Collection and Study of Cerebrospinal Fluid in Patients With Hunter Syndrome

To determine levels of glycosaminoglycans (GAGs), including dermatan sulfate (DS) and
heparan sulfate (HS), GAG-degradation products, and other biomarkers of central nervous
system (CNS) and lysosomal function in cerebrospinal fluid (CSF) in pediatric and adult
patients with Hunter syndrome.

Inclusion Criteria:

- The patient is male and has a documented diagnosis of Hunter syndrome (MPSII).

- The adult patient has completed a cognitive assessment at screening/baseline or
within the previous 3 months and has been determined to have an intelligence quotient
(IQ) ≥78. Note: cognitive evaluation of pediatric patients is not required.

- The adult patient or the adult patient's legally authorized representative(s) has
voluntarily signed an Institutional Review Board/Independent Ethics
Committee-approved informed consent form after all relevant aspects of the study have
been explained and discussed.

- The pediatric patient must be scheduled to undergo a non-study related lumbar
puncture or other medical or diagnostic procedure that requires the administration of
general anesthesia. The pediatric patient's parent(s) or legally authorized
representative(s) must have provided written informed consent (with patient assent as
relevant), after all relevant aspects of the study have been explained and discussed,
to allow CSF sample collection for this study in conjunction with performance of the
non-study related procedure requiring general anesthesia.

Exclusion Criteria:

- The patient has a history of complications from a previous lumbar puncture(s) or
technical challenges in conducting lumbar puncture.

- The patient has received a hematopoietic stem cell transplant.

- The patient has taken aspirin, non-steroidal anti-inflammatory drugs (NSAIDs), or
other over-the-counter or prescription medications that could affect blood clot
formation within the 7 days prior to lumbar puncture, or has ingested such
medications within 7 days prior to any study-related procedure in which a change in
potential blood clot formation would be deleterious.

- The patient is currently receiving treatment with intrathecal idursulfase-IT.

- The patient is currently enrolled in an interventional clinical trial.

- The patient has participated in a clinical trial of any investigational drug,
including idursulfase-IT, or device within the 30 days prior to study entry.