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Machado-Joseph Disease (MJD)/Spinocerebellar Ataxia Type 3 (SCA3) via the ATXN3 … see more Machado-Joseph Disease (MJD)/Spinocerebellar Ataxia Type 3 (SCA3) via the ATXN3 CAG Repeat Expansion  see less
Clinical Genetic Test
Help
offered by
PreventionGenetics, part of Exact Sciences
View lab's test page
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GTR Test Accession: Help GTR000596301.1
PSYCHIATRICNERVOUS SYSTEMINHERITED DISEASE ... View more
Last updated in GTR: 2021-10-19
View version history
Last annual review date for the lab: 2023-06-19 LinkOut
At a Glance
Test purpose: Help
Diagnosis; Mutation Confirmation; Pre-symptomatic; ...
Conditions (1): Help
Azorean disease
Genes (1): Help
ATXN3 (14q32.12)
Methods (1): Help
Molecular Genetics - Targeted variant analysis: PCR with allele specific hybridization
Target population: Help
Testing for the ATXN3 repeat expansion is recommended for individuals …
Clinical validity: Help
Not provided
Clinical utility: Help
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
13213
View other test codes
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: 13213
Test additional service: Help
Custom Prenatal Testing
    OrderCode: 990
Test development: Help
Test developed by laboratory (no manufacturer test name)
Informed consent required: Help
No
Pre-test genetic counseling required: Help
No
Post-test genetic counseling required: Help
No
Recommended fields not provided:
Lab contact for this test, Contact policy, Test strategy
Conditions Help
Total conditions: 1
Condition/Phenotype Identifier
Test Targets
Genes Help
Total genes: 1
Gene Associated Condition Germline or Somatic Allele (Lab-provided) Variant in NCBI
Methodology
Total methods: 1
Method Category Help
Test method Help
Instrument
Targeted variant analysis
PCR with allele specific hybridization
Other
Clinical Information
Test purpose: Help
Diagnosis; Mutation Confirmation; Pre-symptomatic; Risk Assessment; Screening
Target population: Help
Testing for the ATXN3 repeat expansion is recommended for individuals suspected of having MSCA3 (presentation of progressive cerebellar ataxia and variable findings such as pyramidal and extra-pyramidal signs, peripheral amyotrophy, generalized areflexia, progressive external ophthalmoplegia, facial and lingual muscle twitches, and bulging eyes). Testing is also recommended for individuals with … View more
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:
Clinical validity, Clinical utility, Is research allowed on the sample after clinical testing is complete?, Sample negative report, Sample positive report
Technical Information
Test Procedure: Help
This test is designed to only detect pathogenic expansions of a poly-glutamine CAG repeat in exon 10 of the ATXN3 gene but does not assess for CAA interruptions. Our assay involves two amplicon-length assays from both the 3’ and 5’ ends of the repeat region to determine lengths of repeats. … View more
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
This test for repeat expansions in ATXN3 has approximately 100% clinical sensitivity for detection of MJD/SCA3 (Paulson and Shakkottai. 2020. PubMed ID: 20301375).
Proficiency testing (PT):
Is proficiency testing performed for this test? Help
Yes

Method used for proficiency testing: Help
Intra-Laboratory
VUS:
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:
Test Confirmation, Assay limitations, Description of internal test validation method, Citations for Analytical validity, PT Provider, Description of PT method, Major CAP category, CAP category, CAP test list
Regulatory Approval
FDA Review: Help
Category: FDA exercises enforcement discretion
Additional Information

IMPORTANT NOTE: NIH does not independently verify information submitted to GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.