dimitra Kotzamani
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Konstantinos Notas
- AHEPA General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Irene Skoula
- Neurogenetics Laboratory, Medical School, University of Crete, Heraklion, Crete, Greece
| | - Stefanos Ioannidis
- Neurology Department, University Hospital of Crete, Heraklion, Crete, Greece
| | - Eirini Klothaki
- Neurology Department, University Hospital of Crete, Heraklion, Crete, Greece
| | - Sophia Erimaki
- Neurophysiology Unit, University Hospital of Crete, Heraklion, Crete, Greece
| | - Georgios Stavropoulos
- Hippokratio General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Vassilios Vassilikos
- Hippokratio General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Georgios Amoiridis
- Neurophysiology Unit, University Hospital of Crete, Heraklion, Crete, Greece
| | - Georgios Efthimiadis
- AHEPA General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Athanasios Evangeliou
- Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Panayiotis Mitsias
- Neurology Department, University Hospital of Crete, Heraklion, Crete, Greece.,Neurophysiology Unit, University Hospital of Crete, Heraklion, Crete, Greece.,Department of Neurology, Henry Ford Hospital/Wayne State University, Detroit, Michigan, USA
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Barton ER, Pacak CA, Stoppel WL, Kang PB. The ties that bind: functional clusters in limb-girdle muscular dystrophy. Skelet Muscle. 2020;10:22. [PMID: 32727611 PMCID: PMC7389686 DOI: 10.1186/s13395-020-00240-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/16/2020] [Indexed: 12/13/2022] Open
Abstract
The limb-girdle muscular dystrophies (LGMDs) are a genetically pleiomorphic class of inherited muscle diseases that are known to share phenotypic features. Selected LGMD genetic subtypes have been studied extensively in affected humans and various animal models. In some cases, these investigations have led to human clinical trials of potential disease-modifying therapies, including gene replacement strategies for individual subtypes using adeno-associated virus (AAV) vectors. The cellular localizations of most proteins associated with LGMD have been determined. However, the functions of these proteins are less uniformly characterized, thus limiting our knowledge of potential common disease mechanisms across subtype boundaries. Correspondingly, broad therapeutic strategies that could each target multiple LGMD subtypes remain less developed. We believe that three major "functional clusters" of subcellular activities relevant to LGMD merit further investigation. The best known of these is the glycosylation modifications associated with the dystroglycan complex. The other two, mechanical signaling and mitochondrial dysfunction, have been studied less systematically but are just as promising with respect to the identification of significant mechanistic subgroups of LGMD. A deeper understanding of these disease pathways could yield a new generation of precision therapies that would each be expected to treat a broader range of LGMD patients than a single subtype, thus expanding the scope of the molecular medicines that may be developed for this complex array of muscular dystrophies.
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Dardas Z, Swedan S, Al-Sheikh Qassem A, Azab B. The impact of exome sequencing on the diagnostic yield of muscular dystrophies in consanguineous families. Eur J Med Genet 2020; 63:103845. [PMID: 31953240 DOI: 10.1016/j.ejmg.2020.103845] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/04/2019] [Accepted: 01/11/2020] [Indexed: 10/25/2022]
Abstract
Muscular dystrophies (MDs) are a heterogeneous group of inherited disorders that are characterized by progressive skeletal muscle weakness and dystrophic changes on muscle biopsy. The broad genetic and clinical heterogeneity of MDs make the accurate diagnosis difficult via conventional approaches. This study investigated 23 patients from eight unrelated consanguineous families with MDs. Previous clinical assessments did not accurately clarify the type of their MD and/or misdiagnose them with another disease. Exome sequencing (ES) is an efficient, time-saving, and cost-effective tool, enabling disease-causing variant (DCV) detection in affected individuals. We investigated the use of ES to diagnose MD and discover the underlying genetic etiology. We achieved a remarkable diagnostic success rate of 87.5% (7 out of 8 families) which is the highest rate reported thus far compared to previous studies. We identified two novel pathogenic variants in DYSF gene (c.4179delG, c.1149+3G > C). The latter variant impacts the splicing machinery of DYSF mRNA. Moreover, we further assessed the pathogenicity of four recurrent variants ((DYSF, c.4076T > C), (GMPPB, c.458C > T), (SGCA, c.739G > A) (TTN, c.7331G > A), designated their neurological impact and added new phenotypes in patients with these variants. To our knowledge, this is the first study applying an ES-based comprehensive molecular diagnosis to Jordanian cohort with MDs. Our findings confirmed that ES is a powerful approach for the diagnosis of MD patients. This efficient method of molecular diagnosis is crucial for guiding patient clinical care, genetic counseling, and most importantly, paving the way for gene therapy which is currently in clinical trials.
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Affiliation(s)
- Zain Dardas
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan; Department of Pathology and Microbiology and Forensic Medicine, School of Medicine, The University of Jordan, Amman, Jordan.
| | - Samer Swedan
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | | | - Belal Azab
- Department of Pathology and Microbiology and Forensic Medicine, School of Medicine, The University of Jordan, Amman, Jordan; Human and Molecular Genetics, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA.
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Rubegni A, Malandrini A, Dosi C, Astrea G, Baldacci J, Battisti C, Bertocci G, Donati MA, Dotti MT, Federico A, Giannini F, Grosso S, Guerrini R, Lenzi S, Maioli MA, Melani F, Mercuri E, Sacchini M, Salvatore S, Siciliano G, Tolomeo D, Tonin P, Volpi N, Santorelli FM, Cassandrini D. Next-generation sequencing approach to hyperCKemia: A 2-year cohort study. Neurol Genet 2019; 5:e352. [PMID: 31517061 PMCID: PMC6705647 DOI: 10.1212/nxg.0000000000000352] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/21/2019] [Indexed: 01/31/2023]
Abstract
Objective Next-generation sequencing (NGS) was applied in molecularly undiagnosed asymptomatic or paucisymptomatic hyperCKemia to investigate whether this technique might allow detection of the genetic basis of the condition. Methods Sixty-six patients with undiagnosed asymptomatic or paucisymptomatic hyperCKemia, referred to tertiary neuromuscular centers over an approximately 2-year period, were analyzed using a customized, targeted sequencing panel able to investigate the coding exons and flanking intronic regions of 78 genes associated with limb-girdle muscular dystrophies, rhabdomyolysis, and metabolic and distal myopathies. Results A molecular diagnosis was reached in 33 cases, corresponding to a positive diagnostic yield of 50%. Variants of unknown significance were found in 17 patients (26%), whereas 16 cases (24%) remained molecularly undefined. The major features of the diagnosed cases were mild proximal muscle weakness (found in 27%) and myalgia (in 24%). Fourteen patients with a molecular diagnosis and mild myopathic features on muscle biopsy remained asymptomatic at a 24-month follow-up. Conclusions This study of patients with undiagnosed hyperCKemia, highlighting the advantages of NGS used as a first-tier diagnostic approach in genetically heterogeneous conditions, illustrates the ongoing evolution of molecular diagnosis in the field of clinical neurology. Isolated hyperCKemia can be the sole feature alerting to a progressive muscular disorder requiring careful surveillance.
