What is Duchennes Muscular Dystrophy?
Duchennes Muscular Dystrophy (DMD) is caused by a mutation of the dystrophin gene, the gene that carries the genetic information or “recipe” for the construction of the dystrophin protein. Without the proper genetic information, the body does not produce a functional version of the dystrophin protein, which normally serves to surround the muscles cells, maintain their structure and hold the muscles together. The dystrophin protein is the largest protein in the body, is found dispersed throughout the skeletal, cardiac and smooth muscle tissue and is also believed to carry signals in and out of muscle fibers. Without this protein, the muscles become increasingly weaker, until the body can no longer survive. Since the dystrophin gene is carried on the X-chromosome, the disease is either passed on by a mother that is a genetic carrier of the mutated dystrophin gene or is caused by a spontaneous mutation in the dystrophin gene after conception. This means that a mother carrying a healthy gene can give rise to a child with DMD. Because the dystrophin gene is carried on the X-chromosome, this disease usually affects boys, since girls have two X-chromosomes and can fall back on one if the other carries a faulty gene.
Is this a Common Disease?
At present, more than 20,000 children in the United States suffer from this fatal disease, and more than 100,000 worldwide. On average, these children succumb to Duchennes by their early twenties. Typically during their school-age years, in conjunction with all of the other problems surrounding this disease, they suffer from learning disabilities, social isolation and behavioral issues.
The Centers for Disease Control and Prevention (CDC) is working with researchers in Arizona, Colorado, Georgia, Iowa, and Western New York to set up the Muscular Dystrophy Surveillance Tracking and Research Network (MD STARnet). These areas of the country were specifically chosen because of the high instance of this disease among its young boys. The MD STARnet project will act as a surveillance network for annual collection of medical history data and basic demographic information for Duchennes muscular dystrophy patients for the purpose of answering epidemiologic and clinical questions.
Currently, there are more than 15 clinical trials underway for drugs developed to treat various aspects of DMD. Many are expected to be on the market within the next couple of years and clinicians have expressed a great amount of hope and confidence in many of these drugs and their potential to correct detrimental aspects of the disease. As various groups around the world are focusing on DMD, funding to support DMD research has significantly increased over the past couple of years. With continuing support there is great hope that we will save this generation of boys.
RNA based antisense oligonucleotides inducing exon skipping is a potentially promising therapeutic tool to treat many boys with DMD. Some of the most promising research is currently being conducted by a group called the “MDEX Consortium,” which is focusing on “morpholinos” (exon skipping compound) The FDA previously approved the use of morpholinos in the treatment of certain types of cancer.