- Spinal Muscular Atrophies (SMAs) are a group of autosomal recessive inherited disorders characterized by progressive weakness of the lower motor neurons, manifesting as muscle weakness, atrophy and paralysis. It typically presents during infancy or early childhood and the severity of the disease correlates with the age of onset. The clinical and genetic phenotypes incorporate a broad spectrum that is differentiated according to the age of onset, pattern of muscle involvement, and inheritance pattern. There are four types of spinal muscular atrophies, described based on age when accompanying clinical features appear. Type 1 SMA (Werdnig-Hoffman disease) is associated with death within the first two years of life usually due to respiratory failure or aspiration pneumonia.
- The Igenomix Spinal Muscular Atrophies Precision Panel can serve as an accurate diagnostic tool 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.
- The Igenomix Spinal Muscular Atrophies Precision Panel is indicated in patients with a clinical suspicion or diagnosis of Spinal Muscular Atrophy presenting with the following manifestations:
- Symmetric muscle weakness and hypotonia
- Limb and joint deformities
- Fasciculations of the tongue
- Absent deep tendon reflexes
- Flaccid “frog like” posture
- Restrictive respiratory insufficiency
The clinical utility of this panel is:
- The genetic and molecular diagnosis for an accurate clinical diagnosis of a symptomatic patient.
- Early initiation of treatment with a multidisciplinary team in the form of neuroprotective approaches to support muscle strength and function, orthopaedic intervention, appropriate physical therapy and rehabilitation, and prevention of complications.
- Initiation of novel therapeutic strategies including measures to selectively address survival motor neuron protein deficiency with SMN1 gene replacement or modulation of SMN2 encoded protein levels.
- Risk assessment and genetic counselling of asymptomatic family members according to the mode of inheritance.
- Improvement of delineation of genotype-phenotype correlation.
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Arnold, E. S., & Fischbeck, K. H. (2018). Spinal muscular atrophy. Handbook of clinical neurology, 148, 591–601. https://doi.org/10.1016/B978-0-444-64076-5.00038-7
Arnold, W. D., Kassar, D., & Kissel, J. T. (2015). Spinal muscular atrophy: diagnosis and management in a new therapeutic era. Muscle & nerve, 51(2), 157–167. https://doi.org/10.1002/mus.24497
Kariyawasam, D., Carey, K. A., Jones, K. J., & Farrar, M. A. (2018). New and developing therapies in spinal muscular atrophy. Paediatric respiratory reviews, 28, 3–10. https://doi.org/10.1016/j.prrv.2018.03.003
Lunn, M. R., & Wang, C. H. (2008). Spinal muscular atrophy. The Lancet, 371(9630), 2120-2133. doi:10.1016/s0140-6736(08)60921-6
Frugier, T., Nicole, S., Cifuentes-Diaz, C., & Melki, J. (2002). The molecular bases of spinal muscular atrophy. Current Opinion in Genetics & Development, 12(3), 294-298. doi:10.1016/s0959-437x(02)00301-5