scholarly journals A 20-year Clinical and Genetic Neuromuscular Cohort Analysis in Lebanon: An International Effort

2021 ◽  
pp. 1-18
Author(s):  
Andre Megarbane ◽  
Sami Bizzari ◽  
Asha Deepthi ◽  
Sandra Sabbagh ◽  
Hicham Mansour ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Muscular Atrophy ◽  
Neuromuscular Disorders ◽  
Cohort Analysis ◽  
Becker Muscular Dystrophy ◽  
Molecular Data ◽  
Motor Neuron Diseases ◽  
Charcot Marie Tooth Disease ◽  
High Prevalence ◽  
Tooth Disease

Background: Clinical and molecular data on the occurrence and frequency of inherited neuromuscular disorders (NMD) in the Lebanese population is scarce. Objective: This study aims to provide a retrospective overview of hereditary NMDs based on our clinical consultations in Lebanon. Methods: Clinical and molecular data of patients referred to a multi-disciplinary consultation for neuromuscular disorders over a 20-year period (1999–2019) was reviewed. Results: A total of 506 patients were diagnosed with 62 different disorders encompassing 10 classes of NMDs. 103 variants in 49 genes were identified. In this cohort, 81.4%of patients were diagnosed with motor neuron diseases and muscular dystrophies, with almost half of these described with spinal muscular atrophy (SMA) (40.3%of patients). We estimate a high SMA incidence of 1 in 7,500 births in Lebanon. Duchenne and Becker muscular dystrophy were the second most frequently diagnosed NMDs (17%of patients). The latter disorders were associated with the highest number of variants (39) identified in this study. A highly heterogeneous presentation of Limb Girdle Muscular Dystrophy and Charcot-Marie-Tooth disease was notably identified. The least common disorders (5.5%of patients) involved congenital, metabolic, and mitochondrial myopathies, congenital myasthenic syndromes, and myotonic dystrophies. A review of the literature for selected NMDs in Lebanon is provided. Conclusions: Our study indicates a high prevalence and underreporting of heterogeneous forms of NMDs in Lebanon- a major challenge with many novel NMD treatments in the pipeline. This report calls for a regional NMD patient registry.

scholarly journals Current Genetic Survey and Potential Gene-Targeting Therapeutics for Neuromuscular Diseases

2020 ◽  
Vol 21 (24) ◽  
pp. 9589
Author(s):  
Wei Chiu ◽  
Ya-Hsin Hsun ◽  
Kao-Jung Chang ◽  
Aliaksandr A. Yarmishyn ◽  
Yu-Jer Hsiao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Muscular Dystrophy ◽  
Motor Neuron ◽  
Muscular Atrophy ◽  
Neuromuscular Disorders ◽  
Neuromuscular Diseases ◽  
Premature Termination Codon ◽  
Becker Muscular Dystrophy ◽  
Functional Impairments ◽  
Motor Neuron Diseases

Neuromuscular diseases (NMDs) belong to a class of functional impairments that cause dysfunctions of the motor neuron-muscle functional axis components. Inherited monogenic neuromuscular disorders encompass both muscular dystrophies and motor neuron diseases. Understanding of their causative genetic defects and pathological genetic mechanisms has led to the unprecedented clinical translation of genetic therapies. Challenged by a broad range of gene defect types, researchers have developed different approaches to tackle mutations by hijacking the cellular gene expression machinery to minimize the mutational damage and produce the functional target proteins. Such manipulations may be directed to any point of the gene expression axis, such as classical gene augmentation, modulating premature termination codon ribosomal bypass, splicing modification of pre-mRNA, etc. With the soar of the CRISPR-based gene editing systems, researchers now gravitate toward genome surgery in tackling NMDs by directly correcting the mutational defects at the genome level and expanding the scope of targetable NMDs. In this article, we will review the current development of gene therapy and focus on NMDs that are available in published reports, including Duchenne Muscular Dystrophy (DMD), Becker muscular dystrophy (BMD), X-linked myotubular myopathy (XLMTM), Spinal Muscular Atrophy (SMA), and Limb-girdle muscular dystrophy Type 2C (LGMD2C).

scholarly journals Barriers and facilitators to clinical trial participation among parents of children with pediatric neuromuscular disorders

2018 ◽  
Vol 15 (2) ◽  
pp. 139-148 ◽  
Author(s):  
Holly L Peay ◽  
Barbara B Biesecker ◽  
Benjamin S Wilfond ◽  
Jill Jarecki ◽  
Kendall L Umstead ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Muscular Dystrophy ◽  
Spinal Muscular Atrophy ◽  
Muscular Atrophy ◽  
Neuromuscular Disorders ◽  
Becker Muscular Dystrophy ◽  
Barriers And Facilitators ◽  
Trial Participation ◽  
Clinical Trial Participation ◽  
Parental Interest

Background/aims: Pediatric rare disease presents a challenging situation of high unmet need and a limited pool of potential clinical trial participants. Understanding perspectives of parents of children who have not participated in trials may facilitate approaches to optimize participation rates. The objective of this study was to explore factors associated with parental interest in enrolling children with pediatric neuromuscular disorders in clinical trials. Methods: Parents of individuals with Duchenne or Becker muscular dystrophy and spinal muscular atrophy were recruited through advocacy organizations, a registry, and clinics. These parents ( N = 203) completed a questionnaire including assessments of barriers and facilitators to clinical trial participation, parents’ interest in trial participation, and their perceptions of others’ views about participation in a clinical trial. Results: Trial interest in participating parents was high (64% combined group). The most highly endorsed barrier to participation was the possibility of receiving placebo, followed by not having enough information on risks and trial procedures. Compared to parents of children with Duchenne or Becker muscular dystrophy, parents of children with spinal muscular atrophy endorsed significantly more information and knowledge barriers. The greatest facilitators of participation were (1) confidence in improving disease understanding and (2) guarantee to receive the treatment after a successful trial. A logistic regression model, χ2 (4, n = 188) = 80.64, p < .001, indicated that higher perceived barriers and more frequent trial communication by the provider were associated with lower interest, while positive trial perceptions by the child’s providers and concordance in trial perceptions among those close to the decision-maker were associated with higher interest. Conclusion: We found high parental interest in pediatric neuromuscular trials that was tempered by concerns about the potential for randomization to a placebo arm. Participants perceived that their trial participation would be facilitated by additional education and guidance from their clinicians. Yet, intentions were negatively associated with frequency of provider communication, perhaps reflecting waning parental interest with a greater understanding of limitations in trial access, increased sophistication in their understanding of trial design, and appreciation of potential burden. To support parents’ informed decisions, it is important to educate them to evaluate the quality of research, as well as providing lay information explaining the use of placebo, trial processes, and potential barriers to long-term drug access. Our findings should inform the development of targeted educational content, clinician training, and decision support tools.

scholarly journals The Ubiquitin Proteasome System in Neuromuscular Disorders: Moving Beyond Movement

2020 ◽  
Vol 21 (17) ◽  
pp. 6429 ◽  
Author(s):  
Sara Bachiller ◽  
Isabel M. Alonso-Bellido ◽  
Luis Miguel Real ◽  
Eva María Pérez-Villegas ◽  
José Luis Venero ◽  
...  
Keyword(s):  
Muscular Atrophy ◽  
Neuromuscular Disorders ◽  
Ubiquitin Proteasome System ◽  
Neuromuscular Disorder ◽  
Enzymatic Reactions ◽  
Protein Homeostasis ◽  
Motor Neuron Diseases ◽  
Charcot Marie Tooth Disease ◽  
Ubiquitin System ◽  
Ubiquitin Proteasome

