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Test Code PSYR Psychosine, Whole Blood


Ordering Guidance


This test is recommended for individuals of all ages, infancy through adulthood, for diagnosis or long-term monitoring of patients who have been treated or who are at risk of developing Krabbe disease.

 

If a result is needed within 24 hours, order PSY / Psychosine, Blood Spot.



Shipping Instructions


Must be sent refrigerated.



Necessary Information


1. Patient’s age is required.

2. Date of hematopoietic stem cell transplantation (HSCT), if performed.



Specimen Required


Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: Green top (sodium heparin, lithium heparin)

Specimen Volume: 2 mL


Useful For

Aiding in the biochemical diagnosis of Krabbe disease using whole blood specimens

 

Follow-up of individuals affected with Krabbe disease

 

Follow-up testing after an abnormal newborn screening result for Krabbe disease

 

Monitoring of individuals at risk to develop late onset Krabbe disease

 

Monitoring of individuals with Krabbe disease after hematopoietic stem cell transplantation

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Psychosine, RBC

Specimen Type

Whole blood

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Refrigerated 7 days

Reference Values

Normal <5 pmol/g Hb

Interpretation

An elevation of psychosine is indicative of Krabbe disease or saposin A cofactor deficiency.

Clinical Reference

1. Newborn Screening ACT Sheet [Decreased galactocerebrosidase, elevated psychosine] Krabbe Disease (infantile form). American College of Medical Genetics and Genomics; 2021. Updated May 2022. Accessed June 10, 2024. Available at www.acmg.net/PDFLibrary/Krabbe-Infantile.pdf

2. Newborn Screening ACT Sheet [Decreased galactocerebrosidase, mildly elevated psychosine] Krabbe Disease (late-onset form). American College of Medical Genetics and Genomics; 2021. Updated May 2022. Accessed June 10, 2024. Available www.acmg.net/PDFLibrary/Krabbe-Later-Onset.pdf

3. 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

4. Orsini JJ, Escolar ML, Wasserstein MP, et al. Krabbe disease. In: Adam MP, Mirzaa GM, Pagon R, eds. GeneReviews [Interntet]. University of Washington, Seattle; 2000. Updated October 11, 2018. Accessed August 31, 2023. Available at www.ncbi.nlm.nih.gov/books/NBK1238/

5. 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

6. 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

7. 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. doi:10.1038/s41436-020-0764-y

8. 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. doi:10.1016/j.ymgme.2021.03.016

Day(s) Performed

Tuesday, Thursday

Report Available

3 to 7 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test 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
PSYR Psychosine, RBC 93687-2

 

Result ID Test Result Name Result LOINC Value
606152 Interpretation (PSYR) 59462-2
606145 Psychosine, RBC 93687-2
606151 Reviewed By 18771-6

Testing Algorithm

If the patient has abnormal newborn screening result for Krabbe disease, immediate action should be taken. Refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1,2)