What is Duchenne- and Becker muscular dystrophy?

Duchenne and Becker MD are both X-linked recessive disorders. Both conditions are caused by mutations in the dystrophin gene, which encodes the protein dystrophin. A certain part of the DNA is missing, doubled, or changed so the code cannot be read properly by the body. Males have only one copy of the X chromosome from their mother and one copy of the Y chromosome from their father, that is why mainly man/boys are affected. A woman who has a genetic change in one of her two copies is said to be ‘a carrier’ of Duchenne muscular dystrophy. However, Duchenne and Becker can occur when the gene mutates spontaneously.

Difference between Duchenne and Becker

Where Duchenne patients have a complete lack of the gene that produces dystrophin, Becker patients have lower levels or a shorter version of this muscle-protecting protein. Duchenne symptoms start to show when patients are babies or children. People with Becker have less severe symptoms that will often only show later in life when they become adults. This is why Becker can be seen as a milder form of Duchenne. However, some patients are already showing symptoms at a younger age.

Text adapted from World Duchenne Awareness Day