Disease Directory Spinocerebellar Ataxia
Neurological

Spinocerebellar Ataxia

Also known as: SCA, autosomal dominant cerebellar ataxia, ADCA, SCA1/SCA2/SCA3/SCA6/SCA7 and others

Prevalence

1-5 per 10,000 (Orphanet, all types combined)

Onset

Adult, Adolescent

Type

Autosomal dominant genetic (most types, trinucleotide or other repeat expansion)

Gene

ATXN1 (SCA1), ATXN2 (SCA2), ATXN3 (SCA3/MJD), CACNA1A (SCA6), ATXN7 (SCA7), TBP (SCA17)

About Spinocerebellar Ataxia

Spinocerebellar ataxias (SCAs) are a heterogeneous group of autosomal dominant neurodegenerative disorders characterized by progressive cerebellar ataxia, with over 40 genetic subtypes identified. The most common types (SCA1, SCA2, SCA3, SCA6, SCA7) are caused by CAG trinucleotide repeat expansions in their respective genes, encoding polyglutamine tracts that cause toxic protein aggregation. Clinical features beyond cerebellar ataxia vary by subtype and include pyramidal signs, peripheral neuropathy, ophthalmoplegia, and cognitive decline.

Common Clinical Features

Progressive cerebellar ataxia Dysarthria Nystagmus and oculomotor abnormalities Pyramidal signs (spasticity, hyperreflexia) Peripheral neuropathy Cognitive decline Dysphagia

Clinical Trial Eligibility Tips

What to know before applying to Spinocerebellar Ataxia trials.

SCA subtype must be genetically confirmed — repeat expansion length and subtype are required for all trials

Scale for Assessment and Rating of Ataxia (SARA) score is the primary eligibility and outcome measure

CAG repeat length predicts age of onset and progression rate — this affects trial stratification and eligibility windows

Antisense oligonucleotide (ASO) and gene silencing trials are subtype-specific (e.g., SCA3 ASO trials differ from SCA1)

Patient Resources

Patient Organization

National Ataxia Foundation

Visit website ↗

Natural History Registry

Clinical Research Consortium for Spinocerebellar Ataxias (CRC-SCA) Registry

Join registry ↗

Orphanet

European reference resource for rare diseases (ORPHA:99)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Spinocerebellar Ataxia trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Spinocerebellar Ataxia. Updated daily.

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