Duchenne's Muscular Dystrophy is a condition that involves wasting of muscles and is hereditary in nature. It is a linked disorder wherein the mother is the carrier. Males are affected. The Duchenne type affects only boys (with extremely rare exceptions) and a problem in this gene is known to result in a defect in a single important protein in muscle fibres called dystrophin. Doctors are also working on improving muscle and joint function, and slowing muscle deterioration so that kids, teens, and adults with MD can live as actively and independently as possible.
Duchenne muscular dystrophy is an inherited disorder, characterized by rapidly-worsening muscle weakness that starts in the legs and pelvis, and later affects the whole body. DMD is one of the most prevalent types of muscular dystrophy and is characterized by rapid progression of muscle degeneration that occurs early in life. This makes the muscle cells weak and they gradually break down. A child who is diagnosed with MD gradually loses the ability to do things like walk, sit upright, breathe easily, and move the arms and hands. DMD is named after the French neurologist Guillaume Benjamin Amand Duchenne (1806-1875), who first described the disease in the 1860s. It is due to mutations in the dystrophin gene, which encodes a cell membrane protein in myocytes (muscle cells). Signs of weakness start when the boys are between 3 and 5 years of age (sometimes earlier).
DMD is an inherited disorder. It's caused by incorrect or missing genetic information that prevents the body from making the proteins it needs to build and maintain healthy muscles. It is an X-linked recessive inherited disease . A milder form of this disease is known as Becker's muscular dystrophy (BMD). All the muscular dystrophies are caused by faults in genes (the units of inheritance that parents pass on to their children) and they cause progressive muscle weakness because muscle cells break down and are gradually lost. Dystrophin is required inside muscle cells for structural support; it is thought to strengthen muscle cells by anchoring elements of the internal cytoskeleton to the surface membrane. Boys with DMD develop weak muscles because the muscle fibers that were present at birth are destroyed. There are several major forms of muscular dystrophy, which can affect a child's muscles in different levels of severity. In particular, initial experiments that increase the production of utrophin, a dystrophin relative, in order to compensate for the loss of dystrophin in the mouse are promising and may lead to the development of effective therapies for this devastating disease.
Causes of Duchenne's Muscular Dystrophy
The common Causes of Duchenne's Muscular Dystrophy :
- An absence of dystrophin, a protein that helps keep muscle cells intact.
- While the affected genes have been identified for some forms of muscular dystrophy, such as DMD, BMD, CMD, and most forms of LGMD, the genes responsible for the other forms have not yet been identified
- This condition is inherited in an X-linked recessive pattern and is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two chromosomes and is considered linked .
- Muscle weakness also occurs in the arms, neck, and other areas, but not as severely or as early as in the lower half of the body.
- This form is caused by mutations of the gene for the dystrophin protein and leads to an overabundance of the enzyme creatine kinase .
- Muscular dystrophy is a genetically determined disease, although why the individuals who are genetically the same get MDs of different severity is not known.
Symptoms of Duchenne's Muscular Dystrophy
Some common Symptoms of Duchenne's Muscular Dystrophy :
- Difficulty with motor skills (running, hopping, jumping)
- Muscle weakness.
- Progressive difficulty walking.
- Apparent lack of coordination.
- Chest and back ( scoliosis ).
- Pseudohypertrophy of calf muscles.
- Mild mental retardation, in some cases.
- Waddling gait.
Treatment of Duchenne's Muscular Dystrophy
- Physical therapy and orthopedic instruments ( e.g., wheelchairs , standing frames ) may be helpful.
- The medications mexiletine (Mexitil), phenytoin (Dilantin, Phenytek), carbamazepine (Tegretol, Carbatrol), quinine and procainamide (Procanbid, Pronestyl) may be used to treat the delayed muscle relaxation that occurs in myotonic dystrophy.
- To release the contractures that may develop and that can position joints in painful ways, doctors can perform a tendon release surgery.
- Orthopedic appliances (such as braces and wheelchairs) may improve mobility and the ability for self-care.
- There is no known cure for Duchenne muscular dystrophy. Treatment is aimed at control of symptoms to maximize the quality of life.
- Physical and occupational therapy may be helpful to maintain muscle strength and function.
- The anti-inflammatory corticosteroid medication prednisone may help improve muscle strength and delay the progression of Duchenne MD.
- Because respiratory infections may become a problem in later stages of muscular dystrophy, it's important to be vaccinated for pneumonia and to keep up-to-date with influenza shots.
- The myotonia (delayed relaxation of a muscle after a strong contraction) occurring in myotonic muscular dystrophy may be treated with medications such as quinine , phenytoin , or mexiletine