alpha-glucosidase
Pompe Disease, Glycogen Storage Disease Type II: Alpha-glucosidase Enzyme Analysis
Key Information
Lab:
TAT:
14 days
Price:
$200
CPT Code(s):
82657
Test Code:
BAGUL, BAGUD, BAGUF
Pompe Disease, Glycogen Storage Disease Type II: Alpha-glucosidase Enzyme Analysis
This test measures alpha-glucosidase enzyme activity and can be used as a first-tier test for patients with a clinical suspicion of Pompe disease/glycogen storage disease type II. Confirming deficient enzyme activity is the gold standard in diagnosis and can be used to support the interpretation of GAA variants and follow-up on abnormal newborn screeens.
Note: Sending fibroblasts will extend turnaround to 28 days.
Pompe disease (glycogen storage disease II)
Clinical Information
Pompe disease is caused by a deficiency of the enzyme alpha-glucosidase (GAA), an enzyme that at normal levels will breakdown glycogen in the body. Infantile-onset Pompe disease is characterized by hypotonia, generalized muscle weakness and hypertrophic cardiomyopathy. Death generally occurs within the first year of life due to cardiac and respiratory failure. The later-onset form shows greater variability with a slowly progressive muscle weakness and respiratory insufficiency. The degree of enzyme deficiency is generally related to the severity and age of onset.
Technical Information
4-methylumbelliferyl (4-MU) substrate (leukocytes, fibroblasts) or Liquid chromatography-tandem mass spectrometry (LC-MS/MS) (DBS)
Specimen Requirements
DBS: Approximately 75 uL of blood should be applied to each of the five circles on filter paper dried blood spot card. Allow blood to dry for at least 4 hours before shipping.
Fibroblasts: Tissue sample should be stored in sterile culture media; cultured fibroblasts should be sent in two T25 flasks. Do NOT place tissue in formalin or formaldehyde. Do not freeze tissue.
Leukocytes: Minimum of 5 mL whole blood (7-10 mL preferred) collected in a sodium heparin tube
Transport Instructions
DBS: Ship DBS card at ambient temperature.
Fibroblasts: Ship tissue sample or cultured fibroblasts at ambient temperature
Leukocytes: Whole blood should be shipped at ambient temperature. If leukocytes are being isolated at another laboratory, the pellet should be frozen after specimen processing and shipped frozen on dry ice.
Connect With Our Experts
Call 1-800-473-9411 to speak with our team of laboratory genetic counselors for questions or additional information.
Robin Fletcher, MS, CGC
Falecia Thomas, MS, CGC
Alex Finley, MS, CGC