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Spinocerebellar Ataxia Repeat Expansion Testing

 

Background

Hereditary ataxias are a group of genetic disorders characterised by slowly progressive gat incoordination, often with poor coordination of hands, speech and eye movements and frequent cerebellar atrophy.

The prevalence of autosomal dominant cerebellar ataxias is estimated to be of the order of 1-5 per 100,000 population, with SCA3 the most common worldwide, followed by SCA1, SCA2, SCA6 and SCA7. There are different patterns of distribution of these disorders in different ethnic groups, with a founder effect seen for some SCA sub-types. These 5 SCAs are all caused by triplet repeat expansions in the coding regions of the relevant genes.

Testing at WRGL

Fluorescent PCR is used to perform this testing. The results of the assay can be visualised using GeneMarker software following fragment analysis on a genetic analyser. The possibility of very large expansions refractory to detection by standard methodology is excluded by the use of triplet-primed PCR assays when patients are apparently homozygous for SCA2, SCA3 or SCA7. Positive and negative controls are included in each assay.

Cost, Sample Requirements & Turnaround Times

  

Test

Cost NZD

Sample requirements

Turnaround time

CAG repeat expansion tests for SCA1, 2, 3, 6 and 7

500

4ml of whole blood in EDTA

4 weeks

For urgent cases please contact the laboratory

Testing for individual SCAs

150

4ml of whole blood in EDTA

2 weeks

For urgent cases please contact the laboratory

Spinocerebellar Ataxia (SCA) types 1, 2, 3, 6 and 7 testing

ABOUT US

Wellington Regional Genetics Laboratory (WRGL) provides a comprehensive, integrated diagnostic cytogenetic and molecular genetic testing service

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CONTACT US

(04) 918-5352
wrgl@ccdhb.org.nz