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Test ID GAABS Acid Alpha-Glucosidase, Blood Spot

Useful For

Evaluation of patients of any age with a clinical presentation suggestive of Pompe disease (muscle hypotonia, weakness, or cardiomyopathy)

Method Name

Fluorometric Enzyme Assay

Reporting Name

Acid Alpha-Glucosidase, BS

Specimen Type

Whole blood

Specimen Required

Supplies: Card-Blood Spot Collection (Filter Paper) (T493)


Preferred: Blood spot collection card(T493)

Acceptable: Ahlstrom 226 Filter Paper, Munktell TFN, and Whatman Protein Saver 903 Paper

Specimen Volume: 2 blood spots

Collection Instructions:

1. Do not use device or capillary tube containing EDTA to collect specimen.

2. An alternative blood collection option for a patient >1 year of age is fingerstick.

3. Let blood dry on the filter paper at ambient temperature in a horizontal position for 3 hours.

4. Do not expose specimen to heat or direct sunlight.

5. Do not stack wet specimens.

6. Keep specimen dry.

Additional Information: For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777) in Special Instructions.

Additional Testing Requirements:

Molecular genetic testing of the GAA gene (GAAZ / Pompe Disease, Full Gene Analysis) can be used to determine carrier, pseudodeficiency, or disease status.


Pseudodeficiency results in low measured GAA, but is not consistent with Pompe disease; GAAZ / Pompe Disease, Full Gene Analysis should be performed to resolve the clinical question.

Necessary Information:

Provide a reason for referral and clinical indication with each specimen.

Specimen Minimum Volume

1 blood spot

Specimen Stability Information

Specimen Type Temperature Time
Whole blood Ambient (preferred) 87 days
  Frozen  87 days
  Refrigerated  87 days

Reference Values

Normal >0.5 nmol/mL/hour

Day(s) and Time(s) Performed

Set up Wednesday; report Thursday morning

Performing Laboratory

Mayo Medical Laboratories in Rochester

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
GAABS Acid Alpha-Glucosidase, BS In Process


Result ID Test Result Name Result LOINC Value
30100 Reason For Referral 42349-1
30149 Acid alpha-glucosidase 55827-0
30102 Interpretation (GAABS) 59462-2
30104 Reviewed By No LOINC Needed

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.


1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.

2. If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen (

3. Biochemical Genetics Patient Information (T602) in Special Instructions