DMD is caused by a change in a gene responsible for making the protein dystrophin, which keeps muscles strong and healthy. This change is referred to as a mutation. When there is a mutation in this gene, the protein dystrophin does not work. The muscle cells become weak and they gradually break down. DMD usually affects boys; it is extremely rare in girls. DMD is a progressive disease.
At first, the weakness is mostly in the legs and hips. Those affected fall frequently, have trouble running and climbing stairs, struggle to get up from a sitting position and often walk on their toes. They also develop larger than normal calves. Eventually, the muscle weakness makes walking more difficult and a wheelchair is needed. Gradually, all the muscles become very weak – including the heart muscle and the muscles used for breathing. Duchenne Muscular Dystrophy is an inherited disorder caused by a mutation in the gene that produces dystrophin.
This mutation is passed down from mother to son because the dystrophin gene is located on the X chromosome. If the mother passes on an X chromosome with an altered dystrophin gene to her son, he will develop DMD because he has only one copy of the X chromosome. Girls have two X chromosomes. When they inherit the DMD mutation from their mother, they also inherit a normal copy of the DMD gene from their father. That is why they do not develop the disease.
However, they may be carriers and pass DMD on to their sons. Daily Life with DMD There is no cure yet for DMD. A healthy lifestyle, exercise and medication can contribute to a better quality of life for those with the disease. Jonathan takes a steroid-based medication called Deflazacort to help maintain his muscle strength.
One of the side effects of steroidal medication and a lack of physical activity (as a result of wheelchair use) is a loss of calcium in the bones. This may increase the risk of fractures. Jonathan takes daily doses of calcium, in conjunction with vitamin D, to keep his bones strong. Other possible treatments that may help with some aspects of DMD include physiotherapy to help maintain correct foot position, chiropractic treatments, nutritional supplements and naturopathic preparations.
One of the challenges that Jonathan’s family had to face was adapting Jonathan’s environment to his needs. The local community service centre (C LSC) in their region and the Muscular Dystrophy Association of Canada were able to direct them to the various resources available. Jonathan now has a lift to get him inside the house and another lift to allow him to reach the second floor, which he can operate by himself. There is also a lift from his bedroom to the bathroom, which Jonathan controls with the help of his parents. Jonathan goes to school, and his parents had to choose one that could cater to his needs. Jonathan loves his school and he has several friends.
Three close friends who take care of him are Annie, Sophie and ‘Emilie. Jonathan also has a social worker, Isabelle, who looks after him. Now that he has his new wheelchair, Jonathan can move around the school more easily. He is keen to learn and is curious about everything.
He also loves to tease his friends, his brothers and sister. The Future Gene therapy, or gene replacement, is one of the most promising areas for treatment of DMD. Scientists have developed a synthetic gene that they hope to introduce into the body to “take over” and produce the missing protein, dystrophin. Stem cells, called my oblasts, may also be used in the future to replace damaged muscle.
These cells would fuse to the diseased muscle and produce dystrophin.