1
|
Koehorst E, Odria R, Capó J, Núñez-Manchón J, Arbex A, Almendrote M, Linares-Pardo I, Natera-de Benito D, Saez V, Nascimento A, Ortez C, Rubio MÁ, Díaz-Manera J, Alonso-Pérez J, Lucente G, Rodriguez-Palmero A, Ramos-Fransi A, Martínez-Piñeiro A, Nogales-Gadea G, Suelves M. An Integrative Analysis of DNA Methylation Pattern in Myotonic Dystrophy Type 1 Samples Reveals a Distinct DNA Methylation Profile between Tissues and a Novel Muscle-Associated Epigenetic Dysregulation. Biomedicines 2022; 10:biomedicines10061372. [PMID: 35740394 PMCID: PMC9220235 DOI: 10.3390/biomedicines10061372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/31/2022] [Accepted: 06/07/2022] [Indexed: 11/16/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a progressive, non-treatable, multi-systemic disorder. To investigate the contribution of epigenetics to the complexity of DM1, we compared DNA methylation profiles of four annotated CpG islands (CpGis) in the DMPK locus and neighbouring genes, in distinct DM1 tissues and derived cells, representing six DM1 subtypes, by bisulphite sequencing. In blood, we found no differences in CpGi 74, 43 and 36 in DNA methylation profile. In contrast, a CTCF1 DNA methylation gradient was found with 100% methylation in congenital cases, 50% in childhood cases and 13% in juvenile cases. CTCF1 methylation correlated to disease severity and CTG expansion size. Notably, 50% of CTCF1 methylated cases showed methylation in the CTCF2 regions. Additionally, methylation was associated with maternal transmission. Interestingly, the evaluation of seven families showed that unmethylated mothers passed on an expansion of the CTG repeat, whereas the methylated mothers transmitted a contraction. The analysis of patient-derived cells showed that DNA methylation profiles were highly preserved, validating their use as faithful DM1 cellular models. Importantly, the comparison of DNA methylation levels of distinct DM1 tissues revealed a novel muscle-specific epigenetic signature with methylation of the CTCF1 region accompanied by demethylation of CpGi 43, a region containing an alternative DMPK promoter, which may decrease the canonical promoter activity. Altogether, our results showed a distinct DNA methylation profile across DM1 tissues and uncovered a novel and dual epigenetic signature in DM1 muscle samples, providing novel insights into the epigenetic changes associated with DM1.
Collapse
Affiliation(s)
- Emma Koehorst
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Renato Odria
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Júlia Capó
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Judit Núñez-Manchón
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Andrea Arbex
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
- Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain
| | - Miriam Almendrote
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
- Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain
| | - Ian Linares-Pardo
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Daniel Natera-de Benito
- Neuromuscular Unit, Neuropediatric Department, Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, L'Hospitalet de Llobregat, 08950 Barcelona, Spain
| | - Verónica Saez
- Neuromuscular Unit, Neuropediatric Department, Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, L'Hospitalet de Llobregat, 08950 Barcelona, Spain
| | - Andrés Nascimento
- Neuromuscular Unit, Neuropediatric Department, Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, L'Hospitalet de Llobregat, 08950 Barcelona, Spain
| | - Carlos Ortez
- Neuromuscular Unit, Neuropediatric Department, Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, L'Hospitalet de Llobregat, 08950 Barcelona, Spain
| | - Miguel Ángel Rubio
- Neuromuscular Unit, Department of Neurology, Hospital del Mar, 08003 Barcelona, Spain
| | - Jordi Díaz-Manera
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 3BZ, UK
| | - Jorge Alonso-Pérez
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain
| | - Giuseppe Lucente
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
- Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain
| | - Agustín Rodriguez-Palmero
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
- Pediatric Neurology Unit, Department of Pediatrics, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Alba Ramos-Fransi
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
- Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain
| | - Alicia Martínez-Piñeiro
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
- Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain
| | - Gisela Nogales-Gadea
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| | - Mònica Suelves
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Campus Can Ruti, Universitat Autònoma de Barcelona, 08916 Badalona, Spain
| |
Collapse
|
2
|
Polypoidal choroidal vasculopathy in a patient with DMPK-associated myotonic dystrophy. Doc Ophthalmol 2022; 144:217-226. [DOI: 10.1007/s10633-022-09867-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 02/14/2022] [Indexed: 11/26/2022]
|
3
|
The Biomarker Potential of miRNAs in Myotonic Dystrophy Type I. J Clin Med 2020; 9:jcm9123939. [PMID: 33291833 PMCID: PMC7762003 DOI: 10.3390/jcm9123939] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/19/2020] [Accepted: 12/01/2020] [Indexed: 02/08/2023] Open
Abstract
MicroRNAs (miRNAs) are mostly known for their gene regulation properties, but they also play an important role in intercellular signaling. This means that they can be found in bodily fluids, giving them excellent biomarker potential. Myotonic Dystrophy type I (DM1) is the most frequent autosomal dominant muscle dystrophy in adults, with an estimated prevalence of 1:8000. DM1 symptoms include muscle weakness, myotonia, respiratory failure, cardiac conduction defects, cataracts, and endocrine disturbances. Patients display heterogeneity in both age of onset and disease manifestation. No treatment or cure currently exists for DM1, which shows the necessity for a biomarker that can predict disease progression, providing the opportunity to implement preventative measures before symptoms arise. In the past two decades, extensive research has been conducted in the miRNA expression profiles of DM1 patients and their biomarker potential. Here we review the current state of the field with a tissue-specific focus, given the multi-systemic nature of DM1 and the intracellular signaling role of miRNAs.
Collapse
|
4
|
Pruijn IMJ, van Herpen CML, Pegge SAH, van Engen van Grunsven ACH, Ligtenberg MJ, van den Hoogen FJA. Myotonic dystrophy and recurrent pleomorphic adenomas: Case report and association hypothesis. Neuromuscul Disord 2020; 30:925-929. [PMID: 33077317 DOI: 10.1016/j.nmd.2020.09.029] [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: 05/08/2020] [Revised: 07/23/2020] [Accepted: 09/19/2020] [Indexed: 10/23/2022]
Abstract
We report a case of a patient with concurrent myotonic dystrophy and recurrent pleomorphic adenoma and hypothesize the association between both diseases. A 58-year-old man with classic myotonic dystrophy type 1 was diagnosed with pleomorphic adenoma. Appropriate treatment was commenced. Massive recurrences occurred within 15, 28 and 22 months respectively, after repeated surgical removal. Three case reports on similar occurrences of synchronous myotonic dystrophy and pleomorphic adenoma are discussed and an association between both disease entities is hypothesized. A conceivable association between myotonic dystrophy and pleomorphic adenoma is hypothesized by upregulation of the Wnt/Beta-catenin signaling pathway, initiated by a decreased expression of microRNA, pleomorphic adenoma gene 1 induced Beta-catenin accumulations and alterations in tumor suppressor genes and oncogenes due to RNA processing defects induced by the expanded repeat in the DMPK gene.
