Search Results (572)

Skeletal muscle is vital for movement and metabolism, and its dysfunction underpins disorders like muscular dystrophy and sarcopenia, severely impacting life quality. In these diseases, various cell death pathways are pivotal, driving core pathological features such as fiber loss and chronic inflammation. This study reviews the central role of cell death in skeletal muscle diseases, and analyzes its roles and mechanisms in genetic muscle disorders such as Duchenne muscular dystrophy (DMD), glycogen storage diseases (GSD), mitochondrial myopathies, as well as acquired muscle disorders such as idiopathic inflammatory myopathy, sarcopenia, rhabdomyolysis, and myasthenia gravis (MG). We also explore the potential of cell death-related molecules as biomarkers and discuss emerging therapeutic strategies that target these pathways, aiming to provide new insights for diagnosis and treatment. Full article

Duchenne muscular dystrophy (DMD) is a fatal X-linked neuromuscular disorder caused by mutations in the dystrophin gene. Prime editing is a versatile genome editing technology capable of introducing precise nucleotide changes without generating double-strand DNA breaks, making it a promising approach for correcting pathogenic point mutations. In this study, we applied prime editing to modify mdx-4cv and mdx-5cv mutation-equivalent sites in mouse C2C12 myoblasts in vitro. Initial editing efficiencies were unexpectedly low and were associated with the presence of a 5′-TTCT-3′ motif within engineered prime editing guide RNAs (epegRNAs). epegRNA designs containing this motif exhibited reduced prime editing efficiency, whereas silent substitution eliminating the motif significantly improved editing outcomes, indicating that specific sequence features within epegRNAs can influence editing performance. Rational redesign of epegRNAs to remove this motif substantially enhanced editing efficiency, achieving up to 20% modification at the 4cv target site using an NGG PAM and 21% editing at the 5cv locus using an NGAG PAM. These findings highlight an important sequence-dependent constraint in epegRNA design and provide practical guidance for optimizing prime editing strategies targeting Dmd mutations in vitro. Full article

Background: Cardiomyopathy is a major cause of morbidity and mortality in Duchenne muscular dystrophy (DMD). We evaluated whether N-terminal pro–brain natriuretic peptide (NT-proBNP) identifies severe systolic dysfunction and assessed its diagnostic performance. Methods: Male patients with genetically confirmed DMD and established cardiomyopathy were included if NT-proBNP measurement and echocardiographic ejection fraction (EF) were available within one month. Severe systolic dysfunction was defined as EF < 40%. Clinical, cardiac, and respiratory variables were analysed. ROC analysis with bootstrap validation and exploratory logistic regressions was performed. Results: NT-proBNP levels were significantly higher in patients with EF < 40% (median 843 vs. 81 pg/mL). A cut-off >200 pg/mL identified severe systolic dysfunction with 90.5% sensitivity and 90.9% specificity (AUC 0.96, 95% CI 0.88–1.00). During 24 months of follow-up, five deaths occurred. NT-proBNP showed moderate discrimination for mortality (AUC 0.79) and was associated with mortality in exploratory analysis. Conclusions: NT-proBNP was associated with severe systolic dysfunction in Duchenne cardiomyopathy and may complement imaging. Prospective validation is warranted. Full article

