Acid Alpha-Glucosidase, Leukocytes
Use
This test is crucial for diagnosing Pompe disease, an autosomal recessive disorder causing a deficiency in the lysosomal enzyme acid alpha-glucosidase (GAA). The disease leads to glycogen accumulation, which causes lysosomal swelling and cellular damage, resulting in progressive muscle weakness, cardiomyopathy, and organ dysfunction. Early diagnosis through this test can lead to treatment with enzyme replacement therapy, potentially improving patient prognosis.
Special Instructions
For optimal isolation of leukocytes, it is recommended the specimen arrives refrigerated within 6 days of collection to be stabilized. Specimen collection is advised from Monday through Thursday and not the day before a holiday. Collect and package specimens as close to shipping time as possible. New York clients require informed consent for genetic testing documentation.
Limitations
Pseudodeficiency alleles and carriers may show deficient GAA enzyme activity, leading to false positives for Pompe disease. Therefore, additional biochemical or molecular testing is advised to confirm a Pompe disease diagnosis if current test results are abnormal. Enzyme activity may differ in individuals undergoing enzyme replacement therapy.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 24051-5
- 24051-5
- 59462-2
- 18771-6
Result Turnaround Time
3-7 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
6 mL
Minimum Volume
4 mL
Container
Yellow top (ACD solution B); acceptable: ACD solution A or lavender top (EDTA)
Collection Instructions
Send whole blood specimen in the original tube. Do not aliquot.
Storage Instructions
Refrigerated (preferred) up to 6 days or ambient up to 6 days.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 6 days |
| Refrigerated | 6 days |