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Díaz-Manera J, Urtizberea JA, Schey C, Kole A, von Gallwitz P, Whiting A, Foerster D, Zozulya-Weidenfeller A. Impact of restricted access to, and low awareness of, mexiletine on people with myotonia: a real-world European survey. Neuromuscul Disord 2023; 33:208-217. [PMID: 36706619 DOI: 10.1016/j.nmd.2022.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 12/06/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
Although mexiletine effectively treats myotonia, supply disruptions affected Europe between 2008-2018. MyoPath was a mixed-methods, cross-sectional, market research survey conducted January-June 2018 to evaluate consequences of limited access to/awareness of mexiletine in people with myotonia. Part A: qualitative structured interviews (clinicians; advocates for adult patients); Part B: quantitative online questionnaire completed by people with self-reported history of myotonia. Part A: Interviews (clinicians, n=12; patient advocates, n=5; 12 countries) indicated poor mexiletine awareness among general neurologists. Patients chose between living with myotonia (other treatments were generally unsatisfactory) or importing mexiletine. Part B: Questionnaire respondents, myotonic dystrophy (DM)1, n=213; DM2, n=128; non-dystrophic myotonia (NDM), n=41; other n=8; (11 countries). Of the respondents, 76/390 (20%) people with awareness of/access to mexiletine described profound improvements in myotonia and health-related quality of life following treatment. Respondents with NDM had greatest mexiletine experience (n=28/41). Mexiletine was associated with fewer falls, less muscle stiffness, increased mobility. Treatment interruptions worsened myotonia and were associated with fatigue, pain, dysphagia, breathing difficulty, impaired digestion, poor sleep. However, 36/54 (67%) of currently treated people expressed anxiety about mexiletine's availability: this finding was expected (MyoPath was undertaken before mexiletine's approval in NDM). MyoPath provides the largest European exploration of patients' views regarding impact of mexiletine on myotonia. Anticipated effects of mexiletine differ between people with different myotonic disorders: myotonia is the main symptom in NDM but one of many potential symptoms affecting those with DM. Nevertheless, findings indicate substantial harm caused to people with myotonia when mexiletine awareness/access is limited.
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Affiliation(s)
- Jordi Díaz-Manera
- John Walton Muscular Dystrophy Research Centre, Newcastle University International Centre for Life, Newcastle upon Tyne, United Kingdom.
| | | | - Carina Schey
- Department of Epidemiology, University of Groningen, Groningen, the Netherlands
| | - Anna Kole
- admedicum® Business for Patients GmbH & Co KG, Cologne, Germany
| | | | - Amy Whiting
- admedicum® Business for Patients GmbH & Co KG, Cologne, Germany
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2
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Hofmeister F, Baber L, Ferrari U, Hintze S, Jarmusch S, Krause S, Meinke P, Mehaffey S, Neuerburg C, Tangenelli F, Schoser B, Drey M. Late-onset neuromuscular disorders in the differential diagnosis of sarcopenia. BMC Neurol 2021; 21:241. [PMID: 34172001 PMCID: PMC8229316 DOI: 10.1186/s12883-021-02264-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 06/02/2021] [Indexed: 12/18/2022] Open
Abstract
Background Sarcopenia is the age-related loss of muscle mass and strength. Undiagnosed late-onset neuromuscular disorders need to be considered in the differential diagnosis of sarcopenia. Aim Based on emblematic case reports and current neuromuscular diagnostic guidelines for three common late-onset neuromuscular disorders, a differential diagnostic approach for geriatric patients presenting with a sarcopenic phenotype is given. Methods Patients over 65 years of age with sarcopenia, amyotrophic lateral sclerosis, inclusion body myositis and myotonic dystrophy type 2 were recruited. All patients were assessed for sarcopenia based on the revised European consensus definition. Patients with neuromuscular diseases were diagnosed according to the revised El Escorial criteria and the European neuromuscular centre criteria. Phenotypes and diagnostic criteria for all patients were summarized including their specific histopathological findings. Results All patients with neuromuscular diseases were positively screened for sarcopenia and classified as severe sarcopenic by means of assessment. The clinical phenotype, the evolution pattern of weakness and muscle atrophy combined with laboratory finding including electromyography could unquestionably distinguish the diseases. Discussion Neuromuscular disorders can manifest beyond the age of 65 years and misdiagnosed as sarcopenia. The most common diseases are inclusion body myositis, amyotrophic lateral sclerosis and myotonic dystrophy type 2. A diagnostic work-up for neuromuscular diseases ensures their correct diagnosis by clinical-, electrophysiological, histopathological, and genetic work-up. Conclusions In geriatric patients with a focal or asymmetrical muscular weakness and atrophy, sarcopenia assessment should be extended with patient’s history of disease course. Furthermore, concomitant diseases, analysis of serum creatine kinase, electrophysiological examination, and in selected patients muscle biopsy and gene analysis is needed to rule out a late-onset neuromuscular disorder.
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Affiliation(s)
- Fabian Hofmeister
- Department of Medicine IV, Geriatrics, University Hospital, LMU Munich, Munich, Germany
| | - Lisa Baber
- Department of Medicine IV, Geriatrics, University Hospital, LMU Munich, Munich, Germany
| | - Uta Ferrari
- Department of Medicine IV, Geriatrics, University Hospital, LMU Munich, Munich, Germany
| | - Stefan Hintze
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, LMU Munich, Munich, Germany
| | - Stefanie Jarmusch
- Department of Medicine IV, Geriatrics, University Hospital, LMU Munich, Munich, Germany
| | - Sabine Krause
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, LMU Munich, Munich, Germany
| | - Peter Meinke
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, LMU Munich, Munich, Germany
| | - Stefan Mehaffey
- Department of General-, Trauma- and Reconstructive Surgery, University Hospital, LMU Munich, Munich, Germany
| | - Carl Neuerburg
- Department of General-, Trauma- and Reconstructive Surgery, University Hospital, LMU Munich, Munich, Germany
| | - Fabiana Tangenelli
- Department of Medicine IV, Geriatrics, University Hospital, LMU Munich, Munich, Germany
| | - Benedikt Schoser
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, LMU Munich, Munich, Germany
| | - Michael Drey
- Department of Medicine IV, Geriatrics, University Hospital, LMU Munich, Munich, Germany.
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3
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Roy B, Wu Q, Whitaker CH, Felice KJ. Myotonic Muscular Dystrophy Type 2 in CT, USA: A Single-Center Experience With 50 Patients. J Clin Neuromuscul Dis 2021; 22:135-146. [PMID: 33595997 DOI: 10.1097/cnd.0000000000000340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
ABSTRACT Myotonic dystrophy type 2 (DM2) is an autosomal dominant disorder due to a (CCTG)n repeat expansion in intron 1 of the CNBP gene. In this article, we report the clinicopathologic findings in 50 patients seen at a single site over a 27 year period. DM2 was the fifth most common type of muscular dystrophy seen at our center with a 5-fold lower frequency as compared to DM1. Age of symptom onset ranged from 15 to 72 years, and the mean duration between symptom onset and diagnosis was 7.4 years. Weakness referable to the proximal lower extremities was the presenting symptom in 62% of patients. The degree of generalized weakness varied from severe in 30% to no weakness in 20% of patients. Clinical myotonia was noted in 18% and myotonic discharges on electromyography in 97% of patients. Pain symptoms were uncommon in our cohort. A significant correlation was noted between limb weakness and degree of muscle pathologic changes. There was no correlation between CCTG repeat size and other clinicopathologic findings. Six patients (12%) had cardiac abnormalities including one who developed progressive nonischemic dilated cardiomyopathy ultimately leading to cardiac transplantation. In 21 patients followed for 2 or more years, we noted a mean rate of decline in total Medical Research Council score of about 1% per year.
