Ataxias, hereditary or sporadic, represent a clinically and genetically complex group of neurological disorders that are characterized by uncoordinated body movements and may present with gait abnormalities, dysarthria, apraxia, dysphagia and other pyramidal and extrapyramidal signs. The ataxia symptom can be isolated or part of a multisystemic neurological disorder, presenting at ages ranging from infancy to adulthood, and can be dominant, recessive, X-linked or mitochondrial. Genetic testing for hereditary ataxias remains challenging mostly due to the significant clinical overlap and genetic heterogeneity with more than 500 genes reported to be associated with ataxia or ataxia-like presentation. Targeted exome sequencing is regarded as a powerful diagnostic tool for heterogeneous neurological disorders such as ataxia but limited in its ability to detect repeat expansions which are estimated to account for over 50% of dominant hereditary ataxias. The UCGSL provides a comprehensive testing approach for the diagnosis of neurodegenerative disorders that includes a targeted exome sequencing analysis of a predefined, and continually updated set of 500+ genes and a repeat expansion panel consisting of 13 genes. The ataxia exome involves analysis of exome sequencing data in a predefined set of genes associated with ataxia and ataxia-related disorders. Age of onset of symptoms for the included genes ranges from infancy to adulthood.
