DUCHENNE IS A RARE DISEASE CAUSED BY A GENETIC MUTATION
Duchenne muscular dystrophy (DMD) is a disorder in which people are born with a genetic mutation that leads to an absence of or a defect in dystrophin, a protein that protects muscles from damage.
BOYS ARE MORE LIKELY TO BE AFFECTED BY DUCHENNE THAN GIRLS
The gene that carries a Duchenne-causing mutation is found on the X chromosome. Every boy inherits an X chromosome from his mother and a Y chromosome from his father, which is what makes him male, as opposed to girls who get two X chromosomes, one from each parent.
Since girls have two X chromosomes, even if one of the chromosomes is affected by the dystrophin mutation that causes Duchenne, they may still have a healthy gene from the other parent. Girls who have one X chromosome affected by a dystrophin mutation but do not have Duchenne symptoms are known as Duchenne carriers, and they can pass the mutation on to their children.