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Affiliation(s)
- Bhaskar Roy
- Department of Neurology, University of Connecticut School of Medicine, Farmington, CT
| | - Qian Wu
- Department of Pathology and Laboratory Medicine, University of Connecticut School of Medicine, Farmington, CT; and
| | - Charles H Whitaker
- Department of Neuromuscular Medicine, Muscular Dystrophy Association Care Center, Hospital for Special Care, New Britain, CT
| | - Kevin J Felice
- Department of Neuromuscular Medicine, Muscular Dystrophy Association Care Center, Hospital for Special Care, New Britain, CT
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4
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Meola G. Myotonic dystrophy type 2: the 2020 update. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2020; 39:222-234. [PMID: 33458578 PMCID: PMC7783423 DOI: 10.36185/2532-1900-026] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 12/26/2022]
Abstract
The myotonic dystrophies are the commonest cause of adult-onset muscular dystrophy. Phenotypes of DM1 and DM2 are similar, but there are some important differences, including the presence or absence of congenital form, muscles primarily affected (distal vs proximal), involved muscle fiber types (type 1 vs type 2 fibers), and some associated multisystemic phenotypes. There is currently no cure for the myotonic dystrophies but effective management significantly reduces the morbidity and mortality of patients. For the enormous understanding of the molecular pathogenesis of myotonic dystrophy type 1 and myotonic dystrophy type 2, these diseases are now called "spliceopathies" and are mediated by a primary disorder of RNA rather than proteins. Despite clinical and genetic similarities, myotonic dystrophy type 1 and type 2 are distinct disorders requiring different diagnostic and management strategies. Gene therapy for myotonic dystrophy type 1 and myotonic dystrophy type 2 appears to be very close and the near future is an exciting time for clinicians and patients.
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Affiliation(s)
- Giovanni Meola
- Department of Biomedical Sciences for Health, University of Milan, Italy.,Department of Neurorehabilitation Sciences, Casa di Cura del Policlinico, Milan, Italy
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5
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Alì M, Monti CB, Melazzini L, Cardani R, Fossati B, Cavalli M, Chow K, Secchi F, Meola G, Sardanelli F. Rare Disease: Cardiac Risk Assessment With MRI in Patients With Myotonic Dystrophy Type 1. Front Neurol 2020; 11:192. [PMID: 32265828 PMCID: PMC7098463 DOI: 10.3389/fneur.2020.00192] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 02/28/2020] [Indexed: 12/11/2022] Open
Abstract
Introduction: To evaluate myocardial strain and extracellular volume in myotonic dystrophy type 1 (DM1) patients as potential imaging biomarkers of subclinical cardiac pathology. Materials and methods: We retrospectively analyzed 9 DM1 patients without apparent cardiac disease who had undergone cardiac magnetic resonance at our center. Patients were age- and sex-matched with healthy controls. The Mann-Whitney U test was used to compare cardiac strain between the two groups. The t-test was used to compare the extracellular volume obtained in DM1 patients with that in healthy subject. Spearman's ρ was used for studying the associations among imaging parameters. Results: Global cardiac strain (median -19.1%; IQR -20.5%, -16.5%) in DM1 patients was lower (p = 0.011) than that in controls (median-21.7%; IQR-22.7%,-21.3%). Global extracellular volume in DM1 patients (median 32.3%; IQR 29.3%,36.8%) was significantly (p = 0.008) higher than that reported in literature in healthy subjects (median 25.6%; IQR 19.9%,31.9%). Global cardiac strain showed a strong, positive correlation with septal strain (ρ = 0.767, p = 0.016) and with both global (ρ = 0.733 p = 0.025) and septal extracellular volume (ρ = 0.767, p = 0.016). Discussion: The increase in cardiac extracellular volume and decrease in strain are signs of early cardiac pathology in DM1. Physicians dealing with DM1 may take into consideration cardiac magnetic resonance as a screening tool to identify early cardiac involvement in this condition.
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Affiliation(s)
- Marco Alì
- Unit of Diagnostic Imaging and Stereotactic Radiosurgery, C.D.I. Centro Diagnostico Italiano S.p.A., Milan, Italy.,Unit of Radiology, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Caterina Beatrice Monti
- PhD Course in Integrative Biomedical Research, Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Luca Melazzini
- PhD Course in Integrative Biomedical Research, Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Rosanna Cardani
- Laboratory of Muscle Histopathology and Molecular Biology, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Barbara Fossati
- Unit of Neurology, IRCCS Policlinico San Donato, San Donato Milanese, Italy.,Department of Neurorehabilitation Sciences, Casa di Cura del Policlinico, Milan, Italy
| | - Michele Cavalli
- Postgraduate School in Neurology, University of Milan, Milan, Italy
| | - Kelvin Chow
- Siemens Medical Solutions USA Inc., Chicago, IL, United States
| | - Francesco Secchi
- Unit of Radiology, IRCCS Policlinico San Donato, San Donato Milanese, Italy.,Department of Biomedical Sciences for Health, University of Milan, San Donato Milanese, Italy
| | - Giovanni Meola
- Unit of Neurology, IRCCS Policlinico San Donato, San Donato Milanese, Italy.,Department of Neurorehabilitation Sciences, Casa di Cura del Policlinico, Milan, Italy.,Department of Biomedical Sciences for Health, University of Milan, San Donato Milanese, Italy
| | - Francesco Sardanelli
- Unit of Radiology, IRCCS Policlinico San Donato, San Donato Milanese, Italy.,Department of Biomedical Sciences for Health, University of Milan, San Donato Milanese, Italy
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6
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Angelini C, Pinzan E. Advances in imaging of brain abnormalities in neuromuscular disease. Ther Adv Neurol Disord 2019; 12:1756286419845567. [PMID: 31105770 PMCID: PMC6503605 DOI: 10.1177/1756286419845567] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 03/05/2019] [Indexed: 01/18/2023] Open
Abstract
Brain atrophy, white matter abnormalities, and ventricular enlargement have been described in different neuromuscular diseases (NMDs). We aimed to provide a comprehensive overview of the substantial advancement of brain imaging in neuromuscular diseases by consulting the main libraries (Pubmed, Scopus and Google Scholar) including the more common forms of muscular dystrophies such as dystrophinopathies, dystroglycanopathies, myotonic dystrophies, facioscapulohumeral dystrophy, limb-girdle muscular dystrophy, congenital myotonia, and congenital myopathies. A consistent, widespread cortical and subcortical involvement of grey and white matter was found. Abnormalities in the functional connectivity in brain networks and metabolic alterations were observed with positron emission tomography (PET) and single photon emission computed tomography (SPECT). Pathological brain changes with cognitive dysfunction seemed to be frequently associated in NMDs. In particular, in congenital muscular dystrophies (CMDs), skeletal muscular weakness, severe hypotonia, WM abnormalities, ventricular dilatation and abnormalities in cerebral gyration were observed. In dystroglycanopathy 2I subtype (LGMD2I), adult patients showed subcortical atrophy and a WM periventricular involvement, moderate ventriculomegaly, and enlargement of subarachnoid spaces. Correlations with clinical features have been observed with brain imaging characteristics and alterations were prominent in congenital or childhood onset cases. In myotonic dystrophy type 2 (DM2) symptoms seem to be less severe than in type 1 (DM1). In Duchenne and Becker muscular dystrophies (DMD, BMD) cortical atrophy is associated with minimal ventricular dilatation and WM abnormalities. Late-onset glycogenosis type II (GSD II) or Pompe infantile forms are characterized by delayed myelination. Only in a few cases of oculopharyngeal muscular dystrophy (OPMD) central nervous system involvement has been described and associated with executive functions impairment.
