Acid Alpha-Glucosidase Reflex, Leukocytes
Use
This test is used for the diagnosis of Pompe disease, serving as a confirmatory reflex following the evaluation through a six-enzyme panel. Pompe disease, or glycogen storage disease type II, is an autosomal recessive disorder caused by a deficiency of the lysosomal enzyme acid alpha-glucosidase due to variants in the GAA gene. This deficiency leads to glycogen accumulation in lysosomes, causing symptoms like progressive muscle weakness, cardiomyopathy, and potentially death if not treated. Early diagnosis is crucial as enzyme replacement therapy is available, which can improve prognosis.
Special Instructions
The test is only orderable as a reflex and linked to the LSD6W - Lysosomal Disorders, Six-Enzyme Panel, Leukocytes. Remember to handle the specimen carefully by sending it in the original tube without aliquoting. Preanalytical processing is completed Monday through Saturday, with assays performed on Monday and Wednesday.
Limitations
Pseudodeficiency may lead to low acid alpha-glucosidase activity without indicating Pompe disease. Individuals receiving enzyme replacement therapy may show normal enzyme levels, and additional biochemical or molecular analysis is needed if enzyme deficiency is detected during screening. Molecular analysis of the GAA gene is critical for distinguishing between pseudodeficiency alleles and true disease-causing variants.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
Result Turnaround Time
4-10 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
6 mL
Minimum Volume
Not provided
Container
Yellow top (ACD solution B preferred, ACD solution A or lavender top (EDTA) acceptable)
Collection Instructions
Send whole blood specimen in original tube. Do not aliquot.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 6 days |
| Refrigerated | 6 days |