Spinocerebellar Ataxia Type 2 via the ATXN2 CAG Repeat Expansion
GTR Test Accession: Help GTR000591850.1
Last updated in GTR: 2020-09-18
Last annual review date for the lab: 2023-06-19 LinkOut
At a Glance
Diagnosis; Mutation Confirmation; Pre-symptomatic; ...
Parkinson disease, late-onset; Spinocerebellar ataxia type 2
Genes (1): Help
ATXN2 (12q24.12)
Molecular Genetics - Targeted variant analysis: PCR with allele specific hybridization
Testing for ATXN2 repeat expansions is recommended for individuals suspected …
Not provided
Not provided
Ordering Information
Offered by: Help
PreventionGenetics, part of Exact Sciences
View lab's website
View lab's test page
Specimen Source: Help
Who can order: Help
  • Genetic Counselor
  • Health Care Provider
  • Licensed Physician
Test Order Code: Help
How to Order: Help
Please visit Lab website for details. Additional specimen types may be acceptable based on method. Please contact us about prenatal cases.
Order URL
Test service: Help
Clinical Testing/Confirmation of Mutations Identified Previously
    OrderCode: 12976
Test additional service: Help
Custom Prenatal Testing
    OrderCode: 990
Test development: Help
Test developed by laboratory (no manufacturer test name)
Informed consent required: Help
Pre-test genetic counseling required: Help
Post-test genetic counseling required: Help
Recommended fields not provided:
Conditions Help
Total conditions: 2
Condition/Phenotype Identifier
Test Targets
Genes Help
Total genes: 1
Gene Associated Condition Germline or Somatic Allele (Lab-provided) Variant in NCBI
Total methods: 1
Method Category Help
Test method Help
Targeted variant analysis
PCR with allele specific hybridization
Applied Biosystems 3730 capillary sequencing instrument
Clinical Information
Test purpose: Help
Diagnosis; Mutation Confirmation; Pre-symptomatic; Risk Assessment; Screening
Target population: Help
Testing for ATXN2 repeat expansions is recommended for individuals suspected to have SCA2 (presentation of progressive ataxia and dysarthria, nystagmus, and slow saccadic eye movement) in addition to a family history consistent with autosomal dominant inheritance.
Variant Interpretation:
What is the protocol for interpreting a variation as a VUS? Help
The PreventionGenetics protocol for interpreting sequence variants has been carefully developed over a period of 10 years. We are conservative in our interpretations. We do not label a variant as pathogenic or benign without conclusive evidence. Although we use a variety of software to assist us in interpretation, we rely … View more

Are family members with defined clinical status recruited to assess significance of VUS without charge? Help
Yes. Please visit our website for details at https://www.preventiongenetics.com/forms.php for Targeted variant tests.

Will the lab re-contact the ordering physician if variant interpretation changes? Help
Yes. Please visit our website for details http://preventiongenetics.com/
Recommended fields not provided:
Technical Information
Test Procedure: Help
This test is designed to detect pathogenic expansions of the poly-glutamine CAG repeat in exon 1 of ATXN2. Our assay is similar to an assay described by Van Damme et al. (Van Damme et al. 2011. PubMed ID: 21562247). A combination of amplicon-length analysis and repeat-primed PCR is used to … View more
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
This test for repeat expansions in ATXN2 has near 100% clinical sensitivity for detection of SCA2 (Pulst. 2019. PubMed ID: 20301452).
Proficiency testing (PT):
Is proficiency testing performed for this test? Help

Method used for proficiency testing: Help
Software used to interpret novel variations Help
GeneSplicer, Human Splicing Finder, MaxEntScan, Mutation Taster, NNSPLICE, PolyPhen 2, SIFT and Splice Site Finder.

Laboratory's policy on reporting novel variations Help
Sequence variants found in our patients are contributed to ClinVar. Anonymous patient sequence data will also be shared with researchers for preparation of peer-reviewed publications.
Recommended fields not provided:
Regulatory Approval
FDA Review: Help
Category: FDA exercises enforcement discretion
Additional Information

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