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Mair D, Biskup S, Kress W, Abicht A, Brück W, Zechel S, Knop KC, Koenig FB, Tey S, Nikolin S, Eggermann K, Kurth I, Ferbert A, Weis J. Differential diagnosis of vacuolar myopathies in the NGS era. Brain Pathol 2020; 30:877-896. [PMID: 32419263 PMCID: PMC8017999 DOI: 10.1111/bpa.12864] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/10/2020] [Accepted: 05/07/2020] [Indexed: 12/12/2022] Open
Abstract
Altered autophagy accompanied by abnormal autophagic (rimmed) vacuoles detectable by light and electron microscopy is a common denominator of many familial and sporadic non-inflammatory muscle diseases. Even in the era of next generation sequencing (NGS), late-onset vacuolar myopathies remain a diagnostic challenge. We identified 32 adult vacuolar myopathy patients from 30 unrelated families, studied their clinical, histopathological and ultrastructural characteristics and performed genetic testing in index patients and relatives using Sanger sequencing and NGS including whole exome sequencing (WES). We established a molecular genetic diagnosis in 17 patients. Pathogenic mutations were found in genes typically linked to vacuolar myopathy (GNE, LDB3/ZASP, MYOT, DES and GAA), but also in genes not regularly associated with severely altered autophagy (FKRP, DYSF, CAV3, COL6A2, GYG1 and TRIM32) and in the digenic facioscapulohumeral muscular dystrophy 2. Characteristic histopathological features including distinct patterns of myofibrillar disarray and evidence of exocytosis proved to be helpful to distinguish causes of vacuolar myopathies. Biopsy validated the pathogenicity of the novel mutations p.(Phe55*) and p.(Arg216*) in GYG1 and of the p.(Leu156Pro) TRIM32 mutation combined with compound heterozygous deletion of exon 2 of TRIM32 and expanded the phenotype of Ala93Thr-caveolinopathy and of limb-girdle muscular dystrophy 2i caused by FKRP mutation. In 15 patients no causal variants were detected by Sanger sequencing and NGS panel analysis. In 12 of these cases, WES was performed, but did not yield any definite mutation or likely candidate gene. In one of these patients with a family history of muscle weakness, the vacuolar myopathy was eventually linked to chloroquine therapy. Our study illustrates the wide phenotypic and genotypic heterogeneity of vacuolar myopathies and validates the role of histopathology in assessing the pathogenicity of novel mutations detected by NGS. In a sizable portion of vacuolar myopathy cases, it remains to be shown whether the cause is hereditary or degenerative.
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Affiliation(s)
- Dorothea Mair
- Institute of Neuropathology, RWTH Aachen University, Aachen, Germany.,Department of Neurology, Kassel School of Medicine, Klinikum Kassel, Kassel, Germany.,University of Southampton, Southampton, UK
| | - Saskia Biskup
- Centre for Genomics and Transcriptomics CeGaT, Tübingen, Germany
| | - Wolfram Kress
- Institute of Human Genetics, University Würzburg, Würzburg, Germany
| | | | - Wolfgang Brück
- Institute of Neuropathology, Göttingen University, Göttingen, Germany
| | - Sabrina Zechel
- Institute of Neuropathology, Göttingen University, Göttingen, Germany
| | | | | | - Shelisa Tey
- Institute of Neuropathology, RWTH Aachen University, Aachen, Germany
| | - Stefan Nikolin
- Institute of Neuropathology, RWTH Aachen University, Aachen, Germany
| | - Katja Eggermann
- Institute of Human Genetics, RWTH Aachen University, Aachen, Germany
| | - Ingo Kurth
- Institute of Human Genetics, RWTH Aachen University, Aachen, Germany
| | - Andreas Ferbert
- Department of Neurology, Kassel School of Medicine, Klinikum Kassel, Kassel, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University, Aachen, Germany
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Multisystem Myotilinopathy, including Myopathy and Left Ventricular Noncompaction, due to the MYOT Variant c.179C>T. Case Rep Cardiol 2020; 2020:5128069. [PMID: 32509353 PMCID: PMC7244945 DOI: 10.1155/2020/5128069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 04/18/2020] [Accepted: 05/05/2020] [Indexed: 11/20/2022] Open
Abstract
Left ventricular hypertrabeculation/noncompaction is a myocardial abnormality of unknown etiology/pathogenesis, which is frequently associated with neuromuscular disorders or chromosomal defects. LVHT in association with a MYOT mutation has not been reported. The patient is a 72-year-old male with a history of strabismus in childhood, asymptomatic creatine-kinase elevation since age 42 years, slowly progressive lower limb weakness since age 60 years, slowly progressive dysarthria and dysphagia since age 62 years, and recurrent episodes of arthralgias and myalgias since age 71 years. He also had arterial hypertension, diverticulosis, hyperlipidemia, coronary heart disease, and a hiatal hernia with reflux esophagitis. Clinical exam revealed mild quadruparesis and proximal wasting of the legs. Whole exome sequencing revealed a known variant in the MYOT gene. Muscle biopsy, previously assessed as inclusion body myopathy, was compatible with the genotype after revision. Cardiologic work-up revealed a left anterior hemiblock, mild myocardial thickening, and noncompaction. This case shows that myotilinopathy may manifest as a multisystem disease, including noncompaction.
