An Observational Study Evaluating Anti-Idursulfase Serum Antibody Response in Hunter Syndrome Patients

Inclusion Criteria

• •Patients must meet all of the following criteria to be considered eligible for enrollment:
• •The patient is male and enrolled in the HOS (i.e., meets the entry criteria of a documented diagnosis of Hunter syndrome)
• •The patient is ≥ 5 years-old
• •The patient is on idursulfase treatment or scheduled to begin idursulfase treatment within 30 days of study enrollment
• •The patient, patient's parent(s), or patient's legally authorized guardian must have voluntarily signed an Institutional Review Board (IRB)/Independent Ethics Committee (IEC)-approved informed consent form after all relevant aspects of the study have been explained and discussed with the patient, patient's parent(s), or patient's legally authorized guardian.