Gene therapy restores sight in a form of hereditary blindness
Achromatopsia affects about 1 in 30,000 Americans, silencing cone photoreceptors in the retina. The result is nearly complete color blindness and poor central vision. Three years ago, scientists led by Bo Chang at The Jackson Laboratory identified a mouse model for achromatopsia through vision screening. Chang identified the genetic mutation underlying the achromatopsia, and scientists elsewhere found an analogous human mutation. Now, in a paper published online in the May 21, 2007, edition of Nature Medicine, Chang and collaborators at the University of Florida led by John J. Alexander report that they have reversed blindness in achromatopsia mice through gene therapy, delivering working copies of the gene directly to cone cells. Within two months, nearly all the mice receiving the therapy had normal electrical readings in their retinas and displayed normal visual acuity. Successfully rescuing cone cell function through gene therapy has significant clinical potential in humans for treating a wide range of degenerative eye diseases.
