Mucopolysaccharidosis (MPS) VI Clinical Surveillance Program (CSP)

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.