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HelpTest Code LAB3462 Spinocerebellar Ataxia Panel
Clinical System Name
Spinocerebellar Ataxia Panel
Synonyms
SCAPN
Ataxia Panel
SCA1
SCA2
SCA3
SCA6
SCA7
MJD
Description
This test includes CAG repeat of the indicated gene for a specific type of spinocerebellar atxia: ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7
Sample Requirements
Specimen: Whole blood
Container(s): Lavender/EDTA; Yellow/ACD is also acceptable
Preferred Vol: 5.0 mL
Minimum Vol: 2.0 mL
Specimen: DNA
Container(s): Sterile plastic tube
Preferred Vol: 10 µg of purified DNA at a concentration of at least 20 µg/ml
Minimum Vol:
Alternative Specimen (e.g. salvia or buccal): Alternate Specimen Collection Kits for Genetic Testing
Processing Instructions
Reject due to: Dark Green/Sodium Heparin tube. Formalin-fixed paraffin-embedded tissues.
Spin: N
Aliquot: N
Temp: RT
Storage location: Do not spin or separate specimen. Store whole blood in the CPA room temp Send Outs rack.
Off-site collection: Do not spin or separate specimen. Transport at room temp.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole blood | Room temp |
3 d |
| Refrigerated | 7 d | |
| Frozen |
Unacceptable |
|
| Extracted DNA | Room temp | 3-4 d |
| Refrigerated | 1 y | |
| Frozen | Indefinitely |
Availability
| STAT | Performed | TAT |
|---|---|---|
| N |
Weekly |
2 - 3 w |
Performing Laboratory
University of Washington Medical Center
Department of Laboratory Medicine
Genetics Lab
1959 NE Pacific St, NW220
Seattle, WA 98195
Phone Number: (206) 520-4600
Department
Department: Send Outs/Genetic
Phone Number: (206) 987-2563
Reference Range
Interpretive report provided.
Methodology
Method: Polymerase Chain Reaction (PCR)/Capillary Electrophoresis
The region containing the CAG repeat of the indicated gene for a specific type of spinocerebellar atxia (ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7) was amplified and fragment lengths determined by comparison to molecular weight standards after capillary electrophoresis. This test was developed and its performance characteristics determined by the Department of Laboratory Medicine at the University of Washington.
Special Instructions
Clinical Utility
The dominant cerebellar ataxias are a clinically and genetically heterogeneous group of disorders that cannot be differentiated reliably from each other on a clinical basis. DNA testing is highly sensitive and specific and provides a definitive diagnosis for an estimated 50-60% of White patients with findings of dominant cerebellar ataxia. Patient DNA is analyzed to determine the number of CAG trinucleotide repeats located within each allele of the five causative genes; an abnormally large number of CAG repeats is diagnostic for the disease.
Indications for testing include:
- Symptomatic testing for patients with ataxia and a family history of ataxia
- Differential diagnosis for isolated cases of unexplained progressive ataxia (expect a relatively low positive rate)
- Presymptomatic testing for at-risk family members with appropriate genetic counseling
Send Out Instructions
| Reference Test Name: |
Spinocerebellar Ataxia Panel |
| Reference Test Number: |
SCAPN |
| Instructions: |
Send out Monday - Friday with the UW courier. |