Neuromuscular disorders (NMDs) affect 1 in 3000 people worldwide. There are more than 150 different types of NMDs, where the common feature is the loss of muscle strength. These disorders are classified according to their neuroanatomical location, as motor neuron diseases, peripheral nerve diseases, neuromuscular junction diseases, and muscle diseases. Over the years, numerous studies have pointed to protein homeostasis as a crucial factor in the development of these fatal diseases. The ubiquitin–proteasome system (UPS) plays a fundamental role in maintaining protein homeostasis, being involved in protein degradation, among other cellular functions. Through a cascade of enzymatic reactions, proteins are ubiquitinated, tagged, and translocated to the proteasome to be degraded. Within the ubiquitin system, we can find three main groups of enzymes: E1 (ubiquitin-activating enzymes), E2 (ubiquitin-conjugating enzymes), and E3 (ubiquitin–protein ligases). Only the ubiquitinated proteins with specific chain linkages (such as K48) will be degraded by the UPS. In this review, we describe the relevance of this system in NMDs, summarizing the UPS proteins that have been involved in pathological conditions and neuromuscular disorders, such as Spinal Muscular Atrophy (SMA), Charcot–Marie–Tooth disease (CMT), or Duchenne Muscular Dystrophy (DMD), among others. A better knowledge of the processes involved in the maintenance of proteostasis may pave the way for future progress in neuromuscular disorder studies and treatments.

scholarly journals Becker muscular dystrophy associated with sarcomeric hypertrophic cardiomyopathy in a paediatric patient: a case report

2019 ◽  
Vol 3 (3) ◽  
Author(s):  
Paola Dolader ◽  
Ella Field ◽  
Anna Sarkozy ◽  
Juan Pablo Kaski
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Muscular Dystrophy ◽  
Neuromuscular Disorders ◽  
Elevated Serum ◽  
Becker Muscular Dystrophy ◽  
Neuromuscular Disorder ◽  
Chain Gene ◽  
Septal Hypertrophy ◽  
History Of ◽  
Myocardial Involvement

Abstract Background  Becker muscular dystrophy (BMD) is a neuromuscular disorder associated with myocardial involvement. The most frequent presentation is dilated cardiomyopathy. There have been isolated reports of hypertrophic cardiomyopathy (HCM) in association with BMD, but it is unclear whether these patients had an additional aetiology. Case summary  A 10-year-old boy was diagnosed with BMD having presented with a history of muscular pain during exercise and elevated serum creatine kinase levels. A cardiac screening was arranged and the echocardiogram confirmed an asymmetric septal hypertrophy. Given the unusual finding of HCM in this patient with BMD, we performed genetic testing for HCM-causing mutations and identified a likely pathogenic variant in heterozygosis in the beta-myosin heavy chain gene. Discussion  This case highlights the importance of considering additional aetiologies of cardiac disease in the presence of infrequent phenotypic expressions in neuromuscular disorders.

Homozygous Expression of a Dominant Gene Causing Peroneal Muscular Atrophy (Charcot-Marie-Tooth Disease)

1974 ◽  
Vol 23 (S1) ◽  
pp. 217-220 ◽  
Author(s):  
H. Warner Kloepfer ◽  
James M. Killian
Keyword(s):  
Clinical Features ◽  
Nerve Conduction ◽  
Peripheral Nerves ◽  
Muscular Atrophy ◽  
Dominant Gene ◽  
Conduction Time ◽  
Charcot Marie Tooth ◽  
Charcot Marie Tooth Disease ◽  
Peroneal Muscular Atrophy ◽  
Tooth Disease

This study involves the presentation of a kindred from Southwestern Louisiana showing 66 individuals who were heterozygous for a rare dominant gene for a type of Charcot-Marie-Tooth disease with hypertrophy of peripheral nerves. Two marriages between heterozygotes resulted in the occurrence of five homozygous offsprings. Clinical features of these previously undescribed homozygotes are compared to the clinical features of the classic type of heterozygote. The value of using nerve-conduction time to detect the asymptomatic heterozygote for Charcot-Marie-Tooth disease is discussed.

scholarly journals Charcot-Marie-Tooth disease type 2S: Case report of a rare form associated with spinal muscular atrophy type IV

