A Prospective Natural History Study of Progression of Subjects With Duchenne Muscular Dystrophy.

This is a prospective study. All DMD patients that fulfil the inclusion/exclusion criteria
are eligible although the study is weighted towards ambulant subjects aged 3 years or older.
There will be 7 study visits and subjects will be in the study for a maximum of 3 years.
Visits will occur every 6 months (+/- 1 month).

Up to 250 DMD subjects planned in the following categories :

- 75 % ambulant subjects aged between 3 and 18 years at study entry

- 25% non-ambulant subjects with a maximum age of 18 years at study entry

Subjects will be asked to perform muscle testing assessment with a clinical evaluator, such
as walking for 6 minutes, climb stairs, breathe in a tube, see how they can move their arms
and legs. They will be asked questions about how they feel overall and perform daily
activities. These measurements will be assessed every 6 months.

Urine and blood samples will be collected once a year to measure biomarkers that will allow
to have a better overview of DMD.

Inclusion Criteria:

- Diagnosis of DMD resulting from a mutation in the DMD gene confirmed by a state of the
art DNA diagnostic technique covering all DMD gene exons.

- Age 3 - 18 years

- Willing and able to comply with protocol requirements

- Life expectancy of at least 3 years

- Able to give informed assent and/or consent in writing signed by the subject and/or
parent(s)/legal guardian (according to local regulations)

Exclusion Criteria:

- Current participation in a clinical study with an Investigational Medicinal Product
(IMP)

- Participation within the previous 1 month in a clinical study with an IMP