Sanfilippo Syndrome (MPS III) Enzyme Panel

Turnaround Time

2 weeks

CPT Code(s)

82657 x4

Cost

$800

Enzymes

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

Sanfilippo syndrome is characterized by progressive developmental delay and behavioral problems. These patients have fewer of the somatic concerns seen in other types of MPS disorders. Sanfilippo syndrome is caused by a defect in one of four enzymes required for the modification and removal of glucosamine residues from heparan sulfate. A defect in one of these four enzymes (types A-D) results in the accumulation of heparan sulfate in the patient's cells and organs which overtime leads to the clinical phenotype. Patients with Sanfilippo syndrome experience delayed development with a progressively deteriorating mental status. Behavior and sleep problems are common as well as coarse facial features and stiff joints. The four types of Sanfilippo syndrome (A-D) are clinically indistinguishable, thus enzyme testing is recommended as an initial diagnostic test.

There are four enzymatically distinct forms of Sanfilippo syndrome with significant clinical overlap. Enzymatic testing is necessary to further distinguish between the following four types. These four enzymes are required for the modification and removal of glucosamine residues from heparan sulfate. These defects result in the accumulation of heparan sulfate in the patient's cells and organs which overtime leads to the clinical phenotype. Enzyme analysis for each type of Sanfilippo syndrome may be ordered individually or as a panel.

4-methylumbelliferyl substrate

Test requires 7- 10 ml of whole blood in a sodium heparin (green top) tube. Leukocytes are used for enzyme analysis for Sanfilippo A, C and D. Plasma is used for enzyme analysis for Sanfilippo B. Enzymes can also be measured via fibroblasts for all four types.

Whole blood samples for enzyme testing should be shipped at ambient temperature and must arrive at the laboratory the next day.