Duchenne 's Muscular Dystrophy : A Progressive Genetic Disorder Essay

1. The meaning of Duchenne muscular dystrophy is a severe form of muscular dystrophy caused by a genetic defect that can be characterized by a disturbed growth of cardiac and skeletal muscles. It usually affects boys. In 1861, a French neurologist, Guillaume B. Duchenne, was the first person to give a detailed description of this syndrome.

The mother, who is a carrier, inherits an X-Linked or sex-linked faulty gene. The result is producing an affected son and or a daughter being a carrier. The second way is an affected male producing children, particularly daughters. All daughters born to fathers with x-linked muscular dystrophy will be carriers; on the contrary their sons will be unaffected. Scientists link this to a genetic mutation in the gene, appearing most often for the first time in a family.

Duchenne muscular dystrophy was first discovered by Guillaume Benjamin Amand Duchenne in the 1860’s, but due to lack of medical knowledge little was known until the 1980’s. It was in 1986 that researchers that were supported by the MDA, muscular dystrophy association, identified the particular X-chromosome that leads to DMD, Duchenne muscular dystrophy. Dystrophin is the protein that is associated with the gene and was named in 1987.The DMD gene is the second largest gene to date, and it produces dystrophin.(Genome, 2013) Lack of the protein Dystrophin in the muscle cells causes them to weaken and become fragile. (MDA, 2015). DMD is an inherited disorder, but there are rare cases where it can spontaneously appear in a child with no previous family history due to a random mutation in moms X-chromosome. DMD is a gender specific disease that only appears in males.

DMD also only affects males, but women can unknowingly be carriers of the disease. They may not know they carry it if they have no brothers or were adopted.

Duchenne Muscular Dystrophy is the most common muscular dystrophy disorder. In the United States DMD affects 1 in 3,500 males. 2/3 of those cases are passed down for the mothers and 1/3 are random mutations. Internationally the statistics are similar. (Medscape, 2015)

Duchenne muscular dystrophy is a gender-linked inherited disorder. To illustrate, males only have one X chromosome, therefore they do not have a second X chromosome to make up for the damaged gene. Females can only become carriers of the disease, as females have a second X chromosomes to make up for the damaged gene.

However, if Ben’s parents have decided to have other children, their children run the risk of having DMD or being a carrier of DMD. There is no way to reduce these risks, but there is a chance that their children will not have the same problems as Ben.

According to the MediLexicon Medical Dictionary, muscular dystrophy is defined as a general term for a number of hereditary, progressive degenerative disorders affecting skeletal muscles, and often other organ systems (Staff). Basically what that means is that muscular dystrophy is a genetic disorder that is passed down that affects the skeletal muscles and other organs by slowly breaking them down. Since it is genetic, it is not contagious and you cannot catch it from someone who has it. MD weakens muscles over time, so children, teens, and adults who have the disease can gradually lose the ability to do the things most people take for granted, like walking or sitting up. Someone with MD might start having muscle problems as a baby or

Duchenne Muscular Dystrophy (also referred to as DMD) is a type of muscular dystrophy that weakens the muscles that we need to support our body, body weight, to stand, and to move around. It also can cause you to have scoliosis. Some of the main causes for DMD are genetic disorders, mutations, and DMD has to be passed down throughout everyone in that family for generations. The symptoms you can have if you have DMD are weak muscles, lack of strength, and difficulty walking. DMD is a negative mutation because it affects your muscles horribly bad that you can get a disability of walking and even moving. You need to tell your doctor immediately if you experience any symptoms. If you don't tell your doctor, you may find yourself in a very difficult situation where you can't get up or can't get something you need. When you do talk to your doctor, you will have an advantage of getting the help you need.