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Affiliation(s)
- Anna Rubegni
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Alessandro Malandrini
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Claudia Dosi
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Guja Astrea
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Jacopo Baldacci
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Carla Battisti
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Giulia Bertocci
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - M Alice Donati
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - M Teresa Dotti
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Antonio Federico
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Fabio Giannini
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Salvatore Grosso
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Renzo Guerrini
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Sara Lenzi
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Maria A Maioli
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Federico Melani
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Eugenio Mercuri
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Michele Sacchini
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Simona Salvatore
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Gabriele Siciliano
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Deborah Tolomeo
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Paola Tonin
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Nila Volpi
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Filippo M Santorelli
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
| | - Denise Cassandrini
- IRCCS Fondazione Stella Maris (A.R., G.A., J.B., G.B., S.L., F.M.S., D.C.), Pisa, Italy; Department of Medicine (A.M., C.B., M.T.D., A.F., F.G., S.S., N.V.), Surgery and Neurosciences, University of Siena; Department of Clinical and Experimental Medicine (C.D., G.S., D.T.), University of Pisa; Metabolic Disease Unit (M.A.D., M.S.), AOU Meyer Children Hospital, Florence; Department of Molecular and Developmental Medicine (S.G.), University of Siena, Siena; Pediatric Neurology (R.G., F.M.), AOU Meyer Children Hospital, Florence; Neurophysiopathology Multiple Sclerosis Center Hospital Binaghi (M.A.M.), Cagliari; Pediatric Neurology and Nemo Clinical Centre (E.M.), Fondazione Policlinico Universitario "A. Gemelli IRCSS", Università Cattolica del Sacro Cuore, Rome; and Department of Neurosciences (P.T.), Biomedicine and Movement Sciences, University of Verona, Italy
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Xie Z, Hou Y, Yu M, Liu Y, Fan Y, Zhang W, Wang Z, Xiong H, Yuan Y. Clinical and genetic spectrum of sarcoglycanopathies in a large cohort of Chinese patients. Orphanet J Rare Dis 2019; 14:43. [PMID: 30764848 PMCID: PMC6376703 DOI: 10.1186/s13023-019-1021-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 02/03/2019] [Indexed: 11/20/2022] Open
Abstract
Background Sarcoglycanopathies comprise four subtypes of autosomal recessive limb-girdle muscular dystrophy (LGMD2C, LGMD2D, LGMD2E, and LGMD2F) that are caused, respectively, by mutations in the SGCG, SGCA, SGCB, and SGCD genes. Knowledge about the clinical and genetic features of sarcoglycanopathies in Chinese patients is limited. The aims of this study were to investigate in detail the clinical manifestations, sarcoglycan expression, and gene mutations in Chinese patients with sarcoglycanopathies and to identify possible correlations between them. Results Of 3638 patients for suspected neuromuscular diseases (1733 with inherited myopathies, 1557 with acquired myopathies, and 348 unknown), 756 patients had next-generation sequencing (NGS) diagnostic panel. Twenty-five patients with sarcoglycanopathies (11.5%) were identified from 218 confirmed LGMDs, comprising 18 with LGMD2D, 6 with LGMD2E, and one with LGMD2C. One patient with LGMD2D also had Charcot-Marie-Tooth 1A. The clinical phenotypes of the patients with LGMD2D or LGMD2E were markedly heterogeneous. Muscle biopsy showed a dystrophic pattern in 19 patients and mild myopathic changes in 6. The percentage of correct prediction of genotype based on expression of sarcoglycan was 36.0% (4 LGMD2D, 4 LGMD2E, and one LGMD2C). There was a statistically significant positive correlation between reduction of α-sarcoglycan level and disease severity in LGMD2D. Thirty-five mutations were identified in SGCA, SGCB, SGCG, and PMP22, 16 of which were novel. Exon 3 of SGCA was a hotspot region for mutations in LGMD2D. The missense mutation c.662G > A (p.R221H) was the most common mutation in SGCA. Missense mutations in both alleles of SGCA were associated with a relative benign disease course. No obvious clinical, sarcoglycan expression, and genetic correlation was found in LGMD2E. Conclusions This study expands the clinical and genetic spectrum of sarcoglycanopathies in Chinese patients and provides evidence that disease severity of LGMD2D may be predicted by α-sarcoglycan expression and SGCA mutation. Electronic supplementary material The online version of this article (10.1186/s13023-019-1021-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhiying Xie
- Department of Neurology, Peking University First Hospital, 8 Xishiku St, Xicheng District, Beijing, 100034, China
| | - Yue Hou
- Department of Neurology, Peking University First Hospital, 8 Xishiku St, Xicheng District, Beijing, 100034, China
| | - Meng Yu
- Department of Neurology, Peking University First Hospital, 8 Xishiku St, Xicheng District, Beijing, 100034, China
| | - Yilin Liu
- Department of Neurology, Peking University First Hospital, 8 Xishiku St, Xicheng District, Beijing, 100034, China
| | - Yanbin Fan
- Department of Pediatrics, Peking University First Hospital, Xishiku St, Xicheng District, Beijing, 100034, China
| | - Wei Zhang
- Department of Neurology, Peking University First Hospital, 8 Xishiku St, Xicheng District, Beijing, 100034, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, 8 Xishiku St, Xicheng District, Beijing, 100034, China
| | - Hui Xiong
- Department of Pediatrics, Peking University First Hospital, Xishiku St, Xicheng District, Beijing, 100034, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, 8 Xishiku St, Xicheng District, Beijing, 100034, China.
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Bulakh MV, Ryzhkova OP, Polyakov AV. Sarcoglycanopathies: Clinical, Molecular and Genetic Characteristics, Epidemiology, Diagnostics and Treatment Options. RUSS J GENET+ 2018. [DOI: 10.1134/s1022795418020059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Reddy HM, Hamed SA, Lek M, Mitsuhashi S, Estrella E, Jones MD, Mahoney LJ, Duncan AR, Cho KA, Macarthur DG, Kunkel LM, Kang PB. Homozygous nonsense mutation in SGCA is a common cause of limb-girdle muscular dystrophy in Assiut, Egypt. Muscle Nerve 2016; 54:690-5. [PMID: 26934379 DOI: 10.1002/mus.25094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 02/22/2016] [Accepted: 02/26/2016] [Indexed: 01/18/2023]
Abstract
INTRODUCTION The genetic causes of limb-girdle muscular dystrophy (LGMD) have been studied in numerous countries, but such investigations have been limited in Egypt. METHODS A cohort of 30 families with suspected LGMD from Assiut, Egypt, was studied using immunohistochemistry, homozygosity mapping, Sanger sequencing, and whole exome sequencing. RESULTS Six families were confirmed to have pathogenic mutations, 4 in SGCA and 2 in DMD. Of these, 3 families harbored a single nonsense mutation in SGCA, suggesting that this may be a common mutation in Assiut, Egypt, originating from a founder effect. CONCLUSIONS The Assiut region in Egypt appears to share at least several of the common LGMD genes found in other parts of the world. It is notable that 4 of the 6 mutations were ascertained by means of whole exome sequencing, even though it was the last approach adopted. This illustrates the power of this technique for identifying causative mutations for muscular dystrophies. Muscle Nerve 54: 690-695, 2016.
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Affiliation(s)
- Hemakumar M Reddy
- Division of Pediatric Neurology, University of Florida College of Medicine, PO Box 100296, Gainesville, Florida, USA, 32610
| | - Sherifa A Hamed
- Department of Neurology and Psychiatry, Assiut University Hospital, Assiut, Egypt
| | - Monkol Lek
- Analytic and Translational Genetics Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of the Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, USA
| | - Satomi Mitsuhashi
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Elicia Estrella
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Michael D Jones
- Division of Pediatric Neurology, University of Florida College of Medicine, PO Box 100296, Gainesville, Florida, USA, 32610
| | - Lane J Mahoney
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Anna R Duncan
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Kyung-Ah Cho
- Division of Pediatric Neurology, University of Florida College of Medicine, PO Box 100296, Gainesville, Florida, USA, 32610
| | - Daniel G Macarthur
- Analytic and Translational Genetics Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of the Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, USA
| | - Louis M Kunkel
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Peter B Kang
- Division of Pediatric Neurology, University of Florida College of Medicine, PO Box 100296, Gainesville, Florida, USA, 32610. .,Department of Neurology and Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, USA.
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14
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Abstract
The limb-girdle muscular dystrophies (LGMDs) are a diverse group of genetic neuromuscular conditions that usually manifest in the proximal muscles of the hip and shoulder girdles. Since the identification of the first gene associated with the phenotype in 1994, an extensive body of research has identified the genetic defects responsible for over 30 LGMD subtypes, revealed an increasingly varied phenotypic spectrum, and exposed the need to move towards a systems-based understanding of the molecular pathways affected. New sequencing technologies, including whole-exome and whole-genome sequencing, are continuing to expand the range of genes and phenotypes associated with the LGMDs, and new computational approaches are helping clinicians to adapt to this new genomic medicine paradigm. However, 60 years on from the first description of LGMD, no curative therapies exist, and systematic exploration of the natural history is still lacking. To enable rapid translation of basic research to the clinic, well-phenotyped and genetically characterized patient cohorts are a necessity, and appropriate outcome measures and biomarkers must be developed through natural history studies. Here, we review the international collaborations that are addressing these translational research issues, and the lessons learned from large-scale LGMD sequencing programmes.
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Affiliation(s)
- Rachel Thompson
- The John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Volker Straub
- The John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
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15
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Turan S, Farruggio AP, Srifa W, Day JW, Calos MP. Precise Correction of Disease Mutations in Induced Pluripotent Stem Cells Derived From Patients With Limb Girdle Muscular Dystrophy. Mol Ther 2016. [PMID: 26916285 DOI: 10.1038/mt.2016.40.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Limb girdle muscular dystrophies types 2B (LGMD2B) and 2D (LGMD2D) are degenerative muscle diseases caused by mutations in the dysferlin and alpha-sarcoglycan genes, respectively. Using patient-derived induced pluripotent stem cells (iPSC), we corrected the dysferlin nonsense mutation c.5713C>T; p.R1905X and the most common alpha-sarcoglycan mutation, missense c.229C>T; p.R77C, by single-stranded oligonucleotide-mediated gene editing, using the CRISPR/Cas9 gene-editing system to enhance the frequency of homology-directed repair. We demonstrated seamless, allele-specific correction at efficiencies of 0.7-1.5%. As an alternative, we also carried out precise gene addition strategies for correction of the LGMD2B iPSC by integration of wild-type dysferlin cDNA into the H11 safe harbor locus on chromosome 22, using dual integrase cassette exchange (DICE) or TALEN-assisted homologous recombination for insertion precise (THRIP). These methods employed TALENs and homologous recombination, and DICE also utilized site-specific recombinases. With DICE and THRIP, we obtained targeting efficiencies after selection of ~20%. We purified iPSC corrected by all methods and verified rescue of appropriate levels of dysferlin and alpha-sarcoglycan protein expression and correct localization, as shown by immunoblot and immunocytochemistry. In summary, we demonstrate for the first time precise correction of LGMD iPSC and validation of expression, opening the possibility of cell therapy utilizing these corrected iPSC.
