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 through transmission of an X-linked recessive gene. DMD codes for the muscle protein, dystrophin. As a result, people who are affected with this disorder are not able to make this protein in their muscles, causing them to become weak and not function properly (NHGRI, 2014). This disorder moves quickly throughout the body and rapidly gets worse. Of the nine different muscular disorders, Duchenne muscular dystrophy is the most prevalent form found in people today (MDA, 2014).
Duchenne muscular dystrophy affects approximately 1 in every 3,500 live male births; that is nearly 20,000 new cases annually. This disorder primarily affects young boys because of the disorder’s location on the “X” chromosome. In very rare cases it affects young girls. A majority of the time, it only causes them to become carriers of the disorder and they never show any symptoms. Duchenne muscular dystrophy is not limited to just one race or culture; it affects all races and cultures. Typically, Duchenne muscular dystrophy can be passed down from an affected parent to their child; although, that is not necessarily true in every case. Approximately 35% of children affected with the disorder do not receive it from their parents. This is possible because the disorder can occur in any child when there is mutation on the “X” chromosome where DMD is located. This means that anybody can be affected by this disorder even if it does not run in their family (PPMD, 2014).
Modes of Inheritance
A majority of people diagnosed with Duchenne muscular dystrophy receive the disorder from their mother. If the mother is a carrier of the disorder, her sons will have a 50% chance of having the disease and her daughters would have a 50% chance of being carriers of the disorder. In very rare cases, the daughters may start to show symptoms. If the father had Duchenne muscular dystrophy, he would not be able to pass the disorder on to any of his sons. It is impossible for a son to get the disorder from his father because he receives only the “Y” chromosome from his father which is necessary to make him a male. Duchenne muscular dystrophy is a mutation found on the “X” chromosome so males can only receive the disorder from their mother. Since the father is forced to pass down his “X” chromosome to any females, there is a 100% chance that every daughter will be a carrier of the disorder because the “X” chromosome contains the mutation (MDA,2014).
Duchenne muscular dystrophy is a genetic disorder and is normally passed down from one generation to the next; however, 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 explanations for why this can occur. First, the mutation that leads to...