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Mensch A, Kraya T, Koester F, Müller T, Stoevesandt D, Zierz S. Whole-body muscle MRI of patients with MATR3-associated distal myopathy reveals a distinct pattern of muscular involvement and highlights the value of whole-body examination. J Neurol 2020; 267:2408-2420. [PMID: 32361838 PMCID: PMC7358922 DOI: 10.1007/s00415-020-09862-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/18/2020] [Accepted: 04/22/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE MATR3-associated distal myopathy is a rare distal myopathy predominantly affecting lower legs as well as wrist- and finger extensors. Whilst most distal myopathies are clinically and genetically well characterized, diagnosis often remains challenging. Pattern-based magnetic resonance imaging (MRI) approaches offer valuable additional information. However, a consistent pattern of muscular affection is missing for most distal myopathies. Thus, the aim of the present study was to establish a disease-specific pattern of muscular involvement in MATR3-associated distal myopathy using whole-body MRI. METHODS 15 patients (25-79 years of age, 7 female) with MATR3-associated distal myopathy were subjected to whole-body MRI. The grade of fatty involution for individual muscles was determined using Fischer-Grading. Results were compared to established MRI-patterns of other distal myopathies. RESULTS There was a predominant affection of the distal lower extremities. Lower legs showed a severe fatty infiltration, prominently affecting gastrocnemius and soleus muscle. In thighs, a preferential involvement of semimembranous and biceps femoris muscle was observed. Severe affection of gluteus minimus muscle as well as axial musculature, mainly affecting the thoracic segments, was seen. A sufficient discrimination to other forms of distal myopathy based solely on MRI-findings of the lower extremities was not possible. However, the inclusion of additional body parts seemed to yield specificity. INTERPRETATION Muscle MRI of patients with MATR3-associated distal myopathy revealed a distinct pattern of muscular involvement. The usage of whole-body muscle MRI provided valuable additional findings as compared to regular MRI of the lower extremities to improve distinction from other disease entities.
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Affiliation(s)
- Alexander Mensch
- Department of Neurology, Martin-Luther-University of Halle-Wittenberg, Halle (Saale), Germany.
| | - Torsten Kraya
- Department of Neurology, Martin-Luther-University of Halle-Wittenberg, Halle (Saale), Germany.,Department of Neurology, Klinikum St. Georg, Leipzig, Germany
| | - Felicitas Koester
- Department of Neurology, Martin-Luther-University of Halle-Wittenberg, Halle (Saale), Germany.,Department of Radiology, Martin-Luther-University of Halle-Wittenberg, Halle (Saale), Germany
| | - Tobias Müller
- Department of Neurology, Martin-Luther-University of Halle-Wittenberg, Halle (Saale), Germany
| | - Dietrich Stoevesandt
- Department of Radiology, Martin-Luther-University of Halle-Wittenberg, Halle (Saale), Germany
| | - Stephan Zierz
- Department of Neurology, Martin-Luther-University of Halle-Wittenberg, Halle (Saale), Germany
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Rudolf G, Suominen T, Penttilä S, Hackman P, Evilä A, Lannes B, Echaniz-Laguna A, Bierry G, Tranchant C, Udd B. Homozygosity of the Dominant Myotilin c.179C>T (p.Ser60Phe) Mutation Causes a More Severe and Proximal Muscular Dystrophy. J Neuromuscul Dis 2018; 3:275-281. [PMID: 27854214 DOI: 10.3233/jnd-150143] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Most myotilinopathy patients present with a dominant late onset distal phenotype and myofibrillar pathology, although the first MYOT mutation in a family reported to have LGMD phenotype. We report here a French family affected with a late onset proximal and distal muscle weakness and myofibrillar myopathy on muscle pathology, in which the siblings known to be clinically affected were homozygous for the c.179C>T (p.Ser60Phe) myotilin gene mutation. One subjectively asymptomatic member of the family was heterozygous for this mutation. This is the first report of a family with patients being homozygous for a known dominant MYOT mutation. Dominant negative mutations are generally considered not to cause a more severe disease in homozygosity, but our data clearly demonstrate the existence of dominant MYOT mutations with a possible dose effect causing a more severe disease phenotype in homozygosity in the spectrum of myofibrillar myopathies (MFM).