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Affiliation(s)
- Soeren Turan
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Alfonso P Farruggio
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Waracharee Srifa
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - John W Day
- Department of Neurology, Stanford University School of Medicine, Stanford, California, USA
| | - Michele P Calos
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
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16
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Turan S, Farruggio AP, Srifa W, Day JW, Calos MP. Precise Correction of Disease Mutations in Induced Pluripotent Stem Cells Derived From Patients With Limb Girdle Muscular Dystrophy. Mol Ther 2016; 24:685-96. [PMID: 26916285 DOI: 10.1038/mt.2016.40] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 02/09/2016] [Indexed: 12/22/2022] Open
Abstract
Limb girdle muscular dystrophies types 2B (LGMD2B) and 2D (LGMD2D) are degenerative muscle diseases caused by mutations in the dysferlin and alpha-sarcoglycan genes, respectively. Using patient-derived induced pluripotent stem cells (iPSC), we corrected the dysferlin nonsense mutation c.5713C>T; p.R1905X and the most common alpha-sarcoglycan mutation, missense c.229C>T; p.R77C, by single-stranded oligonucleotide-mediated gene editing, using the CRISPR/Cas9 gene-editing system to enhance the frequency of homology-directed repair. We demonstrated seamless, allele-specific correction at efficiencies of 0.7-1.5%. As an alternative, we also carried out precise gene addition strategies for correction of the LGMD2B iPSC by integration of wild-type dysferlin cDNA into the H11 safe harbor locus on chromosome 22, using dual integrase cassette exchange (DICE) or TALEN-assisted homologous recombination for insertion precise (THRIP). These methods employed TALENs and homologous recombination, and DICE also utilized site-specific recombinases. With DICE and THRIP, we obtained targeting efficiencies after selection of ~20%. We purified iPSC corrected by all methods and verified rescue of appropriate levels of dysferlin and alpha-sarcoglycan protein expression and correct localization, as shown by immunoblot and immunocytochemistry. In summary, we demonstrate for the first time precise correction of LGMD iPSC and validation of expression, opening the possibility of cell therapy utilizing these corrected iPSC.
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Affiliation(s)
- Soeren Turan
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Alfonso P Farruggio
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Waracharee Srifa
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - John W Day
- Department of Neurology, Stanford University School of Medicine, Stanford, California, USA
| | - Michele P Calos
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
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17
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Fayssoil A, Nardi O, Annane D, Orlikowski D. Left ventricular function in alpha-sarcoglycanopathy and gamma-sarcoglycanopathy. Acta Neurol Belg 2014; 114:257-9. [PMID: 24464767 DOI: 10.1007/s13760-013-0276-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 12/30/2013] [Indexed: 11/25/2022]
Abstract
Sarcoglycanopathies are autosomic recessive muscular dystrophies, secondary to mutations of the sarcoglycan complex. Heart can be involved in sarcoglycanopathies. We sought to analyse left ventricular function in patients with alpha-sarcoglycanopathy and gamma-sarcoglycanopathy. We conducted a retrospective study that aimed to analyse clinical and echocardiographic data of patients with sarcoglycanopathies. Our study included 19 patients: eight patients with alpha-sarcoglycanopathy and 11 patients with gamma-sarcoglycanopathy. Mean age was 37.8 ± 8.7 years in alpha-sarcoglycanopathy and 36 ± 7.3 years in gamma-sarcoglycanopathy. Mean VC was, respectively, 36.3 ± 18 % in alpha-sarcoglycanopathy and 23.5 ± 6.8 % in gamma-sarcoglycanopathy (p 0.05). 1/8 patients disclosed a left ventricular dysfunction with a left ventricular ejection fraction (LVEF) <50 % in alpha-sarcoglycanopathy, whereas 5/11 patients disclosed a left ventricular dysfunction (LVEF < 50 %) in gamma-sarcoglycanopathy. LV was altered in gamma-sarcoglycanopathy than in alpha-sarcoglycanopathy (LVEF at 45.6 ± 18 vs. 59.6 ± 5.9 % p 0.018). We found a significant alteration of the left ventricular function in gamma-sarcoglycanopathy compared to alpha-sarcoglycanopathy.
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Affiliation(s)
- Abdallah Fayssoil
- Réanimation médicale, Hôpital Raymond Poincaré (AP-HP), Université de Versailles SQY, 104 boulevard Raymond Poincaré, 92380, Garches, France,
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18
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Townsend D. Finding the sweet spot: assembly and glycosylation of the dystrophin-associated glycoprotein complex. Anat Rec (Hoboken) 2014; 297:1694-705. [PMID: 25125182 PMCID: PMC4135523 DOI: 10.1002/ar.22974] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [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: 01/10/2014] [Accepted: 03/27/2014] [Indexed: 01/12/2023]
Abstract
The dystrophin-associated glycoprotein complex (DGC) is a collection of glycoproteins that are essential for the normal function of striated muscle and many other tissues. Recent genetic studies have implicated the components of this complex in over a dozen forms of muscular dystrophy. Furthermore, disruption of the DGC has been implicated in many forms of acquired disease. This review aims to summarize the current state of knowledge regarding the processing and assembly of dystrophin-associated proteins with a focus primarily on the dystroglycan heterodimer and the sarcoglycan complex. These proteins form the transmembrane portion of the DGC and undergo a complex multi-step processing with proteolytic cleavage, differential assembly, and both N- and O-glycosylation. The enzymes responsible for this processing and a model describing the sequence and subcellular localization of these events are discussed.
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Affiliation(s)
- Dewayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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19
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Gurrala RR, Alla VM, Aronow WS, Shankar JS, Angamutta MK, Lanka K, Challa S, Nair CK. Occult left ventricular dysfunction diagnosed by myocardial performance index in patients with limb girdle muscle dystrophy: A case control study. Int J Angiol 2012; 16:139-42. [PMID: 22477330 DOI: 10.1055/s-0031-1278268] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The myocardial performance index (MPI) was assessed in 30 patients with limb girdle muscle dystrophy (LGMD) with a normal left ventricular ejection fraction (greater than 50%), as well as in 30 age- and sex-matched healthy adults with a left ventricular ejection fraction greater than 50%. MPIs derived by pulsed-wave Doppler and tissue Doppler were also compared. The MPI was 0.37±0.09 in the LGMD patients and 0.29±0.09 in the control group (P=0.003). These data show that patients with LGMD have occult cardiac dysfunction as evidenced by a higher MPI than the controls. There was good agreement between the MPIs measured by pulsed-wave Doppler and tissue Doppler methods in these patients.
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Affiliation(s)
- Rajashekar R Gurrala
- Department of Cardiology, Nizam's Institute of Medical Sciences, Hyderabad, India
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20
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Boyden SE, Salih MA, Duncan AR, White AJ, Estrella EA, Burgess SL, Seidahmed MZ, Al-Jarallah AS, Alkhalidi HM, Al-Maneea WM, Bennett RR, Alshemmari SH, Kunkel LM, Kang PB. Efficient identification of novel mutations in patients with limb girdle muscular dystrophy. Neurogenetics 2010; 11:449-55. [PMID: 20623375 DOI: 10.1007/s10048-010-0250-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 06/22/2010] [Indexed: 11/11/2022]
Abstract
Limb girdle muscular dystrophy type 2 (LGMD2) is a genetically heterogeneous autosomal recessive disorder caused by mutations in 15 known genes. DNA sequencing of all candidate genes can be expensive and laborious, whereas a selective sequencing approach often fails to provide a molecular diagnosis. We aimed to efficiently identify pathogenic mutations via homozygosity mapping in a population in which the genetics of LGMD2 has not been well characterized. Thirteen consanguineous families containing a proband with LGMD2 were recruited from Saudi Arabia, and for 11 of these families, selected individuals were genotyped at 10,204 single nucleotide polymorphisms. Linkage analysis excluded all but one or two known genes in ten of 11 genotyped families, and haplotype comparisons between families allowed further reduction in the number of candidate genes that were screened. Mutations were identified by DNA sequencing in all 13 families, including five novel mutations in four genes, by sequencing at most two genes per family. One family was reclassified as having a different myopathy based on genetic and clinical data after linkage analysis excluded all known LGMD2 genes. LGMD2 subtypes A and B were notably absent from our sample of patients, indicating that the distribution of LGMD2 mutations in Saudi Arabian families may be different than in other populations. Our data demonstrate that homozygosity mapping in consanguineous pedigrees offers a more efficient means of discovering mutations that cause heterogeneous disorders than comprehensive sequencing of known candidate genes.
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21
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Navarro C, Teijeira S. Molecular diagnosis of muscular dystrophies, focused on limb girdle muscular dystrophies. ACTA ACUST UNITED AC 2009; 3:631-47. [PMID: 23496048 DOI: 10.1517/17530050903313988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Muscular dystrophies include a spectrum of muscle disorders, some of which are phenotypically well characterized. The identification of dystrophin as the causative factor in Duchenne muscular dystrophy has led to the development of molecular genetics and has facilitated the division of muscular dystrophies into distinct groups, among which are the 'limb girdle muscular dystrophies'. OBJECTIVES This article reviews the methodology to be used in the diagnosis of muscular dystrophies, focused on the groups of limb girdle muscular dystrophies, and the development of new strategies to reach a final molecular diagnosis. METHOD A literature review (Medline) from 1985 to the present. CONCLUSION Immunohistochemistry and western blotting analyses of the proteins involved in the various forms of muscular dystrophies have permitted a refined pathological approach necessary to conduct genetic studies and to offer appropriate genetic counseling. The application of molecular medicine in genetic muscular dystrophies also brings great hope to the therapeutic management of these patients.
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Affiliation(s)
- Carmen Navarro
- University Hospital of Vigo, Department of Pathology and Neuropathology, Meixoeiro, s/n, 36200 Vigo - Pontevedra, Spain +34 986 81 11 11 ext. 211661 ; +34 986 27 64 16 ;
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22
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Abstract
Sarcoglycanopathies are a group of autosomal recessive muscle-wasting disorders caused by genetic defects in one of four cell membrane glycoproteins, alpha-, beta-, gamma- or delta-sarcoglycan. These four sarcoglycans form a subcomplex that is closely linked to the major dystrophin-associated protein complex, which is essential for membrane integrity during muscle contraction and provides a scaffold for important signalling molecules. Proper assembly, trafficking and targeting of the sarcoglycan complex is of vital importance, and mutations that severely perturb tetramer formation and localisation result in sarcoglycanopathy. Gene defects in one sarcoglycan cause the absence or reduced concentration of the other subunits. Most genetic defects generate mutated proteins that are degraded through the cell's quality control system; however, in many cases, conformational modifications do not affect the function of the protein, yet it is recognised as misfolded and prematurely degraded. Recent evidence shows that misfolded sarcoglycans could be rescued to the cell membrane by assisting their maturation along the ER secretory pathway. This review summarises the etiopathogenesis of sarcoglycanopathies and highlights the quality control machinery as a potential pharmacological target for therapy of these genetic disorders.
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Affiliation(s)
- Dorianna Sandonà
- Department of Biomedical Sciences, University of Padova, 35121
Padova, Italy
| | - Romeo Betto
- C.N.R. Institute of Neuroscience, Neuromuscular Biology and
Physiopathology, 35121 Padova, Italy
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23
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Xu R, DeVries S, Camboni M, Martin PT. Overexpression of Galgt2 reduces dystrophic pathology in the skeletal muscles of alpha sarcoglycan-deficient mice. Am J Pathol 2009; 175:235-47. [PMID: 19498002 DOI: 10.2353/ajpath.2009.080967] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recent studies have shown that a number of genes that are not mutated in various forms of muscular dystrophy may serve as surrogates to protect skeletal myofibers from injury. One such gene is Galgt2, which is also called cytotoxic T cell GalNAc transferase in mice. In this study, we show that Galgt2 overexpression reduces the development of dystrophic pathology in the skeletal muscles of mice lacking alpha sarcoglycan (Sgca), a mouse model for limb girdle muscular dystrophy 2D. Galgt2 transgenic Sgca(-/-) mice showed reduced levels of myofiber damage, as evidenced by i) normal levels of serum creatine kinase activity, ii) a lack of Evans blue dye uptake into myofibers, iii) normal levels of mouse locomotor activity, and iv) near normal percentages of myofibers with centrally located nuclei. In addition, the overexpression of Galgt2 in the early postnatal period using an adeno-associated virus gene therapy vector protected Sgca(-/-) myofibers from damage, as observed using histopathology measurements. Galgt2 transgenic Sgca(-/-) mice also had increased levels of glycosylation of alpha dystroglycan with the CT carbohydrate, but showed no up-regulation of beta, gamma, delta, or epsilon sarcoglycan. These data, coupled with results from our previous studies, show that Galgt2 has therapeutic effects in three distinct forms of muscular dystrophy and may, therefore, have a broad spectrum of therapeutic potential for the treatment of various myopathies.
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Affiliation(s)
- Rui Xu
- the Departments of Pediatrics, Center for Gene Therapy, Physiology and Cell Biology, Ohio State University College of Medicine, Columbus, Ohio 43205, USA
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24
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Li D, Long C, Yue Y, Duan D. Sub-physiological sarcoglycan expression contributes to compensatory muscle protection in mdx mice. Hum Mol Genet 2009; 18:1209-20. [PMID: 19131360 PMCID: PMC2655768 DOI: 10.1093/hmg/ddp015] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [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] [Received: 12/06/2008] [Revised: 12/31/2008] [Accepted: 01/06/2009] [Indexed: 12/11/2022] Open
Abstract
Sarcoglycans are a group of single-pass transmembrane glycoproteins. In striated muscle, sarcoglycans interact with dystrophin and other dystrophin-associated proteins (DAPs) to form the dystrophin-associated glycoprotein complex (DGC). The DGC protects the sarcolemma from contraction-induced injury. Duchenne muscular dystrophy (DMD) is caused by dystrophin gene mutations. In the absence of dystrophin, the DGC is disassembled from the sarcolemma. This initiates a chain reaction of muscle degeneration, necrosis, inflammation and fibrosis. In contrast to human patients, dystrophin-null mdx mice are only mildly affected. Enhanced muscle regeneration and the up-regulation of utrophin and integrin are thought to protect mdx muscle. Interestingly, trace amounts of sarcoglycans and other DAPs can be detected at the mdx sarcolemma. It is currently unclear whether sub-physiological sarcoglycan expression also contributes to the mild phenotype in mdx mice. To answer this question, we generated delta-sarcoglycan/dystrophin double knockout mice (delta-Dko) in which residual sarcoglycans were completely eliminated from the sarcolemma. Interestingly, utrophin levels were further increased in these mice. However, enhanced utrophin expression did not mitigate disease. The clinical manifestation of delta-Dko mice was worse than that of mdx mice. They showed characteristic dystrophic signs, body emaciation and more macrophage infiltration. Their lifespan was reduced by 60%. Furthermore, delta-Dko muscle generated significantly less absolute muscle force and became more susceptible to contraction-induced injury. Our results suggest that sub-physiological sarcoglycan expression plays a critical role in ameliorating muscle disease in mdx mice. We speculate that low-level sarcoglycan expression may represent a useful strategy to palliate DMD.
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Affiliation(s)
| | | | | | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO, USA
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25
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26
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Davis J, Westfall MV, Townsend D, Blankinship M, Herron TJ, Guerrero-Serna G, Wang W, Devaney E, Metzger JM. Designing heart performance by gene transfer. Physiol Rev 2008; 88:1567-651. [PMID: 18923190 DOI: 10.1152/physrev.00039.2007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The birth of molecular cardiology can be traced to the development and implementation of high-fidelity genetic approaches for manipulating the heart. Recombinant viral vector-based technology offers a highly effective approach to genetically engineer cardiac muscle in vitro and in vivo. This review highlights discoveries made in cardiac muscle physiology through the use of targeted viral-mediated genetic modification. Here the history of cardiac gene transfer technology and the strengths and limitations of viral and nonviral vectors for gene delivery are reviewed. A comprehensive account is given of the application of gene transfer technology for studying key cardiac muscle targets including Ca(2+) handling, the sarcomere, the cytoskeleton, and signaling molecules and their posttranslational modifications. The primary objective of this review is to provide a thorough analysis of gene transfer studies for understanding cardiac physiology in health and disease. By comparing results obtained from gene transfer with those obtained from transgenesis and biophysical and biochemical methodologies, this review provides a global view of cardiac structure-function with an eye towards future areas of research. The data presented here serve as a basis for discovery of new therapeutic targets for remediation of acquired and inherited cardiac diseases.
