cerebellar ataxia

Genetics of Hereditary Cerebellar Ataxia and Hereditary Spastic Paraplegia

Virginia Thornley, M.D.
Neurologist, Epileptologist
March 18, 2019
Introduction
Cerebellar ataxias are rare disorders, only a few types are treatable. This reviews some of the research regarding the genetics of cerebellar ataxias.
Next generation sequencing is a revolutionary way of DNA sequencing that can sequence an entire genome in one day which previously took 10 years. Clinical applications are still pending (1).
Genetics of hereditary cerebellar ataxias
In one study of 87 patients, the genetics were studies. In the probands meaning the first in a genetic line, triplet repeat testing was done. 58% were male. Genetic variants included ANO10, CACNA1A, SPG7 and DRKCG. The detection rate in probands for the trinucleotide repeat was about 13.8%. Those with variants may have a longer duration of disease and a slower progression of the disorder (2).
 
Genetic testing in hereditary spastic paraparesis
In another study where 306 were genetically tested, next generation sequence testing was performed and different genes were found. These include ATL1 (atlastin 1, SPG3),
PAST (spastin, SPG4),  ITPR1, WASHC5 (SPG8),  KIF1A (SPG30), SPG11 spastacsin), KIF5A (SPG10), CYP27A1, and SETX (3).
There are overlapping genetics and clinical symptoms with spinocerebellar ataxia and amyotrophic lateral sclerosis.
Reference
  1. Behjati, S., Tarpey, P., What is next generation sequencing? Arch Dis Child Educ Pract Ed. 2013 Dec; 98(6)236-238
  2. Kang, C., Liang, C., Ahmad, K.E., Gu, Y., Siow, S.F., Colebatch, J.G., Whyte, S., N, K., Cremer, P.D., Corbett, A.J., Davis, R.L., Roscioloi, T., Cowley, M.J., Park, S.J., Sue, C.M., Kumar, K.R. High Degree of Genetic Hetereogeneity for Hereditary Cerebellar Ataxias in Australia, Cerebellum, 2019, Feb. (1):137-146
  3. Elert-Dobkowska, E., Stepniak, I., Krysa, W., Ziora-Jakutowicz, K., Rakowicz, M., Sobanska, A., Pilch, J., Antczak-Marach, D., Zaremba, J., Sulek, A. Next-generation sequencing reveals the broader variant spectrum of hereditary spastic paraplegia and related phenotypes. Neurogenetic, 2019, Feb, doi:10.1007/s10048-019-00565-6
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