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HelpOrder Code GPSYP Glucopsychosine, Plasma
Ordering Guidance
This test is also available as a part of a panel; see HSMP / Hepatosplenomegaly Panel, Plasma. If this test (GPSYP) is ordered with either CTXP / Cerebrotendinous Xanthomatosis, Plasma or OXNP / Oxysterols, Plasma, the individual tests will be canceled and HSMP ordered.
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Green top (sodium heparin, lithium heparin), yellow top (ACD B)
Submission Container/Tube: Plastic vial
Specimen Volume: 0.3 mL
Collection Instructions:
1. Centrifuge at 4° C, if possible
2. Aliquot plasma into plastic vial. Do not disturb or transfer the buffy coat layer.
3. Send frozen
Forms
1. Biochemical Genetics Patient Information (T602)
2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Useful For
Second-tier test when newborn screening results with reduced beta-glucosidase (GBA) activity are identified
Diagnosis and monitoring of patients with Gaucher disease using plasma specimens
Supporting a biochemical diagnosis of Gaucher disease
Monitoring a patient's response to treatment
This test is not useful for identifying carriers of GBA variants.
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Glucopsychosine, PSpecimen Type
PlasmaSpecimen Minimum Volume
0.25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma | Frozen | 65 days |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
GLUCOPSYCHOSINE
Cutoff: ≤0.003 nmol/mL
Method Description
An internal standard is added to an aliquot of plasma, which is then subjected to protein precipitation. Following centrifugation, the supernatant is subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. The MS/MS is operated in the multiple reaction monitoring positive mode to follow the precursor to product species transitions for each analyte and internal standard. The ratio of the extracted peak areas to internal standard determined by the LC-MS/MS is used to calculate the concentration of in the sample.(Unpublished Mayo method)
Day(s) Performed
Tuesday, Thursday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
82542
Genetics Test Information
Gaucher disease is an autosomal recessive lysosomal storage disorder caused by deficient beta-glucosidase activity.
There are 3 described types of Gaucher disease with varying clinical presentations generally distinguished based on whether there is central nervous system involvement.
Glucopsychosine (glucosylsphingosine: lyso-GL1) is elevated in symptomatic patients and supports a diagnosis of Gaucher disease.
Testing Algorithm
For more information see Newborn Screen Follow-up for Gaucher Disease.
If the patient has abnormal newborn screening results for Gaucher disease, refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)