Duchenne Muscular Dystrophy Overview

Duchenne muscular dystrophy is one among a group of inherited genetic disorders characterized by muscular weakness. A genotype X-linked form of the disease, it affects mostly males. Females are rarely affected by this genetic disorder but more often they act as the carriers of the same. The incidence rate of this condition is estimated to be 1 in every 3,600 boys. This form of dystrophy results in muscle degeneration leading to difficulties in walking and breathing, and eventually death. The symptoms start appearing by the age of 5 and muscle weakening progresses with observable loss of muscle mass. By the age of 12, most patients would be confined to a wheelchair. Progressive muscle deterioration leads to the loss of movement and paralysis. The life expectancy of patients is usually 25 years but may vary from individual to individual. During the later stages there is a possibility of abnormal bone movement which leads to curved spine and skeletal deformities. There is no progressive intellectual impairment with age for those children who already have it.

Duchenne muscular dystrophy is a genetic disease where the dystrophin gene has been mutated. This gene is responsible for the production of the protein dystrophin which, in turn, plays a vital role in the structural support of the muscles. Without this protein the cell membrane of the muscle cells become permeable to the extracellular components, leading to the enlargement and explosion of the cells due to internal pressure. Progressive muscular disorder is the main symptom of this disease. The patient experiences difficulty in walking, running, jumping etc. They also fall frequently and have difficulty with motor skills. Muscle fiber deformities and skeletal deformities are also observed in such patients. DNA testing can confirm the diagnosis in many cases by the analysis of the dystrophin gene. If DNA testing fails, a muscle biopsy can be done, the analysis of which can determine whether the protein exists or not. The absence of the dystrophin protein indicates the condition. Prenatal test can also identify most of the common genetic disorders including this form of muscular dystrophy. The prevention of this disease is not possible as of today. The only way is to abort the unborn child if a prenatal test for the condition is positive.

No cure is currently available for this condition but there is a lot of ongoing research in this area, which includes stem cell replacement, gene therapy and exon-skipping. The treatment of a patient with this condition is aimed at controlling the symptoms and improving the quality of life. Corticosteroids increases muscle strength and defers the severity of many of the symptoms of this condition. Since inactivity can worsen the condition of the patient, mild activities like swimming are encouraged. To maintain muscle flexibility and strength, physical therapy is a must. Braces and wheelchairs also improve the mobility and self-care ability of the patient. As the disease progresses, appropriate respiratory support might also be required. Physical therapy is aimed at minimizing the development of contractures and deformities. The secondary complications of physical nature can also be minimized with the help of physical therapy.