Spinocerebellar ataxia 3
is a rare movement disorder that is characterized by ataxia, clumsiness and weakness in the arms and legs, spasticity, a staggering lurching walk easily mistaken for drunkenness, difficulty with speech and swallowing, and involuntary eye movements sometimes accompanied by double vision, and bulging eyes. Some patients have dystonia or symptoms similar to those of Parkinson's disease. Others have twitching of the face or tongue, neuropathy, or problems with urination and the autonomic nervous system. Symptoms can begin any time between childhood and about 70 years of age. Spinocerebellar ataxia 3 is a progressive disease, meaning that symptoms get worse with time. Life expectancy ranges from the mid-thirties for those with severe forms of the disorder to a normal life expectancy for those with mild forms. Spinocerebellar ataxia is inherited in an autosomal dominant pattern and is caused by a trinucleotide repeat expansion in the ataxin-3 gene (ATXN3). Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.