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Neuroepidemiology 2022Myotonic dystrophy (DM), the most common muscular dystrophy in adults, is a group of autosomal inherited neuromuscular disorders characterized by progressive muscle... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Myotonic dystrophy (DM), the most common muscular dystrophy in adults, is a group of autosomal inherited neuromuscular disorders characterized by progressive muscle weakness, myotonia, and cardiac conduction abnormalities. Due to the different gene mutations, DM has been subclassified into DM type 1 (DM1) and type 2 (DM2). However, the prevalence studies on DM and its subtypes are insufficient.
METHODS
The PubMed (1966-2022), MEDLINE (1950-2022), Web of Science (1864-2022), and Cochrane Library (2022) databases were searched for original research articles published in English. The quality of the included studies was assessed by a checklist adapted from Strengthening the Reporting of Observational studies in Epidemiology. To derive the pooled epidemiological prevalence estimates, a meta-analysis was performed using the random-effects model. Heterogeneity was assessed using the Cochrane Q statistic and the I2 statistic.
RESULTS
A total of 17 studies were included in the systematic review and meta-analysis. Of the 17 studies evaluated, 14 studies were considered medium quality, 2 studies were considered high quality, and 1 study was considered low quality. The global prevalence of DM varied widely from 0.37 to 36.29 cases per 100,000. The pooled estimate of the prevalence of DM was 9.99 cases (95% CI: 5.62-15.53) per 100,000. The pooled estimate of the prevalence of DM1 was 9.27 cases (95% CI: 4.73-15.21) per 100,000, ranging from 0.37 to 36.29 cases per 100,000. The pooled estimate of the prevalence of DM2 was 2.29 cases (95% CI: 0.17-6.53) per 100,000, ranging from 0.00 to 24.00 cases per 100,000.
CONCLUSION
Our study provided accurate estimates of the prevalence of DM. The high heterogeneity and the lack of high-quality studies highlight the need to conduct higher quality studies on orphan diseases.
Topics: Adult; Humans; Myotonic Dystrophy; Prevalence
PubMed: 35483324
DOI: 10.1159/000524734 -
Neurological Sciences : Official... Apr 2017Myotonic dystrophy (DM) is the most common adult muscular dystrophy, characterized by autosomal dominant progressive myopathy, myotonia, and multiorgan involvement. To... (Review)
Review
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 in two different genes have been identified: myotonic dystrophy type 1 (DM1) and myotonic dystrophy type 2 (DM2). Aberrant transcription and mRNA processing of multiple genes due to RNA-mediated toxic gain-of function has been suggested to cause the complex phenotype in DM1 and DM2. However, despite clinical and genetic similarities, DM1 and DM2 may be considered as distinct disorders. This review is an update on the latest findings specific to DM2, including explanations for the differences in clinical manifestations and pathophysiology between the two forms of myotonic dystrophies.
Topics: Animals; Humans; Myotonic Dystrophy
PubMed: 28078562
DOI: 10.1007/s10072-016-2805-5 -
International Journal of Molecular... Nov 2021Myotonic dystrophy type 1 (DM1), the most common muscular dystrophy affecting adults and children, is a multi-systemic disorder affecting skeletal, cardiac, and smooth... (Review)
Review
Myotonic dystrophy type 1 (DM1), the most common muscular dystrophy affecting adults and children, is a multi-systemic disorder affecting skeletal, cardiac, and smooth muscles as well as neurologic, endocrine and other systems. This review is on the cardiac pathology associated with DM1. The heart is one of the primary organs affected in DM1. Cardiac conduction defects are seen in up to 75% of adult DM1 cases and sudden death due to cardiac arrhythmias is one of the most common causes of death in DM1. Unfortunately, the pathogenesis of cardiac manifestations in DM1 is ill defined. In this review, we provide an overview of the history of cardiac studies in DM1, clinical manifestations, and pathology of the heart in DM1. This is followed by a discussion of emerging data about the utility of cardiac magnetic resonance imaging (CMR) as a biomarker for cardiac disease in DM1, and ends with a discussion on models of cardiac RNA toxicity in DM1 and recent clinical guidelines for cardiologic management of individuals with DM1.
