Duchenne muscular dystrophy is a rare genetic disorder where the muscle growth degenerates and becomes weak. It is also one of the main types of muscular dystrophy. It is caused because of the lack of a protein called dystrophin that is essential for keeping the muscles together. The signs of this disorder start showing up in the early childhood especially between the age of 3 to 5 and mainly affecting boys and in rare cases, affecting girls as well.
This muscular disorder is not specific to any age, race or culture, however what makes it different from other muscular dystrophies is that it mostly occurs in young boys and men making it a gender specific disorder. It affects one in 3500 males with almost 20,000 cases every year, especially at birth. It happens mostly with males because they have X and Y chromosome both unlike girls who only have two X chromosomes making young men more prone to inheriting damaged genes or related disorders as they lack another X-chromosome that could make up for the damaged gene.
Symptoms of DMD
Since the diagnosis takes place at an early stage it is natural that the signs also manifest during early childhood such as muscular weakness that can start at the age of 3. The weakness affects muscles of the pelvic area, thighs and hips, shoulders, arms as well as legs. Often, the calves get enlarged. As a person enters the teenage he also might have cardiovascular as well as respiratory muscle weakness.
Patients also have weaker head and neck movements. During early years the child is also not able to walk at the average time. Problems also include difficulty in getting up, walking, and running as well as proper speech development. The calves are also abnormally larger and the patient might walk with parted legs, or walking on the toes with chest pointed outwards.
Symptoms can also include weakness of the skeletal muscle, cardiac disorders such as cardiac weakness as early as in childhood or adulthood.
Causes of DMD
This muscular dystrophy was first diagnosed by a French neurologist named Guillaume Benjamin Amand Duchenne in the year 1860. However till then there wasn’t much information about the causes of muscular dystrophy. In the year 1986, a group of MDA researchers determined a specific gene of the X chromosome which when mutated, causes dystrophy also referring to the associated protein i.e. dystrophin that works like a glue, and keeps the muscles intact and maintains the structure of the muscle cells as well. It also transports signals from the external to internal muscle fibers. As already mentioned, boys suffer from DMD more as they only have one X chromosome that makes them more vulnerable to the dystrophic gene damage.
This disorder is also passed from mother to the child but there have been cases of random mutations that occur during pregnancy as they have two X chromosomes with one of them having a normal dystrophic gene.
Duchenne muscular dystrophy life expectancy
Till now, males with DMD mostly have not survived much till their teenage or beyond. However with advanced cardiac and respiratory care, the life expectancy has seen an improvement as people have been able to attend college and get jobs. Some have also been able to get married and have had children. Therefore it can be seen that the life expectancy has increased from teenage to 30s. There are also a few cases of men living till their 40s and even 50s.
- Physical therapy to enhance physical movement and potential such as reducing the effect of contractures and deformities through appropriate stretching exercises and maintain flexibility as well as proper functioning of muscles.
- Minimizing secondary or further through the support of various medical equipments.
- Assisting respiratory exercises for proper respiratory functions. Respiratory support equipments are also used.
- Steroids such as Corticosteroids, prednisolone, deflazacort to increase the energy levels and enhance the overall physical potential.
- Clinical trials such as Randomized controlled trials have often been used to improve muscular strength but have not helped much in reduction of disease or symptom progression as the follow-up time is only up to a year or so.
- Light but effective and doable physical activities like swimming or brisk walks are encouraged as lack of physical activity can make muscle disease even worse.
- Orthopedic support such as appliances (braces, wheelchairs etc) may also be used to enhance self mobility. Appliances such as removable leg braces can help a lot, especially during sleep.