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Affiliation(s)
- Corrado Angelini
- Fondazione Ospedale San Camillo IRCCS, Via
Alberoni 70, Venezia, 30126, Italia
| | - Elena Pinzan
- Fondazione Ospedale San Camillo IRCCS, Venezia,
Italia
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7
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Breukel A, Willmann R, Padberg G, Sterrenburg E, Meijer I. "The impact of European Neuromuscular Centre (ENMC) workshops on the neuromuscular field; 25 years on …". Neuromuscul Disord 2019; 29:330-340. [PMID: 30853171 DOI: 10.1016/j.nmd.2019.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 01/28/2019] [Indexed: 02/06/2023]
Abstract
Since 1992, the European Neuromuscular Centre facilitated workshops to bring experts in the field of neuromuscular disorders together. After organising more than 235 workshops, it is time to evaluate what impact these 25 years of ENMC workshops have had on the neuromuscular research field and on people affected by a neuromuscular condition. To measure this, workshop topics were retrospectively evaluated and bibliometric analyses on the citation scores of ENMC-derived publications were performed. In addition, a personalized survey was used to investigate the actual achievement and implementation of workshop deliverables. The evaluation of 25 years' workshop topics revealed a strong representation of muscular dystrophies, congenital and mitochondrial myopathies. The publications derived from ENMC workshops scored "high impact" as illustrated by the Mean Normalized Citation Score of 1.24. Also 16% of the ENMC papers belong to the top 10% best cited articles in the neuromuscular field. The main outcome of the personalised survey was that 90% of all workshop deliverables were started and either ongoing or completed. Of these deliverables, 78% were implemented in the field; bringing state-of-the-art knowledge and new collaborations to researchers and clinicians, improving designs of clinical trials and innovating tools to make accurate diagnoses.
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Affiliation(s)
- Alexandra Breukel
- European Neuromuscular Centre (ENMC), Lt. Generaal van Heutszlaan 6, Baarn 3743JN, The Netherlands.
| | - Raffaella Willmann
- Schweizerische Stiftung für die Erforschung der Muskelkrankheiten (FSRMM), Cortaillod, Switzerland
| | - George Padberg
- European Neuromuscular Centre (ENMC), Lt. Generaal van Heutszlaan 6, Baarn 3743JN, The Netherlands
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8
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Sellier C, Cerro-Herreros E, Blatter M, Freyermuth F, Gaucherot A, Ruffenach F, Sarkar P, Puymirat J, Udd B, Day JW, Meola G, Bassez G, Fujimura H, Takahashi MP, Schoser B, Furling D, Artero R, Allain FHT, Llamusi B, Charlet-Berguerand N. rbFOX1/MBNL1 competition for CCUG RNA repeats binding contributes to myotonic dystrophy type 1/type 2 differences. Nat Commun 2018; 9:2009. [PMID: 29789616 PMCID: PMC5964235 DOI: 10.1038/s41467-018-04370-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 04/26/2018] [Indexed: 12/30/2022] Open
Abstract
Myotonic dystrophy type 1 and type 2 (DM1, DM2) are caused by expansions of CTG and CCTG repeats, respectively. RNAs containing expanded CUG or CCUG repeats interfere with the metabolism of other RNAs through titration of the Muscleblind-like (MBNL) RNA binding proteins. DM2 follows a more favorable clinical course than DM1, suggesting that specific modifiers may modulate DM severity. Here, we report that the rbFOX1 RNA binding protein binds to expanded CCUG RNA repeats, but not to expanded CUG RNA repeats. Interestingly, rbFOX1 competes with MBNL1 for binding to CCUG expanded repeats and overexpression of rbFOX1 partly releases MBNL1 from sequestration within CCUG RNA foci in DM2 muscle cells. Furthermore, expression of rbFOX1 corrects alternative splicing alterations and rescues muscle atrophy, climbing and flying defects caused by expression of expanded CCUG repeats in a Drosophila model of DM2.
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Affiliation(s)
- Chantal Sellier
- IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, 67404, Illkirch, France
| | - Estefanía Cerro-Herreros
- Translational Genomics Group, Interdisciplinary Research Structure for Biotechnology and Biomedicine BIOTECMED, University of Valencia, 46010, Valencia, Spain
- INCLIVA Health Research Institute, 46010, Valencia, Spain
| | - Markus Blatter
- Institute for Molecular Biology and Biophysics, Swiss Federal Institute of Technology (ETH) Zurich, 8092, Zurich, Switzerland
| | - Fernande Freyermuth
- IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, 67404, Illkirch, France
| | - Angeline Gaucherot
- IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, 67404, Illkirch, France
| | - Frank Ruffenach
- IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, 67404, Illkirch, France
| | - Partha Sarkar
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Jack Puymirat
- Human Genetics Research Unit, Laval University, CHUQ, Ste-Foy, Quebec, QC G1V 4G2, Canada
| | - Bjarne Udd
- Neuromuscular Research Center, Tampere University Hospital, 33521, Tampere, Finland
- Department of Medical Genetics, Folkhälsan Institute of Genetics, Helsinki University, 00290, Helsinki, Finland
- Department of Neurology, Vasa Central Hospital, 65130, Vaasa, Finland
| | - John W Day
- Department of Neurology, Stanford University, San Francisco, CA, 94305, USA
| | - Giovanni Meola
- Department of Biomedical Sciences for Health, University of Milan, 20097, Milan, Italy
- Neurology Unit, IRCCS Policlinico San Donato, San Donato Milanese, 20097, Milan, Italy
| | - Guillaume Bassez
- Sorbonne Université, Inserm, Association Institut de Myologie, Center of Research in Myology, 75013, Paris, France
| | - Harutoshi Fujimura
- Department of Neurology, Toneyama National Hospital, Toyonaka, 560-0045, Japan
| | - Masanori P Takahashi
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, 565-0871, Japan
| | - Benedikt Schoser
- Friedrich-Baur-Institute, Department of Neurology, Ludwig Maximilian University, 80539, Munich, Germany
| | - Denis Furling
- Sorbonne Université, Inserm, Association Institut de Myologie, Center of Research in Myology, 75013, Paris, France
| | - Ruben Artero
- Translational Genomics Group, Interdisciplinary Research Structure for Biotechnology and Biomedicine BIOTECMED, University of Valencia, 46010, Valencia, Spain
- INCLIVA Health Research Institute, 46010, Valencia, Spain
| | - Frédéric H T Allain
- Institute for Molecular Biology and Biophysics, Swiss Federal Institute of Technology (ETH) Zurich, 8092, Zurich, Switzerland
| | - Beatriz Llamusi
- Translational Genomics Group, Interdisciplinary Research Structure for Biotechnology and Biomedicine BIOTECMED, University of Valencia, 46010, Valencia, Spain.
- INCLIVA Health Research Institute, 46010, Valencia, Spain.
| | - Nicolas Charlet-Berguerand
- IGBMC, INSERM U964, CNRS UMR7104, University of Strasbourg, 67404, Illkirch, France.
- UMR7104, Centre National de la Recherche Scientifique, 67404, Illkirch, France.
- Institut National de la Santé et de la Recherche Médicale, U964, 67404, Illkirch, France.
- Université de Strasbourg, 67404, Illkirch, France.
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9
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Sulek A, Lusakowska A, Krysa W, Rajkiewicz M, Kaminska A, Nojszewska M, Kostera-Pruszczyk A, Zdzienicka E, Kubalska J, Rakowicz M, Szirkowiec W, Kwiecinski H, Zaremba J. WITHDRAWN: Evidence for a relatively high proportion of DM2 mutations in a large group of Polish patients. Neurol Neurochir Pol 2018:S0028-3843(18)30152-X. [PMID: 29880430 DOI: 10.1016/j.pjnns.2018.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 04/12/2018] [Indexed: 11/24/2022]
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, 10.1016/j.pjnns.2018.02.008. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.
