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Disease Profile

Spinocerebellar ataxia type 6

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
1-9 / 1 000 000

331 - 2,979

US Estimated

1-9 / 1 000 000

514 - 4,622

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

SCA6; Spinocerebellar ataxia 6


Congenital and Genetic Diseases; Nervous System Diseases


Spinocerebellar ataxia type 6 (SCA6) is a neurological condition characterized by progressive problems with movement. Initial symptoms include problems with coordination and balance (ataxia). Other early signs and symptoms include speech difficulties (dysarthria), involuntary eye movements (nystagmus), and double vision. Over time, individuals with SCA6 may develop loss of coordination in their arms, tremors, and uncontrolled muscle tensing (dystonia). The signs and symptoms of SCA6 typically begin in a person's forties or fifties. Most people with this disorder require wheelchair assistance by the time they are in their sixties. Spinocerebellar ataxia type 6 is caused by mutations in the CACNA1A gene. This condition is inherited in an autosomal dominant pattern.[1]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Difficulty seeing moving objects
Gait ataxia
Inability to coordinate movements when walking
Gaze-evoked horizontal nystagmus
Difficulties in coordination
Incoordination of limb movements
Limb incoordination

[ more ]

Intention tremor
Postural instability
Balance impairment
Progressive cerebellar ataxia
Unsteady gait
Unsteady walk
30%-79% of people have these symptoms
Babinski sign
Choking episodes
Double vision
Poor swallowing
Swallowing difficulties
Swallowing difficulty

[ more ]

Increased reflexes
Vertical nystagmus
5%-29% of people have these symptoms
Eyelid spasm
Eyelid twitching
Involuntary closure of eyelid
Spontaneous closure of eyelid

[ more ]

Difficulty articulating speech
Intermittent migraine headaches
Migraine headache
Migraine headaches

[ more ]

Percent of people who have these symptoms is not available through HPO
Abnormal vestibulo-ocular reflex
Autosomal dominant inheritance
Cerebellar atrophy
Degeneration of cerebellum
Gaze-evoked nystagmus
Genetic anticipation
Impaired smooth pursuit
Worsens with time
Sensory neuropathy
Damage to nerves that sense feeling


Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
  • Spinocerebellar Ataxia: Making an Informed Choice about Genetic Testing is a booklet providing information about spinocerebellar ataxia and is available as a PDF document on the University of Washington Medical Center Web site. Click on the title above to view this resource.


    While there is no specific treatment which can prevent of slow the progression of SCA6, there are therapies available to help manage the symptoms.[2] For instance:[3]


    • Episodes of ataxia, vertigo, and sleep disorders can be treated with medication,
    • Home modifications may be made for safety and convenience,
    • Canes and walkers can allow for continued mobility,
    • Speech therapy and communication devices may help with dysarthria, and
    • Weighted eating utensils and dressing hooks can help patients maintain independence. 

    Affected individuals should be followed annually or semiannually by a neurologist, with consultations as needed with other specialists.[3] More detailed information related to the treatment of SCA6 can be accessed through the GeneReviews Web site.


    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

        In-Depth Information

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Spinocerebellar ataxia type 6. Click on the link to view a sample search on this topic.


          1. Spinocerebellar ataxia type 6. Genetics Home Reference (GHR). 2011; https://ghr.nlm.nih.gov/condition/spinocerebellar-ataxia-type-6. Accessed 10/10/2012.
          2. Frequently Asked Questions About Spinocerebellar Ataxia Type 6 (SCA6). National Ataxia Foundation. 2012; https://www.ataxia.org/pdf/NAF%20Web%20Content%20Publication%20SCA6.pdf. Accessed 10/10/2012.
          3. Gomez CM. Spinocerebellar Ataxia Type 6. GeneReviews. 2008; https://www.ncbi.nlm.nih.gov/books/NBK1140/. Accessed 10/10/2012.

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