1
|
Hartman J, Patki T, Johnson NE. Diagnosis and Management of Myotonic Dystrophy Type 1. JAMA 2024; 331:1227-1228. [PMID: 38466298 DOI: 10.1001/jama.2024.2511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
This JAMA Insights discusses the signs and symptoms, diagnosis, and treatment of myotonic dystrophy type 1.
Collapse
|
2
|
Heidsieck E, Gutschmidt K, Schoser B, Wenninger S. Suitability of the Respicheck questionnaire and Epworth sleepiness scale for therapy monitoring in myotonic dystrophy type 1. Neuromuscul Disord 2023; 33:754-761. [PMID: 37690855 DOI: 10.1016/j.nmd.2023.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 08/08/2023] [Accepted: 08/23/2023] [Indexed: 09/12/2023]
Abstract
Myotonic dystrophy type 1 (DM1) is an autosomal dominant trinucleotide disorder that often leads to respiratory dysfunction resulting in hypoventilation symptoms, reduced quality of life and causing premature death if untreated. To early identify symptoms of hypoventilation, the Respicheck questionnaire was developed as a screening tool. Symptomatic therapies like inspiratory muscle training (IMT) are recommended to strengthen respiratory muscles and reduce or even prevent hypoventilation symptoms. Our study aimed to evaluate the Respicheck questionnaire's suitablility to monitor the efficacy of IMT. Patients with genetically confirmed DM1 were randomly assigned to either IMT - endurance or strength training, or control group. At baseline, end of study and four interim visits, pulmonary function tests, Respicheck questionnaire and Epworth sleepiness scale were assessed. While patients in training groups achieved a substantial improvement after nine months of regular IMT in pulmonary function tests, the Respicheck score did not improve likewise. Similarly, the ESS score did not change significantly in both training and control groups. Consequently, we conclude that either improvement of respiratory function is not necessarily associated with clinical improvement, or respiratory muscle weakness was not the only reason for hypoventilation syndrome, or both questionnaires are not sensitive enough to detect slight clinical changes.
Collapse
Affiliation(s)
- Eva Heidsieck
- Department of Neurology, Ludwig-Maximilians University Munich, Friedrich-Baur-Institute, Ziemssenstr. 1, 80336 Munich, Germany
| | - Kristina Gutschmidt
- Department of Neurology, Ludwig-Maximilians University Munich, Friedrich-Baur-Institute, Ziemssenstr. 1, 80336 Munich, Germany
| | - Benedikt Schoser
- Department of Neurology, Ludwig-Maximilians University Munich, Friedrich-Baur-Institute, Ziemssenstr. 1, 80336 Munich, Germany
| | - Stephan Wenninger
- Department of Neurology, Ludwig-Maximilians University Munich, Friedrich-Baur-Institute, Ziemssenstr. 1, 80336 Munich, Germany.
| |
Collapse
|
3
|
Kleefeld F, Schoser B. The current clinical perception of myotonic dystrophy type 2. Curr Opin Neurol 2023; 36:474-478. [PMID: 37639480 DOI: 10.1097/wco.0000000000001186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
PURPOSE OF REVIEW Myotonic dystrophy type 2 (DM2) is a genetic disorder belonging to the spectrum of myotonic dystrophies. DM2 is characterized by progressive muscle weakness, wasting and muscle pain (myalgia), but can also affect many other organ systems. In this review, we provide an updated overview on the research literature on DM2 with a focus on the management of multisystemic involvement and atypical clinical phenotypes. RECENT FINDINGS Recent studies have focused on different aspects of multisystemic involvement. Early and severe cardiac involvement can occur in DM2 and needs to be managed appropriately. Diabetes has been shown to be more common in DM2 than in DM1, while a combination of symptoms (cataracts, myotonia, tremor) can be used to raise clinical suspicion and initiate genetic testing for DM2. Autoimmune disease has been shown to occur in up to one-third of DM2 patients, possibly due to altered immune pathways. New evidence also suggests a childhood-onset phenotype presenting with foot deformities. SUMMARY The multisystemic aspects of the disease require a multidisciplinary approach for some patients, most likely even including state-of-the-art cardiac and brain imaging to detect and treat complications earlier. Of note, our concept of DM2 as an adult-onset disease is somewhat challenged by evidence suggesting a few pediatric DM2 patients and possibly anticipation, at least in some DM2 families. More studies, including larger cohorts, are needed to better understand this possible early-onset DM2 phenotype variant.
Collapse
Affiliation(s)
- Felix Kleefeld
- Charité-Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health (BIH), Department of Neurology, Charitéplatz 1, 10117 Berlin
| | - Benedikt Schoser
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University, Munich, Germany
| |
Collapse
|
4
|
Boonstra NE, Varhaug KN. Øyesykdom ved dystrophia myotonica type 1. Tidsskr Nor Laegeforen 2023; 143:22-0608. [PMID: 37753768 DOI: 10.4045/tidsskr.22.0608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023] Open
Abstract
Myotonic dystrophy type 1 is one of the most common genetic neuromuscular diseases in adults. The disease not only affects the musculoskeletal system, but is multisystemic, and ocular involvement with cataract formation is a frequent additional finding. To avoid recurrence of secondary opacification that is difficult to treat, the cataract should not be treated with traditional lens replacement. This clinical review article presents ophthalmological findings in cases of myotonic dystrophy type 1 and describes a new surgical method for cataracts in this patient group.
Collapse
|
5
|
Vosse BAH, Horlings CGC, Joosten IBT, Cobben NAM, van Kuijk SMJ, Wijkstra PJ, Faber CG. Role of respiratory characteristics in treatment adherence with noninvasive home mechanical ventilation in myotonic dystrophy type 1, a retrospective study. Neuromuscul Disord 2023; 33:57-62. [PMID: 37635015 DOI: 10.1016/j.nmd.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 07/12/2023] [Accepted: 08/08/2023] [Indexed: 08/29/2023]
Abstract
Chronic respiratory insufficiency is common in patients with myotonic dystrophy type 1 (DM1) and can be treated with noninvasive home mechanical ventilation (HMV). HMV is not always tolerated well resulting in low treatment adherence. We aimed to analyze if baseline respiratory characteristics such as pulmonary function, level of pCO2 and presence of sleep apnea are associated with HMV treatment adherence in DM1 patients. Pulmonary function testing, polysomnography and blood gas measurement data of DM1 patients were retrospectively collected. Initiation of HMV and treatment adherence after one year was documented. Patients with low treatment adherence (average daily use of HMV <5 h) were grouped with patients that discontinued HMV and compared with patients with high treatment adherence (average daily use of HMV >5 h). HMV was initiated in 101 patients. After one year, 58 patients had low treatment adherence. There were no differences between the low and high treatment adherence group regarding the respiratory characteristics. None of the included predictors (gender, age, body mass index, cytosine-thymine-guanine repeat length, FVC, daytime pCO2, bicarbonate, nighttime pCO2, nighttime base excess, apnea-hypopnea index and mean saturation during sleep) was able to significantly predict high treatment adherence. In conclusion, the respiratory characteristics are not associated with treatment adherence with HMV in DM1 patients and cannot be used to identify patients at risk for low HMV treatment adherence.
Collapse
Affiliation(s)
- Bettine Anna Hildegard Vosse
- Department of Pulmonary Diseases and Home Mechanical Ventilation, Maastricht University Medical Centre+, P.O. Box 5800 6202 AZ Maastricht, the Netherlands.
| | | | - Isis Bep Theodora Joosten
- Department of Neurology and School for Mental Health and Neuroscience, Maastricht University Medical Centre+, P.O. Box 5800 6202 AZ Maastricht, the Netherlands
| | - Nicolle Andrée Marie Cobben
- Department of Pulmonary Diseases and Home Mechanical Ventilation, Maastricht University Medical Centre+, P.O. Box 5800 6202 AZ Maastricht, the Netherlands
| | - Sander Martijn Job van Kuijk
- Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht University Medical Centre+, P.O. Box 5800 6202 AZ Maastricht, the Netherlands
| | - Peter Jan Wijkstra
- Department of Pulmonary Diseases and Home Mechanical Ventilation, University Medical Centre Groningen, P.O. Box 30.001 Groningen, the Netherlands
| | - Catharina Gerritdina Faber
- Department of Neurology and School for Mental Health and Neuroscience, Maastricht University Medical Centre+, P.O. Box 5800 6202 AZ Maastricht, the Netherlands
| |
Collapse
|
6
|
Wood H. Restoring myogenesis in myotonic dystrophy. Nat Rev Neurol 2023; 19:508. [PMID: 37553392 DOI: 10.1038/s41582-023-00862-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
|
7
|
Davey EE, Légaré C, Planco L, Shaughnessy S, Lennon CD, Roussel MP, Shorrock HK, Hung M, Cleary JD, Duchesne E, Berglund JA. Individual transcriptomic response to strength training for patients with myotonic dystrophy type 1. JCI Insight 2023; 8:e163856. [PMID: 37318869 PMCID: PMC10443797 DOI: 10.1172/jci.insight.163856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 06/13/2023] [Indexed: 06/17/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1), the most common form of adult-onset muscular dystrophy, is caused by a CTG expansion resulting in significant transcriptomic dysregulation that leads to muscle weakness and wasting. While strength training is clinically beneficial in DM1, molecular effects had not been studied. To determine whether training rescued transcriptomic defects, RNA-Seq was performed on vastus lateralis samples from 9 male patients with DM1 before and after a 12-week strength-training program and 6 male controls who did not undergo training. Differential gene expression and alternative splicing analysis were correlated with the one-repetition maximum strength evaluation method (leg extension, leg press, hip abduction, and squat). While training program-induced improvements in splicing were similar among most individuals, rescued splicing events varied considerably between individuals. Gene expression improvements were highly varied between individuals, and the percentage of differentially expressed genes rescued after training were strongly correlated with strength improvements. Evaluating transcriptome changes individually revealed responses to the training not evident from grouped analysis, likely due to disease heterogeneity and individual exercise response differences. Our analyses indicate that transcriptomic changes are associated with clinical outcomes in patients with DM1 undergoing training and that these changes are often specific to the individual and should be analyzed accordingly.