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Affiliation(s)
- Anna Sulek
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland.
| | | | - Wioletta Krysa
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Marta Rajkiewicz
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Anna Kaminska
- Department of Neurology, Medical University, Warsaw, Poland
| | | | | | - Elzbieta Zdzienicka
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Jolanta Kubalska
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Maria Rakowicz
- Department of Clinical Neurophysiology, Institute of Psychiatry and Neurology, Warsaw, Poland
| | | | | | - Jacek Zaremba
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
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10
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Wenninger S, Montagnese F, Schoser B. Core Clinical Phenotypes in Myotonic Dystrophies. Front Neurol 2018; 9:303. [PMID: 29770119 PMCID: PMC5941986 DOI: 10.3389/fneur.2018.00303] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/18/2018] [Indexed: 12/22/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) and type 2 (DM2) represent the most frequent multisystemic muscular dystrophies in adulthood. They are progressive, autosomal dominant diseases caused by an abnormal expansion of an unstable nucleotide repeat located in the non-coding region of their respective genes DMPK for DM1 and CNBP in DM2. Clinically, these multisystemic disorders are characterized by a high variability of muscular and extramuscular symptoms, often causing a delay in diagnosis. For both subtypes, many symptoms overlap, but some differences allow their clinical distinction. This article highlights the clinical core features of myotonic dystrophies, thus facilitating their early recognition and diagnosis. Particular attention will be given to signs and symptoms of muscular involvement, to issues related to respiratory impairment, and to the multiorgan involvement. This article is part of a Special Issue entitled “Beyond Borders: Myotonic Dystrophies—A European Perception.”
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Affiliation(s)
- Stephan Wenninger
- Friedrich-Baur-Institute, Klinikum der Universität München, Munich, Germany
| | | | - Benedikt Schoser
- Friedrich-Baur-Institute, Klinikum der Universität München, Munich, Germany
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11
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Sulek A, Lusakowska A, Krysa W, Rajkiewicz M, Kaminska A, Nojszewska M, Kostera-Pruszczyk A, Zdzienicka E, Kubalska J, Rakowicz M, Szirkowiec W, Kwiecinski H, Zaremba J. Evidence for a relatively high proportion of DM2 mutations in a large group of Polish patients. Neurol Neurochir Pol 2018; 52:736-742. [PMID: 29588063 DOI: 10.1016/j.pjnns.2018.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/16/2018] [Accepted: 02/26/2018] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Myotonic dystrophies (DMs) type 1 (DM1) and type 2 (DM2) are autosomal dominant, multisystem disorders, considered the most common dystrophies in adults. DM1 and DM2 are caused by dynamic mutations in the DMPK and CNBP genes, respectively. METHODS Molecular analyses were performed by PCR and the modified RP-PCR in patients, in their at-risk relatives and prenatal cases. RESULTS The analysis of Polish controls revealed the range of 5-31 CTG repeats for DM1 and 110-228 bp alleles for DM2. Among 318 confirmed probands - 196 (62%) were DM1 and 122 (38%) - DM2. Within DM1families, 10 subjects carried a low expanded CTG tract (< 100 repeats), which resulted in a full mutation in subsequent generations. Two related individuals had unstable alleles-188 bp and 196 bp without common interruptions. CONCLUSION The relative frequencies of DM1/DM2 among Polish patients were 68% and 32%, respectively, with a relatively high proportion of DM2 mutations (1.6:1).
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Affiliation(s)
- Anna Sulek
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland.
| | - Anna Lusakowska
- Department of Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Wioletta Krysa
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Marta Rajkiewicz
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Anna Kaminska
- Department of Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Monika Nojszewska
- Department of Neurology, Medical University of Warsaw, Warsaw, Poland
| | | | - Elzbieta Zdzienicka
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Jolanta Kubalska
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Maria Rakowicz
- Department of Clinical Neurophysiology, Institute of Psychiatry and Neurology, Warsaw, Poland
| | | | - Hubert Kwiecinski
- Department of Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Jacek Zaremba
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
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Udd B, Brignol TN, Andoni Urtizberea J. [Finland: an ideally valued genetic heritage]. Med Sci (Paris) 2016; 32 Hors série n°2:52-54. [PMID: 27869077 DOI: 10.1051/medsci/201632s215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Si la Finlande est souvent assimilée à une « petite » nation du fait de la taille restreinte de sa population, elle n’en est pas moins un géant en matière de myologie. Sa contribution, très originale, à la découverte de nombreuses myopathies et neuropathies héréditaires est là pour le prouver. Rarement pays aura valorisé son patrimoine génétique autant que la patrie de Sibelius. Particulière par les origines de sa population et fière de sa langue non-indo-européenne, la Finlande cultive pourtant une ouverture d’esprit et une volonté de collaboration sans pareilles. Deux qualités très utiles et très appréciées dans le concert international des équipes travaillant dans le domaine neuromusculaire.
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13
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No relevant excess prevalence of myotonic dystrophy type 2 in patients with suspected fibromyalgia syndrome. Neuromuscul Disord 2016; 26:370-3. [DOI: 10.1016/j.nmd.2016.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 02/19/2016] [Accepted: 03/30/2016] [Indexed: 11/20/2022]
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14
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Lesuis N, van Vliet J, Boers N, den Broeder N, Cats H, Hulscher MEJL, Verrips A, den Broeder AA. The value of routine creatine kinase and thyroid stimulating hormone testing in patients with suspected fibromyalgia: a cross-sectional study. Rheumatology (Oxford) 2016; 55:1273-6. [PMID: 27032423 DOI: 10.1093/rheumatology/kew046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE The aim was to examine the prevalence of abnormal creatine kinase (CK) and thyroid stimulating hormone (TSH) values and previously unknown myopathy or thyroid disease in patients with suspected FM syndrome (FMS). METHODS All adult patients with suspected FMS referred to the study hospital between November 2011 and April 2014 could participate. Patients with a history of myopathy or a previous diagnosis of thyroid disorder were excluded. Outcome measures were the percentages of abnormal CK and TSH values and the final diagnosis in those patients. RESULTS Three hundred and seventy-three patients were included in this study (94% female, mean age 42 years). Of these patients, 7.5% (95% CI: 5.2, 10.6%) had an abnormal CK according to the local reference values. Applying the European Federation of the Neurological Societies guideline, this changed to 0.5% (95% CI: 0.2, 1.9%). In none of these patients was hyperCKaemia-related myopathy diagnosed, and the final diagnosis was FMS in 89% of the patients. Of the total number of patients, 3.5% (95% CI: 2.1, 5.9%) had an elevated TSH and 1.4% (95 CI: 0.6, 3.1%) a lowered TSH, with one patient having a somewhat lowered free thyroid hormone level. The final diagnosis was FMS in all these patients. CONCLUSION Abnormal CK and TSH values are rare in patients with suspected FMS and do not result in an alternative diagnosis. Therefore, it seems that routine testing of CK and TSH levels in patients with suspected FMS referred to secondary care does not contribute to the diagnostic process.
