In a promising result for gene therapy, researchers have dramatically improved the vision of several patients with a rare, inherited eye condition called Leber congenital amaurosis. The early study was intended to simply test the safety of the treatment, but the patients displayed such significant improvement that researchers decided to publicize the results.
Gene therapy works on a simple principle – to replace a malfunctioning gene, and restore function to a part of the body affected by a genetic disorder. In practice, however, it has proved very difficult to find ways to introduce the new gene copies in the correct tissues, and experiments in animals have had mixed results [BBC News].
In the new study, published in the Proceedings of the National Academy of Sciences [subscription required], researchers selected three patients whopossessed defective versions of the RPE65 gene, which normally produces an enzyme that maintains a protective layer of cells ...