Overview
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Spinocerebellar Ataxia (SCA) refers to a heterogeneous group of progressive neurodegenerative diseases of genetic origin. Currently, more than 30 types have been described, most of which are autosomal dominant. Classification is done according to the clinical manifestations or genetic nosology. The most common type is SCA3. Ataxia is defined as the absence of voluntary muscle coordination and loss of control of movement affecting gait stability, eye movement and speech. The clinical hallmark of SCA is loss of balance and coordination accompanied by slurred speech; onset is most often in adult life. The main disease mechanism of these SCAs include toxic RNA gain-of-function, mitochondrial dysfunction, channelopathies, autophagy and transcription dysregulation. The prognosis is dependent upon the individual and genetic properties, but most patients develop severe, irreversible disability, while retaining full mental capacity.
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The Igenomix Spinocerebellar Ataxia Precision Panel can be used as a tool for an accurate diagnosis and differential diagnosis of loss of balance and coordination 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.
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 in the form of orthopaedic care, use of special devices to assist with fine movements as
- 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
Sullivan, R., Yau, W. Y., O’Connor, E., & Houlden, H. (2019). Spinocerebellar ataxia: an update. Journal of neurology, 266(2), 533–544. https://doi.org/10.1007/s00415-018-9076-4
Klockgether, T., Mariotti, C., & Paulson, H. L. (2019). Spinocerebellar ataxia. Nature reviews. Disease primers, 5(1), 24. https://doi.org/10.1038/s41572-019-0074-3
Sun, Y. M., Lu, C., & Wu, Z. Y. (2016). Spinocerebellar ataxia: relationship between phenotype and genotype – a review. Clinical genetics, 90(4), 305–314. https://doi.org/10.1111/cge.12808
Soong, B. W., & Morrison, P. J. (2018). Spinocerebellar ataxias. Handbook of clinical neurology, 155, 143–174. https://doi.org/10.1016/B978-0-444-64189-2.00010-X
Manto, M. (2005). The wide spectrum of spinocerebellar ataxias (SCAs). The Cerebellum, 4(1), 2-6. doi: 10.1080/14734220510007914
Spinocerebellar ataxia. (2019). Nature reviews. Disease primers, 5(1), 25. https://doi.org/10.1038/s41572-019-0081-4
Coarelli, G., Brice, A., & Durr, A. (2018). Recent advances in understanding dominant spinocerebellar ataxias from clinical and genetic points of view. F1000Research, 7, F1000 Faculty Rev-1781. https://doi.org/10.12688/f1000research.15788.1