Test Details
Technology
Methodology
Repeat-primed PCR and fragment length analysis to identify the number of nucleotide repeats
Result Turnaround Time
14 - 21 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
This test includes the following gene(s): ATXN8OS.
Use
This test is used for diagnostic testing and presymptomatic testing for family members.
Limitations
Technologies used do not detect germline mosaicism and do not rule out the presence of large chromosomal aberrations, including rearrangements and gene fusions, or variants in regions or genes not included in this test or possible inter/intragenic interactions between variants. False positive or false negative results may occur for reasons that include: rare genetic variants, sex chromosome abnormalities, pseudogene interference, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples or erroneous representation of family relationships.
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Specimen Requirements
Specimen
Whole blood or PurFlock buccal swab kit or Oragene Dx 500 saliva kit
Volume
4 mL whole blood or PurFlock buccal swab kit or Oragene Dx 500 saliva kit
Minimum Volume
3 mL whole blood or PurFlock buccal swab kit or Oragene Dx 500 saliva kit
Container
Lavender-top (EDTA) tube or yellow-top (ACD-A) tube or PurFlock buccal swab kit or Oragene Dx 500 saliva collection kit
Collection Instructions
Standard phlebotomy; follow PurFlock buccal swab kit or Oragene Dx 500 saliva kit collection instructions. Do not eat, drink, smoke or chew gum 30 minutes prior to collection.
Stability Requirements
| Temperature | Period |
| Room temperature | Whole blood: 14 days; buccal swab: 60 days; saliva: 60 days |
| Refrigerated | Whole blood: 30 days; buccal swab: unstable; saliva: unstable |
| Frozen | All sample types: unstable |
Storage Instructions
Maintain specimen at room temperature or refrigerate at 4°C. Do not freeze.
Causes for Rejection
Frozen or hemolyzed specimen; quantity not sufficient for analysis; improper container