What causes the change in the structure of the dystrophin in the boys with DMD?

Mutations in the DMD gene

Explanation:

Mutations in the DMD gene alter the structure or function of dystrophin or prevent any functional dystrophin from being produced. Muscle cells without enough of this protein become damaged as muscles repeatedly contract and relax with use.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added

this would be called india