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Affiliation(s)
| | | | - Nadine Boers
- Department of Rheumatology, Sint Maartenskliniek
| | | | - Hans Cats
- Department of Rheumatology, Sint Maartenskliniek
| | - Marlies E J L Hulscher
- Radboud Institute for Health Sciences, IQ healthcare, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Aad Verrips
- Department of Neurology, Canisius Wilhelmina Ziekenhuis and
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Finsterer J, Karpatova A, Rauschka H, Loewe-Grgurin M, Frank M, Gencik M. Myotonic dystrophy 2 manifesting with non-alcoholic and non-hepatitic liver cirrhosis. Acta Clin Belg 2015; 70:432-5. [PMID: 26138792 DOI: 10.1179/2295333715y.0000000043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Though the liver is frequently affected in myotonic dystrophy type 1 and 2 (DM1, DM2), non-alcoholic and non-hepatitic liver cirrhosis have not been reported as a manifestation of DM2. CLINICAL PRESENTATION AND INTERVENTION In a 52-year-old Caucasian male with DM2, the disease manifested as myopathy, mild myotonia, cataract, diabetes, erectile dysfunction, gastrointestinal dysmotility, dysarthria, mild myocardial thickening and non-alcoholic and non-hepatitic liver cirrhosis with portal hypertension and oesophageal varicosities since age 48 years. His 69-year-old sister, who carried a CCTG expansion of >300 in intron 1 of the CNBP/ZNF9 gene, also manifested in the liver with hyperbilirubinaemia, hepatopathy and hyperlipidaemia since age 48 years. Liver cirrhosis in the index patient was complicated by hyperamonemia, hepatic encephalopathy and flapping tremor. CONCLUSION Rarely, DM2 may also manifest in the liver with elevated transaminases, steatosis or non-alcoholic, non-hepatitic liver cirrhosis with its common complications. In patients with cryptogenic non-alcoholic, non-hepatitic liver cirrhosis or cataract before age 50 years, DM2 should be excluded.
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Affiliation(s)
- J Finsterer
- Krankenanstalt Rudolfstiftung , Vienna, Austria
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Guo P, Lam SL. New insights into the genetic instability in CCTG repeats. FEBS Lett 2015; 589:3058-63. [PMID: 26384951 DOI: 10.1016/j.febslet.2015.09.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 08/18/2015] [Accepted: 09/08/2015] [Indexed: 11/29/2022]
Abstract
Tetranucleotide CCTG repeat expansion is associated with myotonic dystrophy type 2, which is an inherited and progressive muscle degeneration disease. Yet, no cure is available and the molecular mechanism of repeat expansion remains elusive. In this study, we used high-resolution nuclear magnetic resonance spectroscopy to reveal a mini-dumbbell structure formed by two CCTG repeats. Upon slippage in the nascent strand during DNA replication, the formation of the mini-dumbbell provides a possible pathway for a two-repeat expansion. In addition, fast exchange between two competing mini-dumbbells among three repeats results in a mini-loop structure that accounts for one-repeat expansion. These mini-dumbbell and mini-loop intermediates can also co-exist at multiple sites in CCTG repeats, leading to three or larger size repeat expansions.
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Affiliation(s)
- Pei Guo
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Sik Lok Lam
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
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17
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Lee DH, Park DS, Kim DH, Lee SH, Cho HM. Myotonic Dystrophy Type 1 Complicated With Peripheral Arterial Occlusive Disease: A Case Report. Ann Rehabil Med 2015; 39:645-8. [PMID: 26361604 PMCID: PMC4564715 DOI: 10.5535/arm.2015.39.4.645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 09/17/2014] [Indexed: 11/05/2022] Open
Abstract
Myotonic dystrophy (MD) is the most common adult muscular dystrophy characterized by multi-systemic clinical manifestations involving the brain, smooth muscle, cardiovascular and endocrine systems. However, peripheral arterial occlusive disease (PAOD) is an uncommon presentation of MD type 1 (DM1), which has not been reported in recent literature. A 53-year-old female, previously confirmed as DM1, presented with vague claudication of both lower limbs. The diagnosis of PAOD based on results of ankle-brachial index, ultrasonography, and abdominal computed tomography angiography studies was followed by aortobifemoral artery bypass surgery. Although the arterial patency was restored after the operation, she did not recover from post-operative respiratory complications. Screening of PAOD is necessary for DM1 with general risk factors of occlusive arteriopathy. However, surgery should be reserved for the most severe cases.
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Affiliation(s)
- Dong Hun Lee
- Department of Rehabilitation Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Dong Sik Park
- Department of Rehabilitation Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Dong Hyun Kim
- Department of Rehabilitation Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Sang Hun Lee
- Department of Rehabilitation Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Hee Mun Cho
- Department of Rehabilitation Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
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Liu Q, Zheng YF, Zhu YP, Ling SQ, Li WR. Clinical, pathological and genetic characteristics of a pedigree with myotonic dystrophy type 1. Exp Ther Med 2015; 10:1931-1936. [PMID: 26640575 DOI: 10.3892/etm.2015.2738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 07/23/2015] [Indexed: 11/06/2022] Open
Abstract
The aim of the present study was to investigate the clinical, pathological and molecular genetic characteristics of a pedigree with myotonic dystrophy type 1 (DM1). A series of clinical data from a pedigree with DM1 were collected. Muscle biopsy revealed a typical nuclear ingression within numerous muscle fibers following hematoxylin and eosin staining. Genomic DNA was extracted from the venous blood of two patients and the triplet-primed polymerase chain reaction method was performed to amplify the dystrophia myotonic protein kinase (DMPK) gene. The amplified products were subjected to gene sequencing by capillary fluorescence electrophoresis, and a pathogenic mutation in the DMPK gene comprising >50 cytosine-thymine-guanine repeat sequences was found. DM1 includes multi-system damage, as well as skeletal muscle involvement, and can affect the central nervous system, endocrine glands, skin and heart. A skeletal muscle biopsy and genetic testing can confirm the diagnosis and clarify the severity of the disease. In addition, it is necessary to distinguish DM1 from DM2.
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Affiliation(s)
- Qing Liu
- Department of Neurology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, Shanxi 030009, P.R. China
| | - Yu-Fei Zheng
- Department of Neurology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, Shanxi 030009, P.R. China
| | - Yan-Ping Zhu
- Department of Neurology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, Shanxi 030009, P.R. China
| | - Shi-Qing Ling
- Department of Neurology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, Shanxi 030009, P.R. China
| | - Wei-Rong Li
- Department of Neurology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, Shanxi 030009, P.R. China
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19
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Papadimas GK, Kekou K, Papadopoulos C, Kararizou E, Kanavakis E, Manta P. Phenotypic variability and molecular genetics in proximal myotonic myopathy. Muscle Nerve 2015; 51:686-91. [DOI: 10.1002/mus.24440] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 08/20/2014] [Accepted: 08/25/2014] [Indexed: 11/09/2022]
Affiliation(s)
- George Konstantinos Papadimas
- First Department of Neurology; University of Athens, Medical School; Aeginition Hospital, 74, Vas. Sophias Avenue 11528 Athens Greece
| | - Kiriaki Kekou
- Department of Medical Genetics; University of Athens, Medical School of Athens; Greece
| | - Constantinos Papadopoulos
- First Department of Neurology; University of Athens, Medical School; Aeginition Hospital, 74, Vas. Sophias Avenue 11528 Athens Greece
| | - Evangelia Kararizou
- First Department of Neurology; University of Athens, Medical School; Aeginition Hospital, 74, Vas. Sophias Avenue 11528 Athens Greece
| | - Emmanuel Kanavakis
- Department of Medical Genetics; University of Athens, Medical School of Athens; Greece
- University Research Institute for the Study of Genetic and Malignant Disorders in Childhood, Aghia Sophia Children's Hospital; Athens Greece
| | - Panagiota Manta
- First Department of Neurology; University of Athens, Medical School; Aeginition Hospital, 74, Vas. Sophias Avenue 11528 Athens Greece
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20
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Yu Z, Goodman LD, Shieh SY, Min M, Teng X, Zhu Y, Bonini NM. A fly model for the CCUG-repeat expansion of myotonic dystrophy type 2 reveals a novel interaction with MBNL1. Hum Mol Genet 2014; 24:954-62. [PMID: 25305073 DOI: 10.1093/hmg/ddu507] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Expanded non-coding RNA repeats of CUG and CCUG are the underlying genetic causes for myotonic dystrophy type 1 (DM1) and type 2 (DM2), respectively. A gain-of-function of these pathogenic repeat expansions is mediated at least in part by their abnormal interactions with RNA-binding proteins such as MBNL1 and resultant loss of activity of these proteins. To study pathogenic mechanisms of CCUG-repeat expansions in an animal model, we created a fly model of DM2 that expresses pure, uninterrupted CCUG-repeat expansions ranging from 16 to 720 repeats in length. We show that this fly model for DM2 recapitulates key features of human DM2 including RNA repeat-induced toxicity, ribonuclear foci formation and changes in alternative splicing. Interestingly, expression of two isoforms of MBNL1, MBNL135 and MBNL140, leads to cleavage and concurrent upregulation of the levels of the RNA-repeat transcripts, with MBNL140 having more significant effects than MBNL135. This property is shared with a fly CUG-repeat expansion model. Our results suggest a novel mechanism for interaction between the pathogenic RNA repeat expansions of myotonic dystrophy and MBNL1.
