Gene Therapy to Restore Sight

by Sandra J. Ackerman

November, 2006

A brave dog named Lancelot was the bearer of good news about a previously incurable, degenerative disease of the retina—Leber’s congenital amaurosis (LCA), which causes blindness in infants soon after birth. Lancelot was the first of several subjects in a study demonstrating that LCA could prove amenable to gene therapy, according to recent research presented at SfN.

Paul Sieving, director of the National Eye Institute, described recent work by a large group of researchers, including Gustavo Aguirre, of the University of Pennsylvania and William Hauswirth of the University of Florida, on an animal model of LCA. Dogs blinded by naturally occurring LCA received an injection of the normal gene for the protein RPE65, which is essential to the processing of light by the retina. This gene is mutated in individuals with LCA.

With their mutant RPE65 replaced by the normal form of the gene, the dogs gained the ability to see—an effect that has now lasted several years. “I expect clinical trials of RPE65 to begin by spring 2007,” Sieving said.