Duchenne muscular dystrophy








Listed below are the common signs of Duchenne. If a boy has a combination of these traits, he should be tested for Duchenne:

  • Is not walking by 15 months
  • Has a hard time walking, running, or climbing stairs
  • Is not speaking as well as other kids his age
  • Has calves that look bigger than normal (pseudohypertophy)
  • Walks with his legs apart
  • Walks on his toes and waddles


One of our largest known genes, dystrophin is an important muscle protein that acts as a kind of anchor, holding muscles together by maintaining the structure of muscle cells.


The dystrophin gene is carried on the X-chromosome. As males have only one X-chromosome, this makes them more susceptible to dystrophin damage, as they lack a second X-chromosome to make up for the damaged gene.

When a male’s body is not able to produce any dystrophin at all, he is diagnosed with Duchenne.





Duchenne muscular dystrophy (DMD) is suspected and diagnosed when the following clinical findings are found: a positive family history of DMD, more men affected that women in a family, progressive muscle weakness which is usually greater in the proximal muscles (closest to the trunk of the body) than distal muscles (those farthest away from the hips and shoulders such as those in the hands, feet, lower arms or lower legs), symptoms before the age of 5 years old and wheel chair dependency before age 13.

In addition to a medical history review and physical examination, your doctor may suggest some of the following tests:There are reliable tests to help doctors diagnose a boy with Duchenne. The following tests are typically used to confirm a preliminary diagnosis of Duchenne:

  • Creatine Kinase: Creatine phosphate kinase (also known as CPK or CK) is an enzyme that normally lives inside muscles. Males with Duchenne often have CK levels 10 to 100 times the normal range. Elevated CK levels indicate muscle damage, although a high CK does not confirm a diagnosis of Duchenne.


Duchenne results in progressive loss of strength and is caused by a mutation in the gene that encodes for dystrophin. Because dystrophin is absent, the muscle cells are easily damaged. Eventually, increasing difficulty in breathing due to respiratory muscle dysfunction requires ventilation support, and cardiac dysfunction can lead to heart failure. The progressive muscle weakness leads to serious medical problems, particularly issues relating to the heart and lungs. Young men with Duchenne typically live into their late twenties.




The U.S. Food and Drug Administration (FDA) has granted accelerated approval for eteplirsen (EXONDYS 51) as a once weekly intravenous infusion of 30 milligrams per kilogram for the treatment of Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation in the DMD gene that is amenable to exon 51 skipping. Though, clinical benefit of EXONDYS 51 has not been established. Continued approval for this indication may be contingent upon verification of a clinical benefit in confirmatory trials.

Additional Therapy:



Surgical and other procedures:



Activity is encouraged:
