Progression of DMD

The rates of progression and severity of each case is different. There are four stages that are usually associated with Duchenne MD:

1. Early Phase (diagnosis through age 7)
Once a boy is diagnosed with Duchenne MD, it is often quite difficult to accept or believe that there is anything wrong with him. The onset of physical symptoms may be tough to recognize. Often times he will appear to be improving on the outside while his muscles are deteriorating on the inside. It is during this early phase that the calves may seem overdeveloped. He may appear clumsy and fall a lot. Jumping from a standing position may become near impossible.

2. Transitional Phase (6-12 years)
Between the ages of 6 and 12, Duchenne MD has usually been diagnosed. The child will likely have trouble walking, mostly because his quadriceps (muscles in the front of the thighs) have grown weaker. This tends to keep him off balance as he attempts to shift his weight and walk. He may walk on the balls of his feet or on his toes with a slight, rolling gait. In order to compensate for a feeling of falling forward, boys with Duchenne MD will stick their bellies out and throw their shoulders back to keep their balance as they walk.

When asked to get up off of the floor, he will often put his rear end up in the air first and then "walk" his arms up his legs with his hands until he is standing; using his arms for supports. The medical term for this is “Gowers Maneuver.”

3. Loss of ambulation (8-14 years)
By about 12 years old, he will likely need a wheelchair for at least part of the time as mobility becomes more difficult. His weakened muscles will cause him to tire easily. In most cases teen years are when the most significant loss of skeletal muscle strength takes place. It is at this point that activities involving the arms, legs, or trunk of the body will require assistance or mechanical support. Most boys will retain the use of their fingers through this phase so they can generally still write and use a computer.

4. Adult Stage (15 years)
During the teen years, in addition to skeletal muscle problems, boys with Duchenne MD will often develop heart muscle problems. Heart complications become the main threat to both health and life due to damage and loss of respiratory muscle. The muscle layer of the heart (called “myocardium”) begins to deteriorate, much like the skeletal muscles do. This puts the boys at risk of a heart attack. Major symptoms of myocardium include shortness of breath, fluid in the lungs, or swelling in the feet and lower legs (caused by fluid retention).

Even with the best management currently available, boys with Duchenne MD typically die from respiratory failure and/or cardiac failure in their teens or early twenties at the latest. There is no treatment, and no cure for Duchenne Muscular Dystrophy – it is 100% fatal.