A Sex-Linked (X-Linked) Disorder
Chromosomes are long, threadlike forms of DNA. A male has one X and one Y sex chromosome, and a woman has two X chromosomes.
A sex-linked disorder is caused by an alteration in a gene on the X chromosome [3]. Men have only one copy of each gene on the X chromosome, so they will be affected if any of these genes is affected.
Women have two copies of the X-chromosome, and they are at lower risk of having an X-linked condition because the original copy of the chromosome can usually cover for the mutated part.
It is still possible for a woman to be affected by X-linked disorders [4], but muscular dystrophy is less complicated than when the gene mutation is present in an affected male.
The forms of muscular dystrophy inherited in this way include Duchenne and Becker; these conditions are more complicated in men than females.