Sanfilippo Syndrome A (MPS IIIA): Heparan-N-Sulfatase Enzyme Analysis

Clinical Information

Sanfilippo syndrome is characterized by progressive developmental delay and behavioral problems, with fewer somatic features than other types of mucopolysaccharidosis (MPS) disorders.

The syndrome is caused by a defect in one of four enzymes required for the modification and removal of glucosamine residues from heparan sulfate. Deficiency of any of these enzymes (types A–D) leads to accumulation of heparan sulfate in cells and organs, resulting in the clinical phenotype. Patients typically exhibit delayed development with progressive cognitive decline, behavioral and sleep disturbances, coarse facial features, and joint stiffness. Because the four types (A–D) are clinically indistinguishable, enzyme testing is recommended as an initial diagnostic step.

Technical Information

4-methylumbelliferyl (4-MU) substrate

Specimen Requirements

Fibroblasts: Tissue sample should be stored in sterile culture media or sterile saline; cultured fibroblasts should be sent in two T25 flasks. Do NOT place tissue in formalin or formaldehyde. Do not freeze tissue.
Leukocytes: Minimum of 5 mL whole blood (7-10 mL preferred) collected in a sodium heparin tube

Transport Instructions

Fibroblasts: Ship tissue sample or cultured fibroblasts at ambient temperature
Leukocytes: Whole blood should be shipped at ambient temperature. If leukocytes are being isolated at another laboratory, the pellet should be frozen after specimen processing and shipped frozen on dry ice.