Venous thromboembolism (VTE), comprising deep vein thrombosis and pulmonary embolism, is an important but under-recognised complication in neuromuscular diseases. In adults, emerging epidemiological data suggests increased VTE occurrence in conditions such as Amyotrophic Lateral Sclerosis, myotonic dystrophy, myasthenia gravis, inflammatory neuropathies, inflammatory myopathies, and POEMS syndrome. This heightened risk reflects not only disease-related immobility but also disorder-specific biological mechanisms, including inflammation, endothelial dysfunction and cardiomyopathy-related stasis. Therapies such as corticosteroids, IVIG-related hyperviscosity, long-term central venous access, perioperative immobility, critical illness, and complex orthopaedic procedures have prothrombotic effects. Despite this multifactorial risk profile, disease-specific guidance for thromboprophylaxis is lacking, and current practice relies heavily on extrapolation from general medical and surgical recommendations rather than data derived from neuromuscular cohorts. In children and adolescents, the VTE burden is less well-characterised, but events have been reported in Duchenne and Becker muscular dystrophy, congenital myopathies, and spinal muscular atrophy particularly with advanced motor impairment, severe cardiomyopathy, ventilatory insufficiency, and prolonged hospitalisation. Beyond venous events, selected neuromuscular disorders also exhibit increased arterial thrombosis risk. Myotonic dystrophy and dystrophinopathies are associated with cardiomyopathy and arrhythmia that predispose to systemic embolism and stroke, while inflammatory myopathies may demonstrate arterial events related to vasculitic or endothelial processes, although overall evidence remains limited. This review summarises available empirical and epidemiological evidence on venous and arterial thrombosis across adult and paediatric neuromuscular disorders, outlines disease-specific mechanistic pathways, examines treatment-related contributors, and highlights key evidence gaps that must be addressed to guide rational and targeted prophylaxis strategies in this complex, heterogeneous population. Full article

The dystrophin gene encodes multiple dystrophin isoforms with tissue-specific functions, including several shorter isoforms expressed in the central nervous system and retina. While Duchenne muscular dystrophy (DMD) has historically been characterized as a primary myopathy resulting from loss of the full-length dystrophin Dp427, increasing clinical evidence indicates that dysfunction of shorter dystrophin isoforms contributes to significant extramuscular pathology, including retinal disease. In particular, loss of the Dp71 isoform has been implicated in retinal inflammation, blood–retinal barrier breakdown, and pathological angiogenesis. In this study, we investigated whether low-level residual expression of Dp71 is sufficient to mitigate retinal inflammation in the mdx3Cv mouse model, which displays reduced—but not absent—expression of multiple dystrophin isoforms. Western blot analysis revealed that mdx3Cv retinas express approximately 4% of wild-type Dp71 protein levels. Despite this marked reduction, mdx3Cv mice did not exhibit the inflammatory phenotype previously observed in Dp71-null mice. Retinal VEGF protein levels and VEGF receptor (FLT-1 and KDR) mRNA expression were preserved, while VEGF mRNA levels were modestly reduced. Furthermore, expression of inflammatory markers ICAM-1 and ALOX5AP, leukocyte adhesion to retinal vasculature, Aquaporin-4 expression, and BRB permeability to albumin were all comparable to wild-type littermates. Together, these findings demonstrate that minimal residual expression of Dp71 is sufficient to preserve retinal vascular homeostasis and prevent inflammatory and permeability defects in the mdx3Cv retina. These results further suggest that partial dystrophin restoration—at levels achievable with current exon-skipping or gene-based therapies—may be adequate to prevent or attenuate retinal pathology in DMD, providing a realistic and clinically relevant therapeutic target. Full article