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Affiliation(s)
- Gabrielle Rudolf
- IGBMC, CNRS UMR 7104, INSERM U964, Strasbourg University, France.,Service de Neurologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Tiina Suominen
- Neuromuscular Research Unit, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - Sini Penttilä
- Neuromuscular Research Unit, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - Peter Hackman
- Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Anni Evilä
- Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Béatrice Lannes
- Département d'Anatomopathologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | | | - Guillaume Bierry
- Département de Radiologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Christine Tranchant
- IGBMC, CNRS UMR 7104, INSERM U964, Strasbourg University, France.,Service de Neurologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS, Universitdé Strasbourg, INSERM, Illkirch, France
| | - Bjarne Udd
- Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.,Département d'Anatomopathologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Department of Neurology, Vaasa Central Hospital, Vaasa, Finland
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Bugiardini E, Morrow JM, Shah S, Wood CL, Lynch DS, Pitmann AM, Reilly MM, Houlden H, Matthews E, Parton M, Hanna MG, Straub V, Yousry TA. The Diagnostic Value of MRI Pattern Recognition in Distal Myopathies. Front Neurol 2018; 9:456. [PMID: 29997562 PMCID: PMC6028608 DOI: 10.3389/fneur.2018.00456] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 05/29/2018] [Indexed: 12/14/2022] Open
Abstract
Objective: Distal myopathies are a diagnostically challenging group of diseases. We wanted to understand the value of MRI in the current clinical setting and explore the potential for optimizing its clinical application. Methods: We retrospectively audited the diagnostic workup in a distal myopathy patient cohort, reassessing the diagnosis, whilst documenting the usage of MRI. We established a literature based distal myopathies MRI pattern template and assessed its diagnostic utility in terms of sensitivity, specificity, and potential impact on the diagnostic workup. Results: Fifty-five patients were included; in 38 with a comprehensive set of data the diagnostic work-up was audited. The median time from symptoms onset to diagnosis was 12.1 years. The initial genetic diagnostic rate was 39%; 18% were misdiagnosed as neuropathies and 13% as inclusion body myositis (IBM). Based on 21 publications we established a MRI pattern template. Its overall sensitivity (50%) and specificity (32%) were low. However in some diseases (e.g., MYOT-related myopathy, TTN-HMERF) MRI correctly identified the causative gene. The number of genes suggested by MRI pattern analysis was smaller compared to clinical work up (median 1 vs. 9, p < 0.0001) but fewer genes were correctly predicted (5/10 vs. 7/10). MRI analysis ruled out IBM in all cases. Conclusion: In the diagnostic work-up of distal myopathies, MRI is useful in assisting genetic testing and avoiding misdiagnosis (IBM). The overall low sensitivity and specificity limits its generalized use when traditional single gene test methods are applied. However, in the context of next generation sequencing MRI may represent a valuable tool for interpreting complex genetic results.
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Affiliation(s)
- Enrico Bugiardini
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Jasper M. Morrow
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Sachit Shah
- Neuroradiological Academic Unit, UCL Institute of Neurology, London, United Kingdom
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Claire L. Wood
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle upon Tyne, United Kingdom
| | - David S. Lynch
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Alan M. Pitmann
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Mary M. Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Henry Houlden
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Emma Matthews
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Matt Parton
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Michael G. Hanna
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle upon Tyne, United Kingdom
| | - Tarek A. Yousry
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
- Neuroradiological Academic Unit, UCL Institute of Neurology, London, United Kingdom
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom
- *Correspondence: Tarek A. Yousry
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6
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Magnetic resonance imaging patterns of muscle involvement in genetic muscle diseases: a systematic review. J Neurol 2016; 264:1320-1333. [PMID: 27888415 DOI: 10.1007/s00415-016-8350-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 12/25/2022]
Abstract
A growing body of the literature supports the use of magnetic resonance imaging as a potential biomarker for disease severity in the hereditary myopathies. We performed a systematic review of the medical literature to evaluate patterns of fat infiltration observed in magnetic resonance imaging studies of muscular dystrophy and congenital myopathy. Searches were performed using MEDLINE, EMBASE, and grey literature databases. Studies that described fat infiltration of muscles in patients with muscular dystrophy or congenital myopathy were selected for full-length review. Data on preferentially involved or spared muscles were extracted for analysis. A total of 2172 titles and abstracts were screened, and 70 publications met our criteria for inclusion in the systematic review. There were 23 distinct genetic disorders represented in this analysis. In most studies, preferential involvement and sparing of specific muscles were reported. We conclude that magnetic resonance imaging studies can be used to identify distinct patterns of muscle involvement in the hereditary myopathies. However, larger studies and standardized methods of reporting are needed to develop imaging as a diagnostic tool in these diseases.
