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Ataxin 3 (ATXN3) gene CAG triplet repeat test
Clinical Genetic Test
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offered by
Neurogenetics
View lab's test page
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GTR Test Accession: Help GTR000078647.3
INHERITED DISEASENERVOUS SYSTEMPSYCHIATRIC ... View more
Last updated in GTR: 2015-11-26
View version history
Last annual review date for the lab: 2024-09-04 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: Trinucleotide repeat by PCR or Southern Blot
Target population: Help
Ataxia patients
Clinical validity: Help
Not provided
Clinical utility: Help
Establish or confirm diagnosis
Ordering Information
Offered by: Help
Neurogenetics
View lab's website
View lab's test page
Test short name: Help
SCA3
Specimen Source: Help
Who can order: Help
  • Genetic Counselor
  • Health Care Provider
  • Licensed Physician
Test Order Code: Help
20-5
Contact Policy: Help
Laboratory can only accept contact from health care providers. Patients/families are encouraged to discuss genetic testing options with their health care provider.
How to Order: Help
Completion of the laboratory referral letter by the referring physician/scientist. Provision of a signed informed consent form. Both forms are available on the laboratory website.
Order URL
Test service: Help
Clinical Testing/Confirmation of Mutations Identified Previously
Test development: Help
Test developed by laboratory but exempt from FDA oversight (eg. NYS CLEP approved, offered within a hospital or clinic)
Informed consent required: Help
Yes
Pre-test genetic counseling required: Help
Yes
Post-test genetic counseling required: Help
Yes
Recommended fields not provided:
Lab contact for this test, 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
Trinucleotide repeat by PCR or Southern Blot
Applied Biosystems 3130xl genetic analyser
Clinical Information
Test purpose: Help
Diagnosis; Mutation Confirmation; Pre-symptomatic; Risk Assessment
Clinical utility: Help
Establish or confirm diagnosis
View citations (1)

Target population: Help
Ataxia patients
View citations (1)
  • CAG expansions in a novel gene for Machado-Joseph disease at chromosome 14q32.1. Kawaguchi Y, et al. Nat Genet. 1994;8(3):221-8. doi:10.1038/ng1194-221. PMID: 7874163.
Recommended fields not provided:
Clinical validity, What is the protocol for interpreting a variation as a VUS?, Are family members with defined clinical status recruited to assess significance of VUS without charge?, Will the lab re-contact the ordering physician if variant interpretation changes?, Is research allowed on the sample after clinical testing is complete?, Sample negative report, Sample positive report
Technical Information
Test Procedure: Help
FAM labelled PCR and Applied Biosystems 3031xl automated fragment analysis of the CAG repeat expansion in the 3' end of the ataxin-3 gene (MJD1/SCA3) on chromosome 14q32.1. In most populations, normal ataxin-3 CAG repeat alleles have <48 copies of the CAG repeat. Pathological alleles contain 53 to 86 CAG repeats.
View citations (1)
  • CAG expansions in a novel gene for Machado-Joseph disease at chromosome 14q32.1. Kawaguchi Y, et al. Nat Genet. 1994;8(3):221-8. doi:10.1038/ng1194-221. PMID: 7874163.
Test Confirmation: Help
different method or new sample
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
99% precise
Proficiency testing (PT):
Is proficiency testing performed for this test? Help
Yes

Method used for proficiency testing: Help
Formal PT program

PT Provider: Help
European Molecular Genetics Quality Network, EMQN
Recommended fields not provided:
Assay limitations, Description of internal test validation method, Citations for Analytical validity, Description of PT method, Major CAP category, CAP category, CAP test list
Regulatory Approval
FDA Review: Help
Category: Not Applicable
Additional Information

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