Symptoms can range from mild skeletal muscle weakness or cardiac involvement to severe weakness or cardiac effects and can begin in childhood or adulthood. Most carriers of DMD do not themselves have signs and symptoms of the disease, but a minority do. What are DMD “carriers”?ĭMD carriers are females who have a normal dystrophin gene on one X chromosome and an abnormal dystrophin gene on the other X chromosome. For more about the way gene mutations cause DMD, see Causes/Inheritance. Lack of the dystrophin protein in muscle cells causes them to be fragile and easily damaged.ĭMD has an X-linked recessive inheritance pattern and is passed on by the mother, who is referred to as a carrier. In 1987, the protein associated with this gene was identified and named dystrophin.
In 1986, MDA-supported researchers identified a particular gene on the X chromosome that, when flawed (mutated), leads to DMD. What causes DMD?ĭMD was first described by the French neurologist Guillaume Benjamin Amand Duchenne in the 1860s, but until the 1980s, little was known about the cause of any kind of muscular dystrophy. The disease course for BMD is slower and less predictable compared to DMD. For more about DMD symptoms, see Signs and Symptoms.īecker muscular dystrophy (BMD) is a similar to DMD, but with onset usually in the teens or early adulthood.
Progressive weakness and scoliosis result in impaired pulmonary function, which can eventually cause acute respiratory failure. Later on, the heart and respiratory muscles are affected as well. Other symptoms include enlargement of the calves, a waddling gait, and lumbar lordosis (an inward curve of the spine). The affected child might have difficulty jumping, running, and walking. Usually, the lower external muscles are affected before the upper external muscles. It can begin as early as age 2 or 3, first affecting the proximal muscles (those close to the core of the body) and later affecting the distal limb muscles (those close to the extremities). Muscle weakness is the principal symptom of DMD. In Europe and North America, the prevalence of DMD is approximately 6 per 100,000 individuals. The disease primarily affects boys, but in rare cases it can affect girls. The other three diseases that belong to this group are Becker Muscular dystrophy (BMD, a mild form of DMD) an intermediate clinical presentation between DMD and BMD and DMD-associated dilated cardiomyopathy (heart-disease) with little or no clinical skeletal, or voluntary, muscle disease.ĭMD symptom onset is in early childhood, usually between ages 2 and 3. DMD is one of four conditions known as dystrophinopathies. Duchenne Muscular Dystrophy (DMD) What is Duchenne muscular dystrophy?ĭuchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact.
0 kommentar(er)