Collapse
Affiliation(s)
- Ineke M J Pruijn
- Department of Otolaryngology and Head and Neck Surgery, Radboud university medical center, Postbus 9101, 6500 Nijmegen, the Netherlands.
| | - Carla M L van Herpen
- Department of Medical Oncology, Radboud university medical center, Nijmegen, the Netherlands
| | - Sjoert A H Pegge
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, the Netherlands
| | | | - Marjolijn J Ligtenberg
- Department of Human Genetics and Department of Pathology, Radboud university medical center, Nijmegen, the Netherlands
| | - Frank J A van den Hoogen
- Department of Otolaryngology and Head and Neck Surgery, Radboud university medical center, Postbus 9101, 6500 Nijmegen, the Netherlands
| |
Collapse
|
5
|
Overend G, Légaré C, Mathieu J, Bouchard L, Gagnon C, Monckton DG. Allele length of the DMPK CTG repeat is a predictor of progressive myotonic dystrophy type 1 phenotypes. Hum Mol Genet 2020; 28:2245-2254. [PMID: 31220271 DOI: 10.1093/hmg/ddz055] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/13/2019] [Accepted: 03/13/2019] [Indexed: 12/13/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is an autosomal dominant inherited disorder caused by expansion of a germline and somatically unstable CTG repeat in the DMPK gene. Previously, CTG repeat length at birth has been correlated to patient age at symptom onset. Attempts to correlate CTG repeat length with progressive DM1 phenotypes, such as muscle power, have proven difficult. To better correlate genotype with progressive phenotypes, we have measured CTG repeat tract length and screened for interrupting variant repeats in 192 study participants from a well-characterized Canadian cohort. We have assessed genotype-phenotype correlations with nine progressive measures of skeletal muscle power and respiratory function. We have built statistical models that include confounding factors such as sex, age, height and weight to further explain variation in muscle power. Our analysis reveals a strong correlation between DM1 genotype and respiratory function and skeletal muscle power, as part of a complex model that includes additional modulators such as sex, age, height, weight and the presence or absence of interrupting variant repeats. Distal skeletal muscle measurements, such as hand pinch and grip strength, show the strongest correlation with disease genotype. Detailed analysis of CTG repeat length, and incorporation of confounding factors, greatly improves the predictive ability of these models. They reveal a greater genetic influence on individual progressive phenotypes than on age at symptom onset and for clinical trials will help optimize stratification and explain patient variability. They will also help practitioners prioritize assessment of the muscular power measurements that correlate best with disease severity.
Collapse
Affiliation(s)
- Gayle Overend
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Cécilia Légaré
- Department of Biochemistry, Université de Sherbrooke, Sherbrooke, Québec, Canada.,ECOGENE Biocluster, Chicoutimi, Québec, Canada.,Groupe de recherche interdisciplinaire sur les maladies neuromusculaires, Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-St-Jean, rue de l'Hôpital, Saguenay, Québec, Canada
| | - Jean Mathieu
- École de réadaptation, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Canada.,Groupe de recherche interdisciplinaire sur les maladies neuromusculaires, Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-St-Jean, rue de l'Hôpital, Saguenay, Québec, Canada
| | - Luigi Bouchard
- Department of Biochemistry, Université de Sherbrooke, Sherbrooke, Québec, Canada.,ECOGENE Biocluster, Chicoutimi, Québec, Canada.,Groupe de recherche interdisciplinaire sur les maladies neuromusculaires, Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-St-Jean, rue de l'Hôpital, Saguenay, Québec, Canada
| | - Cynthia Gagnon
- École de réadaptation, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Canada.,Groupe de recherche interdisciplinaire sur les maladies neuromusculaires, Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-St-Jean, rue de l'Hôpital, Saguenay, Québec, Canada
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| |
Collapse
|
6
|
Ballester-Lopez A, Koehorst E, Almendrote M, Martínez-Piñeiro A, Lucente G, Linares-Pardo I, Núñez-Manchón J, Guanyabens N, Cano A, Lucia A, Overend G, Cumming SA, Monckton DG, Casadevall T, Isern I, Sánchez-Ojanguren J, Planas A, Rodríguez-Palmero A, Monlleó-Neila L, Pintos-Morell G, Ramos-Fransi A, Coll-Cantí J, Nogales-Gadea G. A DM1 family with interruptions associated with atypical symptoms and late onset but not with a milder phenotype. Hum Mutat 2019; 41:420-431. [PMID: 31608518 DOI: 10.1002/humu.23932] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 09/18/2019] [Accepted: 10/06/2019] [Indexed: 12/16/2022]
Abstract
Carriage of interruptions in CTG repeats of the myotonic dystrophy protein kinase gene has been associated with a broad spectrum of myotonic dystrophy type 1 (DM1) phenotypes, mostly mild. However, the data available on interrupted DM1 patients and their phenotype are scarce. We studied 49 Spanish DM1 patients, whose clinical phenotype was evaluated in depth. Blood DNA was obtained and analyzed through triplet-primed polymerase chain reaction (PCR), long PCR-Southern blot, small pool PCR, AciI digestion, and sequencing. Five patients of our registry (10%), belonging to the same family, carried CCG interruptions at the 3'-end of the CTG expansion. Some of them presented atypical traits such as very late onset of symptoms ( > 50 years) and a severe axial and proximal weakness requiring walking assistance. They also showed classic DM1 symptoms including cardiac and respiratory dysfunction, which were severe in some of them. Sizes and interrupted allele patterns were determined, and we found a contraction and an expansion in two intergenerational transmissions. Our study contributes to the observation that DM1 patients carrying interruptions present with atypical clinical features that can make DM1 diagnosis difficult, with a later than expected age of onset and a previously unreported aging-related severe disease manifestation.
Collapse
Affiliation(s)
- Alfonsina Ballester-Lopez
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Emma Koehorst
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Miriam Almendrote
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Alicia Martínez-Piñeiro
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Giuseppe Lucente
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Ian Linares-Pardo
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Judit Núñez-Manchón
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Nicolau Guanyabens
- Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Antoni Cano
- Neurology Unit, Neuroscience Department, Hospital de Mataró, Barcelona, Spain
| | - Alejandro Lucia
- Universidad Europea (Faculty of Sport Sciences), Madrid, Spain.,Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain
| | - Gayle Overend
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Sarah A Cumming
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Teresa Casadevall
- Neurology Service, Hospital Comarcal Sant Jaume de Calella, Barcelona, Spain
| | - Irina Isern
- Unitat de Neurologia, Hospital de l'Esperit Sant, Barcelona, Spain
| | | | - Albert Planas
- Servei de medicina interna, Secció de neurologia, Hospital Municipal de Badalona, Barcelona, Spain
| | - Agustí Rodríguez-Palmero
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuropediatric Unit, Pediatric Service, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Laura Monlleó-Neila
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuropediatric Unit, Pediatric Service, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Guillem Pintos-Morell
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Division of Rare Diseases, University Hospital Vall d'Hebron, Barcelona, Spain
| | - Alba Ramos-Fransi
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Jaume Coll-Cantí
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Gisela Nogales-Gadea
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
7
|
Abstract
Myotonic dystrophy is an autosomal dominant muscular dystrophy not only associated with muscle weakness, atrophy, and myotonia but also prominent multisystem involvement. There are 2 similar, but distinct, forms of myotonic dystrophy; type 1 is caused by a CTG repeat expansion in the DMPK gene, and type 2 is caused by a CCTG repeat expansion in the CNBP gene. Type 1 is associated with distal limb, neck flexor, and bulbar weakness and results in different phenotypic subtypes with variable onset from congenital to very late-onset as well as variable signs and symptoms. The classically described adult-onset form is the most common. In contrast, myotonic dystrophy type 2 is adult-onset or late-onset, has proximal predominant muscle weakness, and generally has less severe multisystem involvement. In both forms of myotonic dystrophy, the best characterized disease mechanism is a RNA toxic gain-of-function during which RNA repeats form nuclear foci resulting in sequestration of RNA-binding proteins and, therefore, dysregulated splicing of premessenger RNA. There are currently no disease-modifying therapies, but clinical surveillance, preventative measures, and supportive treatments are used to reduce the impact of muscular impairment and other systemic involvement including cataracts, cardiac conduction abnormalities, fatigue, central nervous system dysfunction, respiratory weakness, dysphagia, and endocrine dysfunction. Exciting preclinical progress has been made in identifying a number of potential strategies including genome editing, small molecule therapeutics, and antisense oligonucleotide-based therapies to target the pathogenesis of type 1 and type 2 myotonic dystrophies at the DNA, RNA, or downstream target level.