Background: Duchenne muscular dystrophy (DMD) is a rare, disabling, and life-threatening X-linked recessive disorder caused by mutations in the dystrophin gene. The current standard of care is treatment with corticosteroids, which aim to decrease inflammation-induced muscle damage and delay disease progression. Here, we aim to describe clinical, genetic, and diagnostic characteristics and evaluate current management practices of DMD patients in the Kingdom of Saudi Arabia (KSA). Methods: This was an ambispective (prospective and retrospective) observational multicenter study evaluating characteristics of patients aged 1–14 years with genetically confirmed DMD in the KSA. The variables of interest were demographics, genetic mutations, clinical characteristics, and initial management. The relationship between the age at diagnosis, initial management plan (standard of care), and age at initiation of treatment on disease outcomes was also evaluated. Results: A total of 226 patients (181 in the retrospective part and 45 in the prospective part) were enrolled. The most common type of genetic mutation was large deletions (134 patients, 59.3%). The median age of first symptom was 2.7 years (IQR: 2.0–4.6 years) and the median age at diagnosis was 7.0 years (IQR: 4.8–8.5 years). Among these patients, the most common initial symptoms were difficulty in walking (87.7%) and waddling gait (41%). The initial management plan for DMD patients involved medication (75.6%) and physical therapy (71.0%). The most frequently prescribed initial medications were vitamin D (82%) and corticosteroids (62.3%). In total, 6/226 patients (2.6%) received ataluren; they all had identified nonsense mutations. The median age of corticosteroid initiation was 7.1 years (IQR: 5.7–8.7). The median age at loss of ambulation (LoA) was 9.8 years (IQR: 8.0–11.4 years) in the non-treated patients; it was 10.1 years (IQR: 9.3–11.2 years) in the steroid-only group and 10.8 years (10.8, 10.8) in the combined ataluren and steroid treatment group. Discussion: Age of diagnosis and age of treatment initiation is relatively late in the KSA. However, early diagnosis and early treatment onset is associated with better clinical outcomes, mainly a delay in LoA. Therefore, there is an urgent need for raising awareness and enhancing early screening in the KSA. Full article

Growth impairment is a clinical manifestation frequently observed in pediatric patients with cardiomyopathy associated with various inherited disorders, including RASopathies, lysosomal storage diseases, neuromuscular disorders, and metabolic conditions. In this narrative review, we explored the genetic and pathophysiological mechanisms underlying the development of both growth and myocardial impairment in Noonan syndrome (NS)—the most common RASopathy—Duchenne and Becker muscular dystrophies, Pompe disease, mucopolysaccharidoses, and mitochondrial diseases. For each condition, we described the cardiac and growth phenotypes, focusing on epidemiology, clinical implications, and disease-specific therapeutic strategies. In the era of precision medicine, innovative etiologic treatments targeting the underlying molecular mechanisms have emerged. Therefore, elucidating the molecular pathways responsible for growth impairment in pediatric inherited cardiomyopathies remains essential for optimizing multidisciplinary management and improving patient outcomes. Full article

Duchenne muscular dystrophy (DMD) is a severe X-linked neuromuscular disease (NMD) caused by loss-of-function mutations in the DMD gene. RNA-based therapies, especially antisense oligonucleotides (ASO)-mediated exon skipping and adenosine deaminase acting on RNA (ADAR)-guided RNA editing, have emerged as complementary approaches that modulate pre-mRNA splicing or correct transcripts without altering genomic DNA. Current phosphorodiamidate morpholino oligomer (PMO) drugs targeting exons 51, 53, and 45 provide mutation-class-specific benefit. At the same time, next-generation delivery strategies (e.g., peptide-conjugated PMOs (PPMOs), antibody–oligonucleotide conjugates (AOC), and endosomal-escape vehicles) aim to improve skeletal, cardiac, and diaphragm exposure. In parallel, RNA editing strategies offer a route to correct select nonsense or missense variants at the base level and may, in principle, restore near-native dystrophin expression. Meaningful translation of these modalities requires predictive large-animal models. A genome-edited microminipig (MMP) bearing DMD exon-23 mutations faithfully recapitulates hallmark features of human DMD. That includes early locomotor deficits, elevated serum creatine kinase (CK) and cardiac troponin T, progressive myocardial fibrosis, and a decline in left-ventricular ejection fraction (LVEF), while maintaining a manageable lifespan of approximately 30 months suitable for long-term studies. In particular, the MMP model provides a practical platform for addressing the persistent challenge of efficient therapeutic delivery to the heart and diaphragm through longitudinal dosing, imaging, and biopsy. In this review, we synthesize clinical progress in exon skipping, outline the promise of RNA editing, and integrate recent insights from Duchenne muscular dystrophy model for microminipigs (DMD-MMPs) as an advanced surrogate for preclinical development and translational evaluation. Full article