Collapse
Affiliation(s)
- Emily E. Davey
- RNA Institute, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, USA
| | - Cécilia Légaré
- RNA Institute, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, USA
- Department of Health Sciences, Université du Québec à Chicoutimi, Saguenay, Québec, Canada
- Groupe de Recherche Interdisciplinaire sur les Maladies Neuromusculaires (GRIMN), Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Saguenay, Quebec, Canada
- Centre de recherche Charles-Le Moyne Saguenay–Lac-Saint-Jean sur les innovations en santé (CR-CSIS), Faculté de médecine et des sciences de la santé de l’Université de Sherbrooke, Site Saguenay, Saguenay, Quebec, Canada
| | - Lori Planco
- RNA Institute, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, USA
| | - Sharon Shaughnessy
- RNA Institute, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, USA
| | - Claudia D. Lennon
- RNA Institute, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, USA
| | - Marie-Pier Roussel
- Groupe de Recherche Interdisciplinaire sur les Maladies Neuromusculaires (GRIMN), Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Saguenay, Quebec, Canada
- Centre de recherche Charles-Le Moyne Saguenay–Lac-Saint-Jean sur les innovations en santé (CR-CSIS), Faculté de médecine et des sciences de la santé de l’Université de Sherbrooke, Site Saguenay, Saguenay, Quebec, Canada
- Department of Basic Sciences, Université du Québec à Chicoutimi, Saguenay, Québec, Canada
| | - Hannah K. Shorrock
- RNA Institute, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, USA
| | - Man Hung
- Department of Orthopaedic Surgery Operations, School of Medicine, University of Utah, Salt Lake City, Utah, USA
- College of Dental Medicine, Roseman University of Health Sciences, South Jordan, Utah, USA
| | - John Douglas Cleary
- RNA Institute, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, USA
| | - Elise Duchesne
- Department of Health Sciences, Université du Québec à Chicoutimi, Saguenay, Québec, Canada
- Groupe de Recherche Interdisciplinaire sur les Maladies Neuromusculaires (GRIMN), Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Saguenay, Quebec, Canada
- Centre de recherche Charles-Le Moyne Saguenay–Lac-Saint-Jean sur les innovations en santé (CR-CSIS), Faculté de médecine et des sciences de la santé de l’Université de Sherbrooke, Site Saguenay, Saguenay, Quebec, Canada
| | - J. Andrew Berglund
- RNA Institute, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, USA
- Department of Biological Sciences, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, USA
| |
Collapse
|
8
|
Abstract
PURPOSE OF REVIEW Myotonic dystrophy type 1 (DM1) and myotonic dystrophy type 2 (DM2) are genetic disorders affecting skeletal and smooth muscle, heart, brain, eyes, and other organs. The multisystem involvement and disease variability of myotonic dystrophy have presented challenges for clinical care and research. This article focuses on the diagnosis and management of the disease. In addition, recent advances in characterizing the diverse clinical manifestations and variability of the disease are discussed. RECENT FINDINGS Studies of the multisystem involvement of myotonic dystrophy, including the most lethal cardiac and respiratory manifestations and their molecular underpinnings, expand our understanding of the myotonic dystrophy phenotype. Advances have been made in understanding the molecular mechanisms of both types of myotonic dystrophy, providing opportunities for developing targeted therapeutics, some of which have entered clinical trials in DM1. SUMMARY Continued efforts focus on advancing our molecular and clinical understanding of DM1 and DM2. Accurately measuring and monitoring the diverse and variable clinical manifestations of myotonic dystrophy in clinic and in research is important to provide adequate care, prevent complications, and find treatments that improve symptoms and life quality.
Collapse
|
9
|
Russo V, Papa AA, Rago A, Ciardiello C, Martino AM, Stazi A, Golino P, Calò L, Nigro G. Arrhythmic CArdiac DEath in MYotonic dystrophy type 1 patients (ACADEMY 1) study: the predictive role of programmed ventricular stimulation. Europace 2022; 24:1148-1155. [PMID: 35861549 DOI: 10.1093/europace/euab282] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 11/05/2021] [Indexed: 09/13/2023] Open
Abstract
AIMS Myotonic dystrophy type 1 (DM1) predisposes to the development of life-threatening arrhythmias and sudden cardiac death. Our study aimed to evaluate the prognostic value of programmed ventricular stimulation (PVS) in DM1 patients with conduction system disease. METHODS AND RESULTS Arrhythmic CArdiac DEath in MYotonic dystrophy type 1 patients (ACADEMY 1) is a double-arm non-randomized interventional prospective study. Myotonic dystrophy type 1 patients with permanent cardiac pacing indication were eligible for the inclusion. The study population underwent to pacemaker (PM) or implantable cardioverter-defibrillator (ICD) implantation according to the inducibility of ventricular tachyarrhythmias at PVS. Primary endpoint of the study was a composite of appropriate ICD therapy and cardiac arrhythmic death. The secondary study endpoint was all-cause mortality. Seventy-two adult-onset DM1 patients (51 ± 12 years; 39 male) were enrolled in the study. A ventricular tachyarrhythmia was induced in 25 patients (34.7%) at PVS (PVS+) who underwent dual chambers ICD implantation. The remaining 47 patients (65.3%) without inducible ventricular tachyarrhythmia (PVS-) were treated with dual-chamber PM. During an average observation period of 44.7 ± 10.2 months, nine patients (12.5%) met the primary endpoint, four in the ICD group (16%) and five (10.6%) in the PM group. Thirteen patients died (18.5%), 2 in the ICD group (8%) and 11 in PM group (23.4%). The Kaplan-Meier analysis did not show a significantly different risk of both primary and secondary endpoint event rates between the two groups. CONCLUSIONS The inducibility of ventricular tachyarrhythmias has shown a limited value in the arrhythmic risk stratification among DM1 patients.
Collapse
Affiliation(s)
- Vincenzo Russo
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania 'Luigi Vanvitelli', Monaldi Hospital, Naples 80131, Italy
| | | | - Anna Rago
- Department of Cardiology, Monaldi Hospital, Naples, Italy
| | | | | | - Alessandra Stazi
- Department of Cardiology, Policlinico Casilino Hospital, Rome, Italy
| | - Paolo Golino
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania 'Luigi Vanvitelli', Monaldi Hospital, Naples 80131, Italy
| | - Leonardo Calò
- Department of Cardiology, Policlinico Casilino Hospital, Rome, Italy
| | - Gerardo Nigro
- Cardiology Unit, Department of Medical Translational Sciences, University of Campania 'Luigi Vanvitelli', Monaldi Hospital, Naples 80131, Italy
| |
Collapse
|
10
|
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystem trinucleotide repeat expansion disorder characterized by the misregulated alternative splicing of critical mRNAs. Previous work in a transgenic mouse model indicated that aerobic exercise effectively improves splicing regulation and function in skeletal muscle. In this issue of the JCI, Mikhail et al. describe the safety and benefits of applying this approach in individuals affected by DM1. A 12-week aerobic exercise program improved aerobic capacity and mobility, but not by the mechanism observed in transgenic mice. Here, we consider the possible reasons for this disparity and review other salient findings of the study in the context of evolving DM1 research.
Collapse
|
11
|
Karamlou M, Asaria I, Barron J, Boutros P, Fisher V, Grandinetti R, Johnson J, Richard E, Susko D, Urrutia C, Woolsey B, Baumann R, Cottle J, Sweaney R, Wenzel M, Nusstein J, Hall D. Complications After Dental Sedation: A Myotonic Mystery Case Report. Anesth Prog 2022; 69:26-31. [PMID: 36534775 PMCID: PMC9773408 DOI: 10.2344/anpr-69-02-09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 03/18/2022] [Indexed: 12/23/2022] Open
Abstract
Myotonic dystrophy (dystrophia myotonica; DM) is an uncommon progressive hereditary muscle disorder that can present with variable severity at birth, in early childhood, or most commonly as an adult. Patients with DM, especially type 1 (DM1), are extremely sensitive to the respiratory depressant effects of sedative-hypnotics, anxiolytics, and opioid agonists. This case report describes a 37-year-old male patient with previously undiagnosed DM1 who received dental care under minimal sedation using intravenous midazolam. During the case, the patient experienced 2 brief episodes of hypoxemia, the second of which required emergency intubation after propofol and succinylcholine and resulted in extended hospital admission. A lipid emulsion (Liposyn II 20%) infusion was given approximately 2 hours after the last local anesthetic injection due to slight ST elevation and suspicion of local anesthetic toxicity (LAST). Months after treatment, the patient suffered a fall resulting in a fatal traumatic brain injury. Complications noted in this case report were primarily attributed to the unknown diagnosis of DM1, although additional precipitating factors were likely present. This report also provides a basic review of the literature and clinical guidelines for managing myotonic dystrophy patients for dental care with local anesthesia, sedation, or general anesthesia.
Collapse
Affiliation(s)
- Milad Karamlou
- Former Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Iman Asaria
- Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Jaime Barron
- Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Petra Boutros
- Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Vincent Fisher
- Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Rachel Grandinetti
- Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Julian Johnson
- Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Emily Richard
- Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - David Susko
- Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Cristobal Urrutia
- Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Bryce Woolsey
- Chief Resident, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Ronald Baumann
- Former Assistant Professor and Attending, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - James Cottle
- Assistant Professor and Attending, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Richard Sweaney
- Assistant Professor and Attending, The Ohio State University College of Dentistry General Practice Residency Program, Columbus, Ohio
| | - Mark Wenzel
- Program Director and Hospital Attending, The Ohio State University College of Dentistry General Practice Residency Program and Wexner Medical Center, Columbus, Ohio
| | - John Nusstein
- Professor and Chair Division of Endodontics, The Ohio State University College of Dentistry, Columbus, Ohio
| | - David Hall
- Associate Professor and Hospital Attending, The Ohio State University College of Dentistry General Practice Residency Program and Wexner Medical Center, Columbus, Ohio
| |
Collapse
|
12
|
Abstract
Myotonic dystrophy (DM) types 1 (DM1) and 2 (DM2) are caused by autosomal dominant gain-of-function RNA which are, in turn, created by the expansion of repeat sequences in the DMPK and ZNF9 genes, respectively. The expansions are highly unstable and biased for further expansion in somatic cells and across generations. Despite the different genes involved, DM1 and DM2 share several clinical features due to having the similar underlying mechanism of repetitive RNA-mediated toxicity. Both disorders manifest as multisystemic conditions with features including myotonia, cataract development, and abnormalities in cardiac conduction. At present, there is no cure for DM and treatments mostly aim at symptom management. Among the therapeutics being developed, antisense therapy using gapmers is one of the most promising. Compared to other antisense oligonucleotides, gapmers maintain the ability to induce RNase H cleavage while having enhanced target binding affinity and nuclease resistance. This chapter will consolidate the different strategies studied thus far to develop a treatment for DM1 through the targeting of toxic repetitive RNA using gapmers.