Collapse
Affiliation(s)
- Samantha LoRusso
- Department of Neurology, The Ohio State University, 395 West 12th Avenue, Columbus, OH, 43210, USA
| | - Benjamin Weiner
- The Ohio State University College of Medicine, The Ohio State University, 370 West 9th Avenue, Columbus, OH, 43210, USA
| | - W David Arnold
- Department of Neurology, The Ohio State University, 395 West 12th Avenue, Columbus, OH, 43210, USA.
| |
Collapse
|
8
|
Park D, Lee SH, Shin JH, Park JS. Lower limb muscle magnetic resonance imaging in myotonic dystrophy type 1 correlates with the six-minute walk test and CTG repeats. Neuromuscul Disord 2018; 28:29-37. [DOI: 10.1016/j.nmd.2017.08.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 08/04/2017] [Accepted: 08/17/2017] [Indexed: 01/08/2023]
|
9
|
Fujino H, Shingaki H, Suwazono S, Ueda Y, Wada C, Nakayama T, Takahashi MP, Imura O, Matsumura T. Cognitive impairment and quality of life in patients with myotonic dystrophy type 1. Muscle Nerve 2017; 57:742-748. [PMID: 29193182 DOI: 10.1002/mus.26022] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 11/25/2017] [Accepted: 11/27/2017] [Indexed: 01/25/2023]
Abstract
INTRODUCTION This study sought to clarify whether specific cognitive abilities are impaired in patients with myotonic dystrophy type 1 (DM1) as well as to investigate the relationships among quality of life (QoL), cognitive function, and psychological factors. METHODS Sixty patients with DM1 were evaluated on cognitive functioning (abstract reasoning, attention/working memory, executive function, processing speed, and visuoconstructive ability), apathy, depression, excessive daytime sleepiness, fatigue, and QoL. QoL was assessed by 2 domains of the Muscular Dystrophy Quality of Life Scale (Psychosocial Relationships and Physical Functioning and Health). RESULTS More than half of the patients exhibited cognitive impairment in attention/working memory, executive function, processing speed, and visuoconstructive ability. The Psychosocial Relationships factor was associated with processing speed, attention/working memory, and apathy, whereas depression and fatigue were associated with 2 QoL domains. DISCUSSION Our study identified specific cognitive impairments in DM1. Specific cognitive functions and psychological factors may be potential contributors to QoL. Muscle Nerve 57: 742-748, 2018.
Collapse
Affiliation(s)
- Haruo Fujino
- Department of Special Needs Education, Oita University, 700 Dannoharu, Oita, Japan, 870-1192.,Graduate School of Human Sciences, Osaka University, Osaka, Japan
| | - Honoka Shingaki
- Graduate School of Human Sciences, Osaka University, Osaka, Japan
| | - Shugo Suwazono
- Department of Neurology, National Hospital Organization Okinawa Hospital, Okinawa, Japan
| | | | - Chizu Wada
- Department of Neurology, National Hospital Organization Akita National Hospital, Yurihonjo, Japan
| | | | - Masanori P Takahashi
- Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Osaka, Japan.,Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Osamu Imura
- Graduate School of Human Sciences, Osaka University, Osaka, Japan
| | - Tsuyoshi Matsumura
- Department of Neurology, National Hospital Organization Toneyama National Hospital, Osaka, Japan
| |
Collapse
|
10
|
Hogrel JY, Ollivier G, Ledoux I, Hébert LJ, Eymard B, Puymirat J, Bassez G. Relationships between grip strength, myotonia, and CTG expansion in myotonic dystrophy type 1. Ann Clin Transl Neurol 2017; 4:921-925. [PMID: 29296622 PMCID: PMC5740258 DOI: 10.1002/acn3.496] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/02/2017] [Accepted: 10/02/2017] [Indexed: 02/01/2023] Open
Abstract
In myotonic dystrophy type 1, several studies have suggested causal relationships between CTG repeat length and the severity of symptoms, such as weakness or myotonia. We aimed to explore these relationships in a large population of 144 DM1 patients. All patients underwent clinical and functional assessments using a standardized test for grip strength and myotonia assessment. Myotonia was assessed using a fully automatic software based on mathematical modeling of relaxation force curve. CTG repeat length was statistically correlated with both myotonia and grip strength, which are two major primary neuromuscular symptoms of DM1 patients. However, these relationships are not clinically meaningful and not predictive at the individual level.
Collapse
Affiliation(s)
| | | | | | | | - Bruno Eymard
- Institut de Myologie GH Pitié-Salpêtrière Paris France
| | | | | |
Collapse
|
11
|
Clinical characteristics of pregnancies complicated by congenital myotonic dystrophy. Obstet Gynecol Sci 2017; 60:323-328. [PMID: 28791262 PMCID: PMC5547078 DOI: 10.5468/ogs.2017.60.4.323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/25/2016] [Accepted: 12/05/2016] [Indexed: 11/23/2022] Open
Abstract
Objective Although the conventional prevalence of myotonic dystrophy is 1:8,000, the prevalence in Korean population was recently reported as 1:1,245. With higher domestic result than expected, we aimed to investigate the clinical characteristics of pregnancies complicated by congenital myotonic dystrophy in our institution. Methods We have reviewed 11 paired cases of neonates diagnosed with congenital myotonic dystrophy and their mothers between July 2004 and May 2014, with clinical features including maternal history of infertility, prenatal ultrasonographic findings, and neonatal outcomes. Cytosine-thymine-guanine (CTG) repeat expansion in the myotonic dystrophy protein kinase gene of both neonates and their mothers was also examined. Results None of mother was aware of their myotonic dystrophy traits before pregnancy. History of infertility followed by assisted reproductive technology accounted for 57.1% (4/7). Distinctive prenatal ultrasonographic finding was severe idiopathic polyhydramnios (66.7%, 4/6) with median amniotic fluid index of 43 (range, 37 to 66). In 37.5% (3/8) cases, decreased fetal movement was evident during prenatal ultrasound examination. For neonatal outcomes, more than half (6/11) were complicated with preterm birth and the proportion of 1-minute Apgar score <4 and 5-minute Apgar score <7 was 44.4% (4/9) and 66.7% (6/9), respectively. Most of neonates were admitted to the neonatal intensive care unit (9/10) because of hypotonia with respiratory problems and there was one infant death. Median number of cytosine-thymine-guanine repeats in mothers and neonates was 400 (range, 166 to 1,000) and 1,300 (range, 700 to 2,000), respectively. Conclusion Our data suggest that severe idiopathic polyhydramnios with decreased fetal movement in pregnant women, especially with a history of infertility, requires differential diagnosis of congenital myotonic dystrophy.
