Spinocerebellar ataxia 3 (SCA3) is a rare, inherited form of ataxia. Signs and symptoms may begin between childhood and late adulthood and vary greatly. Symptoms may include slowly progressive clumsiness in the arms and legs; a manner of walking (gait) that may be mistaken for drunkenness; difficulty speaking and swallowing; impaired eye movements or vision; and lower limb spasticity. Some people with SCA3 develop dystonia or symptoms similar to those of Parkinson’s disease; twitching of the face or tongue; nerve damage (neuropathy); or problems with urination and the autonomic nervous system. SCA3 is caused by a mutation in the ATXN3 gene and inheritance is autosomal dominant. There is no medication that slows the progressive course of the disease; management aims to relieve some symptoms and improve quality of life. Life expectancy ranges from the mid-30s for those with the most severe forms, to a nearly normal life expectancy for those with milder forms.