Collapse
Affiliation(s)
- Quynh Nguyen
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
- The Friends of Garret Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada.
| |
Collapse
|
13
|
Marsh S, Hanson B, Wood MJA, Varela MA, Roberts TC. Application of CRISPR-Cas9-Mediated Genome Editing for the Treatment of Myotonic Dystrophy Type 1. Mol Ther 2020; 28:2527-2539. [PMID: 33171139 PMCID: PMC7704741 DOI: 10.1016/j.ymthe.2020.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/03/2020] [Accepted: 10/08/2020] [Indexed: 12/15/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a debilitating multisystemic disorder, caused by expansion of a CTG microsatellite repeat in the 3' untranslated region of the DMPK (dystrophia myotonica protein kinase) gene. To date, novel therapeutic approaches have focused on transient suppression of the mutant, repeat-expanded RNA. However, recent developments in the field of genome editing have raised the exciting possibility of inducing permanent correction of the DM1 genetic defect. Specifically, repurposing of the prokaryotic CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 (CRISPR-associated protein 9) system has enabled programmable, site-specific, and multiplex genome editing. CRISPR-based strategies for the treatment of DM1 can be applied either directly to patients, or indirectly through the ex vivo modification of patient-derived cells, and they include excision of the repeat expansion, insertion of synthetic polyadenylation signals upstream of the repeat, steric interference with RNA polymerase II procession through the repeat leading to transcriptional downregulation of DMPK, and direct RNA targeting of the mutant RNA species. Potential obstacles to such therapies are discussed, including the major challenge of Cas9 and guide RNA transgene/ribonuclear protein delivery, off-target gene editing, vector genome insertion at cut sites, on-target unintended mutagenesis (e.g., repeat inversion), pre-existing immunity to Cas9 or AAV antigens, immunogenicity, and Cas9 persistence.
Collapse
Affiliation(s)
- Seren Marsh
- University of Oxford Medical School, Medical Sciences Division, University of Oxford, Oxford OX3 9DU, UK
| | - Britt Hanson
- Department of Physiology, Anatomy and Genetics, Oxford OX1 3QX, UK; Department of Paediatrics, University of Oxford, Oxford OX1 3QX, UK
| | - Matthew J A Wood
- Department of Paediatrics, University of Oxford, Oxford OX1 3QX, UK; MDUK Oxford Neuromuscular Centre, UK
| | - Miguel A Varela
- Department of Paediatrics, University of Oxford, Oxford OX1 3QX, UK
| | - Thomas C Roberts
- Department of Paediatrics, University of Oxford, Oxford OX1 3QX, UK; MDUK Oxford Neuromuscular Centre, UK.
| |
Collapse
|
14
|
Yoon SH, Baek JH, Leem J. Improved grip myotonia in a patient with myotonic dystrophy type 1 following electroacupuncture therapy: A CARE-compliant case report. Medicine (Baltimore) 2020; 99:e21845. [PMID: 32925721 PMCID: PMC7489697 DOI: 10.1097/md.0000000000021845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
RATIONALE Myotonic dystrophy type 1 (DM1) is an autosomal-dominant disorder associated with a short life expectancy and various symptoms, including grip myotonia. Even though grip myotonia decreases quality of life, activities of daily living (ADLs), and work performance, very few interventions provide symptomatic relief. PATIENT CONCERNS In this case report, we present a patient with DM1 and gradually worsening grip myotonia. A 35-year-old woman developed grip myotonia at age 27. She had no underlying diseases or family history of relevant conditions, including DM1. She was unresponsive to medication for several years. DIAGNOSIS Her symptoms gradually worsened, and she was finally diagnosed with DM1 via genetic, neurologic, and laboratory testing in a tertiary hospital at age 32. She tried several medication therapies; however, she stopped medication at age 34 due a perceived poor response and several adverse events. INTERVENTION At the age of 35, she underwent 29 sessions (10 minutes per session) of electroacupuncture therapy on TE9 acupuncture point with 120 Hz electrical stimulation over 3 months. OUTCOMES After 3 months, relaxation time after maximal voluntary isometric contraction decreased from 59 to 2 seconds with treatment. Her Michigan Hand Outcomes Questionnaire score improved (total score, 66.6-75.9; ADL sub-score, 59.7-73.6; function sub-score, 70-90; satisfaction sub-score, 75-91.7). Her Measure Yourself Medical Outcome Profile 2 score also improved from 4.33 to 2. There were no serious adverse events. LESSONS Electroacupuncture is a potential treatment modality and produced an immediate antimyotonic effect, and cumulative long-term treatment effect, in a patient with DM1 and grip myotonia. Other notable treatment outcomes included improving relaxation time, hand function, ADLs, and overall satisfaction. Electroacupuncture is a potential treatment modality for patients with DM1 and grip myotonia. Further prospective clinical studies are warranted to confirm this hypothesis.
Collapse
Affiliation(s)
- Sang-Hoon Yoon
- Chung-Yeon Central Institute
- Chung-Yeon Korean Medicine Hospital, Seo-gu, Gwangju
| | - Jang-Hyun Baek
- Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine
| | - Jungtae Leem
- Chung-Yeon Central Institute
- Research and Development Institute, CY Pharma Co., Gangnam-gu, Seoul, Republic of Korea
| |
Collapse
|
15
|
Montagnese F, Rastelli E, Stahl K, Massa R, Schoser B. How to capture activities of daily living in myotonic dystrophy type 2? Neuromuscul Disord 2020; 30:796-806. [PMID: 32888768 DOI: 10.1016/j.nmd.2020.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/01/2020] [Accepted: 07/28/2020] [Indexed: 01/05/2023]
Abstract
Myotonic dystrophy type 2 (DM2) lacks validated patients´ reported outcomes (PROs). This represents a limit for monitoring disease progression and perceived efficacy of symptomatic treatments. Our aim was to investigate whether PROs for activities of daily living designed for other neuromuscular diseases could be used in DM2. Sixty-six DM2 patients completed the following PROs: DM1-Activ-c, Rasch-built Pompe-specific activity (R-PAct) scale, McGill-pain questionnaire, fatigue and daytime sleepiness scale and Beck depression inventory (BDI-II). Clinical data and motor outcome measures (6-minutes walking test - 6MWT, manual muscle testing, quick motor function test and myotonia behavior scale) were collected as well. Patients underwent one visit at baseline and one after 10 months. Ceiling/flooring effects, criterion validity and discriminant validity were calculated. DM1-activ-c and R-PAct showed acceptable ceiling effects despite being built for myotonic dystrophy type 1 and Pompe disease, respectively. The difficulty hierarchy of the single items was better preserved in R-PAct than in DM1-Activ-c. Both tests showed excellent criterion validity highly correlating with 6MWT, quick motor function test, myalgia and disease duration. They could partially discriminate patients with different disability grades. These results suggest that DM1-Activ-c, slightly better than R-PAct, might be adopted for monitoring activities of daily living also in DM2, at least until disease-specific PROs will be available.
Collapse
Affiliation(s)
- Federica Montagnese
- Friedrich-Baur-Institute, Department of Neurology, Klinikum der Universität, Ludwig-Maximilians-University, Ziemssenstr. 1, Munich 80336, Germany.
| | - Emanuele Rastelli
- Friedrich-Baur-Institute, Department of Neurology, Klinikum der Universität, Ludwig-Maximilians-University, Ziemssenstr. 1, Munich 80336, Germany
| | - Kristina Stahl
- Friedrich-Baur-Institute, Department of Neurology, Klinikum der Universität, Ludwig-Maximilians-University, Ziemssenstr. 1, Munich 80336, Germany
| | - Roberto Massa
- Neuromuscular Diseases Unit, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
| | - Benedikt Schoser
- Friedrich-Baur-Institute, Department of Neurology, Klinikum der Universität, Ludwig-Maximilians-University, Ziemssenstr. 1, Munich 80336, Germany
| |
Collapse
|
16
|
Yadava RS, Yu Q, Mandal M, Rigo F, Bennett CF, Mahadevan MS. Systemic therapy in an RNA toxicity mouse model with an antisense oligonucleotide therapy targeting a non-CUG sequence within the DMPK 3'UTR RNA. Hum Mol Genet 2020; 29:1440-1453. [PMID: 32242217 PMCID: PMC7268549 DOI: 10.1093/hmg/ddaa060] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/19/2020] [Accepted: 03/30/2020] [Indexed: 12/17/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1), the most common adult muscular dystrophy, is an autosomal dominant disorder caused by an expansion of a (CTG)n tract within the 3' untranslated region (3'UTR) of the dystrophia myotonica protein kinase (DMPK) gene. Mutant DMPK mRNAs are toxic, present in nuclear RNA foci and correlated with a plethora of RNA splicing defects. Cardinal features of DM1 are myotonia and cardiac conduction abnormalities. Using transgenic mice, we have demonstrated that expression of the mutant DMPK 3'UTR is sufficient to elicit these features of DM1. Here, using these mice, we present a study of systemic treatment with an antisense oligonucleotide (ASO) (ISIS 486178) targeted to a non-CUG sequence within the 3'UTR of DMPK. RNA foci and DMPK 3'UTR mRNA levels were reduced in both the heart and skeletal muscles. This correlated with improvements in several splicing defects in skeletal and cardiac muscles. The treatment reduced myotonia and this correlated with increased Clcn1 expression. Furthermore, functional testing showed improvements in treadmill running. Of note, we demonstrate that the ASO treatment reversed the cardiac conduction abnormalities, and this correlated with restoration of Gja5 (connexin 40) expression in the heart. This is the first time that an ASO targeting a non-CUG sequence within the DMPK 3'UTR has demonstrated benefit on the key DM1 phenotypes of myotonia and cardiac conduction defects. Our data also shows for the first time that ASOs may be a viable option for treating cardiac pathology in DM1.