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Affiliation(s)
| | - Lindsey D Goodman
- Neurosciences Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | | | | | | - Nancy M Bonini
- Department of Biology and Neurosciences Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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21
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García-Alcover I, Colonques-Bellmunt J, Garijo R, Tormo JR, Artero R, Álvarez-Abril MC, López Castel A, Pérez-Alonso M. Development of a Drosophila melanogaster spliceosensor system for in vivo high-throughput screening in myotonic dystrophy type 1. Dis Model Mech 2014; 7:1297-306. [PMID: 25239918 PMCID: PMC4213733 DOI: 10.1242/dmm.016592] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Alternative splicing of pre-mRNAs is an important mechanism that regulates cellular function in higher eukaryotes. A growing number of human genetic diseases involve splicing defects that are directly connected to their pathology. In myotonic dystrophy type 1 (DM1), several clinical manifestations have been proposed to be the consequence of tissue-specific missplicing of numerous genes. These events are triggered by an RNA gain-of-function and resultant deregulation of specific RNA-binding factors, such as the nuclear sequestration of muscleblind-like family factors (MBNL1–MBNL3). Thus, the identification of chemical modulators of splicing events could lead to the development of the first valid therapy for DM1 patients. To this end, we have generated and validated transgenic flies that contain a luciferase-reporter-based system that is coupled to the expression of MBNL1-reliant splicing (spliceosensor flies), to assess events that are deregulated in DM1 patients in a relevant disease tissue. We then developed an innovative 96-well plate screening platform to carry out in vivo high-throughput pharmacological screening (HTS) with the spliceosensor model. After a large-scale evaluation (>16,000 chemical entities), several reliable splicing modulators (hits) were identified. Hit validation steps recognized separate DM1-linked therapeutic traits for some of the hits, which corroborated the feasibility of the approach described herein to reveal promising drug candidates to correct missplicing in DM1. This powerful Drosophila-based screening tool might also be applied in other disease models displaying abnormal alternative splicing, thus offering myriad uses in drug discovery.
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Affiliation(s)
- Irma García-Alcover
- Valentia BioPharma, Scientific Park of the University of Valencia, Paterna, Valencia 46980, Spain. Department of Genetics, University of Valencia, Burjassot, Valencia 46010, Spain
| | - Jordi Colonques-Bellmunt
- Valentia BioPharma, Scientific Park of the University of Valencia, Paterna, Valencia 46980, Spain
| | - Raquel Garijo
- Valentia BioPharma, Scientific Park of the University of Valencia, Paterna, Valencia 46980, Spain
| | - José R Tormo
- Valentia BioPharma, Scientific Park of the University of Valencia, Paterna, Valencia 46980, Spain
| | - Rubén Artero
- Department of Genetics, University of Valencia, Burjassot, Valencia 46010, Spain. INCLIVA Health Research Institute, Valencia 46010, Spain
| | | | - Arturo López Castel
- Valentia BioPharma, Scientific Park of the University of Valencia, Paterna, Valencia 46980, Spain.
| | - Manuel Pérez-Alonso
- Valentia BioPharma, Scientific Park of the University of Valencia, Paterna, Valencia 46980, Spain. Department of Genetics, University of Valencia, Burjassot, Valencia 46010, Spain. INCLIVA Health Research Institute, Valencia 46010, Spain
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Meola G, Cardani R. Myotonic dystrophies: An update on clinical aspects, genetic, pathology, and molecular pathomechanisms. Biochim Biophys Acta Mol Basis Dis 2014; 1852:594-606. [PMID: 24882752 DOI: 10.1016/j.bbadis.2014.05.019] [Citation(s) in RCA: 213] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/19/2014] [Accepted: 05/20/2014] [Indexed: 01/18/2023]
Abstract
Myotonic dystrophy (DM) is the most common adult muscular dystrophy, characterized by autosomal dominant progressive myopathy, myotonia and multiorgan involvement. To date two distinct forms caused by similar mutations have been identified. Myotonic dystrophy type 1 (DM1, Steinert's disease) is caused by a (CTG)n expansion in DMPK, while myotonic dystrophy type 2 (DM2) is caused by a (CCTG)n expansion in ZNF9/CNBP. When transcribed into CUG/CCUG-containing RNA, mutant transcripts aggregate as nuclear foci that sequester RNA-binding proteins, resulting in spliceopathy of downstream effector genes. However, it is now clear that additional pathogenic mechanism like changes in gene expression, protein translation and micro-RNA metabolism may also contribute to disease pathology. Despite clinical and genetic similarities, DM1 and DM2 are distinct disorders requiring different diagnostic and management strategies. This review is an update on the recent advances in the understanding of the molecular mechanisms behind myotonic dystrophies. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis.
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Affiliation(s)
- Giovanni Meola
- Department of Neurology, IRCCS Policlinico San Donato, University of Milan, San Donato Milanese, Milan, Italy; Laboratory of Muscle Histopathology and Molecular Biology, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy.
| | - Rosanna Cardani
- Laboratory of Muscle Histopathology and Molecular Biology, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy.
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Genome wide identification of aberrant alternative splicing events in myotonic dystrophy type 2. PLoS One 2014; 9:e93983. [PMID: 24722564 PMCID: PMC3983107 DOI: 10.1371/journal.pone.0093983] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 03/10/2014] [Indexed: 02/01/2023] Open
Abstract
Myotonic dystrophy type 2 (DM2) is a genetic, autosomal dominant disease due to expansion of tetraplet (CCTG) repetitions in the first intron of the ZNF9/CNBP gene. DM2 is a multisystemic disorder affecting the skeletal muscle, the heart, the eye and the endocrine system. According to the proposed pathological mechanism, the expanded tetraplets have an RNA toxic effect, disrupting the splicing of many mRNAs. Thus, the identification of aberrantly spliced transcripts is instrumental for our understanding of the molecular mechanisms underpinning the disease. The aim of this study was the identification of new aberrant alternative splicing events in DM2 patients. By genome wide analysis of 10 DM2 patients and 10 controls (CTR), we identified 273 alternative spliced exons in 218 genes. While many aberrant splicing events were already identified in the past, most were new. A subset of these events was validated by qPCR assays in 19 DM2 and 15 CTR subjects. To gain insight into the molecular pathways involving the identified aberrantly spliced genes, we performed a bioinformatics analysis with Ingenuity system. This analysis indicated a deregulation of development, cell survival, metabolism, calcium signaling and contractility. In conclusion, our genome wide analysis provided a database of aberrant splicing events in the skeletal muscle of DM2 patients. The affected genes are involved in numerous pathways and networks important for muscle physio-pathology, suggesting that the identified variants may contribute to DM2 pathogenesis.
