U.S. flag

An official website of the United States government

GTR Home > Conditions/Phenotypes > Spinocerebellar ataxia type 6

Summary

Excerpted from the GeneReview: Spinocerebellar Ataxia Type 6
Spinocerebellar ataxia type 6 (SCA6) is characterized by adult-onset, slowly progressive cerebellar ataxia, dysarthria, and nystagmus. The age of onset ranges from 19 to 73 years; mean age of onset is between 43 and 52 years. Initial symptoms are gait unsteadiness, stumbling, and imbalance (in ~90%) and dysarthria (in ~10%). Eventually all persons have gait ataxia, upper-limb incoordination, intention tremor, and dysarthria. Dysphagia and choking are common. Visual disturbances may result from diplopia, difficulty fixating on moving objects, horizontal gaze-evoked nystagmus, and vertical nystagmus. Hyperreflexia and extensor plantar responses occur in up to 40%-50%. Basal ganglia signs, including dystonia and blepharospasm, occur in up to 25%. Mentation is generally preserved.

Genes See tests for all associated and related genes

  • Also known as: APCA, BI, CACNL1A4, CAV2.1, DEE42, EA2, EIEE42, FHM, HPCA, MHP, MHP1, SCA6, CACNA1A
    Summary: calcium voltage-gated channel subunit alpha1 A

Clinical features

Help

Show allHide all

Practice guidelines

  • EFNS/ENS, 2014
    EFNS/ENS Consensus on the diagnosis and management of chronic ataxias in adulthood.
  • EFNS, 2010
    EFNS guidelines on the molecular diagnosis of ataxias and spastic paraplegias.

IMPORTANT NOTE: NIH does not independently verify information submitted to the GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in the GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.