Collapse
Affiliation(s)
- Ramesh S Yadava
- Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA
| | - Qing Yu
- Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA
| | - Mahua Mandal
- Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA
| | - Frank Rigo
- Ionis Pharmaceuticals Inc., Carlsbad, CA 90210, USA
| | | | - Mani S Mahadevan
- Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA
| |
Collapse
|
17
|
Abstract
PURPOSE OF REVIEW This article describes the clinical features, pathogenesis, prevalence, diagnosis, and management of myotonic dystrophy type 1 and myotonic dystrophy type 2. RECENT FINDINGS The prevalence of myotonic dystrophy type 1 is better understood than the prevalence of myotonic dystrophy type 2, and new evidence indicates that the risk of cancer is increased in patients with the myotonic dystrophies. In addition, descriptions of the clinical symptoms and relative risks of comorbidities such as cardiac arrhythmias associated with myotonic dystrophy type 1 have been improved. SUMMARY Myotonic dystrophy type 1 and myotonic dystrophy type 2 are both characterized by progressive muscle weakness, early-onset cataracts, and myotonia. However, both disorders have multisystem manifestations that require a comprehensive management plan. While no disease-modifying therapies have yet been identified, advances in therapeutic development have a promising future.
Collapse
|
18
|
Kurkiewicz A, Cooper A, McIlwaine E, Cumming SA, Adam B, Krahe R, Puymirat J, Schoser B, Timchenko L, Ashizawa T, Thornton CA, Rogers S, McClure JD, Monckton DG. Towards development of a statistical framework to evaluate myotonic dystrophy type 1 mRNA biomarkers in the context of a clinical trial. PLoS One 2020; 15:e0231000. [PMID: 32287265 PMCID: PMC7156058 DOI: 10.1371/journal.pone.0231000] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 03/13/2020] [Indexed: 12/11/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a rare genetic disorder, characterised by muscular dystrophy, myotonia, and other symptoms. DM1 is caused by the expansion of a CTG repeat in the 3'-untranslated region of DMPK. Longer CTG expansions are associated with greater symptom severity and earlier age at onset. The primary mechanism of pathogenesis is thought to be mediated by a gain of function of the CUG-containing RNA, that leads to trans-dysregulation of RNA metabolism of many other genes. Specifically, the alternative splicing (AS) and alternative polyadenylation (APA) of many genes is known to be disrupted. In the context of clinical trials of emerging DM1 treatments, it is important to be able to objectively quantify treatment efficacy at the level of molecular biomarkers. We show how previously described candidate mRNA biomarkers can be used to model an effective reduction in CTG length, using modern high-dimensional statistics (machine learning), and a blood and muscle mRNA microarray dataset. We show how this model could be used to detect treatment effects in the context of a clinical trial.
Collapse
Affiliation(s)
- Adam Kurkiewicz
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Anneli Cooper
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Emily McIlwaine
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Sarah A. Cumming
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Berit Adam
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Ralf Krahe
- Department of Genetics, University of Texas, MD Anderson Cancer Center, Houston, TX, United States of America
| | - Jack Puymirat
- Laboratory of Human Genetics, CHUL Medical Research Centre, University of Laval, Quebec City, QC, Canada
| | - Benedikt Schoser
- Department of Neurology, Friedrich Baur Institute, Ludwig Maximilians University, Munich, Germany
| | - Lubov Timchenko
- Department of Pediatrics, Division of Neurology, Cincinnati Children’s Hosptial, University of Cincinnati, College of Medicine, Cincinnati, Ohio, United States of America
| | | | - Charles A. Thornton
- University of Rochester, Medical Center School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Simon Rogers
- School of Computing Science, University of Glasgow, Glasgow, United Kingdom
| | - John D. McClure
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Darren G. Monckton
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| |
Collapse
|
19
|
Matsumura T, Takada H, Ishigaki K, Komaki H, Takahashi MP. [Study of medical practices for patients with myotonic dystrophy in Japan-Nationwide specialist survey]. Rinsho Shinkeigaku 2020; 60:120-129. [PMID: 31956155 DOI: 10.5692/clinicalneurol.cn-001347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
To reveal current status of medical practice, we made a nationwide self-questionnaire survey to Japanese certified Neurologists and Child Neurologists. Most specialists seeing patients with myotonic dystrophy (DM) were aware that genetic analysis is approved in health insurance. The ratio of pre-explanation about genetic analysis was also high however written informed consent was not always obtained. Over 60% of specialists regarded motor dysfunction, conduction block/arrhythmia, heart failure, dysphagia, hypoventilation as important complications, while no more than 35% of specialists regarded hypoxia/apnea, multi-organ complications, which are feature of myotonic dystrophy, as important. Over half specialists did not check Holter electrocardiogram, sleep respiratory examination, or swallowing function regularly. This fact implied that cumbersome examinations tended to be refrained from regular assessment. Child neurologists were more aggressive in respiratory care and consultation of cardiovascular specialists. A few neurologists hesitated to introduce mechanical ventilation and tube feeding.
Collapse
Affiliation(s)
- Tsuyoshi Matsumura
- Department of Neurology, National Hospital Organization Osaka Toneyama Medical Center
| | - Hiroto Takada
- Department of Neurology, National Hospital Organization Aomori National Hospital
| | - Keiko Ishigaki
- Department of Pediatrics, Tokyo Woman's Medical University Hospital
| | - Hirofumi Komaki
- Translational Medical Center, National Center of Neurology and Psychiatry
| | | |
Collapse
|
20
|
McNally EM, Mann DL, Pinto Y, Bhakta D, Tomaselli G, Nazarian S, Groh WJ, Tamura T, Duboc D, Itoh H, Hellerstein L, Mammen PPA. Clinical Care Recommendations for Cardiologists Treating Adults With Myotonic Dystrophy. J Am Heart Assoc 2020; 9:e014006. [PMID: 32067592 PMCID: PMC7070199 DOI: 10.1161/jaha.119.014006] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Myotonic dystrophy is an inherited systemic disorder affecting skeletal muscle and the heart. Genetic testing for myotonic dystrophy is diagnostic and identifies those at risk for cardiac complications. The 2 major genetic forms of myotonic dystrophy, type 1 and type 2, differ in genetic etiology yet share clinical features. The cardiac management of myotonic dystrophy should include surveillance for arrhythmias and left ventricular dysfunction, both of which occur in progressive manner and contribute to morbidity and mortality. To promote the development of care guidelines for myotonic dystrophy, the Myotonic Foundation solicited the input of care experts and organized the drafting of these recommendations. As a rare disorder, large scale clinical trial data to guide the management of myotonic dystrophy are largely lacking. The following recommendations represent expert consensus opinion from those with experience in the management of myotonic dystrophy, in part supported by literature-based evidence where available.
Collapse
Affiliation(s)
| | | | - Yigal Pinto
- University of AmsterdamAmsterdamThe Netherlands
| | | | | | | | | | - Takuhisa Tamura
- National Hospital Organization Higashisaitama National HospitalSaitamaJapan
| | - Denis Duboc
- Hopital CochinUniversite Paris DescartesParisFrance
| | - Hideki Itoh
- Shiga University of Medical ScienceShigaJapan
| | | | | |
Collapse
|
21
|
López Castel A, Overby SJ, Artero R. MicroRNA-Based Therapeutic Perspectives in Myotonic Dystrophy. Int J Mol Sci 2019; 20:ijms20225600. [PMID: 31717488 PMCID: PMC6888406 DOI: 10.3390/ijms20225600] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/28/2019] [Accepted: 10/30/2019] [Indexed: 12/20/2022] Open
Abstract
Myotonic dystrophy involves two types of chronically debilitating rare neuromuscular diseases: type 1 (DM1) and type 2 (DM2). Both share similarities in molecular cause, clinical signs, and symptoms with DM2 patients usually displaying milder phenotypes. It is well documented that key clinical symptoms in DM are associated with a strong mis-regulation of RNA metabolism observed in patient’s cells. This mis-regulation is triggered by two leading DM-linked events: the sequestration of Muscleblind-like proteins (MBNL) and the mis-regulation of the CUGBP RNA-Binding Protein Elav-Like Family Member 1 (CELF1) that cause significant alterations to their important functions in RNA processing. It has been suggested that DM1 may be treatable through endogenous modulation of the expression of MBNL and CELF1 proteins. In this study, we analyzed the recent identification of the involvement of microRNA (miRNA) molecules in DM and focus on the modulation of these miRNAs to therapeutically restore normal MBNL or CELF1 function. We also discuss additional prospective miRNA targets, the use of miRNAs as disease biomarkers, and additional promising miRNA-based and miRNA-targeting drug development strategies. This review provides a unifying overview of the dispersed data on miRNA available in the context of DM.
Collapse
Affiliation(s)
- Arturo López Castel
- Translational Genomics Group, Incliva Health Research Institute, Burjassot, 46100 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (Eri Biotecmed), University of Valencia, Burjassot, 46100 Valencia, Spain
- Correspondence: (A.L.C.); (R.A.)
| | - Sarah Joann Overby
- Translational Genomics Group, Incliva Health Research Institute, Burjassot, 46100 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (Eri Biotecmed), University of Valencia, Burjassot, 46100 Valencia, Spain
| | - Rubén Artero
- Translational Genomics Group, Incliva Health Research Institute, Burjassot, 46100 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (Eri Biotecmed), University of Valencia, Burjassot, 46100 Valencia, Spain
- Correspondence: (A.L.C.); (R.A.)
| |
Collapse
|
22
|
Reddy K, Jenquin JR, Cleary JD, Berglund JA. Mitigating RNA Toxicity in Myotonic Dystrophy using Small Molecules. Int J Mol Sci 2019; 20:E4017. [PMID: 31426500 PMCID: PMC6720693 DOI: 10.3390/ijms20164017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 12/26/2022] Open
Abstract
This review, one in a series on myotonic dystrophy (DM), is focused on the development and potential use of small molecules as therapeutics for DM. The complex mechanisms and pathogenesis of DM are covered in the associated reviews. Here, we examine the various small molecule approaches taken to target the DNA, RNA, and proteins that contribute to disease onset and progression in myotonic dystrophy type 1 (DM1) and 2 (DM2).