Collapse
|
12
|
Esposito F, Cè E, Rampichini S, Monti E, Limonta E, Fossati B, Meola G. Electromechanical delays during a fatiguing exercise and recovery in patients with myotonic dystrophy type 1. Eur J Appl Physiol 2017; 117:551-566. [PMID: 28194519 DOI: 10.1007/s00421-017-3558-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/24/2017] [Indexed: 01/08/2023]
Abstract
PURPOSE The partitioning of the electromechanical delay by an electromyographic (EMG), mechanomyographic (MMG) and force combined approach can provide further insight into the electrochemical and mechanical processes involved with skeletal muscle contraction and relaxation. The aim of the study was to monitor by this combined approach the changes in delays' electrochemical and mechanical components throughout a fatiguing task and during recovery in patients with myotonic dystrophy type 1 (DM1), who present at the skeletal muscle level fibres rearrangement, muscle weakness and myotonia, especially in the distal muscles. METHODS After assessing maximum voluntary contraction (MVC), 14 male patients with DM1 and 14 healthy controls (HC) performed a fatiguing exercise at 50% MVC until exhaustion. EMG, MMG, and force signals were recorded from tibialis anterior and vastus lateralis muscles. The electromechanical delay during contraction (DelayTOT) and relaxation (R-DelayTOT) components, EMG and MMG root mean square (RMS) and mean frequency (MF) were calculated off-line. RESULTS The fatiguing exercise duration was similar in both groups. In patients with DM1, delays components were significantly longer compared to HC, especially in the distal muscle during relaxation. Delays components recovered quickly from the fatiguing exercise in HC than in patients with DM1 in both muscles. CONCLUSIONS The alterations in delays observed in DM1 during the fatiguing exercise may indicate that also the lengthening of the electrochemical and mechanical processes during contraction and relaxation could play a role in explaining exercise intolerance in this pathology.
Collapse
Affiliation(s)
- Fabio Esposito
- Department of Biomedical Sciences for Health (SCIBIS), Università degli Studi di Milano, Via G. Colombo 71, 20133, Milan, Italy. .,IRCCS Fondazione don Gnocchi, Centro di Medicina dello Sport, via Capecelatro 66, 20148, Milan, Italy.
| | - Emiliano Cè
- Department of Biomedical Sciences for Health (SCIBIS), Università degli Studi di Milano, Via G. Colombo 71, 20133, Milan, Italy
| | - Susanna Rampichini
- Department of Biomedical Sciences for Health (SCIBIS), Università degli Studi di Milano, Via G. Colombo 71, 20133, Milan, Italy
| | - Elena Monti
- Department of Biomedical Sciences for Health (SCIBIS), Università degli Studi di Milano, Via G. Colombo 71, 20133, Milan, Italy
| | - Eloisa Limonta
- Department of Biomedical Sciences for Health (SCIBIS), Università degli Studi di Milano, Via G. Colombo 71, 20133, Milan, Italy
| | - Barbara Fossati
- IRCCS Policlinico San Donato, Piazza Malan 2, 20097, San Donato Milanese (MI), Italy
| | - Giovanni Meola
- Department of Biomedical Sciences for Health (SCIBIS), Università degli Studi di Milano, Via G. Colombo 71, 20133, Milan, Italy.,IRCCS Policlinico San Donato, Piazza Malan 2, 20097, San Donato Milanese (MI), Italy
| |
Collapse
|
13
|
Electromechanical delay components during skeletal muscle contraction and relaxation in patients with myotonic dystrophy type 1. Neuromuscul Disord 2016; 26:60-72. [DOI: 10.1016/j.nmd.2015.09.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/15/2015] [Accepted: 09/19/2015] [Indexed: 12/20/2022]
|
14
|
Impact of habitual exercise on the strength of individuals with myotonic dystrophy type 1. Am J Phys Med Rehabil 2015; 93:739-46; quiz 747-8. [PMID: 24743456 DOI: 10.1097/phm.0000000000000088] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE It remains unclear whether habitual physical activity can attenuate the rate of progressive muscle strength loss in individuals with myotonic dystrophy type 1 (DM1). The aim of this study was to identify whether there were any strength differences between DM1 patients who were habitually active or sedentary. DESIGN Knee extension, handgrip, and elbow flexion quantitative strength measurements were investigated in the DM1 patients using isokinetic dynamometry. Strength was compared between the patients who followed self-selected formal exercise plans for at least 1 yr, those who were sedentary (controls), and those who initiated or terminated a formal exercise routine. RESULTS Physically active DM1 patients with midrange CTG repeat size (100-500 CTG repeat sizes) had significantly stronger handgrip and knee extension and elbow flexion torques as compared with their sedentary counterparts with the same CTG repeat range. The DM1 patients who began a formal exercise routine experienced a significant improvement in knee extension torque measurements (+24.3%) in comparison with those who were habitually active or sedentary. CONCLUSIONS These data suggest that there is an association between physical activity and strength. This may be shown to be a useful tool for the management of this condition. Further investigations into the relationships between physical exercise, muscle weakness, and genetic factors are needed before evidence-based recommendations can be made.
Collapse
|
15
|
Panaite PA, Kuntzer T, Gourdon G, Barakat-Walter I. Respiratory failure in a mouse model of myotonic dystrophy does not correlate with the CTG repeat length. Respir Physiol Neurobiol 2013; 189:22-6. [PMID: 23811192 DOI: 10.1016/j.resp.2013.06.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 06/20/2013] [Accepted: 06/20/2013] [Indexed: 01/03/2023]
Abstract
Myotonic dystrophy (DM1) is a multisystemic disease caused by an expansion of CTG repeats in the region of DMPK, the gene encoding DM protein kinase. The severity of muscle disability in DM1 correlates with the size of CTG expansion. As respiratory failure is one of the main causes of death in DM1, we investigated the correlation between respiratory impairment and size of the (CTG)n repeat in DM1 animal models. Using pressure plethysmography the respiratory function was assessed in control and transgenic mice carrying either 600 (DM600) or >1300 CTG repeats (DMSXL). The statistical analysis of respiratory parameters revealed that both DM1 transgenic mice sub-lines show respiratory impairment compared to control mice. In addition, there is no significant difference in breathing functions between the DM600 and DMSXL mice. In conclusion, these results indicate that respiratory impairment is present in both transgenic mice sub-lines, but the severity of respiratory failure is not related to the size of the (CTG)n expansion.
