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Context: Vamorolone, a novel "dissociative" steroid, demonstrated similar efficacy in muscle function relative to prednisone 0.75 mg/kg/day but improved linear growth and bone turnover markers in a randomized trial of pediatric Duchenne muscular dystrophy (DMD)., Objectives: To determine the frequency of adrenal suppression (AS) induced by vamorolone and prednisone in pediatric DMD, and to assess cortisol thresholds using a monoclonal antibody immunoassay., Methods: Post-hoc analysis of cortisol levels was performed on data from a randomized, double-blind, placebo- and prednisone-controlled 24-week trial of vamorolone with a 24-week crossover extension. Morning and ACTH-stimulated cortisol levels were measured using the Elecsys II immunoassay, with AS defined as a stimulated cortisol of <500nmol/L ("historical threshold") and <400nmol/L ("revised threshold")., Results: Mean age at enrolment was 5.41±0.86 years (N=118). At Week 24, proportion of participants with AS using the historical and revised cortisol thresholds, respectively, were as follows: prednisone 0.75 mg/kg/day=100% (25/25) and 92.0% (23/25); vamorolone 6 mg/kg/day=95.2% (20/21) and 90.5% (19/21); vamorolone 2 mg/kg/day=84.2% (16/19) and 47.5% (9/19); and placebo=20.0% (4/20) and 0% (0/20). Morning and peak ACTH-stimulated cortisol were strongly correlated in steroid-treated boys (Spearman correlation week 48=0.83)., Conclusions: AS after vamorolone and prednisone was frequent and vamorolone-associated AS appeared dose-dependent. A lower stimulated cortisol threshold may be appropriate when using a monoclonal assay. We recommend hydrocortisone for glucocorticoid stress dosing in patients receiving vamorolone., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Objectives: Healthcare professionals (HCPs) need to identify potentially serious musculoskeletal (MSK) presentations in children and refer them to specialists appropriately. Our aim was to develop 'pGALSplus' (paediatric gait, arms, legs and spine plus) to support clinical assessment, aid decision-making and assess feasibility and acceptability in exemplar MSK pathologies., Methods: We used a three-phase mixed methods approach: phase 1, preliminary stakeholder engagement and scoping review to propose pGALSplus; phase 2, iterative development of pGALSplus involving an expert working group; and phase 3, testing the feasibility of pGALSplus in exemplar MSK conditions [JIA, mucopolysaccharidoses (MPS), muscular dystrophy (MD), developmental coordination disorder (DCD) and healthy controls (HCs)]. The final pGALSplus was derived from analysis of phase 3 data and feedback from HCPs, families and expert consensus input from an international e-survey ( n  = 22) and virtual event ( n  = 13)., Results: Feasibility was tested in 45 children (JIA, n  = 10; MPS, n  = 6; MD, n  = 9; DCD, n  = 10; HCs, n  = 10). Overall the assessment was achievable in the target age range (2-10 years) and quick to complete [median 12 min (range 8-20)], with high acceptability from families. Expert feedback deemed pGALSplus to be very useful and of particular use to non-specialists in MSK paediatrics. The final pGALSplus comprises 26 clinical observations/skills with a colour-coding approach to aid decision-making and identification of more serious MSK presentations and additional resources to support its use in clinical practice., Conclusions: pGALSplus is a novel evidence- and consensus-based assessment building on pGALS, with high acceptability and feasibility. As community-based MSK assessment in children becomes more established, we propose that pGALSplus will facilitate and inform decision-making to promote access to specialist care., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Late-onset Pompe Disease (LOPD) is a rare genetic disorder caused by the deficiency of acid alpha-glucosidase leading to progressive cellular dysfunction due to the accumulation of glycogen in the lysosome. The mechanism of relentless muscle damage - a classic manifestation of the disease - has been extensively studied by analysing the whole muscle tissue; however, little, if any, is known about transcriptional heterogeneity among nuclei within the multinucleated skeletal muscle cells. This is the first report of application of single nuclei RNA sequencing to uncover changes in the gene expression profile in muscle biopsies from eight patients with LOPD and four muscle samples from age and gender matched healthy controls. We matched these changes with histology findings using GeoMx Spatial Transcriptomics to compare the transcriptome of control myofibers from healthy individuals with non-vacuolated (histologically unaffected) and vacuolated (histologically affected) myofibers of LODP patients. We observed an increase in the proportion of slow and regenerative muscle fibers and macrophages in LOPD muscles. The expression of the genes involved in glycolysis was reduced, whereas the expression of the genes involved in the metabolism of lipids and amino acids was increased in non-vacuolated fibers, indicating early metabolic abnormalities. Additionally, we detected upregulation of autophagy genes, and downregulation of the genes involved in ribosomal and mitochondrial function leading to defective oxidative phosphorylation. The upregulation of the genes associated with inflammation, apoptosis and muscle regeneration was observed only in vacuolated fibers. Notably, enzyme replacement therapy - the only available therapy for the disease - showed a tendency to restore metabolism dysregulation, particularly within slow fibers. A combination of single nuclei RNA sequencing and spatial transcriptomics revealed the landscape of normal and the diseased muscle, and highlighted the early abnormalities associated with the disease progression. Thus, the application of these two new cutting-edge technologies provided insight into the molecular pathophysiology of muscle damage in LOPD and identified potential avenues for therapeutic intervention., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Background and Aims: Mitral valve surgery and, more recently, mitral transcatheter edge-to-edge repair (TEER) are the two treatments of severe mitral regurgitation in eligible patients. Clinical comparison of both therapies remains limited by the number of patients analysed. The objective of this study was to analyse the outcomes of mitral TEER vs. isolated mitral valve surgery at a nationwide level in France., Methods: Based on the French administrative hospital discharge database, the study collected information for all consecutive patients treated for mitral regurgitation with isolated TEER or isolated mitral valve surgery between 2012 and 2022. Propensity score matching was used for the analysis of outcomes., Results: A total of 57 030 patients were found in the database. After matching on baseline characteristics, 2160 patients were analysed in each arm. At 3-year follow-up, TEER was associated with significantly lower incidence of cardiovascular death (hazard ratio 0.685, 95% confidence interval 0.563-0.832; P = .0001), pacemaker implantation, and stroke. Non-cardiovascular death (hazard ratio 1.562, 95% confidence interval 1.238-1.971; P = .0002), recurrent pulmonary oedema, and cardiac arrest were more frequent after TEER. No significant differences between the two groups were observed regarding all-cause death (hazard ratio 0.967, 95% confidence interval 0.835-1.118; P = .65), endocarditis, major bleeding, atrial fibrillation, and myocardial infarction., Conclusions: Our results suggest that TEER for severe mitral regurgitation was associated with lower cardiovascular mortality than mitral surgery at long-term follow-up. Pacemaker implantation and stroke were less frequently observed after TEER., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Musculoskeletal (MSK) problems in children are common, and health-care professionals must identify those requiring onward referral. Paediatric gait, arms, legs and spine (pGALS) is an MSK assessment to discern abnormal joints. We aimed to identify MSK assessments to add to pGALS (pGALSplus) to facilitate decision-making in the context of exemplar conditions representing a spectrum of MSK presentations, namely JIA, mucopolysaccharidoses, muscular dystrophy and developmental co-ordination disorder. A literature review identified 35 relevant articles that focused on clinical assessments [including questionnaire(s), physical examination and functional tests] used by health-care professionals in the context of the exemplar conditions. We provide a description of these assessments and the rationale regarding how they, or components of such tools, might be useful within pGALSplus. This process provides a foundation for further work to develop and validate pGALSplus., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Sarcoglycanopathies include four subtypes of autosomal recessive limb-girdle muscular dystrophies (LGMDR3, LGMDR4, LGMDR5 and LGMDR6) that are caused, respectively, by mutations in the SGCA, SGCB, SGCG and SGCD genes. Delta-sarcoglycanopathy (LGMDR6) is the least frequent and is considered an ultra-rare disease. Our aim was to characterize the clinical and genetic spectrum of a large international cohort of LGMDR6 patients and to investigate whether or not genetic or protein expression data could predict a disease's severity. This is a retrospective study collecting demographic, genetic, clinical and histological data of patients with genetically confirmed LGMDR6 including protein expression data from muscle biopsies. We contacted 128 paediatric and adult