Collapse
Affiliation(s)
- Kaalak Reddy
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA.
| | - Jana R Jenquin
- Center for NeuroGenetics and Biochemistry & Molecular Biology, University of Florida, Gainesville, FL 32608, USA
| | - John D Cleary
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - J Andrew Berglund
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA.
- Center for NeuroGenetics and Biochemistry & Molecular Biology, University of Florida, Gainesville, FL 32608, USA.
| |
Collapse
|
23
|
Lo Scrudato M, Poulard K, Sourd C, Tomé S, Klein AF, Corre G, Huguet A, Furling D, Gourdon G, Buj-Bello A. Genome Editing of Expanded CTG Repeats within the Human DMPK Gene Reduces Nuclear RNA Foci in the Muscle of DM1 Mice. Mol Ther 2019; 27:1372-1388. [PMID: 31253581 PMCID: PMC6697452 DOI: 10.1016/j.ymthe.2019.05.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 05/22/2019] [Accepted: 05/29/2019] [Indexed: 12/21/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is caused by a CTG repeat expansion located in the 3' UTR of the DMPK gene. Expanded DMPK transcripts aggregate into nuclear foci and alter the function of RNA-binding proteins, leading to defects in the alternative splicing of numerous pre-mRNAs. To date, there is no curative treatment for DM1. Here we investigated a gene-editing strategy using the CRISPR-Cas9 system from Staphylococcus aureus (Sa) to delete the CTG repeats in the human DMPK locus. Co-expression of SaCas9 and selected pairs of single-guide RNAs (sgRNAs) in cultured DM1 patient-derived muscle line cells carrying 2,600 CTG repeats resulted in targeted DNA deletion, ribonucleoprotein foci disappearance, and correction of splicing abnormalities in various transcripts. Furthermore, a single intramuscular injection of recombinant AAV vectors expressing CRISPR-SaCas9 components in the tibialis anterior muscle of DMSXL (myotonic dystrophy mouse line carrying the human DMPK gene with >1,000 CTG repeats) mice decreased the number of pathological RNA foci in myonuclei. These results establish the proof of concept that genome editing of a large trinucleotide expansion is feasible in muscle and may represent a useful strategy to be further developed for the treatment of myotonic dystrophy.
Collapse
Affiliation(s)
- Mirella Lo Scrudato
- Genethon, INSERM UMR_S951, Univ Evry, Université Paris Saclay, 91000 Evry, France
| | - Karine Poulard
- Genethon, INSERM UMR_S951, Univ Evry, Université Paris Saclay, 91000 Evry, France
| | - Célia Sourd
- Genethon, INSERM UMR_S951, Univ Evry, Université Paris Saclay, 91000 Evry, France
| | - Stéphanie Tomé
- INSERM UMR 1163, Institut Imagine, Université Paris Descartes-Sorbonne Paris Cité, 75015 Paris, France
| | - Arnaud F Klein
- INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, Sorbonne Université, 75013 Paris, France
| | - Guillaume Corre
- Genethon, INSERM UMR_S951, Univ Evry, Université Paris Saclay, 91000 Evry, France
| | - Aline Huguet
- INSERM UMR 1163, Institut Imagine, Université Paris Descartes-Sorbonne Paris Cité, 75015 Paris, France
| | - Denis Furling
- INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, Sorbonne Université, 75013 Paris, France
| | - Geneviève Gourdon
- INSERM UMR 1163, Institut Imagine, Université Paris Descartes-Sorbonne Paris Cité, 75015 Paris, France
| | - Ana Buj-Bello
- Genethon, INSERM UMR_S951, Univ Evry, Université Paris Saclay, 91000 Evry, France.
| |
Collapse
|
24
|
Raaijmakers RHL, Ripken L, Ausems CRM, Wansink DG. CRISPR/Cas Applications in Myotonic Dystrophy: Expanding Opportunities. Int J Mol Sci 2019; 20:ijms20153689. [PMID: 31357652 PMCID: PMC6696057 DOI: 10.3390/ijms20153689] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 02/06/2023] Open
Abstract
CRISPR/Cas technology holds promise for the development of therapies to treat inherited diseases. Myotonic dystrophy type 1 (DM1) is a severe neuromuscular disorder with a variable multisystemic character for which no cure is yet available. Here, we review CRISPR/Cas-mediated approaches that target the unstable (CTG•CAG)n repeat in the DMPK/DM1-AS gene pair, the autosomal dominant mutation that causes DM1. Expansion of the repeat results in a complex constellation of toxicity at the DNA level, an altered transcriptome and a disturbed proteome. To restore cellular homeostasis and ameliorate DM1 disease symptoms, CRISPR/Cas approaches were directed at the causative mutation in the DNA and the RNA. Specifically, the triplet repeat has been excised from the genome by several laboratories via dual CRISPR/Cas9 cleavage, while one group prevented transcription of the (CTG)n repeat through homology-directed insertion of a polyadenylation signal in DMPK. Independently, catalytically deficient Cas9 (dCas9) was recruited to the (CTG)n repeat to block progression of RNA polymerase II and a dCas9-RNase fusion was shown to degrade expanded (CUG)n RNA. We compare these promising developments in DM1 with those in other microsatellite instability diseases. Finally, we look at hurdles that must be taken to make CRISPR/Cas-mediated editing a therapeutic reality in patients.
Collapse
Affiliation(s)
- Renée H L Raaijmakers
- Department of Cell Biology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain Cognition and Behavior, 6525 GA Nijmegen, The Netherlands
| | - Lise Ripken
- Department of Cell Biology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands
| | - C Rosanne M Ausems
- Department of Cell Biology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain Cognition and Behavior, 6525 GA Nijmegen, The Netherlands
| | - Derick G Wansink
- Department of Cell Biology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands.
| |
Collapse
|
25
|
Ota K, Nakamura Y, Nakamura E, Takashima S, Oka M, Ota K, Sakaue M, Sano Y, Takasu A. Massive abscess with prolonged respiratory failure due to newly diagnosed myotonic dystrophy: A case report. Medicine (Baltimore) 2019; 98:e15427. [PMID: 31027145 PMCID: PMC6831368 DOI: 10.1097/md.0000000000015427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
RATIONALE Myotonic dystrophy is a progressive multisystem genetic heterogeneous disorder. General anesthesia with opioids increases the risk of prolonged postanesthetic respiratory recovery in myotonic dystrophy patients. PATIENT CONCERNS A 20-year-old previously healthy woman was transferred to our emergency department for further workup of respiratory failure, and massive ascites with abscess caused by endometriosis. Hypercapnic respiratory failure persisted under intensive care unit (ICU) management, but finally improved after cessation of fentanyl as a sedative agent. DIAGNOSIS Myotonic dystrophy type 1. INTERVENTIONS Massive ascites with abscess was accordingly managed by drainage, antibiotics, and an antifungal agent. Myotonic dystrophy type 1 was confirmed after molecular genetic testing revealed a cytosine-thymine-guanine repeat length of 400 to 450 in the DMPK gene. OUTCOMES The patient was discharged without complications on hospital day 69. LESSONS Myotonic dystrophy should be considered when hypercapnic respiratory failure persists in sedated ICU patients. Opioids should not be used for perioperative management of patients with myotonic dystrophy.
Collapse
Affiliation(s)
| | - Yoshitsugu Nakamura
- Division of Neurology, Department of Internal Medicine IV, Osaka Medical College, Osaka, Japan
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Souidi A, Zmojdzian M, Jagla K. Dissecting Pathogenetic Mechanisms and Therapeutic Strategies in Drosophila Models of Myotonic Dystrophy Type 1. Int J Mol Sci 2018; 19:E4104. [PMID: 30567354 PMCID: PMC6321436 DOI: 10.3390/ijms19124104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 12/08/2018] [Accepted: 12/13/2018] [Indexed: 12/16/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1), the most common cause of adult-onset muscular dystrophy, is autosomal dominant, multisystemic disease with characteristic symptoms including myotonia, heart defects, cataracts and testicular atrophy. DM1 disease is being successfully modelled in Drosophila allowing to identify and validate new pathogenic mechanisms and potential therapeutic strategies. Here we provide an overview of insights gained from fruit fly DM1 models, either: (i) fundamental with particular focus on newly identified gene deregulations and their link with DM1 symptoms; or (ii) applied via genetic modifiers and drug screens to identify promising therapeutic targets.
Collapse
Affiliation(s)
- Anissa Souidi
- GReD, INSERM U1103, CNRS, UMR6293, University of Clermont Auvergne, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France.
| | - Monika Zmojdzian
- GReD, INSERM U1103, CNRS, UMR6293, University of Clermont Auvergne, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France.
| | - Krzysztof Jagla
- GReD, INSERM U1103, CNRS, UMR6293, University of Clermont Auvergne, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France.
| |
Collapse
|
27
|
Wang Y, Hao L, Wang H, Santostefano K, Thapa A, Cleary J, Li H, Guo X, Terada N, Ashizawa T, Xia G. Therapeutic Genome Editing for Myotonic Dystrophy Type 1 Using CRISPR/Cas9. Mol Ther 2018; 26:2617-2630. [PMID: 30274788 PMCID: PMC6225032 DOI: 10.1016/j.ymthe.2018.09.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 08/30/2018] [Accepted: 09/06/2018] [Indexed: 12/18/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is caused by a CTG nucleotide repeat expansion within the 3' UTR of the Dystrophia Myotonica protein kinase gene. In this study, we explored therapeutic genome editing using CRISPR/Cas9 via targeted deletion of expanded CTG repeats and targeted insertion of polyadenylation signals in the 3' UTR upstream of the CTG repeats to eliminate toxic RNA CUG repeats. We found paired SpCas9 or SaCas9 guide RNA induced deletion of expanded CTG repeats. However, this approach incurred frequent inversion in both the mutant and normal alleles. In contrast, the insertion of polyadenylation signals in the 3' UTR upstream of the CTG repeats eliminated toxic RNA CUG repeats, which led to phenotype reversal in differentiated neural stem cells, forebrain neurons, cardiomyocytes, and skeletal muscle myofibers. We concluded that targeted insertion of polyadenylation signals in the 3' UTR is a viable approach to develop therapeutic genome editing for DM1.