2021 ◽  
Vol 12 ◽  
pp. 1-6
Author(s):  
Marco Orsini ◽  
Acary Souza Bulle Oliveira ◽  
Antônio Marcos da Silva Catharino ◽  
Mauricio Sant’ Anna Junior ◽  
Felipe dos Santos Souza ◽  
...  
Keyword(s):  
Case Report ◽  
Spinal Muscular Atrophy ◽  
Muscular Atrophy ◽  
Disease Type ◽  
Rare Form ◽  
Charcot Marie Tooth ◽  
Spinal Muscular Atrophy Type ◽  
Charcot Marie Tooth Disease ◽  
Type Iv ◽  
Tooth Disease

Dystrophinopathy in a Family Due to a Rare Nonsense Mutation Causing Predominant Behavioral Phenotype

2019 ◽  
Vol 18 (04) ◽  
pp. 210-213
Author(s):  
Yohei Harada ◽  
Seth T. Sorensen ◽  
Akilandeswari Aravindhan ◽  
Vikki Stefans ◽  
Aravindhan Veerapandiyan
Keyword(s):  
Intellectual Disability ◽  
Muscular Dystrophy ◽  
Behavioral Problems ◽  
Nonsense Mutation ◽  
Neuromuscular Disorders ◽  
Elevated Serum ◽  
Becker Muscular Dystrophy ◽  
Genetic Changes ◽  
Dmd Gene ◽  
Neurobehavioral Deficits

AbstractDystrophinopathies are a group of X-linked neuromuscular disorders resulting from mutations in DMD gene that encodes dystrophin. The clinical spectrum includes Duchenne muscular dystrophy, Becker muscular dystrophy, X-linked cardiomyopathy, and intellectual disability without involvement of skeletal muscle. Cognitive and behavioral problems are commonly seen among patients with dystrophinopathy. DMD gene is the largest human gene, consisting of 79 exons that produce dystrophin protein. Patients with genetic changes involving shorter dystrophin isoforms such as Dp140 and Dp71 are suggested to have higher rates of intellectual disability, attention-deficit/hyperactivity disorder, and other neuropsychiatric comorbidities. We describe three brothers who presented with prominent neurobehavioral deficits of varying degree, mild proximal weakness, and elevated serum creatine kinase due to a rare nonsense mutation, c.1702C > T; p.Gln568X, in exon 14 of DMD gene. Further studies are needed to better understand the effects of this rare mutation.

scholarly journals The Duchenne muscular dystrophy gene and cancer

2020 ◽  
Author(s):  
Leanne Jones ◽  
Michael Naidoo ◽  
Lee R. Machado ◽  
Karen Anthony
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Protein ◽  
Neuromuscular Disorders ◽  
Becker Muscular Dystrophy ◽  
Gene Products ◽  
Large Gene ◽  
Cancer Types ◽  
And Function ◽  
Dystrophin Protein

Abstract Background Mutation of the Duchenne muscular dystrophy (DMD) gene causes Duchenne and Becker muscular dystrophy, degenerative neuromuscular disorders that primarily affect voluntary muscles. However, increasing evidence implicates DMD in the development of all major cancer types. DMD is a large gene with 79 exons that codes for the essential muscle protein dystrophin. Alternative promotor usage drives the production of several additional dystrophin protein products with roles that extend beyond skeletal muscle. The importance and function(s) of these gene products outside of muscle are not well understood. Conclusions We highlight a clear role for DMD in the pathogenesis of several cancers, including sarcomas, leukaemia’s, lymphomas, nervous system tumours, melanomas and various carcinomas. We note that the normal balance of DMD gene products is often disrupted in cancer. The short dystrophin protein Dp71 is, for example, typically maintained in cancer whilst the full-length Dp427 gene product, a likely tumour suppressor, is frequently inactivated in cancer due to a recurrent loss of 5’ exons. Therefore, the ratio of short and long gene products may be important in tumorigenesis. In this review, we summarise the tumours in which DMD is implicated and provide a hypothesis for possible mechanisms of tumorigenesis, although the question of cause or effect may remain. We hope to stimulate further study into the potential role of DMD gene products in cancer and the development of novel therapeutics that target DMD.

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