Pompe Disease, Blood Spot
Use
This test is used to diagnose Pompe disease, an autosomal recessive disorder caused by deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). It evaluates patients with clinical presentations such as muscle hypotonia, weakness, or cardiomyopathy, typical of Pompe disease, and differentiates true cases from false positives, including GAA enzyme pseudodeficiency.
Special Instructions
Due to reference range differences, this test is suitable for patients older than 6 weeks of age. For younger patients, alternative testing should be considered (PD2T / Pompe Disease Second-Tier Newborn Screening, Blood Spot).
Limitations
For asymptomatic individuals, this test may not detect some late-onset and variant forms of Pompe disease. Carrier status for Pompe disease cannot be reliably detected. Positive results require follow-up molecular genetic analysis of the GAA gene. Improper specimen handling may lead to false results.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 63416-2
- 59462-2
- 18771-6
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 Blood spots
Minimum Volume
1 Blood spot
Container
Blood Spot Collection Card
Collection Instructions
Completely fill at least 3 circles on the filter paper card, approximately 100 microliters blood per circle, and let dry. Do not expose to direct sunlight, heat, or stack wet specimens.
Storage Instructions
Keep specimen dry.
Causes for Rejection
Blood spot specimen showing serum rings, multiple layers, insufficient quantity, or exposure to elevated temperatures.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 28 days |
| Refrigerated | 90 days |
| Frozen | 90 days |