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Affiliation(s)
- Jennifer Davis
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
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27
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Kobuke K, Piccolo F, Garringer KW, Moore SA, Sweezer E, Yang B, Campbell KP. A common disease-associated missense mutation in alpha-sarcoglycan fails to cause muscular dystrophy in mice. Hum Mol Genet 2008; 17:1201-13. [PMID: 18252746 DOI: 10.1093/hmg/ddn009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Limb-girdle muscular dystrophy type 2D (LGMD2D) is caused by autosomal recessive mutations in the alpha-sarcoglycan gene. An R77C substitution is the most prevalent cause of the disease, leading to disruption of the sarcoglycan-sarcospan complex. To model this common mutation, we generated knock-in mice with an H77C substitution in alpha-sarcoglycan. The floxed neomycin (Neo)-cassette retained at the targeted H77C alpha-sarcoglycan locus caused a loss of alpha-sarcoglycan expression, resulting in muscular dystrophy in homozygotes, whereas Cre-mediated deletion of the floxed Neo-cassette led to recovered H77C alpha-sarcoglycan expression. Contrary to expectations, mice homozygous for the H77C-encoding allele expressed both this mutant alpha-sarcoglycan and the other components of the sarcoglycan-sarcospan complex in striated muscle, and did not develop muscular dystrophy. Accordingly, conditional rescued expression of the H77C protein in striated muscle of the alpha-sarcoglycan-deficient mice prevented the disease. Adding to the case that the behavior of mutant alpha-sarcoglycan is different between humans and mice, mutant human R77C alpha-sarcoglycan restored the expression of the sarcoglycan-sarcospan complex when introduced by adenoviral vector into the skeletal muscle of previously created alpha-sarcoglycan null mice. These findings indicate that the alpha-sarcoglycan with the most frequent missense mutation in LGMD2D is correctly processed, is transported to the sarcolemma, and is fully functional in mouse muscle. Our study presents an unexpected difference in the behavior of a missense-mutated protein in mice versus human patients, and emphasizes the need to understand species-specific protein quality control systems.
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Affiliation(s)
- Kazuhiro Kobuke
- Howard Hughes Medical Institute, The University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa 52242, USA
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28
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Han R, Bansal D, Miyake K, Muniz VP, Weiss RM, McNeil PL, Campbell KP. Dysferlin-mediated membrane repair protects the heart from stress-induced left ventricular injury. J Clin Invest 2007; 117:1805-13. [PMID: 17607357 PMCID: PMC1904311 DOI: 10.1172/jci30848] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.2] [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: 11/03/2006] [Accepted: 04/10/2007] [Indexed: 12/21/2022] Open
Abstract
Dilated cardiomyopathy is a life-threatening syndrome that can arise from a myriad of causes, but predisposition toward this malady is inherited in many cases. A number of inherited forms of dilated cardiomyopathy arise from mutations in genes that encode proteins involved in linking the cytoskeleton to the extracellular matrix, and disruption of this link renders the cell membrane more susceptible to injury. Membrane repair is an important cellular mechanism that animal cells have developed to survive membrane disruption. We have previously shown that dysferlin deficiency leads to defective membrane resealing in skeletal muscle and muscle necrosis; however, the function of dysferlin in the heart remains to be determined. Here, we demonstrate that dysferlin is also involved in cardiomyocyte membrane repair and that dysferlin deficiency leads to cardiomyopathy. In particular, stress exercise disturbs left ventricular function in dysferlin-null mice and increases Evans blue dye uptake in dysferlin-deficient cardiomyocytes. Furthermore, a combined deficiency of dystrophin and dysferlin leads to early onset cardiomyopathy. Our results suggest that dysferlin-mediated membrane repair is important for maintaining membrane integrity of cardiomyocytes, particularly under conditions of mechanical stress. Thus, our study establishes what we believe is a novel mechanism underlying the cardiomyopathy that results from a defective membrane repair in the absence of dysferlin.
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Affiliation(s)
- Renzhi Han
- Howard Hughes Medical Institute,
Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center,
Department of Molecular Physiology and Biophysics,
Department of Neurology, and
Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Institute of Molecular Medicine and Genetics and
Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA
| | - Dimple Bansal
- Howard Hughes Medical Institute,
Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center,
Department of Molecular Physiology and Biophysics,
Department of Neurology, and
Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Institute of Molecular Medicine and Genetics and
Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA
| | - Katsuya Miyake
- Howard Hughes Medical Institute,
Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center,
Department of Molecular Physiology and Biophysics,
Department of Neurology, and
Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Institute of Molecular Medicine and Genetics and
Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA
| | - Viviane P. Muniz
- Howard Hughes Medical Institute,
Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center,
Department of Molecular Physiology and Biophysics,
Department of Neurology, and
Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Institute of Molecular Medicine and Genetics and
Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA
| | - Robert M. Weiss
- Howard Hughes Medical Institute,
Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center,
Department of Molecular Physiology and Biophysics,
Department of Neurology, and
Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Institute of Molecular Medicine and Genetics and
Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA
| | - Paul L. McNeil
- Howard Hughes Medical Institute,
Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center,
Department of Molecular Physiology and Biophysics,
Department of Neurology, and
Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Institute of Molecular Medicine and Genetics and
Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA
| | - Kevin P. Campbell
- Howard Hughes Medical Institute,
Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center,
Department of Molecular Physiology and Biophysics,
Department of Neurology, and
Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Institute of Molecular Medicine and Genetics and
Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA
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29
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Charniot JC, Desnos M, Zerhouni K, Bonnefont-Rousselot D, Albertini JP, Salama JZ, Bassez G, Komajda M, Artigou JY. Severe dilated cardiomyopathy and quadriceps myopathy due to lamin A/C gene mutation: A phenotypic study. Eur J Heart Fail 2006; 8:249-56. [PMID: 16314145 DOI: 10.1016/j.ejheart.2005.08.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [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: 11/30/2004] [Revised: 07/01/2005] [Accepted: 08/16/2005] [Indexed: 11/17/2022] Open
Abstract
UNLABELLED This study reports a family affected by a new phenotype associated with dilated cardiomyopathy and quadriceps myopathy. METHODS 29 family members underwent a physical and neurological examination, including an electromyogram and biopsy of muscle abnormalities. A cardiac examination was performed in all subjects. RESULTS The family pedigree (n=72) demonstrated that transmission was autosomal dominant. Eleven subjects had cardiac involvement, only four had quadriceps muscle involvement. Cardiac impairment preceded neurological involvement. The mean age for neurological involvement was 44+/-0.8 years (range 43-45) and cardiac involvement was 37+/-7.9 years (range: 24-45). Cardiac involvement consisted of: hypokinetic dilated cardiomyopathy (64%); atrial fibrillation (100%); ventricular arrhythmias (64%); impaired conduction with bundle branch or complete atrio ventricular block (73%). Four patients required pacemakers and anti arrhythmic therapies. Four patients died: two of refractory heart failure and two of sudden death; two patients were resuscitated following cardiac arrest. Three patients required a prophylactic implantable cardiac defibrillator (ICD). Muscle morphological abnormalities were characterized by a variable number of fibers with rimmed vacuoles. The quadriceps deteriorated progressively without impairment of other muscles. Genotypic study showed a lamin A/C gene mutation. CONCLUSIONS This family was affected by a new phenotype composed of an autosomal dominant severe dilated cardiomyopathy with conduction defects or arrhythmias and quadriceps myopathy. Cardiac abnormalities preceded neuromuscular disorders and defined the prognosis of this disease.
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30
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Abstract
In this article, we review the molecular pathology of muscular dystrophies caused by defects of proteins located within or near cell membranes. These disorders include Bethlem myopathy, merosinopathy, dystrophinopathy, sarcoglycanopathies, integrinopathy, dysferlinopathy and caveolinopathy. We refer to these diseases collectively as sarcolemmopathy. Here, we describe the biological functions of these proteins in the context of muscular contractions and their roles in the infrastructure of muscle; defects of muscle infrastructures cause those diseases. As an example, in dystrophinopathy, cell membranes have mechanical defects due to the absence of dystrophin. Cracks of the cell membrane induced by muscle contraction may allow the influx and efflux of substances that trigger muscle cell degeneration. However, such cracks may be resealed on relaxation. In addition, dystrophinopathy causes secondary defects of various dystrophin-associated proteins suggesting that defects in cell signaling participate in the pathologic process. With regard to other sarcolemmopathies, we discuss pathological mechanisms based on available data.
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Affiliation(s)
- E Ozawa
- National Institute of Neuroscience, NCNP, Tokyo, Japan.
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31
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Abstract
Most neuromuscular disorders display only non-specific myopathological features in routine histological preparations. However, a number of proteins, including sarcolemmal, sarcomeric, and nuclear proteins as well as enzymes with defects responsible for neuromuscular disorders, have been identified during the past two decades, allowing a more specific and firm diagnosis of muscle diseases. Identification of protein defects relies predominantly on immunohistochemical preparations and on Western blot analysis. While immunohistochemistry is very useful in identifying abnormal expression of primary protein abnormalities in recessive conditions, it is less helpful in detecting primary defects in dominantly inherited disorders. Abnormal immunohistochemical expression patterns can be confirmed by Western blot analysis which may also be informative in dominant disorders, although its role has yet to be established. Besides identification of specific protein defects, immunohistochemistry is also helpful in the differentiation of inflammatory myopathies by subtyping cellular infiltrates and demonstrating up-regulation of subtle immunological parameters such as cell adhesion molecules. The role of immunohistochemistry in denervating disorders, however, remains controversial in the absence of a reliable marker of muscle fibre denervation. Nevertheless, as well as the diagnostic value of immunocytochemical analysis it may also widen understanding of muscle fibre pathology as well as help in the development of therapeutic strategies.
