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Neuromuscular Disorders : NMD May 2023α-Dystroglycanopathies are a clinically and genetically heterogeneous group of muscular dystrophies associated with the defective glycosylation of α-dystroglycan...
α-Dystroglycanopathies are a clinically and genetically heterogeneous group of muscular dystrophies associated with the defective glycosylation of α-dystroglycan (α-DG). Eighteen genes associated with α-dystroglycanopathies have been identified, and the relative prevalence of genetic subtypes varies with ethnicity. Here, we investigated the clinical and genetic characteristics of α-DG-related muscular dystrophy in the Korean pediatric population. We analyzed the clinical characteristics and variant profiles of 42 patients with α-DG-related muscular dystrophies diagnosed by either reduced glycosylation of α-DG and/or genetic confirmation. Genotype-phenotype correlations were explored by a retrospective medical record review. The muscle-eye-brain disease/Fukuyama congenital muscular dystrophy was the most common phenotype (28/42, 66.7%). Homozygous or compound heterozygous variants were detected in 37 patients belonging to 34 unrelated families (37/42; 88.1%). Pathogenic variants were identified in FKTN (n = 24), POMGNT1 (n = 4), GMPPB (n = 4), FKRP (n = 2), POMT1 (n = 2), and ISPD (n = 1). Compound heterozygous retrotransposal insertions and deep-intronic variants in FKTN were the most common genotypes and were associated with severe phenotypes. This study suggests that α-DG-related muscular dystrophy has a wide range of genotypes and phenotypes according to ethnicity. A stratified genetic test according to ethnicity should be considered to diagnose α-DG-related muscular dystrophy.
Topics: Child; Humans; Dystroglycans; Walker-Warburg Syndrome; Retrospective Studies; Muscular Dystrophies; Genotype; Phenotype; Mutation; Republic of Korea; Pentosyltransferases
PubMed: 37087885
DOI: 10.1016/j.nmd.2023.03.009 -
Disease Models & Mechanisms Feb 2020Muscular dystrophies (MDs) encompass a wide variety of inherited disorders that are characterized by loss of muscle tissue associated with a progressive reduction in... (Review)
Review
Muscular dystrophies (MDs) encompass a wide variety of inherited disorders that are characterized by loss of muscle tissue associated with a progressive reduction in muscle function. With a cure lacking for MDs, preclinical developments of therapeutic approaches depend on well-characterized animal models that recapitulate the specific pathology in patients. The mouse is the most widely and extensively used model for MDs, and it has played a key role in our understanding of the molecular mechanisms underlying MD pathogenesis. This has enabled the development of therapeutic strategies. Owing to advancements in genetic engineering, a wide variety of mouse models are available for the majority of MDs. Here, we summarize the characteristics of the most commonly used mouse models for a subset of highly studied MDs, collated into a table. Together with references to key publications describing these models, this brief but detailed overview would be useful for those interested in, or working with, mouse models of MD.
Topics: Animals; Disease Models, Animal; Gene Targeting; Mice; Muscular Dystrophies
PubMed: 32224495
DOI: 10.1242/dmm.043562 -
Trends in Cell Biology Jan 2019The past decade has seen incredible advances in the field of stem cell biology that have greatly improved our understanding of development and provided important... (Review)
Review
The past decade has seen incredible advances in the field of stem cell biology that have greatly improved our understanding of development and provided important insights into pathological processes. Transcription factors (TFs) play a central role in mediating stem cell proliferation, quiescence, and differentiation. One TF that contributes to these processes is Nuclear Factor One X (NFIX). Recently, NFIX activity has been shown to be essential in multiple organ systems and to have important translational impacts for human health. Here, we describe recent studies showing the contribution of NFIX to muscle development and muscular dystrophies, hematopoiesis, cancer, and neural stem cell biology, highlighting the importance of this knowledge in the development of therapeutic targets.
Topics: Animals; Hematopoiesis; Humans; Muscle Development; Muscular Dystrophies; NFI Transcription Factors; Neoplasms; Neural Stem Cells
PubMed: 30287093
DOI: 10.1016/j.tcb.2018.09.003 -
International Journal of Molecular... Oct 2022Muscular dystrophies are a group of genetic muscular diseases characterized by impaired muscle regeneration, which leads to pathological inflammation that drives muscle... (Review)
Review
Muscular dystrophies are a group of genetic muscular diseases characterized by impaired muscle regeneration, which leads to pathological inflammation that drives muscle wasting and eventually results in weakness, functional dependency, and premature death. The most known causes of death include respiratory muscle failure due to diaphragm muscle decay. There is no definitive treatment for muscular dystrophies, and conventional therapies aim to ameliorate muscle wasting by promoting physiological muscle regeneration and growth. However, their effects on muscle function remain limited, illustrating the requirement for major advancements in novel approaches to treatments, such as nanomedicine. Nanomedicine is a rapidly evolving field that seeks to optimize drug delivery to target tissues by merging pharmaceutical and biomedical sciences. However, the therapeutic potential of nanomedicine in muscular dystrophies is poorly understood. This review highlights recent work in the application of nanomedicine in treating muscular dystrophies. First, we discuss the history and applications of nanomedicine from a broader perspective. Second, we address the use of nanoparticles for drug delivery, gene regulation, and editing to target Duchenne muscular dystrophy and myotonic dystrophy. Next, we highlight the potential hindrances and limitations of using nanomedicine in the context of cell culture and animal models. Finally, the future perspectives for using nanomedicine in clinics are summarized with relevance to muscular dystrophies.
