Jesse Gelsinger was 18 years old in 1999, when he joined one of the first clinical trials of gene therapy. As in any pioneering field of medical science, researchers must strike a balance between advancing knowledge that could help cure devastating diseases and proceeding with caution to protect patients. Yet the quest to control side effects is far from over. Since then, gene therapy has yielded some notable successes. Convinced of the promise of genetic cures and of the potential to find safer, more precise gene delivery methods, they persisted. Serious side effects, some deadly, threatened to derail the field in its early years, prompting researchers to step back and reconsider their approach. Outcomes like Audrey’s would not have been possible without decades of research and patients who volunteered for experimental treatments, knowing they could be risking their lives, to help move gene therapy forward. So far none of the children has shown any serious side effects. After a year and a half, Audrey and one other child were walking with hand support and learning to use muscles they had previously been unable to command. A year postsurgery all six surviving children could control their heads normally, and four could sit independently. The seventh child also improved initially but died seven months later from complications of the disease itself, Bankiewicz says. The results were dramatic: by three months after surgery, six of the seven children stopped having oculogyric crises-the distinctive eye-rolling that is a hallmark of the disease. The children ranged in age from four through nine years old at the beginning of the trial (Audrey was six at the time). The researchers injected the virus directly into each child’s brain near neurons they hoped would start making AADC and, subsequently, dopamine. Seven children participated in the trial. The gene therapy Bankiewicz and his colleagues were testing uses a harmless virus as a vector to introduce an intact version of the gene responsible for making the AADC enzyme. Most children with the condition are unable to talk, sit up or support their own weight.Īfter years of frustration, Audrey’s parents enrolled her in a clinical trial led by Krystof Bankiewicz, a professor of neurosurgery at the University of California, San Francisco, and the Ohio State University College of Medicine. It causes severe developmental and motor disabilities, as well as sleep and mood problems. The extremely rare disorder manifests in infancy and lowers the activity of AADC, an enzyme that is critical for making the brain-signaling chemicals dopamine and serotonin. Genetic tests later diagnosed Audrey with a condition known as aromatic l-amino acid decarboxylase (AADC) deficiency, caused by mutations in a single gene. Finally, they confessed that they did not know how to help and sent Audrey and her parents home with a handful of pamphlets about living with a disability. Her doctors prescribed seizure medication-lots of it-which sedated her but did not stop the eye-rolling. Despite visits to multiple specialists, no one knew what was wrong. Without warning, her body stiffened, and her eyes rolled into the corners of their sockets for hours at a time. Audrey was six months old when her parents first noticed something wasn’t right.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |