Test Catalog

Test ID: PSYR    
Psychosine, Whole Blood

Useful For Suggests clinical disorders or settings where the test may be helpful

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

Genetics Test Information Provides information that may help with selection of the correct genetic test or proper submission of the test request

Krabbe disease (globoid cell leukodystrophy) is an autosomal recessive lysosomal disorder caused by deficient activity of the enzyme galactocerebrosidase (GALC).


Krabbe disease is clinically variable and infantile-onset Krabbe disease is the most severe variant with rapid neurological regression resulting in early death.


Elevations in psychosine support a diagnosis of Krabbe disease; therefore, psychosine quantitation is a useful biomarker in determining if an individual has active disease. In addition, psychosine may be a valuable biomarker to monitor disease progression, or treatment response.


Psychosine may also be elevated in saposin A cofactor deficiency, which results in a similar clinical phenotype to Krabbe disease, but patients typically have normal GALC activity in vitro.

Method Name A short description of the method used to perform the test

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

NY State Available Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name Lists a shorter or abbreviated version of the Published Name for a test

Psychosine, RBC

Aliases Lists additional common names for a test, as an aid in searching

Krabbe disease