Test Code GAAW Acid Alpha-Glucosidase, Leukocytes
Shipping Instructions
For optimal isolation of leukocytes, it is recommended the specimen arrives 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 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 | 
Reference Values
≥1.500 nmol/hour/mg protein
An interpretive report is provided.
Interpretation
When abnormal results are detected, a detailed interpretation is given, including an overview of the results and of their significance, a correlation to available clinical information, elements of differential diagnosis, recommendations for additional biochemical testing and in vitro, confirmatory studies (enzyme assay, molecular analysis), and a phone number to reach one of the laboratory directors in case the referring physician has additional questions.
Clinical Reference
1. Elliott S, Buroker N, Cournoyer JJ, et al. Pilot study of newborn screening for six lysosomal storage diseases using tandem mass spectrometry. Mol Genet Metab. 2016;118(4):304-309. doi:10.1016/j.ymgme.2016.05.015
2. Matern D, Gavrilov D, Oglesbee D, Raymond K, Rinaldo P, Tortorelli S. Newborn screening for lysosomal storage disorders. Semin Perinatol. 2015;39(3):206-216. doi:10.1053/j.semperi.2015.03.005
3. Reuser AJ, Hirschhorn R, Kroos MA. Pompe disease: Glycogen storage disease type II, acid a-glucosidase (acid maltase) deficiency. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019. Accessed July 22, 2025. Available at https://ommbid.mhmedical.com/content.aspx?bookid=2709§ionid=225890450
4. Lin N, Huang J, Violante S, et al. Liquid chromatography-tandem mass spectrometry assay of leukocyte acid alpha-glucosidase for post-newborn screening evaluation of Pompe disease. Clin Chem. 2017;63(4):842-851. doi:10.1373/clinchem.2016.259036
5. Leslie N, Bailey L. Pompe disease. In: Adam MP, Feldman J, Mirzaa GM, et al. GeneReviews [Internet]. University of Washington, Seattle; 1993-2025. Updated November 2, 2023. Accessed July 22, 2025. Available at www.ncbi.nlm.nih.gov/books/NBK1261/
Day(s) Performed
Preanalytical processing: Monday through Saturday.
Assay performed: Monday, Wednesday
Report Available
3 to 7 daysPerforming 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. It 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 | 
|---|---|---|
| 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 |