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Abstract
PURPOSE OF REVIEW Aside from some inflammatory myopathies and very few genetic disorders, there are no therapies that make most patients with myopathies stronger. Consequently, the management of these patients can be frustrating for patients and their families as well as the clinicians taking care of them. Treatment of these patients must involve a comprehensive approach focused on limiting the secondary effects of skeletal muscle weakness, managing comorbidities associated with specific diseases, and, most importantly, optimizing patients' functional abilities and quality of life in terms of their ability to accomplish activities of daily living. While the approach to each patient differs depending on their disease, certain common themes can be addressed in each patient. This review highlights an approach centered on four conceptual themes ("the Four S's"): Strength therapies, Supportive care, Symptomatic therapies, and pSychological support. RECENT FINDINGS Although relatively few well-designed studies have been done that highlight conservative management of patients with various myopathies, an emerging literature helps guide the clinician in certain key areas, especially in relation to cardiac and pulmonary management of these patients. SUMMARY While disease-altering therapies have proven elusive for many muscle diseases, a multimodal approach to the conservative and supportive care of these patients can markedly improve their quality of life. Pharmacologic treatment options for specific myopathies will not be addressed in this article but are covered elsewhere in this issue of CONTINUUM.
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Hilbert JE, Ashizawa T, Day JW, Luebbe EA, Martens WB, McDermott MP, Tawil R, Thornton CA, Moxley RT. Diagnostic odyssey of patients with myotonic dystrophy. J Neurol 2013; 260:2497-504. [PMID: 23807151 PMCID: PMC4162528 DOI: 10.1007/s00415-013-6993-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/30/2013] [Accepted: 06/03/2013] [Indexed: 01/01/2023]
Abstract
The onset and symptoms of the myotonic dystrophies are diverse, complicating their diagnoses and limiting a comprehensive approach to their clinical care. This report analyzes the diagnostic delay (time from onset of first symptom to diagnosis) in a large sample of myotonic dystrophy (DM) patients enrolled in the US National Registry [679 DM type 1 (DM1) and 135 DM type 2 (DM2) patients]. Age of onset averaged 34.0 ± 14.1 years in DM2 patients compared to 26.1 ± 13.2 years in DM1 (p < 0.0001). The most common initial symptom in DM2 patients was leg weakness (32.6 %) compared to grip myotonia in DM1 (38.3 %). Pain was reported as the first symptom in 11.1 % of DM2 and 3.0 % of DM1 patients (p < 0.0001). Reaching the correct diagnosis in DM2 took 14 years on average (double the time compared to DM1) and a significantly higher percentage of patients underwent extended workup including electromyography, muscle biopsies, and finally genetic testing. DM patients who were index cases experienced similar diagnostic delays to non-index cases of DM. Further evaluation of how to shorten these diagnostic delays and limit their impact on burdens of disease, family planning, and symptom management is needed.
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Affiliation(s)
- James E Hilbert
- Department of Neurology, University of Rochester Medical Center, 601 Elmwood Ave, Box 673, Rochester, NY, 14642, USA,
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Garcia-Alcover I, López Castel A, Perez-Alonso M, Artero R. In vivo strategies for drug discovery in myotonic dystrophy disorders. DRUG DISCOVERY TODAY. TECHNOLOGIES 2013; 10:e97-102. [PMID: 24050236 DOI: 10.1016/j.ddtec.2012.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Myotonic dystrophy (DM) is a complex neuromuscular genetic disease for which there is currently no valid therapy. The recent development of non-mammal animal models opened up the possibility of performing drug discovery in vivo, using as screening readout phenotypes with underlying molecular parallels to the disease. In this review we discuss the state of the art technologies already used in large scale drug screening and provide guidance for further development of novel technologies.
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Veyckemans F, Scholtes JL. Myotonic dystrophies type 1 and 2: anesthetic care. Paediatr Anaesth 2013; 23:794-803. [PMID: 23384336 DOI: 10.1111/pan.12120] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/22/2012] [Indexed: 01/19/2023]
Abstract
Myotonic dystrophy is classified as one of the myotonic syndromes although myotonia is only a minor characteristic of it. It is, in fact, also a multisystem disease with cardiac, digestive, ocular, and endocrine abnormalities. Two subgroups are currently identified with many similarities: DM1 refers to classic dystrophia myotonica (Steinert disease), while DM2, formerly called proximal myotonic myopathy has a later onset. The congenital form is present only in DM1. The genetic causes of DM1 and 2 are different but end up in a similar way of altering RNAm processing and splicing of other genes. The anesthetic risk is increased in case of DM1 type. This review summarizes current knowledge concerning the pathophysiology and anesthetic management of this disease in children and adults.
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Affiliation(s)
- Francis Veyckemans
- Anesthesiology, Université catholique de Louvain Medical School, Cliniques universitaires St Luc, Brussels, Belgium.
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Sansone V, Brigonzi E, Schoser B, Villani S, Gaeta M, De Ambroggi G, Bandera F, De Ambroggi L, Meola G. The frequency and severity of cardiac involvement in myotonic dystrophy type 2 (DM2): Long-term outcomes. Int J Cardiol 2013; 168:1147-53. [DOI: 10.1016/j.ijcard.2012.11.076] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 11/11/2012] [Indexed: 11/29/2022]
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Gawel M, Szmidt-Salkowska E, Lusakowska A, Nojszewska M, Sulek A, Krysa W, Rajkiewicz M, Seroka A, Kaminska AM. Value of short exercise and short exercise with cooling tests in the diagnosis of myotonic dystrophies (DM1 AND DM2). Muscle Nerve 2013; 49:277-83. [DOI: 10.1002/mus.23908] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2013] [Indexed: 11/12/2022]
Affiliation(s)
- Malgorzata Gawel
- Department of Neurology; Medical University of Warsaw; Banacha 1A Warsaw 02-097 Poland
| | | | - Anna Lusakowska
- Department of Neurology; Medical University of Warsaw; Banacha 1A Warsaw 02-097 Poland
| | - Monika Nojszewska
- Department of Neurology; Medical University of Warsaw; Banacha 1A Warsaw 02-097 Poland
| | - Anna Sulek
- Department of Genetics; Institute of Psychiatry and Neurology; Warsaw Poland
| | - Wioletta Krysa
- Department of Genetics; Institute of Psychiatry and Neurology; Warsaw Poland
| | - Marta Rajkiewicz
- Department of Genetics; Institute of Psychiatry and Neurology; Warsaw Poland
| | - Andrzej Seroka
- Department of Neurology; Medical University of Warsaw; Banacha 1A Warsaw 02-097 Poland
| | - Anna M. Kaminska
- Department of Genetics; Institute of Psychiatry and Neurology; Warsaw Poland
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Malatesta M, Giagnacovo M, Costanzo M, Cisterna B, Cardani R, Meola G. Muscleblind-like1 undergoes ectopic relocation in the nuclei of skeletal muscles in myotonic dystrophy and sarcopenia. Eur J Histochem 2013; 57:e15. [PMID: 23807294 PMCID: PMC3794341 DOI: 10.4081/ejh.2013.e15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Revised: 02/13/2013] [Accepted: 02/14/2013] [Indexed: 01/24/2023] Open
Abstract
Muscleblind-like 1 (MBNL1) is an alternative splicing factor involved in postnatal development of skeletal muscles and heart in humans and mice, and its deregulation is known to be pivotal in the onset and development of myotonic dystrophy (DM). In fact, in DM patients this protein is ectopically sequestered into intranuclear foci, thus compromising the regulation of the alternative splicing of several genes. However, despite the numerous biochemical and molecular studies, scarce attention has been paid to the intranuclear location of MBNL1 outside the foci, although previous data demonstrated that in DM patients various splicing and cleavage factors undergo an abnormal intranuclear distribution suggestive of impaired RNA processing. Interestingly, these nuclear alterations strongly remind those observed in sarcopenia i.e., the loss of muscle mass and function which physiologically occurs during ageing. On this basis, in the present investigation the ultrastructural localization of MBNL1 was analyzed in the myonuclei of skeletal muscles from healthy and DM patients as well as from adult and old (sarcopenic) mice, in the attempt to elucidate possible changes in its distribution and amount. Our data demonstrate that in both dystrophic and sarcopenic muscles MBNL1 undergoes intranuclear relocation, accumulating in its usual functional sites but also ectopically moving to domains which are usually devoid of this protein in healthy adults. This accumulation/delocalization could contribute to hamper the functionality of the whole splicing machinery, leading to a lower nuclear metabolic activity and, consequently, to a less efficient protein synthesis. Moreover, the similar nuclear alterations found in DM and sarcopenia may account for the similar muscle tissue features (myofibre atrophy, fibre size variability and centrally located nuclei), and, in general, for the aging-reminiscent phenotype observed in DM patients.