Topics: Animals; Humans; Muscles; Myotonic Dystrophy
PubMed: 34769305
DOI: 10.3390/ijms222111874 -
International Journal of Molecular... Sep 2019Circular RNAs (circRNAs) are a class of single-stranded covalently closed RNA rings. Biogenesis of circRNAs, which may occur co-transcriptionally and... (Review)
Review
Circular RNAs (circRNAs) are a class of single-stranded covalently closed RNA rings. Biogenesis of circRNAs, which may occur co-transcriptionally and post-transcriptionally via a back-splicing mechanism, requires the presence of complementary and/or inverted repeat sequences in introns flanking back-spliced exons and is facilitated by RNA-binding proteins. CircRNAs are abundant across eukaryotes; however, their biological functions remain largely speculative. Recently, they have been emerging as new members of a gene regulatory network and contributing factors in various human diseases including cancer, neurological, muscular and cardiovascular disorders. In this review, we present an overview of the current knowledge about circRNAs biogenesis and their aberrant expression in various human disorders. In particular, we focus on the latest discovery of circRNAs global upregulation in myotonic dystrophy type 1 (DM1) skeletal muscles and the role these prospective biomarkers might have for prognosis and therapeutic response in DM1.
Topics: Alternative Splicing; Animals; Biomarkers; Disease Susceptibility; Gene Expression Regulation; Humans; Myotonic Dystrophy; RNA, Circular; RNA-Binding Proteins
PubMed: 31500099
DOI: 10.3390/ijms20184385 -
Drug Discovery Today Nov 2017Myotonic dystrophy type 1 (DM1) is a rare multisystemic neuromuscular disorder caused by expansion of CTG trinucleotide repeats in the noncoding region of the DMPK gene.... (Review)
Review
Myotonic dystrophy type 1 (DM1) is a rare multisystemic neuromuscular disorder caused by expansion of CTG trinucleotide repeats in the noncoding region of the DMPK gene. Mutant DMPK transcripts are toxic and alter gene expression at several levels. Chiefly, the secondary structure formed by CUGs has a strong propensity to capture and retain proteins, like those of the muscleblind-like (MBNL) family. Sequestered MBNL proteins cannot then fulfill their normal functions. Many therapeutic approaches have been explored to reverse these pathological consequences. Here, we review the myriad of small molecules that have been proposed for DM1, including examples obtained from computational rational design, HTS, drug repurposing, and therapeutic gene modulation.
Topics: Animals; Drug Design; Drug Repositioning; Gene Expression Regulation; High-Throughput Screening Assays; Humans; Myotonic Dystrophy; Myotonin-Protein Kinase; Trinucleotide Repeats
PubMed: 28780071
DOI: 10.1016/j.drudis.2017.07.011 -
JAMA Apr 2024
Topics: Humans; Mutation; Myotonic Dystrophy
PubMed: 38466298
DOI: 10.1001/jama.2024.2511 -
Neuromuscular Disorders : NMD May 2022Abnormalities of sleep are common in myotonic dystrophy type 1 (DM1), but few previous studies have combined polysomnography with detailed clinical measures and brain...
Abnormalities of sleep are common in myotonic dystrophy type 1 (DM1), but few previous studies have combined polysomnography with detailed clinical measures and brain imaging. In the present study, domiciliary polysomnography, symptom questionnaires and cognitive evaluation were undertaken in 39 DM1-affected individuals. Structural brain MRI was completed in those without contra-indication (n = 32). Polysomnograms were adequate for analysis in 36 participants. Sleep efficiency was reduced, and sleep architecture altered in keeping with previous studies. Twenty participants (56%) had moderate or severe sleep-disordered breathing (apnoea-hypopnoea index [AHI] ≥ 15). In linear modelling, apnoeas were positively associated with increasing age and male sex. AHI ≥ 15 was further associated with greater daytime pCO and self-reported physical impairment, somnolence and fatigue. Percentage REM sleep was inversely associated with cerebral grey matter volume, stage 1 sleep was positively associated with occipital lobe volume and stage 2 sleep with amygdala volume. Hippocampus volume was positively correlated with self-reported fatigue and somnolence. Linear relationships were also observed between measures of sleep architecture and cognitive performance. Findings broadly support the hypothesis that changes in sleep architecture and excessive somnolence in DM1 reflect the primary disease process in the central nervous system.
