Test Code PSYCF Psychosine, Spinal Fluid
Ordering Guidance
This test is recommended as a diagnostic or monitoring test when spinal fluid is collected primarily to determine protein content in a patient at risk of or monitored for the development of signs of Krabbe disease.
An additional and less invasive diagnostic or monitoring test is measurement of psychosine in red blood cells; see PSYR / Psychosine, Whole Blood.
Shipping Instructions
Send on dry ice. Avoid freeze thaw cycles.
Necessary Information
1. Patient's age is required.
2. Date of hematopoietic stem cell transplantation (HSCT), if performed.
Specimen Required
Container/Tube: Sterile vial.
Specimen Volume: 0.15 mL
Collection Instructions: Do not aliquot.
Useful For
Aiding in the biochemical diagnosis of Krabbe disease using cerebrospinal fluid specimens
Follow-up of individuals affected with Krabbe disease
Follow-up testing after an abnormal newborn screening result for Krabbe disease
Monitoring individuals at risk to develop late onset Krabbe disease
Monitoring individuals with Krabbe disease after hematopoietic stem cell transplantation
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Psychosine, CSFSpecimen Type
CSFSpecimen Minimum Volume
0.1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
CSF | Frozen | 7 days |
Reference Values
Normal < 0.04 nmol/L
Interpretation
An elevation of psychosine is indicative of Krabbe disease or saposin A cofactor deficiency.
Clinical Reference
1. Kwon JM, Matern D, Kurtzberg J, et al. Consensus guidelines for newborn screening, diagnosis and treatment of infantile Krabbe disease. Orphanet J Rare Dis. 2018;13(1):30. doi: 10.1186/s13023-018-0766-x
2. Orsini JJ, Escolar ML, Wasserstein MP, et al. Krabbe disease. In: Adam MP, Mirzaa GM, Pagon RA, eds. GeneReviews[Internet]. University of Washington, Seattle; 2000. Updated October 11, 2018. Accessed August 31, 2023. Available at: www.ncbi.nlm.nih.gov/books/NBK1238/
3. Turgeon CT, Orsini JJ, Sanders KA, et al. Measurement of psychosine in dried blood spots--a possible improvement to newborn screening programs for Krabbe disease. J Inherit Metab Dis. 2015;38(5):923-929
4. Wenger DA, Escolar ML, Luzi P, Rafi MA: Krabbe disease (globoid cell leukodystrophy). In: Valle D, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019. Accessed August 31, 2023. Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225546481&bookid=2709
5. Guenzel AJ, Turgeon CT, Nickander KK, et al. The critical role of psychosine in screening, diagnosis, and monitoring of Krabbe disease. Genet Med. 2020;22(6):1108-1118
6. Thompson-Stone R, Ream MA, Gelb M, et al. Consensus recommendations for the classification and long-term follow up of infants who screen positive for Krabbe disease. Mol Genet Metab. 2021;134(1-2):53-59
Day(s) Performed
Tuesday, Thursday
Report Available
3 to 7 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82542
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
PSYCF | Psychosine, CSF | 93686-4 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
606150 | Interpretation (PSYCF) | 59462-2 |
606146 | Psychosine, CSF | 93686-4 |
605158 | Reviewed By | 18771-6 |
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.