Description of the Disorder
Duchenne muscular dystrophy is a genetic disorder that is characterized by progressive muscle degeneration and weakness. It is caused by a mutation of the DMD gene that can be inherited in an X-linked recessive fashion. DMD encodes for the muscle protein called dystrophin, and people that are affected with this disorder are not able to make this protein in their muscles (NHGRI, 2014). This disorder moves quickly throughout the body and rapidly gets worse. Of the nine different muscular dystrophy, Duchenne muscular dystrophy is the most common form found in people today (MDA, 2014).
Duchenne muscular dystrophy affects about 1 in every 3,500 live male births, that is nearly 20,000 new cases each year. This disorder primarily affects young boys because of the disorders location on the “X” chromosome, but in very rare cases it does affect young girls but a majority of the time it only allows them to be carriers of the disorder and never show any symptoms. Duchenne muscular dystrophy is not limited to just one race or culture, it affects all races and all cultures. The disorder can be passed down from a parent who has the disorder to their child, but about 35% of children affected with the disorder don’t receive it from their parents. The disorder can occur because of a random mutation on the “X” chromosome, this means that anybody can be affected by this disorder even if it does not run in the family (PPMD, 2014).
Modes of Inheritance
A majority of people diagnosed with Duchenne muscular dystrophy, receive the disorder from their mothers. If the mother is a carrier of the disorder, the son has a 50% chance of having the disease along with any of her daughters, although the daughters would only be carriers, or in very rare cases actually show symptoms. If the father had Duchenne muscular dystrophy, he would not be able to pass the disorder on to any of his sons because he has to give his “Y” chromosome to make the child a boy. The father with the disorder could only pass down duchenne muscular dystrophy to a girl child, making the girl a carrier.
Since Duchenne muscular dystrophy is a genetic disorder and it is normally passed down from one generation to the next, it is still possible for a son to be born with Duchenne muscular dystrophy when there was no family history of the disorder. There are two reasons why this could happen. The first reason is that, the mutation that leads to Duchenne muscular dystrophy may have existed in the females of the family for some generations without them knowing. They may not of known about it because the affected “X” chromosome was not given to any of the males before, or maybe the relatives in the past generations did not know what disease he had. The second way that a male could have the disorder without any family history of Duchenne muscular dystrophy would be if the mother had a new genetic mutation that arose in one of her egg cells and then that mutation was...