Myology research highlights
RSS feedMutant SNAP25B causes myasthenia, cortical hyperexcitability, ataxia, and intellectual disability
This study aimed to identify and characterize the molecular basis of a syndrome associated with myasthenia, cortical hyperexcitability, cerebellar ataxia, and intellectual disability. The authors performed in vitro microelectrode studies of neuromuscular transmission, performed exome and Sanger sequencing, and analyzed functional consequences of the identified mutation in expression studies. Neuromuscular transmission at patient endplates was … [Read more]
Quantitative assessment of lingual strength in late-onset Pompe disease
Skeletal muscle disease resulting in weakness is common in late-onset Pompe disease (LOPD). Recent data implicate common bulbar muscle involvement (i.e., the tongue). The authors used quantitative assessment of lingual strength to determine retrospectively the frequency and severity of lingual weakness in LOPD. They additionally examined associations between lingual strength and the presence or absence … [Read more]
Natural history of skeletal muscle involvement in myotonic dystrophy type 1
Myotonic dystrophy type 1 (DM1) is the most frequent muscular dystrophy in adult. The aim of this study was to investigate the natural history of skeletal muscle weakness in adults, in a cross-sectional, retrospective study. In a cohort of 204 adult DM1 patients, the authors quantified muscle impairment, handgrip force and physical disability. Muscle strength … [Read more]
Development of an assay to identify DNA methylation profiles for FSHD
Facioscapulohumeral muscular dystrophy (FSHD) is linked to chromatin relaxation due to epigenetic changes at the 4q35 D4Z4 macrosatellite array. Molecular diagnostic criteria for FSHD are complex and involve analysis of high molecular weight (HMW) genomic DNA isolated from lymphocytes, followed by multiple restriction digestions, pulse-field gel electrophoresis (PFGE), and Southern blotting. A subject is genetically … [Read more]
The presentation, assessment, pathogenesis, and treatment of calcinosis in juvenile dermatomyositis
Calcinosis is one of the hallmark sequelae of juvenile dermatomyositis (JDM), and despite recent progress in the therapy of JDM, dystrophic calcification still occurs in approximately one third of patients. This review discusses the current, albeit limited, understanding of risk factors for the development of calcinosis in JDM, as well as approaches to assessment, and … [Read more]
Substrate reduction via inhibition of glycogen synthase: A promising therapeutic strategy for Pompe Disease
Pompe disease is an autosomal recessive disorder caused by a deficiency of acid α-glucosidase (GAA; EC 3.2.1.20) and the resultant progressive lysosomal accumulation of glycogen in skeletal and cardiac muscles. Enzyme replacement therapy using recombinant human GAA (rhGAA) has proven beneficial in addressing several aspects of the disease such as cardiomyopathy and aberrant motor function. … [Read more]
Becker muscular dystrophy severity is linked to the structure of dystrophin
In-frame exon deletions of the DMD gene produce internally truncated proteins that typically lead to Becker muscular dystrophy (BMD), a milder allelic disorder of Duchenne muscular dystrophy (DMD). In this study, the suthors hypothesized that differences in the structure of mutant dystrophin may be responsible for the clinical heterogeneity observed in Becker patients and they … [Read more]
Dystrophin quantification: Biological and translational research implications
A multi-institution collaboration was formed to compare dystrophin quantification methods, reach a consensus on the most reliable method, and report its biological significance in the context of clinical trials. Five laboratories with expertise in dystrophin quantification performed a data-driven comparative analysis of a single reference set of normal and dystrophinopathy muscle biopsies using quantitative immunohistochemistry … [Read more]
CSF-delivered gene therapy shows promise for SMA
Spinal Muscular Atrophy (SMA) is the most frequent lethal genetic neurodegenerative disorder in infants. The disease is caused by low abundance of the survival of motor neuron (SMN) protein leading to motor neuron degeneration and progressive paralysis. The authors have previously demonstrated that a single intravenous injection (IV) of self-complementary adeno-associated virus 9 carrying the … [Read more]
An unusual case of carotid-cavernous fistula mimicking myasthenia gravis
A carotid-cavernous fistula (CCF) is an abnormal communication between the carotid arterial system and the cavernous sinus. Common symptoms of CCFs include proptosis and ophthalmoplegia, but fluctuating diplopia and presence of ptosis are not typical. Here, the authors present an unusual case of CCF with fluctuating binocular diplopia and ptosis, mimicking myasthenia gravis. Electrodiagnostic testing, … [Read more]
