Sex-linked (X-liked) disorder
DNA is present in every living organism. Chromosomes are the thread-like structure of this DNA. This genetic disorder is the result of a mutation in a gene on the X chromosome. As males have one X and one Y sex chromosomes, which are present in the form of pair. Therefore defect on X chromosomes will make the person affected by the disease. While females have two copies of X chromosomes, therefore they are less likely to develop the disease because healthy gene covers the altered gene and the person becomes a carrier with no sign of disease on the body.
That is why muscular dystrophy is more common in males as compared to females. This is the second inhabitation and cause of muscular dystrophy.