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HelpTest Code LAB2774 Alpha Glucosidase
Clinical System Name
Alpha Glucosidase (Pompe) (LAB2774)
Alpha Glucosidase (Pompe), Fibroblasts (LAB2775)
Synonyms
Pompe
Acid Maltase
Glycogen Storage Disease II (GSD II)
GAA
A Glu Pom
AGluPomFib
Sample Requirements
Specimen: Whole Blood
Container(s): Yellow/ACD A or B, Dark Green/Sodium Heparin Tube
Preferred Vol:2.0 mL
Minimum Vol: 2.0 mL
Note: Also acceptable: newborn blood spots (minimum of 3 spots), or cultured cells from skin fibroblasts (2 confluent T-25 flasks)
Do NOT use gel separator tubes.
Processing Instructions
Reject due to:
Spin: N
Aliquot:N
Temp:RT
Storage location: Biochemical Genetics Box- RT
Processing on weekends: Contact Chem West (x72565) on dayshift. If Chemistry team is unavailable, sample should be stored in RT Biochemical Genetics box.
Off-site collection: Do not spin! Keep at room temperature. Transport Mon-Thurs at room temperature via overnight shipping.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood | Rm Temp |
≤24 hrs |
| Whole Blood | Refrigerated | <24 hrs |
| Dried Blood Spot | Rm Temp | 1 week |
Whole blood samples received > 24 hr after blood collection will still be processsed and test performed if possible.
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | Weekly | 7-10 days |
Contact the Biochemical Genetics Lab for requests outside stated availability (206)987-2216.
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Biochemical Genetics
Phone Number: 206-987-2216
CPT Codes
82657
Methodology
Method: 4 MU fluorometric assay with acarbose inhibition
Analytical Volume:
Limitations:
Reference Range
| Specimen Type | Normal Range |
|
Blood Spot |
21-85 pmol/hr/spot |
| FB (fibroblast) | 40 - 155 nmol/hr/mg protein |
Description
Fluorometric enzyme test for alpha-glucosidase for diagnosis of Pompe disease (glycogen storage disease type II).
Clinical Utility
Pompe disease (glycogen storage disease type II) is an inherited
disorder of glycogen metabolism and a lysosomal storage disease,
caused by a deficiency of the enzyme alpha-glucosidase (also called
GAA and acid-maltase). Individuals with Pompe disease are unable to
use the glycogen stored in the lysosomes for energy, resulting in
the progressive storage of glycogen in the heart, liver, and
skeletal muscle.
Pompe disease can present in infancy with profound hypotonia,
cardiomegaly and cardiomyopathy or later in childhood and adulthood
with progressive muscle weakness and respiratory insufficiency.
Late onset Pompe disease presenting in the second to seventh decade
of life can appear with muscle weakness in the upper and/or lower
extremeties, muscle weakness in the trunk and shortness of breath
after exercise.
This test is not appropriate for determining carrier status or for prenatal diagnosis.
Requisition
Biochemical Genetics Requisition
On the requisition include clinical information needed for appropriate interpretation. (Age, gender, drug therapy and family history)
Special Instructions
Links to:
Consent Forms
Algorithms