Collapse
|
16
|
Statland JM, Bundy BN, Wang Y, Trivedi JR, Raja Rayan D, Herbelin L, Donlan M, McLin R, Eichinger KJ, Findlater K, Dewar L, Pandya S, Martens WB, Venance SL, Matthews E, Amato AA, Hanna MG, Griggs RC, Barohn RJ. A quantitative measure of handgrip myotonia in non-dystrophic myotonia. Muscle Nerve 2012; 46:482-9. [PMID: 22987687 DOI: 10.1002/mus.23402] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Non-dystrophic myotonia (NDM) is characterized by myotonia without muscle wasting. A standardized quantitative myotonia assessment (QMA) is important for clinical trials. METHODS Myotonia was assessed in 91 individuals enrolled in a natural history study using a commercially available computerized handgrip myometer and automated software. Average peak force and 90% to 5% relaxation times were compared with historical normal controls studied with identical methods. RESULTS Thirty subjects had chloride channel mutations, 31 had sodium channel mutations, 6 had DM2 mutations, and 24 had no identified mutation. Chloride channel mutations were associated with prolonged first handgrip relaxation times and warm-up on subsequent handgrips. Sodium channel mutations were associated with prolonged first handgrip relaxation times and paradoxical myotonia or warm-up, depending on underlying mutations. DM2 subjects had normal relaxation times but decreased peak force. Sample size estimates are provided for clinical trial planning. CONCLUSION QMA is an automated, non-invasive technique for evaluating myotonia in NDM.
Collapse
Affiliation(s)
- Jeffrey M Statland
- Department of Neurology, University of Rochester Medical Center, Rochester, New York, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Andersen G, Ørngreen MC, Preisler N, Colding-Jørgensen E, Clausen T, Duno M, Jeppesen TD, Vissing J. Muscle phenotype in patients with myotonic dystrophy type 1. Muscle Nerve 2012; 47:409-15. [PMID: 23169601 DOI: 10.1002/mus.23535] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2012] [Indexed: 11/06/2022]
Abstract
INTRODUCTION The pathogenesis of muscle involvement in patients with myotonic dystrophy type 1 (DM1) is not well understood. In this study, we characterized the muscle phenotype in patients with confirmed DM1. METHODS In 38 patients, muscle strength was tested by hand-held dynamometry. Myotonia was evaluated by a handgrip test and by analyzing the decrement of the compound muscle action potential. Muscle biopsies were assessed for morphological changes and Na(+)-K(+) pump content. RESULTS Muscle strength correlated with a decline in Na(+)-K(+) pump content (r = 0.60, P < 0.001) and with CTG expansion. CTG expansion did not correlate with severity of myotonia, proximal histopathological changes, or Na(+)-K(+) pump content. Histopathologically, we found few centrally placed nuclei (range 0.2-6.9%). CONCLUSIONS The main findings of this study are that muscle weakness correlated inversely with CTG expansion and that central nuclei are not a prominent feature of proximal muscles in DM1.
Collapse
Affiliation(s)
- Grete Andersen
- Neuromuscular Research Unit, Department of Neurology, 3342, Rigshospitalet Blegdamsvej 9, DK-2100, Copenhagen, Denmark.
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Abstract
Clinical and electrical myotonia is caused by a small group of neuromuscular disorders. This article reviews myotonia and its differential diagnosis. The use of electrodiagnostic testing to evaluate the primary myotonic disorders (myotonic dystrophy and the nondystrophic myotonias) is also discussed.
Collapse
Affiliation(s)
- Michael K Hehir
- Department of Neurology, University of Vermont, Burlington, VT 05401, USA.
| | | |
Collapse
|
19
|
Peripheral neuropathy is linked to a severe form of myotonic dystrophy in transgenic mice. J Neuropathol Exp Neurol 2011; 70:678-85. [PMID: 21760538 DOI: 10.1097/nen.0b013e3182260939] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystem disorder with a variable phenotype. The involvement of peripheral nerves in DM1 disease is controversial. The DM1 animal model DM300 transgenic mice that carry 350 to 500 CTG repeats express a mild DM1 phenotype but do not exhibit motor or sensory pathology. Here, we investigated the presence or absence of peripheral neuropathy in transgenic mice (DMSXL) that carry more than 1,300 CTG repeats and display a severe form of DM1. Electrophysiologic, histologic, and morphometric methods were used to investigate the structure and function of peripheral nerves. We observed lower compound muscle action potentials recorded from hind limb muscles and slowing of sciatic nerve conduction velocity in DMSXL versus control mice. Morphometric analyses showed an axonopathy and neuronopathy in the DMSXL mice characterized by a decrease in numbers of myelinated motor axons in sciatic nerve and in spinal cord motor neurons. Pathologic alterations in the structure of hind limb neuromuscular junctions were also detected in the DMSXL mice. These results suggest that peripheral neuropathy can be linked to a large CTG expansion and a severe form of DM1.
Collapse
|
20
|
Heatwole CR, Eichinger KJ, Friedman DI, Hilbert JE, Jackson CE, Logigian EL, Martens WB, McDermott MP, Pandya SK, Quinn C, Smirnow AM, Thornton CA, Moxley RT. Open-label trial of recombinant human insulin-like growth factor 1/recombinant human insulin-like growth factor binding protein 3 in myotonic dystrophy type 1. ACTA ACUST UNITED AC 2010; 68:37-44. [PMID: 20837825 DOI: 10.1001/archneurol.2010.227] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVE To evaluate the safety and tolerability of recombinant human insulin-like growth factor 1 (rhIGF-1) complexed with IGF binding protein 3 (rhIGF-1/rhIGFBP-3) in patients with myotonic dystrophy type 1 (DM1). DESIGN Open-label dose-escalation clinical trial. SETTING University medical center. PARTICIPANTS Fifteen moderately affected ambulatory participants with genetically proven myotonic dystrophy type 1. INTERVENTION Participants received escalating dosages of subcutaneous rhIGF-1/rhIGFBP-3 for 24 weeks followed by a 16-week washout period. MAIN OUTCOME MEASURES Serial assessments of safety, muscle mass, muscle function, and metabolic state were performed. The primary outcome variable was the ability of participants to complete 24 weeks receiving rhIGF-1/ rhIGFBP-3 treatment. RESULTS All participants tolerated rhIGF-1/rhIGFBP-3. There were no significant changes in muscle strength or functional outcomes measures. Lean body muscle mass measured by dual-energy x-ray absorptiometry increased by 1.95 kg (P < .001) after treatment. Participants also experienced a mean reduction in triglyceride levels of 47 mg/dL (P = .002), a mean increase in HDL levels of 5.0 mg/dL (P = .03), a mean reduction in hemoglobin A(1c) levels of 0.15% (P = .03), and a mean increase in testosterone level (in men) of 203 ng/dL (P = .002) while taking rhIGF-1/rhIGFBP-3. Mild reactions at the injection site occurred (9 participants), as did mild transient hypoglycemia (3), lightheadedness (2), and transient papilledema (1). CONCLUSIONS Treatment with rhIGF-1/rhIGFBP-3 was generally well tolerated in patients with myotonic dystrophy type 1. Treatment with rhIGF-1/rhIGFBP-3 was associated with increased lean body mass and improvement in metabolism but not increased muscle strength or function. Larger randomized controlled trials would be needed to further evaluate the efficacy and safety of this medication in patients with neuromuscular disease. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00233519.