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Béhin A, Salort-Campana E, Wahbi K, Richard P, Carlier RY, Carlier P, Laforêt P, Stojkovic T, Maisonobe T, Verschueren A, Franques J, Attarian S, Maues de Paula A, Figarella-Branger D, Bécane HM, Nelson I, Duboc D, Bonne G, Vicart P, Udd B, Romero N, Pouget J, Eymard B. Myofibrillar myopathies: State of the art, present and future challenges. Rev Neurol (Paris) 2015; 171:715-29. [DOI: 10.1016/j.neurol.2015.06.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 05/11/2015] [Accepted: 06/02/2015] [Indexed: 12/18/2022]
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8
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Díaz-Manera J, Llauger J, Gallardo E, Illa I. Muscle MRI in muscular dystrophies. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2015; 34:95-108. [PMID: 27199536 PMCID: PMC4859076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Muscle MRI has become a very useful tool in the diagnosis and follow-up of patients with muscle dystrophies. Muscle MRI provides us about many aspects of the structure and function of skeletal muscles, such as the presence of oedema or fatty infiltration. In the last years many reports have described the particular muscles that are involved in these muscle disease. This knowledge can facilitate the diagnosis in many cases. In the present paper we review the main changes observed in muscle MRI of patients with muscle dystrophies.
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Affiliation(s)
- Jordi Díaz-Manera
- Neuromuscular Disorders Unit, Neurology Department, Hospital Universitari de la Santa Creu i Sant Pau, Barcelona;,Centro de Investigación Básica en Enfermedades Raras (CIBERER);,Address for correspondence: Dr. Jordi Díaz-Manera, Neurology Department, Hospital de la Santa Creu I Sant Pau de Barcelona, C/ Sant Antoni Mª Claret 167, 08025 Barcelona, Spain. E-mail:
| | - Jaume Llauger
- Radiology Department, Hospital Universitari de la Santa Creu i Sant Pau, Barcelona
| | - Eduard Gallardo
- Neuromuscular Disorders Unit, Neurology Department, Hospital Universitari de la Santa Creu i Sant Pau, Barcelona;,Centro de Investigación Básica en Enfermedades Raras (CIBERER)
| | - Isabel Illa
- Neuromuscular Disorders Unit, Neurology Department, Hospital Universitari de la Santa Creu i Sant Pau, Barcelona;,Centro de Investigación Básica en Enfermedades Raras (CIBERER)
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RNAi-mediated Gene Silencing of Mutant Myotilin Improves Myopathy in LGMD1A Mice. MOLECULAR THERAPY-NUCLEIC ACIDS 2014; 3:e160. [PMID: 24781192 PMCID: PMC4013433 DOI: 10.1038/mtna.2014.13] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 03/21/2014] [Indexed: 11/28/2022]
Abstract
Recent progress suggests gene therapy may one day be an option for treating some forms of limb girdle muscular dystrophy (LGMD). Nevertheless, approaches targeting LGMD have so far focused on gene replacement strategies for recessive forms of the disease. In contrast, no attempts have been made to develop molecular therapies for any of the eight dominantly inherited forms of LGMD. Importantly, the emergence of RNA interference (RNAi) therapeutics in the last decade provided new tools to combat dominantly inherited LGMDs with molecular therapy. In this study, we describe the first RNAi-based, preclinical gene therapy approach for silencing a gene associated with dominant LGMD. To do this, we developed adeno-associated viral vectors (AAV6) carrying designed therapeutic microRNAs targeting mutant myotilin (MYOT), which is the underlying cause of LGMD type 1A (LGMD1A). Our best MYOT-targeted microRNA vector (called miMYOT) significantly reduced mutant myotilin mRNA and soluble protein expression in muscles of LGMD1A mice (the TgT57I model) both 3 and 9 months after delivery, demonstrating short- and long-term silencing effects. This MYOT gene silencing subsequently decreased deposition of MYOT-seeded intramuscular protein aggregates, which is the hallmark feature of LGMD1A. Histological improvements were accompanied by significant functional correction, as miMYOT-treated animals showed increased muscle weight and improved specific force in the gastrocnemius, which is one of the most severely affected muscles in TgT57I mice and patients with dominant myotilin mutations. These promising results in a preclinical model of LGMD1A support the further development of RNAi-based molecular therapy as a prospective treatment for LGMD1A. Furthermore, this study sets a foundation that may be refined and adapted to treat other dominant LGMD and related disorders.