Topics: Animals; Muscle, Skeletal; Muscles; Muscular Atrophy; Muscular Dystrophy, Duchenne; Myotonic Dystrophy; Nanomedicine; Pharmaceutical Preparations
PubMed: 36233338
DOI: 10.3390/ijms231912039 -
Seizure Oct 2021Epilepsy is a common, often severe, feature of LAMA2-related muscular dystrophy (LAMA2-RD) and could represent its onset and main manifestation, even in the absence of... (Review)
Review
Epilepsy is a common, often severe, feature of LAMA2-related muscular dystrophy (LAMA2-RD) and could represent its onset and main manifestation, even in the absence of overt muscle involvement. To date, there is no systematic characterization of epilepsy in LAMA2-RD, and its impact on neurodevelopment and on the clinical course remains poorly established. In view of this knowledge gap, we conducted a systematic review of the literature and, as an illustrative example, reported the clinical case of a boy with late-onset LAMA2-related limb-girdle muscular dystrophy presenting with severe epilepsy. Our analyses of the literature data revealed a mean age at first seizure of 8 years, with significant differences between early- versus late-onset disease (5.78 ± 4.11 and 9.00 ± 2.65 years, respectively; p = 0.0007), and complete versus partial merosin deficiency (5.33 ± 3.70 and 10.36 ± 5.49 years, respectively; p = 0.0176). A generalized onset was the most common seizure presentation, regardless of merosin expression levels or the timing of muscular distrophy onset. Cortical malformations were not significantly associated with an earlier epilepsy onset, and were found to be quasi-significantly associated with a greater incidence of focal, or focal and generalized, onset seizures. No clear conclusions could be reached on the electrophysiological and neurodevelopmental features of the disorder, or on the relative efficacy of anti-epileptic treatments; further research on these aspects is needed. This systematic review helps to show that epilepsy in LAMA2-RD may be more than an ancillary manifestation of the disease, but rather one of its core features. A targeted and prompt electroencephalographic and epilepsy assessment, in addition to the specific neuromuscular workup, is therefore mandatory in early clinical management to pursue the best possible outcome for affected children.
Topics: Child; Electroencephalography; Epilepsy; Humans; Laminin; Male; Muscular Dystrophies; Muscular Dystrophies, Limb-Girdle
PubMed: 34325301
DOI: 10.1016/j.seizure.2021.07.020 -
International Journal of Molecular... May 2024Dysferlin is a large transmembrane protein involved in critical cellular processes including membrane repair and vesicle fusion. Mutations in the dysferlin gene () can... (Review)
Review
Dysferlin is a large transmembrane protein involved in critical cellular processes including membrane repair and vesicle fusion. Mutations in the dysferlin gene () can result in rare forms of muscular dystrophy; Miyoshi myopathy; limb girdle muscular dystrophy type 2B (LGMD2B); and distal myopathy. These conditions are collectively known as dysferlinopathies and are caused by more than 600 mutations that have been identified across the gene to date. In this review, we discuss the key molecular and clinical features of LGMD2B, the causative gene , and the associated dysferlin protein structure. We also provide an update on current approaches to LGMD2B diagnosis and advances in drug development, including splice switching antisense oligonucleotides. We give a brief update on clinical trials involving adeno-associated viral gene therapy and the current progress on CRISPR/Cas9 mediated therapy for LGMD2B, and then conclude by discussing the prospects of antisense oligomer-based intervention to treat selected mutations causing dysferlinopathies.
Topics: Humans; Muscular Dystrophies, Limb-Girdle; Dysferlin; Genetic Therapy; Mutation; Oligonucleotides, Antisense; Animals
PubMed: 38891760
DOI: 10.3390/ijms25115572 -
Journal of Clinical Neuromuscular... Mar 2018COL6A and LAMA2 are subtypes of congenital muscular dystrophy.
OBJECTIVES
COL6A and LAMA2 are subtypes of congenital muscular dystrophy.
METHODS
Retrospective chart review of clinical findings, spirometry, muscle histology, muscle ultrasound, neuroimaging, and Electromyography (EMG)/Nerve Conduction Study data in genetically confirmed COL6A and LAMA2 subjects.
RESULTS
We identified 8 COL6A and 6 LAMA2 subjects: the female-to-male ratio was 1.3:1 and the mean age was 11.9 ± 3.6 years. Gross motor delays since birth, proximal muscle weakness, and contractures were noted in both groups. Joint hyperlaxity and skin changes (follicular hyperkeratosis and muscle biopsy scar thinning) were unique to COL6A. Severe scoliosis, macrocephaly, and nonambulatory status were common in LAMA2. Increasing age was associated with poor respiratory function in COL6A. There was central "cloud appearance" on rectus femoris muscle ultrasound in COL6A and white matter T2 hyperintensity on brain magnetic resonance imaging in LAMA2. LAMA2 also showed demyelinating polyneuropathy. Neurogenic changes on EMG and muscle histology were noted in 37% and 33% of COL6A cases, respectively.
