Duchenne's muscular dystrophy is the result of a defective gene on the X This gene is responsible for production of the muscle protein dystrophin. Dystrophin is an integral part of the dystrophin-glycoprotein complex which bears thebrunt of the force generated during muscular contraction. When dystrophin is notproduced, the dystrophin-glycoprotein complex (DCG) is not present. Absence of theDCG leads to tears in the muscle membrane because the muscle membrane bears the forceof muscular contraction alone. Tears in the muscle membrane allow substances to leak inand out of the muscle fibers at random. This uncontrolled "biochemical traffic" leads toeventual death of the muscle fibers. Most of the current research on Duchenne's muscular dystrophy involves genetherapy. Researchers are attempting to find ways to introduce a healthy dystrophin geneinto the afflicted individual. This healthy gene would produce the dystrophin proteinthereby regenerating the DGC, which would in turn curb muscle fiber death. Studies withmice have shown that introduction of the dystrophin gene is effective in treatingDuchenne's muscular dystrophy. However, introduction of the dystrophin gene into thebody is no easy task. Thus, many scientists are focusing their research on ways to presentthe gene to the body. Viruses have a natural inclination to deposit their genetic material in a cell'snucleus and thus are primary candidates for gene transport. The dystrophin gene is arelatively large gene and therefore must be delivered via an adenovirus. The problem withviral delivery is that the immune system of the recipient recognizes the virus as foreign anddestroys both the virus and the protein it is carrying. Researchers at the University ofMichigan-Ann Arbor have developed an adenvirus that is "gutted" of its own geneticmaterial and consists only of a viral shell. These "gutted" adenoviruses elicit fewerimmune responses. However, it is believed that i...
