Psychosine, Blood Spot
Use
This test aids in the biochemical detection of Krabbe disease and saposin A cofactor deficiency. It is utilized as second-tier or follow-up testing after an abnormal newborn screening result for Krabbe disease. The test can detect patients with infantile or late infantile Krabbe disease or saposin A deficiency, which presents with reduced GALC activity and elevated psychosine levels. It is not capable of identifying carriers of Krabbe disease, nor is it intended for long-term monitoring of patients under treatment for Krabbe or for older children and adults at risk of developing the disease.
Special Instructions
This test is recommended for newborns or infants who have not had previous psychosine testing. For patients older than infancy, the PSYR / Psychosine, Whole Blood test should be ordered. Proper collection involves completely filling at least two circles on the filter paper with the blood sample, drying it thoroughly, and ensuring the specimen is not exposed to heat or sunlight.
Limitations
Normal psychosine levels may be observed in patients not yet symptomatic or in those with later onset forms of Krabbe disease or saposin A cofactor deficiency. The test is unsuitable for identifying carriers or for long-term monitoring purposes in children or adults.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 93688-0
- 93688-0
- 18771-6
- 59462-2
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
2 Blood spots
Minimum Volume
1 Blood spot
Container
Card-Blood Spot Collection (Filter Paper)
Collection Instructions
Completely fill at least 2 circles on the filter paper card (approximately 100 microliters blood per circle). Let blood dry on filter paper at ambient temperature in a horizontal position for a minimum of 3 hours. Do not expose specimen to heat or direct sunlight. Do not stack wet specimens. Keep specimen dry.
Causes for Rejection
Blood spot specimen that shows serum rings or has multiple layers; Insufficient specimen; Nonapproved filter paper
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 96 days |
| Refrigerated | 96 days |
| Frozen | 96 days |