A Study to Prospectively Assess Disease Progression in Male Children With X-ALD

This is a non-interventional, multi-center study that follows general principles of periodic
assessment of X-ALD patients in routine practice. No study drug treatment will be given and
no changes to the patient treatment are necessary.

Patients with X-ALD will be recruited and invited to attend a baseline visit. After eligible
patients are enrolled, retrospective and baseline data will be collected. After enrollment,
patients will be seen approximately every 6 months until they meet withdrawal criteria or the
Sponsor terminates the study.

Inclusion Criteria:

- Signed informed consent by patient's parent(s)/legally acceptable representative(s).
In addition, signed children's assent form according to local requirements.

- Males patients 2-13 years of age with a confirmed diagnosis of X-ALD that fall into
one of the following:

- Asymptomatic patients without MRI evidence of cerebral involvement

- Patients with MRI evidence of cerebral involvement (Loes score ≥0.5) with or
without clinical symptoms

- Patient who have HSCT within 3 months from enrollment

Exclusion Criteria:

- Patients who are 14 years of age or older

- Patients who are in a vegetative state

- Patients (or their guardians) who are unwilling or unable to comply with the study
procedures

- Patients who received HSCT more than 3 months before enrollment