Duchenne muscular dystrophy (DMD) is a severe X-linked neuromuscular disorder caused by loss-of-function mutations in the dystrophin gene, leading to progressive muscle degeneration, motor decline, respiratory compromise, and cardiomyopathy. Diagnosis typically occurs in early childhood following recognition of motor delays, markedly elevated creatine kinase, and confirmatory genetic testing. Over the past decade, the therapeutic landscape for DMD has expanded substantially, evolving from exclusively supportive care to patient-centric multifaceted treatment paradigms, including corticosteroids, mutation-specific therapies, small molecule disease-modifying approaches, and gene replacement strategies. Despite these advances, no currently available therapy restores full-length dystrophin or completely halts disease progression. This review provides a clinically oriented comprehensive overview of currently Food and Drug Administration (FDA)-approved medications for DMD, with particular emphasis on corticosteroids, exon-skipping therapies, nonsense mutation readthrough agents, recently approved gene therapy, and select ongoing gene therapy trials. We summarize mechanisms of action, clinical efficacy, safety considerations, regulatory status, and highlight the challenges of integrating these therapies into longitudinal care. Through illustrative clinical vignettes, we highlight the real-world complexity of treatment selection, shared decision-making, and longitudinal care planning in contemporary DMD management. Full article

Duchenne muscular dystrophy (DMD) causes progressive skeletal, respiratory and cardiac muscle weakness in affected males. Most DMD patients develop scoliosis following loss of ambulation. This narrative review describes recommendations for the management of scoliosis in DMD patients using a review of the current literature evidence and a consensus review by the DMD Care UK Spinal Surgery Working Group. Advances in medical treatments have improved life expectancy for DMD patients. Spinal bracing is not effective in preventing the deterioration of scoliosis. Seating and wheelchair adaptations can provide postural support. The multidisciplinary assessment of patients with DMD requiring treatment for scoliosis is reviewed, with particular focus on bone, cardiac and respiratory health. The indications, surgical techniques, and type of spinal instrumentation for surgical management for progressively severe scoliosis with or without pelvic obliquity are discussed. Anaesthetic techniques, intraoperative neuromonitoring, perioperative care, and postoperative management in the ICU are discussed for the optimal management of DMD patients undergoing surgery to correct spinal deformity. Finally, regional and holistic functional assessments, patient satisfaction and long-term health, quality of life, and life expectancy for DMD patients undergoing treatment for spinal deformity are reviewed. Full article

Muscle biopsy has long been regarded as the cornerstone for diagnosing pediatric muscular disorders; however, it is invasive and may be limited by sampling error and inconclusive histopathological findings. This study aimed to evaluate whether whole-exome sequencing (WES) can effectively replace muscle biopsy as a first-line diagnostic approach in children with suspected neuromuscular disorders. Between January 2018 and December 2025, we prospectively enrolled 47 pediatric patients presenting with clinical features suggestive of muscular disorders at a tertiary medical center in Taiwan. The cohort included patients with suspected muscular dystrophies (n = 21), congenital myopathies (n = 23), and multiplex ligation-dependent probe amplification (MLPA)-negative Duchenne muscular dystrophy (DMD; n = 3). All patients underwent WES as the initial diagnostic test without prior muscle biopsy. Trio-based analysis using parental samples was performed in 29.8% of cases. Variant interpretation followed the American College of Medical Genetics and Genomics (ACMG) guidelines. WES identified a definitive molecular diagnosis in 72.3% of patients (34/47). Diagnostic yields varied by subgroup: 100% (3/3) in MLPA-negative DMD, 71.4% (15/21) in muscular dystrophies, and 69.6% (16/23) in congenital myopathies. Pathogenic or likely pathogenic variants were detected in 31 distinct genes, including COL6A1 and COL6A3, which are associated with Ullrich congenital muscular dystrophy. Notably, 58.8% of diagnosed patients (20/34) received molecular diagnoses that differed from their initial clinical impression, encompassing conditions such as ZSWIM6-associated neurodevelopmental disorders, GJB2-related hearing loss, OCRL-associated Lowe syndrome, and various metabolic or syndromic disorders. In all three MLPA-negative DMD cases, WES identified point mutations amenable to mutation-specific therapies. No patient required a muscle biopsy for diagnostic confirmation during the study period. First-tier WES demonstrates high diagnostic utility in pediatric muscular disorders while avoiding invasive muscle biopsy. The high rate of diagnostic reclassification underscores the substantial phenotypic overlap between primary neuromuscular diseases and other neurological or systemic conditions. These findings support the early implementation of genetic testing to enable accurate diagnosis and timely initiation of targeted therapies. Full article