Collapse
Affiliation(s)
- Chad R Heatwole
- University of Rochester Medical Center, Rochester, NY 14642, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Logigian EL, Twydell P, Dilek N, Martens WB, Quinn C, Wiegner AW, Heatwole CR, Thornton CA, Moxley RT. Evoked myotonia can be "dialed-up" by increasing stimulus train length in myotonic dystrophy type 1. Muscle Nerve 2010; 41:191-6. [PMID: 19750543 DOI: 10.1002/mus.21481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is unknown how evoked myotonia varies with stimulus frequency or train length, or how it compares to voluntary myotonia in myotonic dystrophy type 1 (DM1). First dorsal interosseous (FDI) tetanic contractions evoked by trains of 10-20 ulnar nerve stimuli at 10-50 HZ were recorded in 10 DM1 patients and 10 normals. For comparison, maximum voluntary handgrip contractions were also recorded. An automated computer program placed cursors along the declining (relaxation) phase of the force recordings at 90% and 5% of peak force (PF) and calculated relaxation times (RTs) between these points. For all stimulus frequencies and train lengths, evoked RTs were much shorter, and evoked PFs were much greater in normals than in DM1. In normals, evoked RT was independent of stimulus frequency and train length, while in DM1 RT was longer for train lengths of 20 stimuli (mean: 9 s in DM1; 0.20 in normals) than for 10 stimuli (mean: 3 s in DM1, 0.19 in normals), but it did not change with stimulus frequency. In both groups PF increased greatly as stimulus frequency rose from 10-50 HZ but only slightly as train length rose from 10-20 stimuli. Voluntary handgrip RT (mean: 1.9 s) was less than evoked FDI RT (mean: 9 s). In DM1, evoked RT can be "dialed up" by increasing stimulus train length. Evoked myotonia testing utilizing a stimulus paradigm of at least 20 stimuli at 30-50 HZ may be useful in antimyotonic drug trials, particularly when grip RT is normal or equivocal.
Collapse
Affiliation(s)
- Eric L Logigian
- Department of Neurology, University of Rochester Medical Center, Box 673, 601 Elmwood Avenue, Rochester, New York, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Otten RF, Scherschel JA, Lopshire JC, Bhakta D, Pascuzzi RM, Groh WJ. Arrhythmia exacerbation after sodium channel blockade in myotonic dystrophy type 1. Muscle Nerve 2009; 40:901-2. [DOI: 10.1002/mus.21345] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
23
|
Abstract
The lack of a robust quantitative measure of myotonia has been underlined in previous studies. Recent publications have proposed methods to quantify myotonia based on the measurement of force relaxation times during maximal contractions. However, they present several drawbacks mainly due to unstable force, odd peaks or digital noise. A possible solution to this issue consists in fitting the force curve with a convenient regression model. The aim of this study was, therefore, to provide a regression model in order to fit the force relaxation time curve automatically and to provide a robust index for quantitative assessment of myotonia in clinical settings. Force curves were fitted by an asymmetric sigmoidal function. The inverse function was then used to compute various absolute and relative relaxation times automatically. These variables were calculated for 16 controls and 16 patients with myotonic dystrophy type 1 (DM1). All variables were significantly increased in DM1 patients compared to controls. For instance, the relaxation time between 40 and 60% of the initial contraction level was 18.2 (SD: 3.3) ms in controls and 40.1 (SD: 17.7) ms in DM1 patients. All relaxation variables were highly discriminant. Force curve modelling provides an objective and effective quantification of myotonia.
Collapse
Affiliation(s)
- J-Y Hogrel
- Institut de Myologie, GH Pitié-Salpêtrière, 75651 Paris Cedex 13, France.
| |
Collapse
|
24
|
Osborne RJ, Thornton CA. Cell-free cloning of highly expanded CTG repeats by amplification of dimerized expanded repeats. Nucleic Acids Res 2008; 36:e24. [PMID: 18263610 PMCID: PMC2275075 DOI: 10.1093/nar/gkn025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
We describe conditions for producing uninterrupted expanded CTG repeats consisting of up to 2000 repeats using ϕ29 DNA polymerase. Previously, generation of such repeats was hindered by CTG repeat instability in plasmid vectors maintained in Escherichia coli and poor in vitro ligation of CTG repeat concatemers due to strand slippage. Instead, we used a combination of in vitro ligation and ϕ29 DNA polymerase to amplify DNA. Correctly ligated products generating a dimerized repeat tract formed substrates for rolling circle amplification (RCA). In the presence of two non-complementary primers, hybridizing to either strand of DNA, ligations can be amplified to generate microgram quantities of repeat containing DNA. Additionally, expanded repeats generated by rolling circle amplification can be produced in vectors for expression of expanded CUG (CUGexp) RNA capable of sequestering MBNL1 protein in cell culture. Amplification of dimerized expanded repeats (ADER) opens new possibilities for studies of repeat instability and pathogenesis in myotonic dystrophy, a neurological disorder caused by an expanded CTG repeat.
Collapse
Affiliation(s)
- Robert J Osborne
- Department of Neurology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA.
| | | |
Collapse
|
25
|
Boërio D, Hogrel JY, Bassez G, Lefaucheur JP. Neuromuscular excitability properties in myotonic dystrophy type 1. Clin Neurophysiol 2007; 118:2375-82. [PMID: 17890147 DOI: 10.1016/j.clinph.2007.07.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Revised: 07/05/2007] [Accepted: 07/28/2007] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To study neuromuscular excitability in patients with dystrophia myotonica type 1 (DM1). METHODS The neuromuscular recovery cycle following motor nerve stimulation was assessed in 16 DM1 patients who had no sign of peripheral neuropathy or diabetes. Compound muscle action potentials were recorded from the adductor digiti minimi muscle to ulnar nerve stimulation at the wrist. Paired pulses were delivered, consisting of a conditioning stimulus of supramaximal intensity, followed by a submaximal test stimulus. Interstimuli intervals (ISIs) ranged between 1 and 8ms. Durations of the absolute and relative refractory periods (ARP, RRP) and percentages of refractoriness and supernormality at ISIs of 2.6 and 7ms, respectively, were computed using a subtraction method. The results obtained in the series of DM1 patients were compared to those obtained in six patients with other forms of myotonia and to normative values established in a series of age-matched healthy subjects. Correlations were made between excitability parameters, the number of cytosine-thymine-guanine (CTG) repeats, and the severity of myotonia, scored clinically. RESULTS Compared to controls, DM1 patients presented prolonged durations of ARP and RRP, increased refractoriness and reduced supernormality. The decrease in refractoriness correlated with both the number of CTG repeats and the severity of myotonia. CONCLUSIONS Changes in the recovery cycle following supramaximal motor nerve stimulation revealed the existence of subtle alterations of neuromuscular excitability in DM1 patients. SIGNIFICANCE Increase in refractoriness together with a reduced supernormality was consistent with a process of membrane depolarization. Such a depolarization may be related to the loss of chloride channels or to alterations in sodium conductance in the motor axon or the muscle fiber.
