Gene therapy to restore sight

Leber’s congenital amaurosis is a pathology that affects 3000 people in USA and causes loss of sight from birth until reaching complete blindness at about 40 years. This disease interests a gene, RPE65 that helps in rhodopsin synthesis. If this gene is mutated, as occurs in the disease, photoreceptor cells into the retina will die.

During an important study carried out at the University of Pennsylvania, gene therapy was applied to blind dog to restore the activity of RPE65 gene and restore sight, as a consequence. Then, a small- scale study in human started in 2007, to ascertain the safety and efficacy of using virus to carry the RPE65 gene. First results showed that four of six young adults with Leber’s congenital amaurosis, had an improvement in their sight. Nevertheless, researchers knew that children with an intact retina –not already compromised by the disease- could have major benefits from this therapy. Thus, they performed the same study including four children for 8 to 11 years old and obtained great results in terms of increased light sensitivity. This work has been published in Lancet Journal in October, 2009. As all therapies that can improve the life quality of children, this work offers an hope for families that have so serious problems.