Duchenne Muscular Dystrophy Bibliography
Duchenne Muscular Dystrophy Questions


History of Disease:
Duchenne Muscular Dystrophy was discovered by a man named Guillaune Benjamin Amand Duchenne in the nineteenth century. He was a French neurologist who investigated people’s symptoms. He would follow them around, going hospital to hospital trying to diagnose their problems. By 1868, Duchenne had accounted for thirteen children who had become affected by the same symptoms, which he believed was a muscular problem. To prove this, he did the first biopsy to obtain living tissue from a patient for microscopic examination. After word about the biopsy got out, controversy arouse concerning morality of examining living tissue. Throughout all the controversy and disagreements, Duchenne concluded that the disease he was examining was in fact in the muscles.
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How is Duchenne Muscular Dystrophy inherited?
Duchenne Muscular Dystrophy is an inherited disorder that involves rapidly worsening muscle weakness. It is a sex-linked disorder and is caused by a defective gene on the 23 or X chromosome. The reason people develop this disease is because their body fails to produce a functional muscle protein called dystrophin. Duchenne is passed down through the mother’s side usually onto their sons. Males have a greater chance of inheriting this disorder while women are more likely to become carriers. There is a fifty percent chance that the mother will pass it on to their sons and daughters, but daughters most likely become carriers because they did not inherit the trait from both parents. In 2 out of 3 cases, males inherit an altered copy of the chromosome from their mothers. In 1 out of 3 cases the disorder will result from a new mutation in the gene. Duchenne Muscular Dystrophy affects the skeletal muscles, is associated with heart conditions, and delays children’s motor skills. It is the most common childhood disease and 1 out of every 3,600 male infants inherits it.
Early symptoms of Duchenne begin between the ages of two and five. Some of the first signs of it are frequent falling, difficulty getting up in lying or sitting positions, enlargements of calf muscles, inability to raise knees, and the disappearance of knee and ankle jerk. Overtime these symptoms become more apparent and by early adolescence the simplest of tasks are impossible to complete. Stairs become impossible to climb as a teenager and when adolescence is reached, they are unable to walk. Overtime people with this disorder may also develop problems with their heart and eventually will affect their diaphragm up to the point where breathing becomes shallow. Once adolescence is reached, heart problems such as dilated cardiomyopathy, which is a condition that enlarges and weakens ones heart muscles, may appear, walking is impossible and a wheel chair is required to move around and a ventilator is needed for breathing. People who inherit this disease usually have average intelligence, although 1/3 might inherit learning disabilities. This disorder is life-threatening and people who inherit it have a life span of about twenty years old. One rarely lives past that age because one is unable to perform even the simplest of task on their own. That is why females hardly ever inherit the disease. They need the chromosome from both parents, and males do not usually live long enough to reproduce.
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Have any medical advancements been developed to treat or prevent Duchenne Muscular Dystrophy?
While there is no cure for Duchenne Muscular Dystrophy, there are a few ways to make the symptoms more tolerable to live with. The goal is to lengthen the lives of people who have this disorder and make them comfortable. Physical therapy may be extremely helpful to strengthen the muscles and keep them loose. Inactivity can make the disorder even worse. Many people with this disease use walking braces or wheelchairs to help them get around.

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One can get spinal surgeries or breathing aids to help them be more comfortable. Also, in order to slow down the symptoms, one may use steroids. There are support groups as well so that anyone with this disorder can cope with it and be with other people who are in the situation.

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Gene therapy is being looked into for this disorder and one day in the future, there may be a cure. A health care provider should be immediately notified if a child is either having symptoms of Duchenne Muscular Dystrophy or new symptoms seem to have appeared.

-Mutation-

 Duchenne Muscular Dystrophy is caused by a defective or alterted X chromosome. The defect results in the failure to producen the functional muscle protein, Dystrophin.

Duchenne-muscular-dystrophy.jpg Because this disease is a sex-linked disorder, it strikes males more then females. This occurs because males only have one X chromosome, and the disease can occur if the alterted gene is present in the X chromosome, yet, the female must have the mutation on both of her X chromosomes, making it more likely for the male to have the disease.


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Most of the females who have the disorder, only carry it on one of their X chromosomes, which may leave them unaffected, but then they have a 50% chance of passing it on to their sons.





-Characteristics-

Women are able to carry the gene for this disorder but do not show it. Mostly males can get this disorder, but rarely females can get this disorder too. Symptoms are frequent falling, general weakness, difficulty getting up by themselves, and also the difficulty with motor skills. The child has mental retardation.

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Most of the children with this disorder have deformity of spine, heel contracture, and joint contracture. The legs and pelvis muscles start to weaken first and the child loses the ability to walk. The arm and neck muscles are also affected. Most children with Duchenne muscular dystrophy usually have lack of coordination.