Collapse
Affiliation(s)
- Delphine Boërio
- Service de Physiologie--Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique--Hôpitaux de Paris, Créteil, France
| | | | | | | |
Collapse
|
26
|
Moxley RT, Logigian EL, Martens WB, Annis CL, Pandya S, Moxley RT, Barbieri CA, Dilek N, Wiegner AW, Thornton CA. Computerized hand grip myometry reliably measures myotonia and muscle strength in myotonic dystrophy (DM1). Muscle Nerve 2007; 36:320-8. [PMID: 17587223 DOI: 10.1002/mus.20822] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this study was to develop a reliable, sensitive, quantitative measure of grip myotonia and strength and to determine whether CTG repeat length is correlated with grip myotonia and with muscle strength in myotonic dystrophy type 1 (DM1). Three maximum voluntary isometric contractions (MVICs) of the finger flexors (i.e., handgrip) were recorded on 2 successive days using a computerized handgrip myometer in 29 genetically confirmed DM1 patients and 17 normals. An automated computer program calculated MVIC peak force (PF) and relaxation times (RTs) along the declining (relaxation) phase of the force recordings at 90%, 75%, 50%, 10%, and 5% of PF. Patients also underwent quantitative strength testing (QST) manual muscle testing (MMT). The patients had longer grip RTs and lower PFs than normals. RT (90% to 5%) was above the normal mean +2.5 SD in 25 (86%) patients. In DM1, prolongation of RT was mainly in the terminal (50% to 5%), rather than the initial (90% to 50%) phase of relaxation. PFs and RTs for each patient were reproducible on consecutive days. RTs were positively correlated with leukocyte CTG repeat length, whereas measures of muscle strength, such as PF, QST, and MMT, were negatively correlated with repeat length. We conclude that computerized handgrip myometry provides a sensitive, reliable measure of myotonia and strength in DM1 and offers a method to assess natural history and response to treatment.
Collapse
Affiliation(s)
- Richard T Moxley
- Department of Neurology, University of Rochester Medical Center, Box 673, 601 Elmwood Avenue, Rochester, New York 14642, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Logigian EL, Ciafaloni E, Quinn LC, Dilek N, Pandya S, Moxley RT, Thornton CA. Severity, type, and distribution of myotonic discharges are different in type 1 and type 2 myotonic dystrophy. Muscle Nerve 2007; 35:479-85. [PMID: 17230537 DOI: 10.1002/mus.20722] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To characterize and compare electrical myotonia in myotonic dystrophy type 1 (DM1) and type 2 (DM2), 16 patients with genetically confirmed DM1 and 17 patients with DM2 underwent standardized concentric needle electromyography of deltoid, biceps, extensor digitorum communis, first dorsal interosseous, tensor fascia lata (TFL), vastus lateralis (VL), tibialis anterior, and thoracic paraspinal muscles. Eight needle insertions per muscle were made by electromyographers blinded to DM type who recorded the presence and type of myotonia (e.g., classic waxing-waning or less specific waning discharges). Manual muscle testing was performed by a physical therapist. Overall, myotonia was more elicitable in DM1 than DM2; only in VL and TFL was myotonia more elicitable in DM2 than DM1. The major type of myotonia was waxing-waning in DM1, and waning in DM2. Four DM2 (24%), but no DM1 patients had only waning myotonia. In the arms, myotonia was distally predominant in both DM1 and DM2. In the legs, it was distally predominant in DM1, but both proximal and distal in DM2. The severity of myotonia was positively correlated with muscle weakness and with the presence of waxing and waning discharges in DM1, but with neither in DM2. Thus, myotonia is qualitatively and quantitatively different in DM1 than DM2. Except for proximal leg muscles, myotonia is more evocable in DM1 than DM2. It tends to be waxing-waning in DM1 but waning in DM2, thus making electrodiagnosis of DM2 more challenging. Its severity correlates with muscle weakness and the presence of waxing-waning discharges in DM1 but not DM2.
Collapse
Affiliation(s)
- Eric L Logigian
- Neuromuscular Division, Department of Neurology, Box 673, 601 Elmwood Avenue, University of Rochester Medical Center, Rochester, New York 14642, USA.
| | | | | | | | | | | | | |
Collapse
|
28
|
Cleland JC, Logigian EL. Clinical evaluation of membrane excitability in muscle channel disorders: potential applications in clinical trials. Neurotherapeutics 2007; 4:205-15. [PMID: 17395130 DOI: 10.1016/j.nurt.2007.01.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Muscle channelopathies are inherited disorders that cause paralysis and myotonia. Molecular technology has contributed immeasurably to diagnostic testing, to correlation of genotype with phenotype, and to insight into the pathophysiology of these disorders. In most cases, the diagnosis of muscle channelopathy is still made on clinical grounds, but is supported by ancillary laboratory and electrodiagnostic testing such as serum potassium measurement, exercise testing, repetitive nerve stimulation, needle electromyography, calculation of muscle fiber conduction velocity, or electromyography power spectra. Although provocative glucose or potassium challenges are now infrequently performed, they have contributed greatly to our understanding of the pathophysiology of these disorders, and to our ability to differentiate between periodic paralysis types. Despite considerable progress, ample opportunity remains for future clinical research, particularly in expanding genotype-phenotype correlations and in optimizing electrodiagnostic methods. With respect to diagnostic testing, there is a need for accurate, efficient, and cost-effective bedside testing, given the substantial proportion (as high as 20%) of genetically undefined cases. Even in genetically defined cases, minimal clinical expressivity due to incomplete penetrance poses a significant challenge to currently available nonmolecular testing.
Collapse
Affiliation(s)
- James C Cleland
- University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
| | | |
Collapse
|
29
|
Salehi LB, Bonifazi E, Stasio ED, Gennarelli M, Botta A, Vallo L, Iraci R, Massa R, Antonini G, Angelini C, Novelli G. Risk Prediction for Clinical Phenotype in Myotonic Dystrophy Type 1: Data from 2,650 Patients. ACTA ACUST UNITED AC 2007; 11:84-90. [PMID: 17394397 DOI: 10.1089/gte.2006.0511] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystem disorder that affects skeletal and smooth muscle as well as the eye, heart, endocrine system, and central nervous system. DM1 is caused by expansion of a CTG trinucleotidedaggerrepeat in the gene DMPK. Clinical findings in DM1 span a continuum from mild to severe. Although the CTG repeat correlates with the disease phenotype, caution is used in predicting disease severity on the basis of CTG repeat number. This study reports an extensive genotype-phenotype study to evaluate the clinical validity and clinical utility of the molecular genetic test. Data were analyzed by multiple logistic regression, used to estimate the odds ratio (OR) and correlation coefficients for patients phenotype in respect to the categorical variables expansion class, gender, familiarity, and the continuous variables age and disease duration. We assessed disease expression by clinical evaluation and the molecular genetic test in 2,650 patients identified by accurate clinical diagnosis and family segregation. We were able to estimate OR and correlation coefficients for patients phenotype according to CTG number. A genotype-phenotype correlation was established to derivate a clinical predictive risk on the basis of molecular data. This study demonstrates that measurement of triplet expansions in patients' DNA can be considered as a useful tool for DM1 phenotype assessment and presymptomatic testing.
