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. The most common repeat expansion disorders include the autosomal dominant spinocerebellar ataxias (SCAs) and the autosomal recessive Friedreich ataxia. Fragile X-associated tremor/ataxia syndrome (FXTAS), caused by a premutation in the FMR1 gene, is the most common X-linked cause of cerebellar ataxia. Recently, a biallelic intronic expansion in the RFC1 gene has recently been identified in the majority of patients with CANVAS (Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome) and in a proportion of late onset ataxia patients. The concurrent testing option includes simultaneous repeat expansion and exome sequence analysis.

 

 

 

Institutional Price 
$5,000.00
TAT 
6 weeks
CPT Code 
81443
Test Code 
4102
Test Methods 
Exome sequencing
Repeat Expansion Testing
Specimen Types Accepted 
Blood
Saliva
Buccal
Cultured Cells
Extracted DNA
Additional Information 
Reanalysis can be performed once at no additional charge; additional charges may apply for further reanalysis requests.
Repeat expansion testing for a single gene on the Ataxia Repeat Expansion Panel is available in our laboratory. Please contact us directly for cost and CPT code information.