Description : The autosomal dominant cerebellar ataxias (ADCAs) are a clinically and genetically
heterogeneous group of disorders characterized by ataxia, dysarthria, dysmetria, and
intention tremor. All ADCAs involve some degree of cerebellar dysfunction and a varying
degree of signs from other components of the nervous system. A commonly accepted clinical
classification (Harding, 1993) divides ADCAs into 3 different groups based on the
presence or absence of associated symptoms such as brainstem signs or retinopathy.
The presence of pyramidal and extrapyramidal symptoms and ophthalmoplegia makes the
diagnosis of ADCA I, the presence of retinopathy points to ADCA II, and the absence
of associated signs to ADCA III. Genetic linkage and molecular analyses revealed that
ADCAs are genetically heterogeneous even within the various subtypes.;
Inheritance : Autosomal dominant;
Molecular basis : Caused by a pentanucleotide repeat expansion (ATTCT)n in the ataxin 10 gene (ATXN10,
603516.0001).;