Collapse
|
30
|
Laberge L, Veillette S, Mathieu J, Auclair J, Perron M. The correlation of CTG repeat length with material and social deprivation in myotonic dystrophy. Clin Genet 2006; 71:59-66. [PMID: 17204048 DOI: 10.1111/j.1399-0004.2007.00732.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Socioeconomic deprivation has long been recognized as a prominent feature of myotonic dystrophy type 1 (DM1), but studies performed before the discovery of the mutation causing DM1 may have suffered an ascertainment bias towards the more severe forms of the disease. We have sought to clarify the relationship between CTG repeats, muscular impairment, and socioeconomic characteristics of 200 patients with DM1. Patients with DM1 reported lower educational attainment, lower employment rate, lower family income, and higher reliance on social assistance than the reference population. Logistic regression showed, on one hand, that CTG repeats and marital status were significant predictors of social assistance recipiency and, on the other hand, that CTG repeats and gender were significant predictors of low social support from family, after adjustment for age, gender, degree of muscular impairment, CTG repeats, educational level, and marital status. For example, each additional 100 CTG repeats was found to increase the odds of relying on social assistance by about 35% and having low social support by about 22%. The chances of experiencing socioeconomic deprivation are loaded heavily against patients with DM1. The relationship between increased CTG repeat length and higher risk of material and social deprivation must be acknowledged in the clinical management of DM1.
Collapse
Affiliation(s)
- L Laberge
- Groupe ECOBES, Cégep de Jonquière, Université du Québec, à Chicoutimi, Québec, Canada
| | | | | | | | | |
Collapse
|
31
|
Abstract
BACKGROUND Abnormal delayed relaxation of skeletal muscles, known as myotonia, can cause disability in myotonic disorders. Sodium channel blockers, tricyclic antidepressive drugs, benzodiazepines, calcium-antagonists, taurine and prednisone may be of use in reducing myotonia. OBJECTIVES To consider the evidence from randomised controlled trials on the efficacy and tolerability of drug treatment in patients with clinical myotonia due to a myotonic disorder. SEARCH STRATEGY We searched the Cochrane Neuromuscular Disease Group trials register (April 2004), MEDLINE (January 1966 to December 2003) and EMBASE (January 1980 to December 2003). Grey literature was handsearched and reference lists of identified studies and reviews were examined. Authors, disease experts and manufacturers of anti-myotonic drugs were contacted. SELECTION CRITERIA We considered all (quasi) randomised trials of participants with myotonia treated with any drug treatment versus no therapy, placebo or any other active drug treatment. The primary outcome measure was:reduced clinical myotonia using two categories: (1) no residual myotonia or improvement of myotonia or (2) No change or worsening of myotonia. Secondary outcome measures were:(1) clinical relaxation time; (2) electromyographic relaxation time; (3) stair test; (4) presence of percussion myotonia; and (5) proportion of adverse events. DATA COLLECTION AND ANALYSIS Two authors extracted the data independently onto standardised extraction forms and disagreements were resolved by discussion. MAIN RESULTS Nine randomised controlled trials were found comparing active drug treatment versus placebo or another active drug treatment in patients with myotonia due to a myotonic disorder. Included trials were double-blind or single-blind crossover studies involving a total of 137 patients of which 109 had myotonic dystrophy type 1 and 28 had myotonia congenita. The studies were of poor quality. Therefore, we were not able to analyse the results of all identified studies. Two small crossover studies without a washout period demonstrated a significant effect of imipramine and taurine in myotonic dystrophy. One small crossover study with a washout period demonstrated a significant effect of clomipramine in myotonic dystrophy. Meta-analysis was not possible. AUTHORS' CONCLUSIONS Due to insufficient good quality data and lack of randomised studies, it is impossible to determine whether drug treatment is safe and effective in the treatment of myotonia. Small single studies give an indication that clomipramine and imipramine have a short-term beneficial effect and that taurine has a long-term beneficial effect on myotonia. Larger, well-designed randomised controlled trials are needed to assess the efficacy and tolerability of drug treatment for myotonia.
Collapse
Affiliation(s)
- J Trip
- Academisch Ziekenhuis Maastricht (AZM), Department of Neurology, P. Debyelaan 25 Postbus5800, Maastricht, Limburg, Netherlands, 6202 AZ.
| | | | | | | |
Collapse
|
32
|
Abstract
Myotonia congenita is a hereditary chloride channel disorder characterized by delayed relaxation of skeletal muscle (myotonia). It is caused by mutations in the skeletal muscle chloride channel gene CLCN1 on chromosome 7. The phenotypic spectrum of myotonia congenita ranges from mild myotonia disclosed only by clinical examination to severe and disabling myotonia with transient weakness and myopathy. The most severe phenotypes are seen in patients with two mutated alleles. Heterozygotes are often asymptomatic but for some mutations heterozygosity is sufficient to cause pronounced myotonia, although without weakness and myopathy. Thus, the phenotype depends on the mutation type to some extent, but this does not explain the fact that severity varies greatly between heterozygous family members and may even vary with time in the individual patient. In this review, existing knowledge about phenotypic variability is summarized, and the possible contributing factors are discussed.
Collapse
Affiliation(s)
- Eskild Colding-Jørgensen
- Department of Clinical Neurophysiology 19, Glostrup Hospital, University of Copenhagen DK-2600 Glostrup, Denmark.
| |
Collapse
|
33
|
Logigian EL, Blood CL, Dilek N, Martens WB, Moxley RT, Wiegner AW, Thornton CA, Moxley RT. Quantitative analysis of the “warm-up” phenomenon in myotonic dystrophy type 1. Muscle Nerve 2005; 32:35-42. [PMID: 15880468 DOI: 10.1002/mus.20339] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
To quantitate improvement in hand-grip myotonia and muscle strength (i.e., the "warm-up" phenomenon) in myotonic dystrophy type 1 (DM1), six successive, standardized maximum voluntary isometric contractions (MVICs) were recorded on 2 separate days using a computerized isometric hand-grip myometer in 25 genetically confirmed DM1 patients and in 17 normal controls. An automated computer program placed cursors along the declining (relaxation) phase of the MVICs at 90%, 50%, and 5% of peak force (PF) and calculated relaxation times (RTs) between these points. Mean 90% to 5% RT (a measure of myotonia) rapidly declined from 2.5 s in MVIC 1 to 0.8 s in MVIC 6 (warm-up = 1.7 s) in DM1; in controls, it remained 0.4 s for all six MVICs (warm-up = 0). In DM1, 70% of warm-up occurred between MVIC 1 and 2, almost exclusively in the terminal 50% to 5% phase of muscle relaxation. Day 1 warm-up was highly correlated with the severity of myotonia, and with day 2 warm-up. Improvement in myotonia was not accompanied by either transient paresis or improvement in PF. We conclude that, with this testing paradigm: warm-up of myotonia in DM1 can be reliably measured; is proportional to severity of myotonia; occurs rapidly, being most prominent between the first and second grips; mainly results from shortening of the terminal phase of muscle relaxation; and is not accompanied by significant warm-up in force output.
Collapse
Affiliation(s)
- E L Logigian
- Department of Neurology, University of Rochester Medical Center, Box 673, 601 Elmwood Avenue, Rochester, New York 14642, USA.
| | | | | | | | | | | | | | | |
Collapse
|
34
|
What's in the Literature? J Clin Neuromuscul Dis 2004; 6:13-21. [PMID: 19078748 DOI: 10.1097/01.cnd.0000138206.12280.d1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
|