Topics: Disorders of Excessive Somnolence; Fatigue; Humans; Male; Myotonic Dystrophy; Sleep; Sleepiness
PubMed: 35361525
DOI: 10.1016/j.nmd.2022.02.003 -
Neurotherapeutics : the Journal of the... Oct 2018Myotonic dystrophy is an autosomal dominant muscular dystrophy not only associated with muscle weakness, atrophy, and myotonia but also prominent multisystem... (Review)
Review
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.
Topics: Animals; Disease Management; Humans; Mutation; Myotonic Dystrophy; Myotonin-Protein Kinase; RNA-Binding Proteins
PubMed: 30341596
DOI: 10.1007/s13311-018-00679-z -
Current Opinion in Neurology Oct 2023Myotonic dystrophy type 2 (DM2) is a genetic disorder belonging to the spectrum of myotonic dystrophies. DM2 is characterized by progressive muscle weakness, wasting and... (Review)
Review
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.
Topics: Humans; Myotonic Dystrophy; Affect; Autoimmune Diseases; Perception; Diabetes Mellitus, Type 2
PubMed: 37639480
DOI: 10.1097/WCO.0000000000001186 -
Archives of Oral Biology Mar 2017Steinert syndrome, also called myotonic dystrophy type 1, is a genetic disorder with autosomal dominant transmission characterized by myotonia and a multisystemic... (Review)
Review
Steinert syndrome, also called myotonic dystrophy type 1, is a genetic disorder with autosomal dominant transmission characterized by myotonia and a multisystemic clinical picture that affects several tissues of the human body. The most common systemic phenotypes are: muscular, cardiac, respiratory, CNS, ocular, gynecological, digestive, orthopedical, as well as cognitive and psychological symptoms (cognitive decline). Muscles involved in voluntary movement are highly affected by myotonia especially distal muscles of upper limbs. These patients also show changes in face, chewing and pharynx muscles that can lead to swallowing and speech problems, dysphagia and in most cases to food aspiration and suffocation. Poor oral hygiene resulting from reduced motor mobility and reduced saliva flux can lead to gingival inflammation and periodontal disease. Other oral manifestations include disturbances at the temporomandibular articulation, dental occlusion changes and reduction in teeth number as a result of caries. Main causes of death are pneumonia and cardiac arrhythmias. The etiopathogeny of this syndrome is still not clear, conditioning the existence of a specific treatment for this disease. Nowadays, treatments consist on the release of the existing symptoms, in an attempt to give a better life quality to patients. It is very important to implement actions that can prevent complications and consequently decrease death. Treatments should be applied in an early stage of the disease. Bronchoscopy and artificial respiration should be used to prevent pneumonia, and regular electrocardiographic monitoring should be done to evaluate defects in the conductive system. Several approaches have been applied to rehabilitate swallowing dysfunction and avoid aspiration like videofluoroscopy, postural techniques and adjustment of diet type. It is the aim of this paper to clarify the ethiology, diagnosis, systemic and oral characteristics of the syndrome, as well as to discuss treatments to be applied according to patients affected organs.
Topics: Deglutition; Deglutition Disorders; Dental Caries; Humans; Mouth Diseases; Myotonic Dystrophy; Oral Health; Oral Hygiene; Periodontal Diseases; Prognosis; Stomatognathic System Abnormalities
PubMed: 28040606
DOI: 10.1016/j.archoralbio.2016.12.008