14 DAY TRIAL // In a new study published on Saturday, experts announce that they managed to stop the evolution of a dangerous eye disease in children by administering a single DNA shot into their eyes. The gene therapy proved so effective, that the four test subjects were able to walk without help from others in the end, which is very rare in Leber's congenital amaurosis (LCA). In the case of this condition, sufferers start losing their vision from birth and are completely blind by the age of 40. There are currently about 3,000 people suffering from this disease in the United States alone, ScienceNow reports.
In one form of the disease, LCA2, sufferers are born with an abnormality on a gene called RPE65, which usually plays an important role in the production of rhodopsin. This is a pigment that is invaluable to photoreceptor cells, as it represents the active chemical that allows vision cells to detect and process light, and then convert it into electrical signals and send it to the brain. In the pigment's absence, the cells simply wither and die, which, over time, leads to total blindness. University of Pennsylvania (Penn State) researchers announced in 2001 that, by injecting a good copy of the RPE65 gene into the eyes of dogs suffering from LCA2, they were able to restore at least partial vision.
A small safety study on the therapy's effects on humans began in 2007, led by researchers from Penn State and the Children's Hospital of Philadelphia. In all of the patients, a virus containing the good gene was injected in the worst of the eyes. A similar investigation was conducted in the United Kingdom at about the same time. Early results, published last year, showed that four out of six children were able to detect more light following the single shot, and that they could maneuver around an obstacle course better than before. In the new study, published in the October 24 issue of the journal The Lancet, experts detail the full results.
They reveal that there is a significant difference between the way the gene therapy functions in children and adults, and say that the young ones are more susceptible to being positively influenced by the RPE65-carrying virus. According to the scientists, the children involved in the study are now able to recognize faces, play baseball, read large print books, and ride their bikes safely. The investigation “is an incredible launching pad to be able to target other diseases,” Penn State gene-therapy researcher Jean Bennett says. The expert has also been the leader of the new study.