It won't be easy. Gene therapy has had a long run of frustrating failures and several tragic setbacks. Since the first gene therapy experiment at the National Institutes of Health in 1990, thousands of people have received the treatments without any benefit.

In 1999, 18-year-old Jesse Gelsinger of Tucson, Ariz., suffered a fatal immune system reaction that was triggered by gene therapy treatments he was undergoing at the University of Pennsylvania. Three years later, just as gene therapy's reputation was beginning to recover, a second tragedy struck in France.

Researchers there had announced gene therapy's first real success, using it to treat severe combined immunodeficiency disorder, commonly called "bubble boy" disease, in 11 infants. But about two years after undergoing the gene therapy procedure, some of the children developed a leukemia-like illness that researchers believed was caused by the treatment.

Duan is undaunted by gene therapy's troubled history, confident that it's possible to avoid those earlier mistakes. And he remains as enthusiastic about gene therapy as when he first discovered its possibilities a dozen years ago. At the time, Duan was a graduate student at the University of Pennsylvania.

He had come to the United States in 1993 after receiving an undergraduate medical degree in China. His parents had wanted him to be a doctor; he wanted to be a scientist. He reached a career compromise, doing science with direct medical applications. With his medical background, Duan started out his graduate work in reproductive biology. But out of curiosity, he did a rotation in gene therapy. He was hooked immediately.

"Wow," he recalls saying, "this is something more exciting, more fascinating, cutting edge!" At Pennsylvania and later at the University of Iowa, Duan worked under the direction of John Engelhardt, a scientist developing gene therapies for cystic fibrosis. When Duan was ready to set out on his own, Engelhardt suggested he make the switch to muscular dystrophy. "To start your own career you basically have to start new," Duan says. "You can't copy your mentors."

Duchenne muscular dystrophy would appear to be an ideal candidate for gene therapy. Advances in physical therapy can help keep the arms and legs of sick children stretched and flexible. And catabolic steroid drugs, such as prednisone, can delay deterioration of their muscles, even increasing their strength in some cases. But at best the drugs' benefits last a couple of years, and they can cause severe side effects such as weight gain, osteoporosis and psychological distress.

Duchenne muscular dystrophy is caused by a genetic flaw that prevents muscle cells from producing a protein called dystrophin. Because dystrophin links muscle fibers to their outer membranes -- a linkage that allows muscles to work in unison when their fibers contract -- it is essential to normal muscle functioning.

Published by the Office of Research.

©2006 Curators of the University of Missouri. Click here to contact the editor.