Test Code GALCW Galactocerebrosidase, Leukocytes
Ordering Guidance
This test will not detect carrier status. For differentiating alterations from disease-causing variants in affected patients and for carrier detection in family members, molecular sequencing of the GALC gene is necessary. Order KRABZ / Krabbe Disease, Full Gene Analysis and Large (30 kb) Deletion, Varies.
Shipping Instructions
For optimal isolation of leukocytes, it is recommended the specimen arrive refrigerate within 6 days of collection to be stabilized. Collect specimen Monday through Thursday only and not the day before a holiday. Specimen should be collected and packaged as close to shipping time as possible.
Specimen Required
Container/Tube:
Preferred: Yellow top (ACD solution B)
Acceptable: Yellow top (ACD solution A) or lavender top (EDTA)
Specimen Volume: 6 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Biochemical Genetics Patient Information (T602)
3. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Useful For
Diagnosis of Krabbe disease
Follow-up testing for evaluation of an abnormal newborn screening result for Krabbe disease
This test is not intended for carrier detection.
Testing Algorithm
The following information is available:
-Newborn Screen Follow-up for Krabbe Disease: Galactocerebrosidase
-Newborn Screen Follow-up for Krabbe Disease: Galactocerebrosidase and Psychosine
-Newborn Screening Act Sheet Krabbe Disease: Decreased Galactocerebrosidase
Special Instructions
- Informed Consent for Genetic Testing
- Biochemical Genetics Patient Information
- Newborn Screening Act Sheet Krabbe Disease: Decreased Galactocerebrosidase
- Informed Consent for Genetic Testing (Spanish)
- Newborn Screen Follow-up for Krabbe Disease: Galactocerebrosidase
- Newborn Screen Follow-up for Krabbe Disease: Galactocerebrosidase and Psychosine
- Newborn Screen Follow-up for Krabbe Disease: Galactocerebrosidase, Psychosine, and GALC 30kb Deletion
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Galactocerebrosidase, WBCSpecimen Type
Whole Blood ACDSpecimen Minimum Volume
2 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole Blood ACD | Refrigerated (preferred) | 6 days | |
Ambient | 6 days |
Reject Due To
Gross hemolysis | Reject |
Reference Values
≥0.300 nmol/hour/mg protein
An interpretative report will be provided.
Day(s) Performed
Preanalytical processing: Monday through Saturday
Testing performed: Monday, Wednesday
Report Available
5 to 9 daysPerforming Laboratory

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 US Food and Drug Administration.CPT Code Information
82657
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
GALCW | Galactocerebrosidase, WBC | 24084-6 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
606270 | Galactocerebrosidase, WBC | 24084-6 |
606271 | Interpretation | 59462-2 |
606272 | Reviewed By | 18771-6 |