When there is no functioning dystrophin, muscle cells get easily damaged due to repeated contractions and relaxations. Eventually, these weakened muscle cells die, leading to the characteristic muscular deterioration linked to DMD.
DMD can be caused by several thousand possible mutations. Most of them are deletions, missing DNA, which leads to the damaged protein. Contrary to this, a promising DMD treatment includes the rational deletion of the dystrophin gene sequence for the production of a so-called microdystrophin.
In mouse models, many microdystrophins have already been constructed and demonstrated to enhance muscle function. Besides this, microdystrophins have also been used in dog models successfully, DMD’s only huge mammalian model. But, in these studies, microdystrophins need to be delivered to the animal, using a virus which can merely deliver genes in a particular size.