Collapse
Affiliation(s)
- Yanlin Wang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Henan 450000, China
| | - Lei Hao
- Department of Neurology, The Fifth People's Hospital of Chongqing, Chongqing 400062, China
| | - Hongcai Wang
- Department of Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou City, Shandong Province, China; Department of Neurology, University of New Mexico, Albuquerque, NM, USA
| | - Katherine Santostefano
- Department of Pathology, Immunology & Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Arjun Thapa
- Department of Neurology, University of New Mexico, Albuquerque, NM, USA
| | - John Cleary
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA
| | - Hui Li
- Department of Neurology, University of Wisconsin, Madison, WI, USA
| | - Xiuming Guo
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Naohiro Terada
- Department of Pathology, Immunology & Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Tetsuo Ashizawa
- Houston Methodist Neurological Institute and Research Institute, 6670 Bertner Ave. R11-117, Houston, TX, USA
| | - Guangbin Xia
- Department of Neurology, University of New Mexico, Albuquerque, NM, USA; Department of Neuroscience, University of New Mexico, Albuquerque, NM, USA.
| |
Collapse
|
28
|
Abstract
BACKGROUND The last literature review on psychopathological features in Myotonic Dystrophy type 1 had been conducted by Ambrosini and Nurnberg in 1979. Since that date, many researches had been carried out. OBJECTIVE The aim of this study is (i) to systematically obtain and evaluate the relevant literature on psychopathological features, personality, and coping in individuals with adult phenotypes of Myotonic Dystrophy type 1. (ii) To summarize current research findings and draw conclusions for future research. METHODS A systematic search was conducted on Pubmed, PubPsych, PsycInfo, Science Direct, and Scopus covering the period of January 1979 to July 2017. RESULTS In view of our literature review, patients show mild psychopathological problems, such as interpersonal difficulties, lack of interest, dysphoria, concern about bodily functioning, and hypersensibility. However, they do not experience more psychiatric disorder in comparison to the general population, except for personality disorders and depression. We discussed problems concerning depression's assessment tool. Patients also present symptoms of several personality disorders: avoidant personality disorder was the most common. Finally, coping strategies relative to limitations resulting from their disease have a negative impact on their quality of life. CONCLUSIONS In conclusion, Myotonic Dystrophy type 1 patients did not present homogeneous psychopathological and psychological features. However, based on tendencies observed among Myotonic Dystrophy type 1 patients, elements to conceptualize their social difficulties are provided.
Collapse
Affiliation(s)
- Lisa Minier
- Department of Psychology, Laboratoire CliPsyD, EA4430, Université Paris Nanterre, France
| | - Baptiste Lignier
- Department of Psychology, Laboratoire Psy-DREPI, EA 7458, Université de Bourgogne Franche-Comté, Dijon, France
- Espace Psychothérapique, pôle B Côte-d’Or Sud de Psychiatrie Générale, CH La Chartreuse, Dijon, France
| | - Cyrille Bouvet
- Department of Psychology, Laboratoire CliPsyD, EA4430, Université Paris Nanterre, France
| | - Benjamin Gallais
- ÉCOBES - Recherche et transfert, Cégep de Jonquière, QC, Canada
- Groupe de Recherche Interdisciplinaire sur les Maladies Neuromusculaires (GRIMN), Jonquière, QC, Canada
| | - Nathalie Camart
- Department of Psychology, Laboratoire CliPsyD, EA4430, Université Paris Nanterre, France
| |
Collapse
|
29
|
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
|
30
|
Pinto BS, Saxena T, Oliveira R, Méndez-Gómez HR, Cleary JD, Denes LT, McConnell O, Arboleda J, Xia G, Swanson MS, Wang ET. Impeding Transcription of Expanded Microsatellite Repeats by Deactivated Cas9. Mol Cell 2017; 68:479-490.e5. [PMID: 29056323 PMCID: PMC6013302 DOI: 10.1016/j.molcel.2017.09.033] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 09/05/2017] [Accepted: 09/22/2017] [Indexed: 12/14/2022]
Abstract
Transcription of expanded microsatellite repeats is associated with multiple human diseases, including myotonic dystrophy, Fuchs endothelial corneal dystrophy, and C9orf72-ALS/FTD. Reducing production of RNA and proteins arising from these expanded loci holds therapeutic benefit. Here, we tested the hypothesis that deactivated Cas9 enzyme impedes transcription across expanded microsatellites. We observed a repeat length-, PAM-, and strand-dependent reduction of repeat-containing RNAs upon targeting dCas9 directly to repeat sequences; targeting the non-template strand was more effective. Aberrant splicing patterns were rescued in DM1 cells, and production of RAN peptides characteristic of DM1, DM2, and C9orf72-ALS/FTD cells was drastically decreased. Systemic delivery of dCas9/gRNA by adeno-associated virus led to reductions in pathological RNA foci, rescue of chloride channel 1 protein expression, and decreased myotonia. These observations suggest that transcription of microsatellite repeat-containing RNAs is more sensitive to perturbation than transcription of other RNAs, indicating potentially viable strategies for therapeutic intervention.
Collapse
Affiliation(s)
- Belinda S Pinto
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA
| | - Tanvi Saxena
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA
| | - Ruan Oliveira
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA
| | - Héctor R Méndez-Gómez
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA
| | - John D Cleary
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA
| | - Lance T Denes
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA
| | - Ona McConnell
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA
| | - Juan Arboleda
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA
| | - Guangbin Xia
- Department of Neurology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA
| | - Maurice S Swanson
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA
| | - Eric T Wang
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; Center for NeuroGenetics, University of Florida, Gainesville, FL 32610, USA.
| |
Collapse
|
31
|
LaDonna KA, Watling CJ, Ray SL, Piechowicz C, Venance SL. Evolving Motivations: Patients' and Caregivers' Perceptions About Seeking Myotonic Dystrophy (DM1) and Huntington's Disease Care. Qual Health Res 2017; 27:1727-1737. [PMID: 28799481 DOI: 10.1177/1049732317711901] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Patient-centered care provision is challenging under ideal circumstances; myotonic dystrophy (DM1) and Huntington's disease (HD) are examples of chronic, progressive health conditions that may challenge its limits. If we can understand how care unfolds in these conditions, health care providers may be better equipped to address patients' needs. Constructivist grounded theory informed data collection and analysis. Fourteen patients with DM1 or HD, and 10 caregivers participated in semistructured interviews. Constant comparative analysis was used to identify themes. Participants attended clinic to seek expert information and social support. Medical management, altruism, and support provided the motivation. However, motivations evolved, with clinic becoming more important for caregivers as patients deteriorated. Clinic was conceptualized as a "safe space" to actively participate in health care and research. In the absence of disease-halting or curative treatments, participants perceived that they derived a therapeutic benefit from seeking care and from engaging in education and advocacy.
Collapse
Affiliation(s)
- Kori A LaDonna
- 1 Centre for Education Research and Innovation, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Christopher J Watling
- 1 Centre for Education Research and Innovation, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- 2 Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University and London Health Sciences Centre, London, Ontario, Canada
| | - Susan L Ray
- 3 Arthur Labatt School of Nursing, Faculty of Health Sciences, Western University, London, Ontario, Canada
| | - Christine Piechowicz
- 2 Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University and London Health Sciences Centre, London, Ontario, Canada
| | - Shannon L Venance
- 2 Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University and London Health Sciences Centre, London, Ontario, Canada
| |
Collapse
|
32
|
Meola G, Cardani R. Myotonic dystrophies: An update on clinical aspects, genetic, pathology, and molecular pathomechanisms. Biochim Biophys Acta Mol Basis Dis 2014; 1852:594-606. [PMID: 24882752 DOI: 10.1016/j.bbadis.2014.05.019] [Citation(s) in RCA: 205] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/19/2014] [Accepted: 05/20/2014] [Indexed: 01/18/2023]
Abstract
Myotonic dystrophy (DM) is the most common adult muscular dystrophy, characterized by autosomal dominant progressive myopathy, myotonia and multiorgan involvement. To date two distinct forms caused by similar mutations have been identified. Myotonic dystrophy type 1 (DM1, Steinert's disease) is caused by a (CTG)n expansion in DMPK, while myotonic dystrophy type 2 (DM2) is caused by a (CCTG)n expansion in ZNF9/CNBP. When transcribed into CUG/CCUG-containing RNA, mutant transcripts aggregate as nuclear foci that sequester RNA-binding proteins, resulting in spliceopathy of downstream effector genes. However, it is now clear that additional pathogenic mechanism like changes in gene expression, protein translation and micro-RNA metabolism may also contribute to disease pathology. Despite clinical and genetic similarities, DM1 and DM2 are distinct disorders requiring different diagnostic and management strategies. This review is an update on the recent advances in the understanding of the molecular mechanisms behind myotonic dystrophies. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis.
Collapse
Affiliation(s)
- Giovanni Meola
- Department of Neurology, IRCCS Policlinico San Donato, University of Milan, San Donato Milanese, Milan, Italy; Laboratory of Muscle Histopathology and Molecular Biology, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy.
| | - Rosanna Cardani
- Laboratory of Muscle Histopathology and Molecular Biology, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy.
| |
Collapse
|
33
|
Zhao Y, Ishiura S. [Current studies in myotonic dystrophy]. Brain Nerve 2014; 66:259-264. [PMID: 24607950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Myotonic dystrophy (DM) is a genetic, progressive, multisystemic disease with muscular disorder as its primary symptom. There are two types of DM (DM1 and DM2) caused by mutations in different genes, and in Japan, DM occurs with an incidence of approximately 1 in 20,000. The pathogenic mechanism underlying the disease is RNA toxicity caused by transcripts of aberrantly elongated CTG or CCTG repeats located in the 3' untranslated region or in the intron. The current treatments for DM is limited to symptomatic care. In this review, we will discuss several new therapeutic strategies based on recent studies of RNA toxicity.
