Sanfilippo Syndrome (MPS III): Urine Monitoring (Total GAGs, HS)

Turnaround Time

10 days

CPT Code(s)

83864 x2

Cost

$300

Enzymes

• Sanfilippo syndrome A (MPS IIIA)
• Sanfilippo syndrome B (MPS IIIB)
• Sanfilippo syndrome C (MPS IIIC)
• Sanfilippo syndrome D (MPS IIID)

The mucopolysaccharidoses are a group of inherited lysosomal storage disorders, each with a distinctive phenotype and a progressive course due to a specific enzyme deficiency. These enzymes are involved in the degradation of specific glycosaminoglycans. Glycosaminoglycans are typically elevated in the urine of affected patents. 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.

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.

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

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