What is duchenne muscular dystrophy (DMD)?
Duchenne muscular dystrophy (DMD) is a congenital and hereditary form of muscular dystrophy. The disease mainly affects men since the recessive gene that is located on the X chromosome on the basis of the condition, and men have only one X-chromosome. Like other X-linked disorders, also it is inherited through the mother, if she bearer thereof.
The disease is caused by the absence of the protein dystrophin in the muscle cell. Your muscles are not functioning as it should and there is a reduced muscle strength. Often one sees a pseudohypertrofie the calf muscles; the calves are very pronounced because of increased fatty tissue and connective tissue, the muscle itself is very weak. The weakness of these children can hardly come straight from lying or sitting position (Gower's sign: hands pushing the thighs to get up from a sitting position). Scoliosis, pathological fractures due to osteoporosis, fatty infiltration of the heart muscle and respiratory failure with respiratory infections are among the most frequently occurring complications and can lead to death.
The disease is progressive and affects more and more muscle tissue so that at the age of 12 to 13 years a wheelchair is inevitable. At age 25, the disease has progressed so far that patients are permanently dependent on a breathing machine. However, the decline will continue and eventually on 35- to 40-years of age die, most men who suffer from the disease. Duchenne muscular dystrophy occurs mainly in boys / men but can occur in rare cases in girls / women. Duchenne's disease may indicate malignant hyperthermia in general anesthesia, a life threatening condition. Patients with Duchenne muscular dystrophy should mention this at all operations to the doctor.
The disease is incurable. Gene therapy treatments (exon skipping) are examined in the mdx mouse model and human DMD gene-cell lines and human. The purpose of this approach is to Duchenne's disease as to form in a condition that is more similar to the - less serious - of Becker muscular dystrophy.
In 2008 an article was published about a study in Leiden where some human patients with an oligonucleotide according to this principle (exon skipping) was injected locally (at the injection site) the protein dystrophin somewhat (3 to 12% of normal levels) subjects produced. This is an important finding, but a widely applicable method is still far.