Collapse
Affiliation(s)
- Yimeng Zhao
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo
| | | |
Collapse
|
34
|
Lindvall B. [Neuromuscular diseases are many but rare]. Lakartidningen 2013; 110:752-753. [PMID: 23662534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
|
35
|
Savić Pavićević D, Miladinović J, Brkušanin M, Šviković S, Djurica S, Brajušković G, Romac S. Molecular genetics and genetic testing in myotonic dystrophy type 1. Biomed Res Int 2013; 2013:391821. [PMID: 23586035 PMCID: PMC3613064 DOI: 10.1155/2013/391821] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 02/05/2013] [Indexed: 12/29/2022]
Abstract
Myotonic dystrophy type 1 (DM1) is the most common adult onset muscular dystrophy, presenting as a multisystemic disorder with extremely variable clinical manifestation, from asymptomatic adults to severely affected neonates. A striking anticipation and parental-gender effect upon transmission are distinguishing genetic features in DM1 pedigrees. It is an autosomal dominant hereditary disease associated with an unstable expansion of CTG repeats in the 3'-UTR of the DMPK gene, with the number of repeats ranging from 50 to several thousand. The number of CTG repeats broadly correlates with both the age-at-onset and overall severity of the disease. Expanded DM1 alleles are characterized by a remarkable expansion-biased and gender-specific germline instability, and tissue-specific, expansion-biased, age-dependent, and individual-specific somatic instability. Mutational dynamics in male and female germline account for observed anticipation and parental-gender effect in DM1 pedigrees, while mutational dynamics in somatic tissues contribute toward the tissue-specificity and progressive nature of the disease. Genetic test is routinely used in diagnostic procedure for DM1 for symptomatic, asymptomatic, and prenatal testing, accompanied with appropriate genetic counseling and, as recommended, without predictive information about the disease course. We review molecular genetics of DM1 with focus on those issues important for genetic testing and counseling.
Collapse
Affiliation(s)
- Dušanka Savić Pavićević
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Jelena Miladinović
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Miloš Brkušanin
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Saša Šviković
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Svetlana Djurica
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Goran Brajušković
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| | - Stanka Romac
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia
| |
Collapse
|
36
|
|
37
|
Wahbi K, Meune C, Porcher R, Bécane HM, Lazarus A, Laforêt P, Stojkovic T, Béhin A, Radvanyi-Hoffmann H, Eymard B, Duboc D. Electrophysiological study with prophylactic pacing and survival in adults with myotonic dystrophy and conduction system disease. JAMA 2012; 307:1292-301. [PMID: 22453570 DOI: 10.1001/jama.2012.346] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Up to one-third of patients with myotonic dystrophy type 1 die suddenly. Thus far, no intervention has effectively prevented sudden death. OBJECTIVE To determine whether an invasive strategy based on systematic electrophysiological studies and prophylactic permanent pacing is associated with longer survival in patients presenting with myotonic dystrophy type 1 and major infranodal conduction delays than a noninvasive strategy. DESIGN, SETTING, AND PATIENTS A retrospective study, the DM1 Heart Registry included 914 consecutive patients older than 18 years with genetically confirmed myotonic dystrophy type 1 who were admitted to the Neurological Unit of the Myology Institute of Pitié-Salpêtrière Hospital, a teaching medical center in Paris, France, between January 2000 and December 2009. INTERVENTIONS Among 486 patients whose electrocardiogram showed a PR interval greater than 200 milliseconds, a QRS duration greater than 100 milliseconds, or both, the outcome of 341 (70.2%) who underwent an invasive strategy was compared with 145 (29.8%) who underwent a noninvasive strategy. A propensity score risk adjustment and propensity-based matching analysis was used to account for selection biases. MAIN OUTCOME MEASURES Rates of overall survival (main outcome measure) and sudden death, respiratory death, and other deaths (secondary outcome measures). RESULTS Over a median follow-up of 7.4 years (range, 0-9.9 years), 50 patients died in the invasive strategy group and 30 died in the noninvasive strategy group (hazard ratio [HR], 0.74 [95 CI, 0.47-1.16]; P = .19), corresponding to an overall 9-year survival of 74.4% (95% CI, 69.2%-79.9%). Regardless of the technique used to adjust for between-group differences in baseline characteristics, the invasive strategy was associated with a longer survival, with adjusted HRs ranging from 0.47 (95% CI, 0.26-0.84; P = .01) for a covariate-adjusted analysis of propensity-matched data to 0.61 (95% CI, 0.38-0.99; P = .047) for an analysis adjusted for propensity score quintiles. The survival difference was largely attributable to a lower incidence of sudden death, which occurred in 10 patients in the invasive strategy group and in 16 patients in the noninvasive strategy group, with HRs ranging from 0.24 (95% CI, 0.10-0.56; P = .001) for an analysis adjusted for propensity score quintiles and covariates to 0.28 (95% CI, 0.13-0.61; P = .001) for an unadjusted analysis of propensity-matched data. CONCLUSION Among patients with myotonic dystrophy type 1, an invasive strategy was associated with a higher rate of 9-year survival than a noninvasive strategy. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01136330.
Collapse
Affiliation(s)
- Karim Wahbi
- Pierre et Marie Curie-Paris 6 University, Myology Institute, Pitié-Salpêtrière Hospital, 75013 Paris, France.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Takahashi MP. [Myotonic dystrophy-from pathomechanism as a RNA disease to future clinical trials]. Rinsho Shinkeigaku 2012; 52:1393-1396. [PMID: 23574979 DOI: 10.5692/clinicalneurol.52.1393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The understanding of the pathomechanism of myotonic dystrophy (DM) has been greatly improved since the recognition as an mRNA disease. Pre-mRNA containing repeats sequesters or activates proteins such as MBNL and CELF that bind to an mRNA motif similar to repeat. Consequently, the regulation of mRNA splicing, a normal function of these proteins, is perturbed. Over 30 miss-splicing events have been documented including muscle chloride channel which is responsible for myotonia. Such molecular events might serve as a target for therapeutic intervention. An important genetic feature of DM is the instability of expanded repeats between generations and organs. Since pathogenesis is connected to repeat length, manipulation of the repeat expansion size (somatic instability) might be also a potential therapeutic strategy. With accumulation of pathomechanistic studies, clinical trials are highly expected. Our recent survey in Osaka Japan revealed the need of standardized management employing currently available therapies, which should be prerequisite for trials. Clinical trials for DM will face challenges including lack of reliable outcome measures and enrollment of highly restricted cohort. Global initiative to form international DM registry have been taken to facilitate natural history studies and trials. In Japan, the development of DM registry has just started.
Collapse
|
39
|
Abstract
OBJECTIVE Respiratory muscle weakness causes alveolar hypoventilation and reduced lung compliance in neuromuscular disorders. Lung inflation is important to prevent secondary pulmonary complications however respiratory and laryngeal dysfunction often hamper lung inflation. There is a need for a convenient and low-cost device that enables effective lung inflation. We tested a lung inflation training method using a positive end-expiratory pressure (PEEP) valve. METHODS Vital capacity (VC), maximum insufflation capacity (MIC) and peak cough flow (PCF) as well as PEEP lung inflation capacity (PIC) were assessed in 93 neuromuscular patients. Consecutive PIC training was done for 4 months in six tracheostomized Duchenne muscular dystrophy (DMD) patients and PIC was assessed before and after training. RESULTS PIC training was practicable in all participants and no serious adverse events were detected. PIC was significantly higher than VC or MIC in all disorders, although MIC was higher than VC in DMD only. Patients with dysphagia showed lower MIC and PCF compared with non dysphagic patients. PIC was as low as 345±77 mL in tracheostomized DMD patients; however consecutive training increased it up to 619±205 mL. CONCLUSION The PEEP valve enabled effective lung inflation regardless of laryngeal function. Consecutive training can improve lung condition even in advanced cases. Early introduction of PIC training could be effective at preventing respiratory complications in patients with neuromuscular disorders.
Collapse
Affiliation(s)
- Tsuyoshi Matsumura
- Department of Neurology, National Hospital Organization Toneyama National Hospital, Japan.
| | | | | | | | | |
Collapse
|
40
|
Nakamori M, Takahashi MP. [Myotonic dystrophy: therapeutic approaches to RNA toxicity]. Brain Nerve 2011; 63:1161-1168. [PMID: 22068468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Myotonic dystrophy (DM) is the most common hereditary muscle disease in adults, caused by unstable genomic expansions of simple sequence repeats. The mutant RNA transcripts containing the expanded repeat give rise to a toxic gainoffunction by perturbing splicing factors in the nucleus, leading to the misregulation of alternative pre-mRNA splicing. Although no curative treatment exists, recent advances in research and pharmaceutical technology have provided clues for therapeutic intervention in DM. Herein, we review the RNA-dominant mechanism of DM and potential therapeutic approaches for degrading or neutralizing the toxic RNA, restoring splicing factors, correcting splicing misregulation, and stabilizing the repeat.
Collapse
Affiliation(s)
- Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine, Suida, Osaka, Japan
| | | |
Collapse
|
41
|
Rodrigues E Rodrigues L, Barbosa M, Ramos S, Pontes M, Coelho E, Proença E. A newborn with hypotonia and abnormal facies. BMJ 2011; 342:d2938. [PMID: 21659364 DOI: 10.1136/bmj.d2938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Lia Rodrigues E Rodrigues
- Paediatric Department of Centro Hospitalar Póvoa-Varzim/Vila Conde Largo da Misericórdia, 4490-421 Póvoa de Varzim, Portugal
| | | | | | | | | | | |
Collapse
|
42
|
LaDonna KA, Koopman WJ, Venance SL. Myotonic dystrophy (DM1) and dysphagia: the need for dysphagia management guidelines and an assessment tool. Can J Neurosci Nurs 2011; 33:42-46. [PMID: 21560885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Myotonic dystrophy (DM1) is the most prevalent muscular dystrophy occurring in adulthood. DM1 is a multi-systemic disorder resulting in early-onset cataracts, cardiac rhythm problems, muscle weakness, ptosis, and cognitive and psychiatric manifestations. Dysphagia is one of the most problematic symptoms of DM1 because it may cause weight loss, aspiration pneumonias or sudden death. The purpose of this review is to describe the characteristics of DM1 that make dysphagia management problematic, and to address the need for disease-specific guidelines and a clinical tool to aid in diagnosing and managing dysphagia in this population.
