Spinocerebellar ataxia 17: full phenotype in a 42 CAG/CAA-repeats carrier.
Spinocerebellar ataxia 17 (SCA17) is one of the most heterogeneous forms of autosomal dominant cerebellar ataxia with a wide clinical spectrum, which can imitate other motor disorders. The article presents an observation of a 51-year-old woman with slowly progressive coordination disorders and changes in handwriting manifested at the age of 39 years. Neurologic examination reveals severe cerebellar ataxia, choreiform hyperkinesis, polyneuropathy, cognitive and mental disorders; magnetic resonance imaging (MRI) of the brain shows moderate diffuse atrophy of the cerebral cortex, severe atrophy of the cerebellum hemispheres. Molecular analysis of the TBP demonstrates an allele with 42 CAG/CAG-repeats suggesting that an allele of this size could be an allele associated with the full clinical spectrum of SCA17.