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Affiliation(s)
- D S Tews
- Edinger-Institute of the Johann-Wolfgang Goethe-University, Frankfurt, Germany.
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32
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Iwata Y, Shigekawa M, Wakabayashi S. Cardiac syntrophin isoforms: Species-dependent expression, association with dystrophin complex and subcellular localization. Mol Cell Biochem 2005; 268:59-66. [PMID: 15724438 DOI: 10.1007/s11010-005-2998-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Syntrophin is known to be a component of the dystrophin-glycoprotein complex (DGC), a membrane/cytoskeleton-anchoring structure that is essential for the maintenance of viability of sarcolemma. We purified DGC from hearts of human and several animal species, and compared their protein composition. While almost all components of DGC were present in various species, proteins with the apparent molecular mass of 50-65 kDa corresponding to syntrophin isoforms were very different among them. Three isoforms of syntrophin (alpha1, beta1, beta2) were expressed in hamster, rat and canine ventricles, whereas only alpha1-isoform was mainly expressed in human and rabbit ventricles. Immunohistochemical analysis revealed that alpha1-and beta2-syntrophins were co-localized in sarcolemma and in T-tubules of canine ventricles. However, despite membrane localization of most syntrophins, subcellular fractionation revealed that part of syntrophins were recovered in the cytosolic fraction devoid of other components of DGC, raising the possibility that syntrophins may play multiple roles in various intracellular sites of cardiac muscle cells. Species-dependent expression and unique subcellular localization of syntrophins in cardiac muscle may contribute to the variable severity of muscle dysgenesis caused by the same primary defect in components of DGC of human and other animal species.
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Affiliation(s)
- Yuko Iwata
- Department of Molecular Physiology, National Cardiovascular Center Research Institute, Fujishiro-dai, Suita, Osaka, Japan.
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33
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Hackman P, Juvonen V, Sarparanta J, Penttinen M, Aärimaa T, Uusitalo M, Auranen M, Pihko H, Alén R, Junes M, Lönnqvist T, Kalimo H, Udd B. Enrichment of the R77C α-sarcoglycan gene mutation in finnish LGMD2D patients. Muscle Nerve 2004; 31:199-204. [PMID: 15736300 DOI: 10.1002/mus.20267] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Limb-girdle muscular dystrophy 2D (LGMD2D) is caused by mutations in the alpha-sarcoglycan gene (SGCA). The most frequently reported mutation, 229CGC>TGC (R77C) in exon 3 of SGCA, results in the substitution of arginine by cysteine. We present here the clinical, immunohistochemical, and genetic data of 11 Finnish patients with LGMD2D caused by mutations in SGCA. Mutational analysis showed 10 patients homozygous and 1 compound heterozygous for R77C. A wide spectrum of SGCA mutations has been reported previously. Our results show an enrichment of R77C in Finland, further underlined by the observed carrier frequency of 1 per 150. According to the annual birth rate of approximately 60,000 in Finland, one LGMD2D patient with a homozygous mutation is expected to be born every 1 or 2 years on average. The presence of an ancient founder mutation is indicated by the fact that all patients shared a short common haplotype extending > or = 790 kilobases. Our results emphasize the need to include the SGCA gene R77C mutation test in routine DNA analyses of severe dystrophinopathy-like muscular dystrophies in Finland, and suggest that the applicability of this test in other populations should be studied as well.
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Affiliation(s)
- P Hackman
- Folkhälsan Institute of Genetics and Department of Medical Genetics, University of Helsinki, Biomedicum, Helsinki, Finland.
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34
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Abstract
Limb girdle muscular dystrophies (LGMDs) are a genetically heterogeneous group of primary myopathies involving progressive weakness and wasting of the muscles in the hip and shoulder girdles, with distal spread to the bulbar or respiratory musculature in rare cases. Depending on the mode of genetic transmission, six autosomal dominant forms (LGMD1A-F, 10-25%) and ten autosomal recessive forms (LGMD2A-J, 75-90%) are currently known. The prevalence of LGMDs is 0.8/100,000. These conditions are caused by mutations in genes encoding for myotilin (5q31, LGMD1A), lamin A/C (1q11-q21.2, LGMD1B), caveolin-3 (3p25, LGMD1C), unknown proteins (7q, LGMD1D, 6q23, LGMD1E, 7q32.1-32.2., LGMD1F), calpain-3 (15q15.1-21.1, LGMD2A), dysferlin (2p13.3-13.1, LGMD2B), gamma-sarcoglycan (13q12, LGMD2C), alpha-sarcoglycan, also known as adhalin (17q12-q21.3, LGMD2D), beta-sarcoglycan (4q12, LGMD2E), delta-sarcoglycan (5q33-q34, LGMD2F), telethonin (17q11-q12, LGMD2G), E3-ubiquitin ligase (9q31-q34.1, LGMD2H), fukutin-related protein (19q13.3, LGMD2I), and titin (2q31, LGMD2J). Cardiac involvement has been described for LGMD1B-E, LGMD2C-G, and LGMD2I. The time of onset varies between early childhood and middle age. There is no male or female preponderance. Disease progression and life expectancy vary widely, even among different members of the same family. The diagnosis is based primarily on DNA analysis. The history, clinical neurological examinations, blood chemistry investigations, electromyography, and muscle biopsy also provide information that is helpful for the diagnosis. No causal therapy is currently available.
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Affiliation(s)
- J Finsterer
- Neurologische Abteilung, KA Rudolfstiftung, Wien, Osterreich.
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35
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Abstract
The limb-girdle muscular dystrophies are a diverse group of muscle-wasting disorders characteristically affecting the large muscles of the pelvic and shoulder girdles. Molecular genetic analyses have demonstrated causative mutations in the genes encoding a disparate collection of proteins involved in all aspects of muscle cell biology. Muscular dystrophy includes a spectrum of disorders caused by loss of the linkage between the extracellular matrix and the actin cytoskeleton. Within this are the forms of limb-girdle muscular dystrophy caused by deficiencies of the sarcoglycan complex and by aberrant glycosylation of alpha-dystroglycan caused by mutations in the fukutin-related protein gene. However, other forms of this disease have distinct pathophysiological mechanisms. For example, deficiency of dysferlin disrupts sarcolemmal membrane repair, whilst loss of calpain-3 may exert its pathological influence either by perturbation of the IkappaBalpha/NF-kappaB pathway, or through calpain-dependent cytoskeletal remodelling. Caveolin-3 is implicated in numerous cell-signalling pathways and involved in the biogenesis of the T-tubule system. Alterations in the nuclear lamina caused by mutations in laminA/C, sarcomeric changes in titin, telethonin or myotilin at the Z-disc, and subtle changes in the extracellular matrix proteins laminin-alpha2 or collagen VI can all lead to a limb-girdle muscular dystrophy phenotype, although the specific pathological mechanisms remain obscure. Differential diagnosis of these disorders requires the careful application of a broad range of disciplines: clinical assessment, immunohistochemistry and immunoblotting using a panel of antibodies and extensive molecular genetic analyses.
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Affiliation(s)
- S H Laval
- Institute of Human Genetics, International Centre for Life, Newcastle-upon-Tyne, UK
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36
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Love DR. Limb girdle muscular dystrophy: use of dHPLC and direct sequencing to detect sarcoglycan gene mutations in a New Zealand cohort. Clin Genet 2004. [PMID: 15032976 DOI: 10.1111/j..2004.00193.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Dinçer P, Balci B, Yuva Y, Talim B, Brockington M, Dinçel D, Torelli S, Brown S, Kale G, Haliloglu G, Gerçeker FO, Atalay RC, Yakicier C, Longman C, Muntoni F, Topaloglu H. A novel form of recessive limb girdle muscular dystrophy with mental retardation and abnormal expression of α-dystroglycan. Neuromuscul Disord 2003; 13:771-8. [PMID: 14678799 DOI: 10.1016/s0960-8966(03)00161-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The limb girdle muscular dystrophies are a heterogeneous group of conditions characterized by proximal muscle weakness and disease onset ranging from infancy to adulthood. We report here eight patients from seven unrelated families affected by a novel and relatively mild form of autosomal recessive limb girdle muscular dystrophy (LGMD2) with onset in the first decade of life and characterized by severe mental retardation but normal brain imaging. Immunocytochemical studies revealed a significant selective reduction of alpha-dystroglycan expression in the muscle biopsies. Linkage analysis excluded known loci for both limb girdle muscular dystrophy and congenital muscular dystrophies in the consanguineous families. We consider that this represents a novel form of muscular dystrophy with associated brain involvement. The biochemical studies suggest that it may belong to the growing number of muscular dystrophies with abnormal expression of alpha-dystroglycan.