Duchenne’s muscular dystrophy is one of the most common forms over childhood muscular dystrophy and primarily affects boys; in total there are 30 different forms of muscular dystrophy 50% being duchenne’s muscular dystrophy (NIH, 2013). This type of muscular dystrophy usually begins to show symptoms around the pre-school age and affects the lower extremities first. By the age of twelve, most boys are in a wheelchair as the trunk muscles being to weaken leading to scoliosis and kyphosis. Eventually the diaphragm begins to weaken and young men with Duchenne’s muscular dystrophy will need assistance with breathing through the use of a ventilator (Naff, C. 2012). According to the 1st Edition of Perspectives on Disease and Disorders Muscular Dystrophy by the age of eighteen most young men would have experienced a cardio myopathy (weakening or the heart muscle) (Naff, C. 2012). Duchenne’s muscular dystrophy (DMD) is a chromosome X-linked and genetically inherited neuromuscular disease. The New England Journal of Medicine reports that Duchenne’s muscular dystrophy affects 1 in 3500 new born baby boys. Duchenne’s

Duchenne Muscular Dystrophy or DMD for short is a genetic disease that affects the skeletal muscles causing muscle degeneration and muscle wasting. Duchenne Muscular Dystrophy is an X-linked recessive chromosomal disease, which is caused by mutations in the DMD Gene (Regenerative Medicine). This Disease affects 1 in 3600 boys (Regenerative Medicine). A male born with this disease experiences respiratory dysfunction, trouble ambulation, cognitive impairment, some even experience premature death. Unfortunately, there is no cure for DMD, but there are research studies in the works for different therapies to help reverse this gene mutation and to elevate symptoms associate with this disease.

The ability to walk is something that our society seems to take for granted. A neuromuscular disease can take that ability away instantly. As with any neuromuscular disease, the body’s muscles are specifically attacked. Normally that attack is caused by a lack or mutation of a specific gene. Duchenne Muscular Dystrophy (DMD) has a direct relationship with a lack of dystrophin synthesis. It is possible that the dystrophin synthesis can be increased by manipulation of microRNA-31.

Family history is a big part in diagnosing a person with (DMD) since it’s a genetic disease. Patients with a family history of (DMD) can get a screening including fetuses in the womb. Genetic testing for these conditions in future pregnancies of an affected individual or parents of an affected individual can be done before birth through amniocentesis or chorionic villus sampling (Quercia). Amniocentesis is when doctors take fluid from the amniotic sack and test it for and chromosomal abnormalities. (The main trait that causes (MD) is the protein dystrophin. Women pass on the genetic disease and are the carriers. Women that are carriers of (DMD) can have mild symptoms but won't be affected as a much as a male would since females have an unaltered X chromosome. The most common mechanisms of mutation are deletions and duplications largely clustered in the “hot spot,” a DNA sequence associated with an abnormally high frequency of mutation or recombination (MD). The dystrophin gene defect is affecting males in two out of three cases due to the X-linked inheritance (MD). One third of the cases of the gene defect is due to the defect happening as a result of a mutation in the germ cells of parents (MD). Scientists also believe that since the mother is the carrier of (DMD) that the egg cell has a dystrophin gene

The symptoms are also effected by the age of the carrier. If an adult is experiencing muscle weakness especially in the leg, hand, neck, and face, and myotonia, which is uncontrollable contraction of muscles, they should be suspected of having DM1. If a newborn has hypotonia, facial muscle weakness, general weakness, positional malformations, or respiratory insufficiency, it should also be suspected of having DM1. Many testes are available to be able to determine if you have DM1. Some tests include electromyography, serum CK concentration, and a muscle biopsy. Checking allele sizes also help to determine whether or not you are positive for DM1. Unfortunately, since the disorder is rare, it is very difficult to predict a prognosis on it. “Non-molecular testing that has been used in the past to establish the diagnosis of DM1 currently has little role in diagnosis and is primarily used if molecular testing of DMPK does not identify the CTG repeat expansion and other myopathies are being considered.” (Thomas D. Bird).

Fist case of Duchenne Muscular Dystrophy (DMD) appeared in 1836 Conte and Gioja described 2 boys with chronic muscle weakness and these boys later developed weakness and hypertrophy of multiple muscle groups (Duchenne, 2015). At the time little was known about DMD and due to the lack of evidences to support his claim and that many scientists thought that Conte and Gioja was describing tuberculosis; therefore they did not receive credit for their work (Duchenne, 2015). Years later, a French neurologist, Guillaume Duchenne will know for his work in faradism and his understanding of muscle disease evaluated 13 boys with DMD and he notice that the muscle tissue loss in the calf is replaced by fat making it look bigger than normal. (Duchenne, 2015).