Background: Duchenne muscular dystrophy (DMD) is a severe neuromuscular disorder caused by the absence of functional dystrophin, leading to progressive muscle degeneration, inflammation, and alterations in the central nervous system. The sustained inflammatory response in DMD increases glial activation and the release of tumor necrosis factor alpha (TNF-α), which contributes to muscle fiber damage. Here, we investigated the anti-inflammatory and neuroprotective effects of Etanercept, a TNF-α receptor-blocking therapeutic, on the spinal cord of MDX mice, a widely used model of DMD. Methods: Adult male MDX and control C57BL/10 mice received vehicle or Etanercept (3, 6, or 12 mg/Kg, intraperitoneally (i.p.)) every 72 h for two weeks, along with daily gait assessment. At the end of treatment, flow cytometry and immunolabeling analyses were performed in the lumbar spinal cord. Results: Etanercept at 12 mg/Kg reduced astrogliosis and microglial activation; restored synaptic markers, including synaptophysin, glutamic acid decarboxylase 65 (GAD-65), and vesicular glutamate transporter 1 (VGLUT-1); and decreased pro-inflammatory cytokines. The treatment reduced GFAP+/TNF-α+ astrocytes and significantly downregulated Th1 lymphocyte polarization in treated MDX mice. These cellular effects were accompanied by improvements in locomotor function. Conclusions: Together, our findings indicate that TNF-α blockade by Etanercept exerts neuroprotective and anti-inflammatory actions in the spinal cord of dystrophic mice, providing new insights into the impact of TNF-α signaling on neuroinflammatory processes in DMD. Full article

Background/Objectives: Recombinant adeno-associated virus (AAV) vectors have revolutionized gene therapy for monogenic diseases such as Duchenne muscular dystrophy (DMD). However, high systemic doses required for muscle transduction cause a spectrum of toxicities ranging from transient hepatic inflammation to fatal multi-organ failure leading to death. These adverse events have reshaped the risk–benefit considerations for gene therapy in DMD. Methods: We conducted a narrative review describing complications associated with AAV-mediated gene therapies in the DMD field. PubMed and Clinicaltrials databases were used to search for peer-reviewed manuscripts published between 1987 and 2025. Publicly available abstracts and press releases were also used to describe AAV-mediated adverse events that have been discovered. Priority was given to large prospective cohorts, meta-analyses, and high-impact publications. Results: We outlined the mechanistic basis of AAV toxicity—spanning innate and adaptive immune activation, vector–host interactions, transgene overexpression, and host vulnerability—and discussed their therapeutic implications for DMD. We also highlighted ongoing strategies for vector re-design, immune modulation, patient selection, and regulatory adaptation, aiming to improve efficacy with safety in the next generation of muscular dystrophy gene therapies. Conclusions: Patient safety remains the number one priority in the AAV-mediated gene therapies field. Achieving long-term benefits requires continued optimization of existing vectors, implementation of strict criteria for patient selection, and regulation of immune responses, with close collaboration and transparent dialog among scientists, clinicians, and regulatory agencies, informed by both successful cases as well as tragic deaths reported in the fields of neuromuscular diseases. Full article

