OTHER KINDS OF GENE THERAPY
Fortunately, putting in a dystrophin gene isn't the only way to do gene therapy. Researchers have made a lot of progress in gene therapy strategies since the early 1990s.
What seemed like science fiction only a few years ago, such as changing the way a cell "reads" the DNA to make a protein, now looks very possible. It may be that these gene correction strategies will surpass gene insertion strategies in the future.
Another route is what's sometimes called a compensatory protein strategy. MDA researchers have recently found that there's a protein, now called utrophin, that can possibly substitute for dystrophin in muscle fibers (or so mouse experiments suggest).
The gene for utrophin is on chromosome 6, not the X chromosome, and boys with DMD can have perfectly normal utrophin genes and utrophin proteins. Some researchers have theorized that, if boys with Duchenne could just make more utrophin, this protein might fit into the muscle fiber in place of dystrophin and either stop or slow muscle degeneration.
MDA researchers are working feverishly to find ways to make the body produce more utrophin. The ultimate goal is a chemical that could be developed into a drug that would "rev up" protein production from the utrophin gene.
Failing that, inserting a utrophin gene instead of a dystrophin gene might be a way around at least some of the immunologic problems that worry researchers. Since the immune system of a boy with DMD has seen utrophin all his life, it's highly unlikely that this protein would provoke an immunologic rejection. However, all the other problems associated with gene delivery, including the use of immune-system-provoking viruses, would still have to be tackled.
Research
MDA IS HERE TO HELP
MDA supports more research on neuromuscular diseases than any other private-sector organization in the world, allocating more than $22 million a year to its research program.
MDA funds some 400 teams of the world's top scientists in the field. Duchenne muscular dystrophy is a major focus of those projects. Since the mid-1980s, MDA scientists have located the genes responsible, when flawed, for most of the genetic neuromuscular disorders in MDA's program, beginning with their finding of the Duchenne and Becker gene in 1986. These discoveries have provided doctors with better diagnostic and genetic testing techniques.
Building on that knowledge, scientists have created a correctly functioning synthetic gene to replace the flawed gene in Duchenne and Becker muscular dystrophies. In 1998, MDA-backed investigators began plans for preparing to undertake human trials of gene therapy for Duchenne and other forms of muscular dystrophy. The Association established its first gene therapy center at the University of Pennsylvania, which will accommodate expanded gene therapy clinical trials that show promise of leading to treatments to stop the destructiveness of muscular dystrophy.
Other MDA scientists are pursuing the role of utrophin in DMD and whether this protein could be used to "replace" missing dystrophin. In addition to this research, MDA helps develop and test potential new drug treatments for DMD and other disorders. |
Next... Research Other Than Gene Therapy  |
