A Cerebrospinal Fluid Collection Study in Pediatric and Adult Patients With Hunter Syndrome

Hunter syndrome (mucopolysaccharidosis II [MPS II]) is characterized by lysosomal glycosaminoglycan (GAG) accumulation. Although a majority of patients with MPS II experience neurocognitive involvement, few data are available on cerebrospinal fluid (CSF) GAG levels in these patients. This study measured GAG levels in CSF collected from 9 patients with MPS II, including 4 adults (aged ≥18 years) with normal cognition, and 5 children, 3 of them with cognitive impairment. The CSF total GAG levels were generally higher in the 3 patients with cognitive impairment (range 842.9-2360.9 ng/mL) versus those with normal cognitive status (range 356.8-1181.1 ng/mL). Heparan sulfate levels, as measured by mass spectrometry, generally followed a similar pattern, with patients with the severe phenotype having the highest values. These data, limited by small sample size, suggest CSF GAG levels and heparan sulfate levels may be higher in patients with cognitive impairment versus patients with cognitively intact MPS II.