Spinocerebellar Ataxia Type 1, 2, 3, 6, or 7, Repeat Expansion Analysis, Varies
Use
This test is used for diagnostic or predictive testing when clinical symptoms or family history specifically suggests one of the spinocerebellar ataxias (SCA) such as types 1, 2, 3, 6, or 7. It assesses for CAG repeat expansions within genes like ATXN1, ATXN2, ATXN3, CACNA1A, or ATXN7, which are implicated in these SCA subtypes. This can help identify individuals at risk or affected by these genetic disorders, guiding further management and counseling.
Special Instructions
Inform consent is required for New York clients. The test should not be ordered concurrently with other general SCA panels like SCAP. Clinical consultation for prenatal specimens is necessary.
Limitations
This test does not serve as a gene panel for all types of spinocerebellar ataxia. It is important to ensure that the suspected type aligns with those assessed by this test (SCA1, 2, 3, 6, or 7). Negative results do not exclude the possibility of a variant present below the detection limits of the assay. Somatic mosaicism may cause discrepancies in repeat size between blood and other tissues. Rare polymorphisms in primer binding regions may result in false negatives.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 21769-5
- 21769-5
- 36911-6
- 69047-9
- 42349-1
- 31208-2
- 85069-3
- 62364-5
- 18771-6
Result Turnaround Time
21-28 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
0.5 mL
Container
Lavender top (EDTA) or yellow top (ACD)
Collection Instructions
Invert several times to mix blood. Send the whole blood specimen in the original tube. Do not aliquot.
Patient Preparation
A previous bone marrow transplant from an allogenic donor will interfere with testing. For instructions for testing patients with such a history, contact the lab.
Causes for Rejection
Specimens will be evaluated for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |