Long-term Evaluation on Height and Weight in Patients With MPS II Who Started Treatment at < 6 Years of Age

Inclusion Criteria:

- Group 1: Prospective Patient Group

1. The patient is male.

2. The patient is Elaprase-naïve at study entry.

3. The patient must have a documented diagnosis of MPS II. Of the 3 criteria below,
the combinations (3a AND 3b) or (3a AND 3c) will be accepted as diagnostic of MPS
II:

1. The patient has a deficiency in I2S enzyme activity of ≤10% of the lower
limit of the normal range as measured in plasma, fibroblasts, or leukocytes
(based on the reference laboratory's normal range). AND

2. The patient has a documented mutation in the I2S gene. OR

3. The patient has a normal enzyme activity level of one other sulfatase as
measured in plasma, fibroblasts, or leukocytes (based on the normal range of
measuring laboratory).

4. The patient will be <6 years of age at the start of Elaprase treatment.

5. The patient, patient's parent(s) or legally authorized guardian(s) 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. Consent of the patient's parent(s) or
legally authorized guardian(s) and the patient's assent, as relevant, must be
obtained.

Group 2: Retrospective Data Inclusion Criteria:

Retrospective Patient Group patients will be enrolled in HOS and not Study SHP-ELA-401;
however, their growth data may be included in the analysis for Study SHP-ELA-401 if the
following data inclusion criteria are met.

1. The patient is male.

2. The patient is enrolled in HOS.

3. The patient was <6 years of age at the start of Elaprase treatment.

4. The patient received Elaprase weekly treatment for at least 5 years.

5. The patient had a height assessment and a weight assessment documented within 3 months
before or after Elaprase treatment start.

6. The patient has had annual height and weight assessments from start of Elaprase
through age 10 years.

7. The patient, patient's parent(s), or legally authorized guardian(s) agree(s) to data
collection.

8. The patient, patient's parent(s), or legally authorized guardian(s) must have signed
an IRB/IEC-approved informed consent form after all relevant aspects of the HOS study
have been explained and discussed. Consent of the patient's parent(s) or legally
authorized guardian(s) and the patient's assent, as relevant, must be obtained.

Exclusion Criteria:

- Group 1: Prospective Patient Group

1. The patient has received treatment with any investigational drug or device within
the 30 days prior to study entry.

2. The patient has received or is receiving treatment with idursulfase-IT.

3. The patient has received growth hormones, a cord blood infusion, or a bone marrow
transplant at any time.

4. The patient has received blood product transfusions within 90 days prior to
Screening.

5. The patient is unable to comply with the protocol as determined by the
Investigator.

Group 2: Retrospective Data Exclusion Criteria:

HOS patients that meet the following criteria are not eligible to be included into the
Study SHP-ELA-401 Primary Growth Analysis:

1. Patient was treated with growth hormone or other medications or interventions intended
to promote growth in the time period covered by the analysis.