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Spinocerebellar ataxia type 8

Synonym(s) SCA8
Prevalence Unknown
Inheritance Autosomal dominant
Age of onset Adult
  • G11.2
  • C1837454
  • C537307
MedDRA -


Disease definition

Spinocerebellar ataxia type 8 (SCA8) is a subtype of type I autosomal dominant cerebellar ataxia (ADCA type I; see this term) characterized by cerebellar ataxia and cognitive dysfunction in almost three quarters of patients and pyramidal and sensory signs in approximately a third of patients.


Prevalence is unknown. However, SCA8 accounts for approximately 3% of ADCA cases.

Clinical description

Other features include dysexecutive disorders and commonly psychiatric disorders.


SCA8 is caused by a trinucleotide repeat on 13q21 that produces a polyglutamine expansion in the ataxin 8 gene (ATXN8). SCA8 is thought to result from RNA-mediated neurotoxicity.


Prognosis is relatively good. Disease usually progresses slowly over decades. Life expectancy is not significantly reduced.

Expert reviewer(s)

  • Dr Shinsuke FUJIOKA
  • Dr Nathaniel WHALEY
  • Dr Zbigniew WSZOLEK

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Detailed information

Summary information
Review article
Article for general public
Clinical genetics review
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