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Tasca G, Ricci E, Monforte M, Laschena F, Ottaviani P, Rodolico C, Barca E, Silvestri G, Iannaccone E, Mirabella M, Broccolini A. Muscle imaging findings in GNE myopathy. J Neurol 2012; 259:1358-65. [PMID: 22231866 DOI: 10.1007/s00415-011-6357-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 11/22/2011] [Accepted: 12/05/2011] [Indexed: 11/25/2022]
Abstract
GNE myopathy (MIM 600737) is an autosomal recessive muscle disease caused by mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene. Besides the typical phenotype, characterized by the initial involvement of the distal leg muscles that eventually spreads proximally with sparing of the quadriceps, uncommon presentations with a non-canonical clinical phenotype, unusual muscle biopsy findings or both are increasingly recognized. The aim of our study was to characterize the imaging pattern of pelvic and lower limb muscles in GNE myopathy, thus providing additional diagnostic clues useful in the identification of patients with atypical features. We retrospectively evaluated muscle MRI and CT scans of a cohort of 13 patients heterogeneous for GNE mutations and degree of clinical severity. We found that severe involvement of the biceps femoris short head and, to a lesser extent, of the gluteus minimus, tibialis anterior, extensor hallucis and digitorum longus, soleus and gastrocnemius medialis was consistently present even in patients with early or atypical disease. The vastus lateralis, not the entire quadriceps, was the only muscle spared in advanced stages, while the rectus femoris, vastus intermedius and medialis showed variable signs of fatty replacement. Younger patients showed hyperintensities on T2-weighted sequences in muscles with a normal or, more often, abnormal T1-weighted signal. Our results define a pattern of muscle involvement that appears peculiar to GNE myopathy. Although these findings need to be further validated in a larger cohort, we believe that the recognition of this pattern may be instrumental in the initial clinical assessment of patients with possible GNE myopathy.
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Jin L. The actin associated protein palladin in smooth muscle and in the development of diseases of the cardiovasculature and in cancer. J Muscle Res Cell Motil 2011; 32:7-17. [PMID: 21455759 DOI: 10.1007/s10974-011-9246-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Accepted: 03/22/2011] [Indexed: 02/06/2023]
Abstract
Palladin is an actin associated protein serving as a cytoskeleton scaffold, and actin cross linker, localizing at stress fibers, focal adhesions, and other actin based structures. Recent studies showed that palladin plays a critical role in smooth muscle differentiation, migration, contraction, and more importantly contributes to embryonic development. This review will focus on the functions and possible mechanisms of palladin in smooth muscle and in pathological conditions such as cardiovascular diseases and cancers.
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Affiliation(s)
- Li Jin
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.
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12
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Reilich P, Krause S, Schramm N, Klutzny U, Bulst S, Zehetmayer B, Schneiderat P, Walter MC, Schoser B, Lochmüller H. A novel mutation in the myotilin gene (MYOT) causes a severe form of limb girdle muscular dystrophy 1A (LGMD1A). J Neurol 2011; 258:1437-44. [PMID: 21336781 DOI: 10.1007/s00415-011-5953-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 02/07/2011] [Indexed: 01/04/2023]
Abstract
Here we describe a patient with limb girdle muscular dystrophy 1A (LGMD1A) due to a novel myotilin gene (MYOT) mutation with late onset, rapid progression, loss of ambulation and respiratory failure. The onset of weakness in proximal muscles and muscle MRI findings are clearly different from the pattern identified in myofibrillar myopathies (MFM) related to MYOT mutations. Moreover, there was very limited evidence of myofibrillar pathology in several muscle biopsies obtained during the disease course. We conclude, that MYOT mutations need to be considered as a rare cause of adult-onset, dominant LGMD without clear-cut MFM pathology.
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Affiliation(s)
- Peter Reilich
- Friedrich-Baur-Institut, Department of Neurology, Ludwig-Maximilians-University, Munich, Germany.
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