CONCLUSIONS
COL6A has unique skin changes, central cloud appearance on muscle ultrasound. LAMA2 has demyelinating polyneuropathy and white matter changes on brain imaging. The presence of neurogenic changes on EMG and muscle histology in COL6A suggests motor axonal neuropathy. Genetic testing remains the gold standard in confirming COL6A congenital muscular dystrophy.
Topics: Action Potentials; Adolescent; Child; Collagen Type VI; Electromyography; Female; Genetic Testing; Humans; Laminin; Male; Muscle, Skeletal; Muscular Dystrophies; Mutation; Neural Conduction; Neuroimaging; Retrospective Studies
PubMed: 29465610
DOI: 10.1097/CND.0000000000000198 -
Perceptual and Motor Skills Apr 2017The aim of this study was to investigate the relationship between Performance of Upper Limb (PUL) and Jebsen-Taylor Test (JTT) to assess and monitor upper limb function...
The aim of this study was to investigate the relationship between Performance of Upper Limb (PUL) and Jebsen-Taylor Test (JTT) to assess and monitor upper limb function progression in patients with muscular dystrophy. Thirty patients diagnosed with Duchenne muscular dystrophy, limb-girdle muscular dystrophy, Becker muscular dystrophy, myotonic dystrophy Type 1, and fascioscapulohumeral dystrophy were submitted to the shoulder, elbow, and wrist domains of PUL, and to JTT subtests. Spearman tests investigated the relationships between PUL and JTT total scores and domains. Correlations were classified as strong ( r ≥ 0.70), moderate (0.40 ≤ r < 0.70), or weak ( r ≤ 0.40). There were strong correlations between the PUL and JTT total scores ( r = -0.706). Although JTT measures time and PUL provides kinesiologic scores, these measures were related. Therefore, muscle synergies, which control the compensatory movements and motor functions involving mainly shoulder, elbow, wrist, and finger movements, are related to timed performance in patients with muscular dystrophies.
Topics: Adolescent; Adult; Child; Cross-Sectional Studies; Exercise Test; Female; Humans; Male; Middle Aged; Muscular Dystrophies; Reproducibility of Results; Upper Extremity; Young Adult
PubMed: 28361653
DOI: 10.1177/0031512516688834 -
Acta Myologica : Myopathies and... Oct 2016Although the presence of cognitive deficits in Duchenne muscular dystrophy or myotonic dystrophy DM1 is well established in view of brain-specific expression of affected... (Review)
Review
Although the presence of cognitive deficits in Duchenne muscular dystrophy or myotonic dystrophy DM1 is well established in view of brain-specific expression of affected muscle proteins, in other neuromuscular disorders, such as congenital myopathies and limb-girdle muscular dystrophies, cognitive profiles are poorly defined. Also, there are limited characterization of the cognitive profile of children with congenital muscular dystrophies, notwithstanding the presence of cerebral abnormality in some forms, and in spinal muscular atrophies, with the exception of distal spinal muscular atrophy (such as the DYN1CH1- associated form). Starting from the Duchenne muscular dystrophy, which may be considered a kind of paradigm for the co-occurrence of learning disabilities in the contest of a progressive muscular involvement, the findings of neuropsychological (or cognitive) dysfunctions in several forms of neuromuscular diseases will be examined and reviewed.
Topics: Humans; Intellectual Disability; Learning Disabilities; Muscular Diseases; Muscular Dystrophies; Muscular Dystrophies, Limb-Girdle; Muscular Dystrophy, Duchenne; Myotonic Dystrophy; Spinal Muscular Atrophies of Childhood
PubMed: 28344438
DOI: No ID Found -
Neurodegenerative Disease Management Oct 2021Limb-girdle muscular dystrophies (LGMDs) represent a major group of muscle disorders. Treatment is sorely needed and currently expanding based on safety and efficacy... (Review)
Review
Limb-girdle muscular dystrophies (LGMDs) represent a major group of muscle disorders. Treatment is sorely needed and currently expanding based on safety and efficacy adopting principles of single-dosing gene therapy for monogenic autosomal recessive disorders. Gene therapy has made in-roads for LGMD and this review describes progress that has been achieved for these conditions. This review first provides a background on the definition and classification of LGMDs. The major effort focuses on progress in LGMD gene therapy, from experimental studies to clinical trials. The disorders discussed include the LGMDs where the most work has been done including calpainopathies (LGMD2A/R1), dysferlinopathies (LGMD2B/R2) and sarcoglycanopathies (LGMD2C/R5, LGMD2D/R3, LGMD2E/R4). Early success in clinical trials provides a template to move the field forward and potentially apply emerging technology like CRISPR/Cas9 that may enhance the scope and efficacy of gene therapy applied to patient care.
Topics: Humans; Muscular Dystrophies, Limb-Girdle; Sarcoglycanopathies
PubMed: 34472379
DOI: 10.2217/nmt-2020-0066