Order Code GAAW Acid Alpha-Glucosidase, Leukocytes
Shipping Instructions
For optimal isolation of leukocytes, it is recommended the specimen arrive refrigerated within 6 days of collection to be stabilized. Pre-analytical processing is performed Monday through Friday and Sunday. This test may be canceled if specimens are outside of stability when processing occurs. Collect and package specimens for arrival on days when processing is performed.
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 Pompe disease
Genetics Test Information
This test provides diagnostic testing for individuals with decreased alpha-glucosidase activity on newborn screen or clinical signs and symptoms suspicious for Pompe disease.
Testing Algorithm
For testing algorithm information see Newborn Screen Follow-up for Pompe Disease.
For Newborn Screening ACT Sheet for Pompe Disease (Glycogen Storage Disease Type II) information, visit www.acmg.net/PDFLibrary/Pompe.pdf.
Special Instructions
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Acid Alpha-Glucosidase, LeukocytesSpecimen Type
Whole Blood ACDSpecimen Minimum Volume
4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood ACD | Refrigerated (preferred) | 6 days |
| Ambient | 6 days |
Reject Due To
| Gross hemolysis | Reject |
Reference Values
≥1.500 nmol/hour/mg protein
An interpretive report is provided.
Method Description
The specimens are incubated with a mix of substrate and internal standard for acid alpha-glucosidase and alpha-galactosidase (GLA). The reaction is then stopped using acetonitrile, centrifuged, and a portion of the supernatant is prepared for analysis by liquid chromatography-tandem mass spectrometry. GLA is included to verify sample integrity.(Unpublished Mayo method)
Day(s) Performed
Preanalytical processing: Monday through Friday, Sunday
Assay performed: Monday, Wednesday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
82657
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| GAAW | Acid Alpha-Glucosidase, Leukocytes | 24051-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 606267 | Acid Alpha-Glucosidase, Leukocytes | 24051-5 |
| 606268 | Interpretation | 59462-2 |
| 606269 | Reviewed By | 18771-6 |