Gene therapy restores rare genetic blindnes
A novel gene therapy developed by University of Oxford researchers may restore vision to patients with a previously incurable form of blindness. The results of the pioneering study where six people were successfully treated for the disease were published on Thursday (January 16).
Choroideremia is a rare, male-exclusive genetic disease in which photoreceptors in the retina and the underlying vascular layer, known as the choroid, degenerate. The process begins in childhood and develops into blindness in old age.
The disease is caused by a defective CHM gene. The faulty gene fails to produce REP-1, a protein essential for sustaining photoreceptors in the retina. Without REP-1, cells in the retina begin to die, causing blindness.
In this novel therapy, a functional copy of the gene is inserted into a virus vector, which is then delivered to degenerating photoreceptors in the retina. While this technique cannot regenerate cells that have already been destroyed, it can restore normal functioning to defective cells.
"We're trying to rescue the cells that are there already, to return the function of those cells to normal," Robert MacLaren, who heads this study, said in a New Scientist report. "What we can't do is bring back the cells that have already gone. That's one of the distinguishing features between stem cell therapy, which is to regenerate lost tissue, and gene therapy, which at the moment is there to sustain cells that would otherwise die."
Six of the nine patients enrolled in the therapy reported improved vision six months following treatment.
NEXT ON TOMONEWS
Ohio and Missouri having (lethal injection) drug problems