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Affiliation(s)
- Pervin Dinçer
- Department of Medical Biology, Hacettepe University, Ankara, Turkey
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38
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Yan W, Ma L, Burns KH, Matzuk MM. HILS1 is a spermatid-specific linker histone H1-like protein implicated in chromatin remodeling during mammalian spermiogenesis. Proc Natl Acad Sci U S A 2003; 100:10546-51. [PMID: 12920187 PMCID: PMC193598 DOI: 10.1073/pnas.1837812100] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Chromatin remodeling is a major event that occurs during mammalian spermiogenesis, the process of spermatid maturation into spermatozoa. Nuclear condensation during spermiogenesis is accomplished by replacing somatic histones (linker histone H1 and core histones) and the testis-specific linker histone, H1t, with transition proteins and protamines. It has long been thought that H1t is the only testis-specific linker histone, and that all linker histones are replaced by transition proteins, and subsequently by protamines during spermiogenesis. Here, we report the identification and characterization of a spermatid-specific linker histone H1-like protein (termed HILS1) in the mouse and human. Both mouse and human HILS1 genes are located in intron 8 of the alpha-sarcoglycan genes. HILS1 is highly expressed in nuclei of elongating and elongated spermatids (steps 9-15). HILS1 displays several biochemical properties that are similar to those of linker histones, including the abilities to bind reconstituted mononucleosomes, produce a chromatosome stop during micrococcal nuclease digestion, and aggregate chromatin. Because HILS1 is expressed in late spermatids that do not contain core histones, HILS1 may participate in spermatid nuclear condensation through a mechanism distinct from that of linker histones. Because HILS1 also belongs to the large winged helix/forkhead protein superfamily, HILS1 may also regulate gene transcription, DNA repair, and/or other chromosome processes during mammalian spermiogenesis.
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Affiliation(s)
- Wei Yan
- Department of Pathology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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39
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Abstract
Fifteen forms of limb-girdle muscular dystrophies (5 autosomal dominant and 10 autosomal recessive) have already been found. The 10 genes responsible for the autosomal recessive forms, which account for more than 90% of the cases, had their product identified. This review will focus on the most recent data on autosomal recessive-limb-girdle muscular dystrophy and on our own experience of more than 300 patients studied from 120 families who were classified (based on DNA, linkage and muscle protein analysis) in eight different forms of autosomal recessive-limb-girdle muscular dystrophy. Genotype-phenotype correlations in this highly heterogeneous group confirm that patients with mutations in different genes may be clinically indistinguishable. On the other hand, for most forms of autosomal recessive-limb-girdle muscular dystrophy a discordant phenotype, ranging from a relatively severe course to mildly affected or asymptomatic carriers may be seen in patients carrying the same mutation even within the same family. A gender difference in the severity of the phenotype might exist for some forms of autosomal recessive-limb-girdle muscular dystrophy, such as calpainopathy and telethoninopathy but not for others, such as dysferlinopathies or sarcoglycanopathies. Understanding similarities in patients affected by mutations in different genes, differences in patients carrying the same mutations or why some muscles are affected while others are spared remains a major challenge. It will depend on future knowledge of gene expression, gene and protein interactions and on identifying modifying genes and other factors underlying clinical variability.
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Affiliation(s)
- Mayana Zatz
- Human Genome Research Center, Departamento de Biologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, Cidade Universitária, CEP 05508-900, Sao Paulo, Brazil.
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40
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Jones KJ, Compton AG, Yang N, Mills MA, Peters MF, Mowat D, Kunkel LM, Froehner SC, North KN. Deficiency of the syntrophins and alpha-dystrobrevin in patients with inherited myopathy. Neuromuscul Disord 2003; 13:456-67. [PMID: 12899872 DOI: 10.1016/s0960-8966(03)00066-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [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: 10/27/2022]
Abstract
The syntrophins and dystrobrevins are members of the dystrophin-associated protein complex, and are thought to function as modular adaptors for signalling proteins recruited to the sarcolemmal membrane. We have characterised the expression of the syntrophins (alpha-, beta1-, and beta2-) and alpha-dystrobrevin by immunohistochemistry in normal human muscle and in biopsies from 162 patients with myopathies of unknown aetiology (with normal staining for dystrophin and other dystrophin-associated proteins). Unlike mice, beta2-syntrophin is expressed at the sarcolemma in post-natal human skeletal muscle. Deficiency of alpha-dystrobrevin +/- beta2-syntrophin was present in 16/162 (10%) patients, compared to age-matched controls. All patients presented with congenital-onset hypotonia and weakness, although there was variability in clinical severity. Two major clinical patterns emerged: patients with deficiency of beta2-syntrophin and alpha-dystrobrevin presented with severe congenital weakness and died in the first year of life, and two patients with deficiency of alpha-dystrobrevin had congenital muscular dystrophy with complete external ophthalmoplegia. We have sequenced the coding regions of alpha-dystrobrevin and beta2-syntrophin in these patients, and identified a new isoform of dystrobrevin, but have not identified any mutations. This suggests that disease causing mutations occur outside the coding region of these genes, in gene(s) encoding other components of the syntrophin-dystrobrevin subcomplex, or in gene(s) responsible for their post-translational modification and normal localisation.
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Affiliation(s)
- K J Jones
- Institute for Neuromuscular Research, The Children's Hospital at Westmead, Locked Bag 4001, NSW 2145, Westmead, Australia
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41
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Guyon JR, Mosley AN, Zhou Y, O'Brien KF, Sheng X, Chiang K, Davidson AJ, Volinski JM, Zon LI, Kunkel LM. The dystrophin associated protein complex in zebrafish. Hum Mol Genet 2003. [DOI: 10.1093/hmg/ddg071] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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42
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Bushby KMD, Beckmann JS. The 105th ENMC sponsored workshop: pathogenesis in the non-sarcoglycan limb-girdle muscular dystrophies, Naarden, April 12-14, 2002. Neuromuscul Disord 2003; 13:80-90. [PMID: 12467737 DOI: 10.1016/s0960-8966(02)00183-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- K M D Bushby
- Institute of Human Genetics, International Centre for Life, Central Parkway, NE1 3BZ, Newcastle upon Tyne, UK.
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43
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Abstract
The dystrophin-glycoprotein complex (DGC) is a multisubunit complex that connects the cytoskeleton of a muscle fiber to its surrounding extracellular matrix. Mutations in the DGC disrupt the complex and lead to muscular dystrophy. There are a few naturally occurring animal models of DGC-associated muscular dystrophy (e.g. the dystrophin-deficient mdx mouse, dystrophic golden retriever dog, HFMD cat and the delta-sarcoglycan-deficient BIO 14.6 cardiomyopathic hamster) that share common genetic protein abnormalities similar to those of the human disease. However, the naturally occurring animal models only partially resemble human disease. In addition, no naturally occurring mouse models associated with loss of other DGC components are available. This has encouraged the generation of genetically engineered mouse models for DGC-linked muscular dystrophy. Not only have analyses of these mice led to a significant improvement in our understanding of the pathogenetic mechanisms for the development of muscular dystrophy, but they will also be immensely valuable tools for the development of novel therapeutic approaches for these incapacitating diseases.
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Affiliation(s)
- Madeleine Durbeej
- Howard Hughes Medical Institute, Department of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
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44
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Abstract
Duchenne muscular dystrophy was described in the medical literature in the early 1850s but the molecular basis of the disease was not determined until the late 1980s. The cloning of dystrophin led to the identification of a large complex of proteins that plays an important, although not yet well understood, role in muscle biology. Concomitant with the elucidation of the function of dystrophin and its associated proteins has been the pursuit of therapeutic options for muscular dystrophy. Although there is still no cure for this disorder, great advances are being made in the areas of gene introduction and cell transplant therapy.
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Affiliation(s)
- K F O'Brien
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA.
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45
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Cagliani R, Comi GP, Tancredi L, Sironi M, Fortunato F, Giorda R, Bardoni A, Moggio M, Prelle A, Bresolin N, Scarlato G. Primary beta-sarcoglycanopathy manifesting as recurrent exercise-induced myoglobinuria. Neuromuscul Disord 2001; 11:389-94. [PMID: 11369190 DOI: 10.1016/s0960-8966(00)00207-8] [Citation(s) in RCA: 29] [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] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We report an unusual presentation of a primary beta-sarcoglycanopathy (LGMD type 2E). A 12- year-old boy came to our attention after six episodes of exercise-induced myoglobinuria. Electromyogram showed mild myopathic features of the proximal lower limb muscles. Electrocardiogram was normal. Neurological examination revealed normal muscle strength and reduced deep tendon reflexes. A muscle biopsy showed rare regenerating fibers; the immunohistochemistry was normal for dystrophin, while all the sarcoglycans were diffusely decreased. Western blot analysis showed a relevant decrease of all sarcoglycan proteins and a mild dystrophin reduction. beta-Sarcoglycan gene analysis demonstrated a compound heterozygous status for these mutations: a novel A-T base pair substitution at nucleotide 85 in exon 2, changing the codon Arg to a stop codon; a C-T base pair substitution at nucleotide 272 in exon 3 changing a Arg to a Cys residue. We consider that exercise-induced myoglobinuria may be the presenting sign of primary beta-sarcoglycanopathy.