Background/Objectives: Cardiomyopathy (CM) is a leading cause of morbidity and mortality in Duchenne muscular dystrophy (DMD) patients. Ferroptosis, an iron-dependent form of cell death characterized by lipid peroxidation, is implicated in various cardiovascular diseases. However, the role of ferroptosis in DMD-CM remains unexplored. Methods: Here, we used dystrophin and utrophin double-knockout (mdx:utr^−/−) mice as a model that exhibits cardiac pathological phenotypes similar to those seen in DMD patients to investigate the potential role of ferroptosis. Results: We observed an increased level of iron deposition and lipid peroxidation in the hearts of mdx:utr^−/− mice. Live/Dead viability assays revealed that mdx:utr^−/− cardiomyocytes exhibited greater susceptibility to ferroptosis than WT cardiomyocytes both at baseline and upon exposure to ferroptosis inducers. We also used mdx:utr^−/− mice with a heterozygous sarcolipin (SLN) knockout background (sln^+/−) to investigate the effect of SLN reduction on ferroptosis susceptibility in DMD-CM. Notably, ferroptosis was significantly suppressed in cardiomyocytes from mdx:utr^−/−:sln^+/− mice (p < 0.01). Western blot analysis confirmed the upregulation of transferrin receptor 1 (TfR1) and 15-lipoxygenase-1 (15LOX1), along with the downregulation of heme oxygenase-1 (HMOX-1) and ferroptosis suppressor protein 1 (FSP1) in mdx:utr^−/− hearts, while glutathione peroxidase 4 (GPX4) levels remained unchanged. A similar pattern of alterations in ferroptosis-related biomarkers was observed in human heart samples from DMD patients compared to healthy controls. Conclusions: Our results provide direct evidence that ferroptosis contributes to the pathology of DMD-CM and suggest that reducing SLN expression and inhibiting ferroptosis may represent potential therapeutic strategies for this condition. Full article

Muscle degeneration is the hallmark of muscular dystrophies—genetically heterogeneous disorders traditionally approached through the lens of molecular pathogenesis or symptomatic management in isolation. Here, we present a deliberately interdisciplinary synthesis that bridges molecular genetics, clinical phenotyping, and evidence-based orthopedic decision-making to address a significant critical gap: the lack of genotype-informed, function-oriented frameworks for musculoskeletal complications. We re-evaluate disease entities—not only by their molecular etiology (e.g., DMD, LMNA, DUX4 dysregulation), but through the prism of orthopedic manifestations as diagnostic gateways and therapeutic milestones. For instance, early rigid spine in LMNA-related dystrophy is not merely a sign of contracture, but a red flag demanding cardiac risk stratification before surgical planning, in alignment with current consensus. Similarly, scoliosis management in Duchenne muscular dystrophy is discussed through quantitative decision thresholds (Cobb angle ≥ 20–30°, FVC ≥ 30–35%) derived from long-term outcome studies, rather than general clinical recommendations. Critically, we confront challenges posed by disease-modifying therapies: patients now survive into their 30s and 40s, yet develop novel, therapy-exacerbated orthopedic phenotypes (e.g., steroid-induced osteoporosis, atypical spinal rigidity). Therefore, we argue that precision orthopedics—tailored surveillance, genotype-stratified intervention timing (e.g., D4Z4 repeat-guided monitoring in FSHD, and realistic functional goal-setting (e.g., scapular arthrodesis for overhead function)—should become the gold standard of care. For example, desminopathies may show marked phenotypic variability even within the same mutation. Our review thus serves not only as a molecular overview, but as a practical roadmap for neurologists, geneticists, orthopedic surgeons, and rehabilitation specialists seeking to translate genomic insights into durable functional outcomes. Full article