neuromuscular units around the world that reviewed genetic data of patients with a clinical diagnosis of a neuromuscular disorder. We identified 30 patients with a confirmed diagnosis of LGMDR6 of which 23 patients were included in this study. Eighty-seven per cent of the patients had consanguineous parents. Ninety-one per cent of the patients were symptomatic at the time of the analysis. Proximal muscle weakness of the upper and lower limbs was the most common presenting symptom. Distal muscle weakness was observed early over the course of the disease in 56.5% of the patients. Cardiac involvement was reported in five patients (21.7%) and four patients (17.4%) required non-invasive ventilation. Sixty per cent of patients were wheelchair-bound since early teens (median age of 12.0 years). Patients with absent expression of the sarcoglycan complex on muscle biopsy had a significant earlier onset of symptoms and an earlier age of loss of ambulation compared to patients with residual protein expression. This study confirmed that delta-sarcoglycanopathy is an ultra-rare neuromuscular condition and described the clinical and molecular characteristics of the largest yet-reported collected cohort of patients. Our results showed that this is a very severe and quickly progressive disease characterized by generalized muscle weakness affecting predominantly proximal and distal muscles of the limbs. Similar to other forms of sarcoglycanopathies, the severity and rate of progressive weakness correlates inversely with the abundance of protein on muscle biopsy., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain.)

Background: Pharmacological doses of glucocorticoids (GC) reduce inflammation and preserve muscle function in boys with Duchenne muscular dystrophy (DMD). Delayed puberty and bone fragility are consequences of GC treatment. The aim of this study was to determine the acceptability of a 2-year pubertal induction regimen using 4-weekly testosterone injections and examine changes in physique, bone integrity, muscle pathology (assessed by MRI) and muscle function., Methods: Fifteen prepubertal males with DMD, aged 12-17 years and receiving GC, were treated with an incremental testosterone regimen for 2 years. Participants completed a Treatment Satisfaction Questionnaire (TSQM). Data on BMI, bone density, muscle pathology and function were collected at baseline and 2 years later., Results: Testosterone injections were well tolerated, with high TSQM scores. Baseline BMI z-score was 2.16 (0.90) and 1.64 (1.35) 2 years later. Median testosterone levels were 9.7 nmol/L (IQR: 5.7-11.1) 6-9 months after the last injection with an associated increase in testicular volume. Lumbar spine z-score was 0.22 (s.d. 2.21) at baseline and 0.35 (s.d. 2.21) after 2 years. Upper and lower limb muscle contractile cross-sectional area increased in all participants during the trial (P = 0.05 and P < 0.01, respectively). There was a reduction in T2 relaxation times in most muscle groups with stable upper limb muscle function., Conclusion: Incremental monthly testosterone injections were well tolerated, promoted endogenous testosterone production and had a positive impact on the skeleton and contractile muscle bulk with evidence suggesting a beneficial impact on the underlying disease process.

Sarcoglycanopathies comprise four subtypes of autosomal recessive limb-girdle muscular dystrophies (LGMDR3, LGMDR4, LGMDR5 and LGMDR6) that are caused, respectively, by mutations in the SGCA, SGCB, SGCG and SGCD genes. In 2016, several clinicians involved in the diagnosis, management and care of patients with LGMDR3-6 created a European Sarcoglycanopathy Consortium. The aim of the present study was to determine the clinical and genetic spectrum of a large cohort of patients with sarcoglycanopathy in Europe. This was an observational retrospective study. A total of 33 neuromuscular centres from 13 different European countries collected data of the genetically confirmed patients with sarcoglycanopathy followed-up at their centres. Demographic, genetic and clinical data were collected for this study. Data from 439 patients from 13 different countries were collected. Forty-three patients were not included in the analysis because of insufficient clinical information available. A total of 159 patients had a confirmed diagnosis of LGMDR3, 73 of LGMDR4, 157 of LGMDR5 and seven of LGMDR6. Patients with LGMDR3 had a later onset and slower progression of the disease. Cardiac involvement was most frequent in LGMDR4. Sixty per cent of LGMDR3 patients carried one of the following mutations, either in a homozygous or heterozygous state: c.229C>T, c.739G>A or c.850C>T. Similarly, the most common mutations in LMGDR5 patients were c.525delT or c.848G>A. In LGMDR4 patients the most frequent mutation was c.341C>T. We