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Affiliation(s)
- R Cagliani
- Centro Dino Ferrari, Istituto di Clinica Neurologica, Università degli Studi di Milano, IRCCS Ospedale Maggiore Policlinico, Via F. Sforza 35, 20122, Milan, Italy
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46
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Politano L, Nigro V, Passamano L, Petretta V, Comi LI, Papparella S, Nigro G, Rambaldi PF, Raia P, Pini A, Mora M, Giugliano MA, Esposito MG, Nigro G. Evaluation of cardiac and respiratory involvement in sarcoglycanopathies. Neuromuscul Disord 2001; 11:178-85. [PMID: 11257475 DOI: 10.1016/s0960-8966(00)00174-7] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.8] [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: 01/16/2023]
Abstract
Sarcoglycanopathies constitute a subgroup of limb-girdle recessive muscular dystrophies due to defects in sarcoglycan complex that comprises five distinct transmembrane proteins called alpha-, beta-, gamma-, delta-and epsilon-sarcoglycans. As it is well known that sarcoglycans are expressed both in heart and in skeletal muscles and a complete deficiency in delta-sarcoglycan is the cause of the Syrian hamster BIO.14 cardiomyopathy, we studied cardiac and respiratory involvement in 20 patients with sarcoglycanopathies by clinical, electrocardiographic, echocardiographic, scintigraphic and spirometric assessments. A normal heart function was found in 31.3% of all patients; a preclinical cardiomyopathy in 43.7%; an arrhythmogenic cardiomyopathy in 6.3% and initial signs of dilated cardiomyopathy in 18.7%. In one patient the data were examined retrospectively. No correlation was found between cardiac and skeletal muscle involvement. With reference to the type of sarcoglycanopathy, signs of hypoxic myocardial damage occurred in beta-, gamma- and delta-sarcoglycanopathies, while initial signs of a dilated cardiomyopathy in gamma- and delta-sarcoglycanopathies were found. A normal respiratory function was observed in 23.5% of all patients, a mild impairment in 35.4%, a moderate impairment in 29.4%, and a severe impairment in 11.7%.
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Affiliation(s)
- L Politano
- Dipartimento di Internistica Clinica e Sperimentale, Sezione di Cardiomiologia e Genetica Medica, Seconda Università di Napoli, I Policlinico, Piazza Miraglia, 80138, Naples, Italy.
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47
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Mahjneh I, Marconi G, Bushby K, Anderson LV, Tolvanen-Mahjneh H, Somer H. Dysferlinopathy (LGMD2B): a 23-year follow-up study of 10 patients homozygous for the same frameshifting dysferlin mutations. Neuromuscul Disord 2001; 11:20-6. [PMID: 11166162 DOI: 10.1016/s0960-8966(00)00157-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [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: 10/18/2022]
Abstract
The limb-girdle muscular dystrophies are a group of inherited neuromuscular disorders which are clinically and genetically heterogeneous. We have been able to carry out a follow-up study on 10 patients from a large Palestinian family with a confirmed mutation in the dysferlin gene. These patients have been followed for more than 23 years since the onset of the disease. They all had normal developmental milestones. The onset of the disease was usually in the second decade, more rarely in the third and fourth decades. The first symptoms were difficulty with running and climbing stairs. Patients showed a distinct type of gait due to the unique pattern of muscle involvement which was characterised by early involvement of the posterior muscle compartment of the thighs and legs (hamstrings, adductors, gastrocnemius and soleus). The shoulder and upper limb musculature became involved later, especially supra and infraspinatus and biceps. In the early stages of disease these patients may clinically show only proximal lower limb-girdle muscle weakness; however, the use of muscle imaging techniques were very important, always detecting in these patients also distal lower limb muscle involvement, so that the pattern of muscle involvement found in dysferlin deficiency may not strictly conform to the definition of limb-girdle muscular dystrophy. The pattern of muscular dystrophy is essentially uniform and has clearly distinct features (involving mainly the initial pattern of muscle involvement and the mode of gait) which differ significantly from the well reported clinical features associated with sarcoglycanopathy, calpainopathy and Miyoshi myopathy.
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Affiliation(s)
- I Mahjneh
- Division of Neurology, Kainuu Central Hospital, Sotkamontie 13, 87140, Kajaani, Finland.
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Barresi R, Moore SA, Stolle CA, Mendell JR, Campbell KP. Expression of gamma -sarcoglycan in smooth muscle and its interaction with the smooth muscle sarcoglycan-sarcospan complex. J Biol Chem 2000; 275:38554-60. [PMID: 10993904 DOI: 10.1074/jbc.m007799200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [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: 11/06/2022] Open
Abstract
The sarcoglycan complex in striated muscle is a heterotetrameric unit integrally associated with sarcospan in the dystrophin-glycoprotein complex. The sarcoglycans, alpha, beta, gamma, and delta, are mutually dependent with regard to their localization at the sarcolemma, and mutations in any of the sarcoglycan genes lead to limb-girdle muscular dystrophies type 2C-2F. In smooth muscle beta- and delta-sarcoglycans are associated with epsilon-sarcoglycan, a glycoprotein homologous to alpha-sarcoglycan. Here, we demonstrate that gamma-sarcoglycan is also a component of the sarcoglycan complex in the smooth muscle. First, we show the presence of gamma-sarcoglycan in a number of smooth muscle-containing organs, and we verify the existence of identical transcripts in skeletal and smooth muscle. The specificity of the expression of gamma-sarcoglycan in smooth muscle was confirmed by analysis of smooth muscle cells in culture. Next, we provide evidence for the association of gamma-sarcoglycan with the sarcoglycan-sarcospan complex by biochemical analysis and comparison among animal models for muscular dystrophy. Moreover, we find disruption of the sarcoglycan complex in the vascular smooth muscle of a patient with gamma-sarcoglycanopathy. Taken together, our results prove that the sarcoglycan complex in vascular and visceral smooth muscle consists of epsilon-, beta-, gamma-, and delta-sarcoglycans and is associated with sarcospan.
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Affiliation(s)
- R Barresi
- Howard Hughes Medical Institute, Department of Physiology and Biophysics and Department of Neurology, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
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Straub V, Donahue KM, Allamand V, Davisson RL, Kim YR, Campbell KP. Contrast agent-enhanced magnetic resonance imaging of skeletal muscle damage in animal models of muscular dystrophy. Magn Reson Med 2000; 44:655-9. [PMID: 11025524 DOI: 10.1002/1522-2594(200010)44:4<655::aid-mrm22>3.0.co;2-t] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Membrane lesions play an early role in the pathogenesis of muscular dystrophy. Using a new albumin-targeted contrast agent (MS-325), sarcolemmal integrity of two animal models for muscular dystrophy was studied by MRI. Intravenously injected MS-325 does not enter skeletal muscle of normal mice. However, mdx and Sgca-null mutant mice, animal models for Duchenne and sarcoglycan-deficient limb-girdle muscular dystrophy, respectively, showed significant accumulation of MS-325 in skeletal muscle. The results suggest that contrast agent-enhanced MRI could serve as a common, noninvasive imaging procedure for evaluating the localization, extent, and mechanisms of skeletal muscle damage in muscular dystrophy. Furthermore, this method is expected to facilitate assessment of therapeutic approaches in these diseases.
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Affiliation(s)
- V Straub
- Howard Hughes Medical Institute, Department of Physiology and Biophysics and Department of Neurology, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA
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50
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Abstract
Autosomal recessive muscular dystrophies called "sarcoglycanopathies" result from mutations in the genes encoding alpha-, beta-, gamma-, or delta-sarcoglycan complex components. The present study involved six unrelated families from Northern Italy showing mutations in the beta- or gamma-sarcoglycan genes. An 8 bp duplication in the beta-sarcoglycan gene and 1 bp insertion in the gamma-sarcoglycan gene occur with high frequency in our population. These mutations have never been reported thus far in other countries. Many patients are homozygotes for a single mutation, although they derived from non-consanguineous marriages. We suggest that these alleles are "private" mutations of this geographical region. A panel of highly informative microsatellite markers that map in the beta- and gamma-sarcoglycan gene locus was used to assess the haplotypes among affected patients and control population, in order to test the presence of linkage disequilibrium. We found that the 8 bp duplication in the beta-sarcoglycan gene and the 1 bp insertion in the gamma-sarcoglycan gene are in linkage disequilibrium with neighbouring polymorphisms. The recurrence of specific sarcoglycan mutations in Northern Italy is probably due to a founder effect, combined with a relative genetic isolation.
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Affiliation(s)
- M Fanin
- Regional Neuromuscular Center, Department of Neurological and Psychiatric Sciences, University of Padova, Italy.
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