Test Catalog

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Test ID: HEX4    
Glucotetrasaccharides, Urine

Useful For Suggests clinical disorders or settings where the test may be helpful

Diagnosing Pompe disease, when used in conjunction with acid alpha-glucosidase enzyme activity assays and molecular genetic analysis of the GAA gene

 

Monitoring Pompe patients on enzyme replacement therapy

 

May support the diagnosis and monitoring of other glycogen storage disorders; however, glucose tetrasaccharide (Glc4) excretion appears to be less consistently elevated in glycogen storage disorders other than Pompe disease

 

This test is not useful for carrier screening

Highlights

Increased accumulation of glycogen in the lysosome is a typical finding due to lack of the lysosomal enzyme acid alpha-glucosidase (GAA). Excess glycogen is degraded to glucotetrasaccharide, which is excreted in urine.

 

Most individuals with glycogen storage disorder type II (GSD II, Pompe disease) and other glycogen storage disorders excrete glucotetrasaccharides in their urine.

 

Measuring glucotetrasaccharide in the urine can be helpful when employed in conjunction with GAA enzyme activity assay and molecular genetic analysis of the GAA gene.

 

Measuring glucotetrasaccharide in the urine of GSD II patients undergoing enzyme replacement therapy (ERT) has been reported as a useful tool for monitoring the effects of treatment.

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

See Newborn Screen Follow-up for Pompe Disease in Special Instructions.

Special Instructions Library of PDFs including pertinent information and forms related to the test

Method Name A short description of the method used to perform the test

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

NY State Available Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name Lists a shorter or abbreviated version of the Published Name for a test

Glucotetrasaccharides, U

Aliases Lists additional common names for a test, as an aid in searching

Glucotetrasaccharides
Glucose tetrasaccharides
Glc4
Hexose tetrasaccharide
Hex4