identified onset of symptoms before 10 years of age and residual protein expression lower than 30% as independent risk factors for losing ambulation before 18 years of age, in LGMDR3, LGMDR4 and LGMDR5 patients. This study reports clinical, genetic and protein data of a large European cohort of patients with sarcoglycanopathy. Improving our knowledge about these extremely rare autosomal recessive forms of LGMD was helped by a collaborative effort of neuromuscular centres across Europe. Our study provides important data on the genotype-phenotype correlation that is relevant for the design of natural history studies and upcoming interventional trials in sarcoglycanopathies., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Duchenne muscular dystrophy is caused by mutations in the DMD gene that disrupt the open reading frame and prevent the full translation of its protein product, dystrophin. Restoration of the open reading frame and dystrophin production can be achieved by exon skipping using antisense oligonucleotides targeted to splicing elements. This approach aims to transform the Duchenne muscular dystrophy phenotype to that of the milder disorder, Becker muscular dystrophy, typically caused by in-frame dystrophin deletions that allow the production of an internally deleted but partially functional dystrophin. There is ongoing debate regarding the functional properties of the different internally deleted dystrophins produced by exon skipping for different mutations; more insight would be valuable to improve and better predict the outcome of exon skipping clinical trials. To this end, we have characterized the clinical phenotype of 17 patients with Becker muscular dystrophy harbouring in-frame deletions relevant to on-going or planned exon skipping clinical trials for Duchenne muscular dystrophy and correlated it to the levels of dystrophin, and dystrophin-associated protein expression. The cohort of 17 patients, selected exclusively on the basis of their genotype, included 4 asymptomatic, 12 mild and 1 severe patient. All patients had dystrophin levels of >40% of control and significantly higher dystrophin (P = 0.013), β-dystroglycan (P = 0.025) and neuronal nitric oxide synthase (P = 0.034) expression was observed in asymptomatic individuals versus symptomatic patients with Becker muscular dystrophy. Furthermore, grouping the patients by deletion, patients with Becker muscular dystrophy with deletions with an end-point of exon 51 (the skipping of which could rescue the largest group of Duchenne muscular dystrophy deletions) showed significantly higher dystrophin levels (P = 0.034) than those with deletions ending with exon 53. This is the first quantitative study on both dystrophin and dystrophin-associated protein expression in patients with Becker muscular dystrophy with deletions relevant for on-going exon skipping trials in Duchenne muscular dystrophy. Taken together, our results indicate that all varieties of internally deleted dystrophin assessed in this study have the functional capability to provide a substantial clinical benefit to patients with Duchenne muscular dystrophy.

Amyotrophic lateral sclerosis (ALS) is a progressive, lethal neurodegenerative disease without any effective therapy. To evaluate the potential of wild-type bone marrow (BM)-derived stem cells to modify the ALS phenotype, we generated BM chimeric Cu/Zn superoxide dismutase (SOD1) mice by transplantation of BM cells derived from mice expressing green fluorescent protein (GFP) in all tissues and from Thy1-YFP mice that express a spectral variant of GFP (yellow fluorescent protein) in neurons only. In the recipient cerebral cortex, we observed rare GFP+ and YFP+ neurons, which were probably generated by cell fusion, as demonstrated by fluorescence in situ hybridization (FISH) analysis, suggesting that this phenomenon is not limited to Purkinje cells. GFP-positive microglial cells were extensively present in both the brain and spinal cord of the affected animals. Completely differentiated and immature GFP+ myofibres were also present in the heart and skeletal muscles of SOD1 mice, confirming that BM cells can participate in striated muscle tissue regeneration. Moreover, wild-type BM chimeric SOD1 mice showed a significantly delayed disease onset and an increased life span, probably due to a positive 'non-neuronal environmental' effect rather than to neuronogenesis. This improvement in SOD1-G93A mouse survival is comparable with that previously obtained using some safer pharmacological agents. BM transplantation-related complications in humans preclude its clinical application for ALS treatment. However, our data suggest that further studies aimed at improving the degree of tissue chimerism by BM-derived cells may provide valuable insights into strategies to slow ALS progression.