Overview
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Congenital Muscular Dystrophies are an inherited group of progressive myopathic disorders resulting from defects in a number of genes responsible for normal muscle function, resulting in progressive muscle weakness without a central or peripheral nerve abnormality. The genes responsible for these diseases are specific muscle proteins that allow for proper contraction and relaxation of the muscles. Muscular dystrophies are classified according to the clinical phenotype, pathology and mode of inheritance. Inheritance pattern includes X-lined, autosomal recessive and autosomal dominant. Some examples include:
- X-linked: Duchenne, Becker, Emery-Dreifuss
- Autosomal dominant: Facioscapulohumeral, distal, ocular, oculopharyngeal
- Autosomgal recessive: Limb-girdle form
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Congenital Myopathies are a group of genetic diseases that predominantly affect the muscles. The typical features can be found in neonates and infants, children or even adults. The classification of congenital myopathies follows a genetic criterion. However, the genotype-phenotype correlation remains variable and overlapping with congenital muscular dystrophies. Some examples of congenital myopathies include Nemaline Myopathy, Central Core Disease and Multiminicore Disease amongst others. Both congenital myopathies and muscular dystrophies carry a high risk of developing restrictive lung disease and orthopedic deformities.
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The Igenomix Congenital Muscular Dystrophies and Myopathies Precision Panel can be used as a tool for an accurate diagnosis and differential diagnosis of muscle weakness ultimately leading to a better management and prognosis of the disease. It provides a comprehensive analysis of the genes involved in this disease using next-generation sequencing (NGS) to fully understand the spectrum of relevant genes involved, and their high or intermediate penetrance.
Indication
- The Igenomix Congenital Muscular Dystrophies and Myopathies Precision Panel is used for patients with a clinical suspicion or diagnosis with or without the following symptoms:
- Early-onset muscle weakness
- Decreased muscle tone
- Hypoactive deep tendon reflexes
- Delayed motor milestones
- Muscle atrophy
- Abnormally fixed joints
- Muscle deformities and contractures
- Family history of congenital myopathy or muscle dystrophy
Clinical Utility
The clinical utility of this panel is:
- The genetic and molecular confirmation for an accurate clinical diagnosis of a symptomatic patient.
- Early initiation of treatment involving a multidisciplinary team focusing on intensive physiotherapy and rehabilitation, bracing and surgical interventions and medical care to prevent complications and improve symptoms.
- Risk assessment of asymptomatic family members according to the mode of inheritance via genetic counselling.
- Improvement of delineation of genotype-phenotype correlation given the variability of severity and course of disease.
References
Cassandrini, D., Trovato, R., Rubegni, A., Lenzi, S., Fiorillo, C., & Baldacci, J. et al. (2017). Congenital myopathies: clinical phenotypes and new diagnostic tools. Italian Journal Of Pediatrics, 43(1). doi: 10.1186/s13052-017-0419-z
Colombo, I., Scoto, M., Manzur, A., Robb, S., Maggi, L., & Gowda, V. et al. (2014). Congenital myopathies: Natural history of a large pediatric cohort. Neurology, 84(1), 28-35. doi: 10.1212/wnl.0000000000001110
Millichap, J. (2010). Congenital Muscular Dystrophies and Cognitive Impairment. Pediatric Neurology Briefs, 24(11), 87. doi: 10.15844/pedneurbriefs-24-11-8
Butterfield R. J. (2019). Congenital Muscular Dystrophy and Congenital Myopathy. Continuum (Minneapolis, Minn.), 25(6), 1640–1661. https://doi.org/10.1212/CON.0000000000000792
Sundaram, C., Uppin, M., & Meena, A. (2013). Spectrum of congenital myopathies: A single centre experience. Neurology India, 61(3), 254. doi: 10.4103/0028-3886.115064
Falsaperla, R., Praticò, A. D., Ruggieri, M., Parano, E., Rizzo, R., Corsello, G., Vitaliti, G., & Pavone, P. (2016). Congenital muscular dystrophy: from muscle to brain. Italian journal of pediatrics, 42(1), 78. https://doi.org/10.1186/s13052-016-0289-9
Gilbreath, H. R., Castro, D., & Iannaccone, S. T. (2014). Congenital myopathies and muscular dystrophies. Neurologic clinics, 32(3), 689–viii. https://doi.org/10.1016/j.ncl.2014.04.006