Mucopolysaccharidosis VII, Sly Syndrome : Urine Monitoring

Test Information

This test includes quantitative total glycosaminoglycans and dermatan and chondroitin sulfate (uDS, uCS)
component GAGs and can be used a monitoring tool for patients with Sly syndrome (MPS VII).

Turnaround Time

10 days

CPT Code(s)

83864 x2

Cost

$300

Clinical Information

Sly syndrome, or mucopolysaccharidosis type VII, is a lysosomal storage disorder resulting from deficient enzyme activity of beta-glucuronidase. This autosomal recessive disorder has a highly variable phenotype. The most severe form presents prenatally as hydrops fetalis. Patients with a less severe phenotype present with hepatomegaly, skeleltal anomalies and coarse facies. The degree of cognitive impairment varies with the mildest cases surviving into adulthood.

Indications

For patients with an existing MPS diagnosis, measurement of glycosaminoglycans in urine can be used to monitor the effectiveness of treatments such as bone marrow translpant or enzyme replacement therapies.

Methodology

Quantitative analysis of total glycosaminoglycans (GAGs) is performed using a 1,9-dimethylene blue (DMB) colorimetric reaction that is measured by spectrophotometry at a wavelength of 656 nm. GAG measurements are reported relative to the creatinine concentration in the patient's urine.

Quantification of individual glycosaminoglycans -chondroitin sulfate (uCS), dermatan sulfate (uDS), heparan sulfate (uHS), and keratan sulfate (uKS)- is performed using liquid chromatography-tandem mass spectrometry.

Specimen Requirements

At least 3 ml of a random catch sample of urine is needed for MPS urine monitoring.

Transport Instructions

Urine samples should be frozen after collection. Samples must be sent frozen via overnight delivery or courier, preferably on dry ice.

Have Questions Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Analytes and Biomarkers, Biochemical Testing, Urine Monitoring
Lucy's Story

Lucy's Story

When our daughter Lucy had a metabolic crisis at 7 days old, we were shocked and devastated to find out that she was born with a rare genetic disorder (MSUD). Her newborn screening results did not make it back in time to prevent the crisis, and no one at our local hospital was familiar with the disease. They did not know how to treat her. Calls were made to Greenwood Genetic Center to confirm her diagnosis...

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