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Affiliation(s)
- M Malatesta
- Dipartimento di Scienze Neurologiche, Neuropsicologiche, Morfologiche e Motorie, Sezione di Anatomia e Istologia, Università di Verona, 37134 Verona, Italy.
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Udd B, Krahe R. The myotonic dystrophies: molecular, clinical, and therapeutic challenges. Lancet Neurol 2012; 11:891-905. [DOI: 10.1016/s1474-4422(12)70204-1] [Citation(s) in RCA: 335] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Abstract
The muscular dystrophies are a group of inherited diseases affecting skeletal muscle that also affect cardiac muscle. Cardiac involvement occurs as a degenerative process with fibrosis and fatty replacement of the myocardium. Electrophysiologists are asked to participate in the care of muscular dystrophy patients because of the risk of atrial arrhythmias, conduction disease, bradycardia, ventricular arrhythmias, and sudden death. Duchenne, Becker, and limb-girdle types 2C-2F and 2I are muscular dystrophies in which the development of a dilated cardiomyopathy is common. Arrhythmias and conduction disease occur after the development of the dilated cardiomyopathy. Patients are considered for pacemakers or implantable cardioverter-defibrillators on the basis of guidelines used for nonischemic cardiomyopathies. Myotonic types 1 and 2, Emery-Dreifuss, limb-girdle type 1B, and facioscapulohumeral muscular dystrophies present with conduction disease and associated arrhythmias and variably with a dilated cardiomyopathy. In myotonic type 1, Emery-Dreifuss, and limb-girdle type 1B muscular dystrophies, conduction abnormalities are frequent and often require pacing. Recent studies support the use of prophylactic implantable cardioverter-defibrillators rather than pacemakers. In all the muscular dystrophies, respiratory muscle involvement can impact quality and quantity of life and needs to be factored in when considering a prophylactic device.
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Affiliation(s)
- William J Groh
- Department of Medicine, Division of Cardiology, Krannert Institute of Cardiology, Indiana University, Indianapolis, Indiana.
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Abstract
Myotonic Dystrophy Type-2 (DM2) is an autosomal dominant disease caused by the expansion of a CCTG tetraplet repeat. It is a multisystemic disorder, affecting skeletal muscles, the heart, the eye, the central nervous system and the endocrine system. Since microRNA (miRNA) expression is disrupted in Myotonic Dystrophy Type-1 and many other myopathies, miRNAs deregulation was studied in skeletal muscle biopsies of 13 DM2 patients and 13 controls. Eleven miRNAs were deregulated: 9 displayed higher levels compared to controls (miR-34a-5p, miR-34b-3p, miR-34c-5p, miR-146b-5p, miR-208a, miR-221-3p and miR-381), while 4 were decreased (miR-125b-5p, miR-193a-3p, miR-193b-3p and miR-378a-3p). To explore the relevance of DM2 miRNA deregulation, the predicted interactions between miRNA and mRNA were investigated. Global gene expression was analyzed in DM2 and controls and bioinformatic analysis identified more than 1,000 miRNA/mRNA interactions. Pathway and function analysis highlighted the involvement of the miRNA-deregulated mRNAs in multiple aspects of DM2 pathophysiology. In conclusion, the observed miRNA dysregulations may contribute to DM2 pathogenetic mechanisms.
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Nuclear ribonucleoprotein-containing foci increase in size in non-dividing cells from patients with myotonic dystrophy type 2. Histochem Cell Biol 2012; 138:699-707. [PMID: 22706481 DOI: 10.1007/s00418-012-0984-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2012] [Indexed: 10/28/2022]
Abstract
Myotonic dystrophies (DM) are genetically based neuromuscular disorders characterized by the accumulation of mutant transcripts into peculiar intranuclear foci, where different splicing factors (among which the alternative splicing regulator muscleblind-like 1 protein, MBNL1) are ectopically sequestered. The aim of the present investigation was to describe the dynamics of the DM-specific intranuclear foci in interphase nuclei and during mitosis, as well as after the exit from the cell cycle. Primary cultures of skin fibroblasts from DM2 patients were used, as a model system to reproduce in vitro, as accurately as possible, the in vivo conditions. Cycling and resting fibroblasts were investigated by immunocytochemical and morphometric techniques, and the relative amounts of MBNL1 were also estimated by western blotting. MBNL1-containing foci were exclusively found in the nucleus during most of the interphase, while being observed in the cytoplasm during mitosis when they never associate with the chromosomes; the foci remained in the cytoplasm at cytodieresis, and underwent disassembly in early G1 to be reformed in the nucleus at each cell cycle. After fibroblasts had stopped dividing in late-passage cultures, the nuclear foci were observed to progressively increase in size. Interestingly, measurements on muscle biopsies taken from the same DM2 patients at different ages demonstrated that, in the nuclei of myofibers, the MBNL1-containing foci become larger with increasing patient's age. As a whole, these results suggest that in non-dividing cells of DM2 patients the sequestration in the nuclear foci of factors needed for RNA processing would be continuous and progressive, eventually leading to the onset (and the worsening with time) of the pathological traits. This is consistent with the evidence that in DM patients the most affected organs or tissues are those where non-renewing cells are mainly present, i.e., the central nervous system, heart and skeletal muscle.
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Hilbert JE, Kissel JT, Luebbe EA, Martens WB, McDermott MP, Sanders DB, Tawil R, Thornton CA, Moxley RT. If you build a rare disease registry, will they enroll and will they use it? Methods and data from the National Registry of Myotonic Dystrophy (DM) and Facioscapulohumeral Muscular Dystrophy (FSHD). Contemp Clin Trials 2012; 33:302-11. [PMID: 22155025 PMCID: PMC3357007 DOI: 10.1016/j.cct.2011.11.016] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 10/28/2011] [Accepted: 11/22/2011] [Indexed: 01/28/2023]
Abstract
INTRODUCTION Registries are becoming increasingly important for rare diseases as experimental therapies develop. This report describes the methodology behind the National Registry of Myotonic Dystrophy (DM) and Facioscapulohumeral Muscular Dystrophy (FSHD) Patients and Family Members to facilitate the development of other rare disease registries. We also highlight data about the pathophysiology and select burdens of DM and FSHD reported at baseline and longitudinally. METHODS The Registry consists of de-identified, patient reported information collected at baseline and annually and information from review of medical records. Investigators can use the Registry to analyze de-identified data and to facilitate recruitment into clinical studies. RESULTS To date, the Registry has enrolled 1611 members, facilitated 24 studies, and collected data annually for up to 8 years. Genetic test results were obtained in 56.2% of enrollees. Approximately one-third of members used assistive devices and another one-third reported psychological problems at baseline. Wheelchair use was reported for both short and long distances by 7.0% of DM and 18.1% of FSHD members. Approximately 60% of members reported their employment was affected by their disease. CONCLUSIONS Strengths of the Registry include large sample sizes, stringent review of clinical and molecular data, annually updated information, and regular interactions between patients and investigators. Registry data provide new insights into the burdens of DM and FSHD, such as, psychological problems and reduced employment. Opportunities abound for investigators to utilize Registry resources to assess the impact of these and other burdens on health care costs, progression of symptoms, and quality of life.
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Affiliation(s)
- James E Hilbert
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA.
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