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Glycosaminoglycans, urine, random

Lab Section:  Sendout Reference  
Lab Location:  Sendout
Reference Lab: Quest 
Test ID: LAB4822 
Methodology: Colorimetric (1,9-dimethyl-methylene blue) Dye Binding
Schedule: Monday-Friday
Reported: 10 days
Specimen Requirements:  Collection: 20.0 mL Urine in a Yellow Top Tube - Urine.
Pediatric volume: 10 mL.
An early morning specimen is preferred. Freeze immediately and send specimen frozen in a plastic 13 mL urine tube. Patient's age is required.
Transport: Frozen.
Stability: Ambient: unacceptable; Refrigerated: unacceptable; Frozen: 2 weeks


Clinical Indications: The mucopolysaccharidoses (MPSs) are a family of inheritable disorders caused by deficiency of lysomal enzymes required to degrade mucopolysaccharides, also known as glycosaminoglycans (GAGs). The undegraded or partially degraded gags are stored in lysosomes and excreted in the urine. The quantity of excreted urinary gags is age-dependent. Infants secrete more GAGs than adults. Normal urine contains primarily chondroitin sulfate with small quantities of heparin sulfate and dermatan sulfate. Once mucopolysaccharidoses is diagnosed by total GAG analysis, a differential diagnosis based upon the abnormal distribution of sulfated GAGs in urine must be performed. Differential diagnosis is a requirement because many of the various enzyme deficiencies share similar clincal features. These features include a chronic and progressive course, multi-system involvement and organomegaly. Hearing, vision, cardiovascular function and joint mobility are affected. Profound mental retardation is found in the Hurler, Hunter and San Filippo syndromes (MPS types I, II and III), but normal intellectual functioning is retained in other MPSs and some mildly affected Hunter patients.

Reference Interval:  See patient report or consult reference laboratory website.
CPT Code(s): 83864
Last Changed: 11/01/2016 11:32:28
Last Reviewed: 12/26/2016 23:47:49