Pompe Disease Enzyme Analysis
Use
Determination of acid alpha‑glucosidase (GAA) enzymatic activity is critical for assessing Pompe disease, a lysosomal storage disorder characterized by GAA deficiency leading to glycogen accumulation, muscle weakness, cardiomyopathy (especially in infantile-onset), and respiratory dysfunction. The enzyme activity assay supports diagnosis, helps differentiate true disease from pseudodeficiency or carriers, and guides subsequent confirmatory testing such as molecular genetic analysis of the GAA gene. Early identification is actionable given availability of enzyme replacement therapy.
Special Instructions
Whole blood must be spotted on a validated filter paper card (Integrated Genetics‑supplied) and allowed to dry thoroughly prior to packaging in a zip‑lock bag. Time‑sensitive collection: use Monday through Thursday only. Refrigerate after collection; transport with cool packs; do not freeze. Specimen must be received by the laboratory within four days of collection.
Limitations
Results may be affected by improper specimen collection or handling, including hemolysis or delayed transport. The dried blood spot format requires timely delivery—samples received beyond four days may be invalid. Additional time may be needed for confirmatory or reflex molecular testing. The assay assesses enzymatic activity in dried blood and does not directly evaluate GAA gene variants; molecular confirmation is required to confirm diagnosis and carrier status.
Methodology
Other
Biomarkers
LOINC Codes
- 55827-0
- 31208-2
- 55827-0
- N/A
- 51968-6
- 8251-1
- 72486-4
- 62364-5
- 51969-4
Result Turnaround Time
6-8 days
Related Documents
For more information, please review the documents below
Specimen
Other
Volume
2 - 3 mL (unhemolyzed)
Minimum Volume
Not provided
Collection Instructions
Dried blood spot collected from a finger stick or from whole blood collected in a lavender‑top (EDTA) tube spotted onto Integrated Genetics‑supplied and validated filter paper card. Fill 6 circles completely with blood.
Storage Instructions
Refrigerate after collection. Transport to the testing laboratory using cool packs. Do not allow the sample to freeze.
Causes for Rejection
Specimens not received within four days of collection or frozen in transit.