1 May 2007
Gene therapy had been used in an attempt to treat a genetic sight disorder. In the first clinical trial of its kind in humans, a team of clinicians from London's Moorfields Eye Hospital and University College London have introduced functional copies of the RPE65 gene to the retina of a man with Leber's congenital amaurosis, a form of inherited childhood blindness caused by mutations in RPE65 (see press release). This gene encodes an enzyme expressed in the retinal pigment epithelium (RPE), which has an essential role in vision; the mutation in RPE65 gene prevents the normal retinal function in detecting light.It will take months before it is possible to determine whether the gene therapy has been successful in restoring some degree of sight, as has already been demonstrated in canine models, to any of the twelve trial participants. The best results are expected to be from the treatment of younger patients. Experts hope that the eye will prove to be a tractable target for gene therapy because it is a relatively simple and accessible organ; if so, gene therapy could potentially be used for other genetic visual defects.