The objectives of this program are: to further characterize the natural progression of MPS VI disease; to generate and disseminate information on the care and management of MPS VI patients to clinical and medical professionals; to provide a resource to physicians and patients by providing information for optimizing patient care based on aggregate data; to characterize the clinical response to long-term Naglazyme® (galsulfase) treatment; to further characterize the long-term safety of Naglazyme® treatment.

Inclusion Criteria

All patients must meet the following criteria to qualify for enrollment in the CSP:

• Patient or patient's parent or legal guardian, if child is under 18 year old or is unable to consent, has provided a signed Patient Information and Authorization Form.
• Patient has laboratory results confirming a diagnosis of MPS VI disease based on detection of deficient ARSB activity (on fibroblasts, leucocytes or dried blood spots)and/or abnormality on the ARSB gene.
• Patient is willing to undergo general assessments to establish baseline data or permits physician to enter assessment data recorded prior to CSP entry if available in the patient's medical records. General assessments include: urinary GAG level, urinary protein level, serum sample for antibody levels, height, weight, and patient history.

All patients with a confirmed diagnosis of MPS VI disease may participate in the CSP. It is not a requirement that the patients enrolled in the CSP receive Galsulfase 1mg/kg to participate as this is an observational program.