Collapse
|
43
|
Lehmann-Horn F, Jurkat-Rott K, Rüdel R. Diagnostics and therapy of muscle channelopathies--Guidelines of the Ulm Muscle Centre. Acta Myol 2008; 27:98-113. [PMID: 19472919 PMCID: PMC2858942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This article is dedicated to our teacher, Prof. Erich Kuhn, Heidelberg, on the occasion of his 88th birthday on 23rd November 2008. In contrast to muscular dystrophies, the muscle channelopathies, a group of diseases characterised by impaired muscle excitation or excitation-contraction coupling, can fairly well be treated with a whole series of pharmacological drugs. However, for a proper treatment proper diagnostics are essential. This article lists state-of-the-art diagnostics and therapies for the two types of myotonic dystrophies, for recessive and dominant myotonia congenita, for the sodium channel myotonias, for the primary dyskalemic periodic paralyses, for central core disease and for malignant hyperthermia susceptibility in detail. In addition, for each disorder a short summary of aetiology, symptomatology, and pathogenesis is provided.
Collapse
Affiliation(s)
- F Lehmann-Horn
- Institute of Applied Physiology, Ulm University, Ulm, Germany.
| | | | | |
Collapse
|
44
|
Nigro G, Russo V, Vergara P, D'Andrea A, Di Gregorio G, Politano L, Nigro G, Calabrò R. Optimal site for atrial lead implantation in myotonic dystrophy patients: the role of Bachmann's Bundle stimulation. Pacing Clin Electrophysiol 2008; 31:1463-1466. [PMID: 18950304 DOI: 10.1111/j.1540-8159.2008.01210.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
AIM The aim of this study was to identify the optimal site for atrial lead implantation in myotonic dystrophy type 1 (MD1) patients. METHODS The atrial pacing lead was positioned in the high-lateral right atrial wall (site A), then in the right atrial appendage (site B), and finally on the interatrial septum (site C) in 22 patients. Pacing and sensing thresholds were obtained for all sites. The lead was repositioned and fixed at the optimal site, defined as the location with the lowest pacing and the highest sensing thresholds. RESULTS Mean pacing thresholds were 1.46 +/- 0.32 V at site A, 1.45 +/- 0.33 V at site B, and 0.84 +/- 0.24 V at site C. P-wave amplitude was 1.52 +/- 0.45 mV at site A, 1.52 +/- 0.49 mV at site B, and 2.60 +/- 0.48 mV at site C. Atrial lead was implanted at site C in all patients without complications. CONCLUSIONS Interatrial septum in the region of Bachmann's Bundle seems to be the optimal site for atrial lead implantation in MD1 patients.
Collapse
Affiliation(s)
- Gerardo Nigro
- Chair of Cardiology, Second University of Naples-Monaldi Hospital, Naples, Italy
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
Myotonic dystrophy (DM) is a dominantly inherited neurodegenerative disorder for which there is no cure or effective treatment. Investigation of DM pathogenesis has identified a novel disease mechanism that requires development of innovative therapeutic strategies. It is now clear that DM is not caused by expression of a mutant protein. Instead, DM is the first recognized example of an RNA-mediated disease. Expression of the mutated gene gives rise to an expanded repeat RNA that is directly toxic to cells. The mutant RNA is retained in the nucleus, forming ribonuclear inclusions in affected tissue. A primary consequence of RNA toxicity in DM is dysfunction of two classes of RNA binding proteins, which leads to abnormal regulation of alternative splicing, or spliceopathy, of select genes. Spliceopathy now is known to cause myotonia and insulin resistance in DM. As our understanding of pathogenesis continues to improve, therapy targeted directly at the RNA disease mechanism will begin to replace the supportive care currently available. New pharmacologic approaches to treat myotonia and muscle wasting in DM type 1 are already in early clinical trials, and therapies designed to reverse the RNA toxicity have shown promise in preclinical models by correcting spliceopathy and eliminating myotonia. The well-defined ribonuclear inclusions may serve as convenient therapeutic targets to identify new agents that modify RNA toxicity. Continued development of appropriate model systems will allow testing of additional therapeutic strategies as they become available. Although DM is a decidedly complex disorder, its RNA-mediated disease mechanism may prove to be highly susceptible to therapy.
Collapse
Affiliation(s)
- Thurman M Wheeler
- Neuromuscular Disease Center, Department of Neurology, University of Rochester, Rochester, New York 14642, USA.
| |
Collapse
|
46
|
Abstract
In the last few years, muscular dystrophies due to reduced glycosylation of alpha-dystroglycan (ADG) have emerged as a common group of conditions, now referred to as dystroglycanopathies. Mutations in six genes (POMT1, POMT2, POMGnT1, Fukutin, FKRP and LARGE) have so far been identified in patients with a dystroglycanopathy. Allelic mutations in each of these genes can result in a wide spectrum of clinical conditions, ranging from severe congenital onset with associated structural brain malformations (Walker Warburg syndrome; muscle-eye-brain disease; Fukuyama muscular dystrophy; congenital muscular dystrophy type 1D) to a relatively milder congenital variant with no brain involvement (congenital muscular dystrophy type 1C), and to limb-girdle muscular dystrophy (LGMD) type 2 variants with onset in childhood or adult life (LGMD2I, LGMD2L, and LGMD2N). ADG is a peripheral membrane protein that undergoes multiple and complex glycosylation steps to regulate its ability to effectively interact with extracellular matrix proteins, such as laminin, agrin, and perlecan. Although the precise composition of the glycans present on ADG are not known, it has been demonstrated that the forced overexpression of LARGE, or its paralog LARGE2, is capable of increasing the glycosylation of ADG in normal cells. In addition, its overexpression is capable of restoring dystroglycan glycosylation and laminin binding properties in primary cell cultures of patients affected by different genetically defined dystroglycanopathy variants. These observations suggest that there could be a role for therapeutic strategies to overcome the glycosylation defect in these conditions via the overexpression of LARGE.
Collapse
Affiliation(s)
- Francesco Muntoni
- Department of Neuroscience, Dubowitz Neuromuscular Centre, UCL Institute of Child Health & Great Ormond Street Hospital, London, United Kingdom.
| | | | | |
Collapse
|
47
|
Abstract
The collagen VI-related myopathies comprise two major forms, Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD), which show a variable combination of muscle wasting and weakness, joint contractures, distal laxity, and respiratory compromise. Specific diagnosis requires molecular genetic testing showing mutation in one of the three genes involved. This review summarizes current treatments, in particular indication for physiotherapy, orthopedic treatment for correction of foot deformity, scoliosis, and flexion contractures of elbows, and treatment of respiratory failure. The turning point in basic research on collagen VI myopathies was the discovery of an unexpected mitochondrial dysfunction as a pathogenetic mechanism underlying the myopathic syndrome seen in Col6a1 null mice. Treatment of Col6a1(-/-) mice with cyclosporin A (CsA) rescued the mitochondrial dysfunction and decreased apoptosis. Similar mitochondrial defects were revealed in cultures of UCMD patients. The results of an open pilot trial with CsA in five patients with collagen VI-related myopathies are summarized and discussed. With the availability of new potential effective treatments, several challenges must be addressed in conducting trials in orphan diseases and in neuromuscular disorders in particular. Outcome measures are discussed in the context of the expected effect of the cure. Randomized clinical trials often are not feasible for rare diseases, and sometimes would be ethically inappropriate. The need to develop alternative outcome measures or biomarkers using platforms such as genomics and proteomics is stressed in this context.
Collapse
Affiliation(s)
- Luciano Merlini
- Laboratory of Myology, Department of Medical Genetics, University of Ferrara, Ferrara, Italy.
| | | |
Collapse
|
48
|
Ravindra BS, Desai N, Deviprasad S, Bhede V, Ravat S, Sawant P. Myotonic dystrophy in a patient of celiac disease: a new association? Trop Gastroenterol 2008; 29:114-115. [PMID: 18972777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Celiac disease (CD) has long been known to be associated with neurological and psychiatric manifestations; its in association with myotonic dystrophy however has not yet been reported. We report the case of a 27-year old female patient who presented to us with diarrhoea, weight loss, easy fatigability, irritability and alopecia of 8 months duration and was diagnosed to have celiac disease and put on gluten free diet. 8 weeks later she developed neurological symptoms and was found to have myotoni dystrophy in addition. At six month follow up patient had gained 5 kg, but the neurological symptoms remained the same. Treatment of neurological symptoms associated with gluten hypersensitivity depends on the type of neurological syndrome associated. Only exceptionally do these symptoms improve with gluten restriction and, in some patients, the neurological manifestations even progress despite resolution of both pathologic findings and intestinal symptoms.
Collapse
Affiliation(s)
- B S Ravindra
- Department of Gastroenterology, Lokmanya Tilak Medical College & Hospital, Mumbai, India
| | | | | | | | | | | |
Collapse
|
49
|
|
50
|
Noppers IM, Nieuwenhuis JA, Bremmer R, Huisman G, Wijkstra PJ, Zijlstra JG. [Respiratory insufficiency in patients with progressive neuromuscular disease can sometimes be treated effectively with ventilatory support]. Ned Tijdschr Geneeskd 2007; 151:1861-4. [PMID: 17902557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Three patients with myotonic dystrophy (MD) developed respiratory failure. The first was a 55-year-old man with MD who had been admitted elsewhere with pneumonia and respiratory failure. After discharge he was re-admitted with respiratory failure due to respiratory pump failure. Ultimately, he was given a tracheostomy and was ventilated during the night. The second patient was a 38-year-old man who was admitted to the intensive care unit when he could not be weaned off the ventilator following cholecystectomy for symptomatic gall stones. It appeared that he had partial respiratory failure due to MD and overweight. Ultimately he was able to be weaned during the day with nightly non-invasive ventilation. The third patient was a 55-year-old woman who was admitted with recurrent pneumonia and respiratory failure. She appeared to have chronic respiratory failure due to MD. She was ventilated at night via a tracheostomy. All three patients reported a gradual decline in physical and mental performance in the years preceding this acute episode. All three experienced a remarkable recovery of performance after the institution of mechanical ventilatory support. Respiratory failure that develops over a number of years can be easily missed in aging patients with slowly progressing neuromuscular disease. Timely recognition may lead to improved survival and quality of life by the application of non-invasive ventilatory support.
Collapse
Affiliation(s)
- I M Noppers
- Universitair Medisch Centrum Groningen, Postbus 30.001, 9700 RB Groningen
| | | | | | | | | | | |
Collapse
|