Pompe disease (glycogen storage disease II)
Pompe Disease, Glycogen Storage Disease II: Glucose Tetrasaccharide (Glc4) Urine Monitoring
Pompe Disease, Glycogen Storage Disease II: Glucose Tetrasaccharide (Glc4) Urine Monitoring
This test measures glucose tetrasaccharide (Glc4 or Hex4), a biomarker used to evaluate glycogen clearance from cells, and can be used to monitor disease progression or the effectiveness of enzyme replacement therapy in patients with Pompe disease.
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
Liquid chromatography-tandem mass spectrometry (LC-MS/MS)
Specimen Requirements
Urine: A minimum of 2 mL random catch urine
Transport Instructions
Urine: Specimen should be frozen after collection and shipped frozen, preferably 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