A gene-transfer technique is undergoing Phase I trials to test its safety in people with a form of hereditary blindness called Leber congenital amaurosis type 2, or LCA2.

The first adult subject received an injection of trillions of replacement genes into the retina of one eye last week, making the volunteer one of the first people in the world to undergo the procedure.

In all, six adults and then three children between the ages of 8 and 17 will undergo the gene-transfer procedure at UF over the next year or more before safety data are fully evaluated. Names are not being disclosed for privacy reasons. Potential risks are discussed with prospective participants as part of an extensive screening and informed consent process.

The procedure is based on the principle that in LCA, photoreceptor cells in the eyes are unable to respond to light due to a mutation in the RPE65 gene which produces a protein crucial to vision. The therapy delivers functional RPE65 to the retina using a modified adeno-associated virus for delivery.

More details about the procedure and the trial from the University of Florida News.