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Test Code PSYWB Psychosine, Blood

Specimen Required


Preferred: Lavender top (EDTA)

Acceptable: Green top (sodium heparin), yellow top (ACD)

Specimen Volume: 2 mL


1. Biochemical Genetics Patient Information (T602) in Special Instructions.

2. If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.

Secondary ID


Useful For

Aids in the biochemical diagnosis of Krabbe disease


Follow-up of individuals affected with Krabbe disease


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


This test is not capable of identifying carriers of Krabbe disease.

Testing Algorithm

See Newborn Screen Follow-up for Infantile Krabbe Disease in Special Instructions.

Method Name

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

Reporting Name

Psychosine, B

Specimen Type

Whole blood

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Refrigerated (preferred) 7 days
  Ambient  7 days

Reject Due To

No specimen should be rejected.

Reference Values

Normal <3.0 nmol/L psychosine

Day(s) and Time(s) Performed

Patients over 6 weeks of age:

Tuesday, Friday; 12 p.m.


Patients 6 weeks of age or younger:

Monday through Saturday; 4 p.m.

Sunday 1 p.m.

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. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
PSYWB Psychosine, B 93688-0


Result ID Test Result Name Result LOINC Value
601917 Psychosine 93688-0
601918 Reviewed By 18771-6
601919 Interpretation (PSYWB) 59462-2