When a child has DMD, symptoms normally appear before six years old and may appear as early as infancy. The first noticeable symptom is in motor milestones. For example, sitting and standing independently will be more of a challenge. The average age of walking in boys with DMD is 18 months. DMD attacks the leg and pelvic muscles, resulting in a waddle and difficulty climbing stairs. Calf muscles usually enlarge and the muscle tissue eventually is replaced with connective tissue and fat. When the leg muscles contract, the muscles become unusable because the muscle fibers are shortened and fibrosis occurs in connective tissue. Symptoms are usually prevalent in boys ages one to six. There is a steady decline in muscle strength from ageâ??s six to eleven. By age ten, patients may need braces to walk and in a wheelchair by 12. Few individuals with DMD live beyond 30. Cardiomyopathy and breathing complications are common causes of death for DMD patients.
â??About two years ago it became very apparent that a drug that was in trial, a trial of twelve boys who had Duchenne muscular dystrophy, those boys all seemed to stabilize or get better. At their 48 week mark during the trial the muscle biopsy that was taken from them was revealed and actually showing the protein that the boys were lacking. So, the reason for Duchenne muscular dystrophy or the underlying causes of Duchenne muscular dystrophy is a lack of dystrophin in the body. They have none. And the whole idea of exon skipping this technology goes in and it takes out a certain exon and allows a read through of the chromosome and then allows the body to make a truncated dystrophin, thatâ??s what the aim is for the drug, the mechanism of action is for that drug of this technology. Theoretically you would hope that it would turn the child who is taking the drug into a milder form of muscular dystrophy called Becker. Becker patients have a small amount of dystrophin, or a large amount of dystrophin, they just have some dystrophin in their muscles versus none like a child with Duchenne.â??
The mothers along with other parents were responsible for bringing 7 world renowned Duchenne experts to the FDA, where the experts discussed the life-changing results and the lack of side effects with the agency, because the experts agree that this drug and technology could hold the first treatment ever in Duchene.