Specimen Collection Manual and Test Catalog

Adult: 20 mL urine; minimum 10 mL. Pediatric: 4 mL urine; minimum 2 mL.

Include the patient's age with requisition.

An early morning specimen is preferred.

Freeze immediately. Ship specimen frozen on dry ice. Do not thaw.

Frozen.

Room temperature: Unacceptable. Refrigerated Unacceptable. Frozen -20° C: 8 weeks. Frozen -80° C: 8 weeks.

Unfrozen specimens • Specimens outside of listed stability

Quest test code 30422, Urine Glycos

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.