The dominantly inherited spinocerebellar ataxias (SCAs) are a large and diverse group of neurodegenerative diseases. The most prevalent SCAs (SCA1, SCA2, SCA3, SCA6 and SCA7) are caused by expansion of a glutamine-encoding CAG repeat in the affected gene. These SCAs represent a substantial portion of the polyglutamine neurodegenerative disorders and provide insight into this class of diseases as a whole. Recent years have seen considerable progress in deciphering the clinical, pathological, physiological and molecular aspects of the polyglutamine SCAs, with these advances establishing a solid base from which to pursue potential therapeutic approaches.
Bibliographical noteFunding Information:
The authors thank J. Friedrich for designing the artwork that formed the foundation for the figures in this Review. Financial support for the authors’ research was provided by the US National Institute of Neurological Disorders and Stroke, the US National Institutes of Health and the US National Ataxia Foundation.