Writing in the August issue of Molecular Therapy, scientists from the UF Genetics Institute describe how they successfully used gene therapy in mice to treat retinoschisis, a rare genetic disorder that is passed from mothers, who retain their sight, to their sons.
"Currently there is no treatment," said William Hauswirth, Ph.D., the Rybaczki-Bullard professor of ophthalmic molecular genetics. "These children lose their sight gradually, often with devastating results. What happens is the retina actually begins to split in the middle, causing loss of central vision - that's the vision that you need to be able to read or walk around."
Scientists say the gene transfer method eventually could be applied to many eye diseases caused by single gene defects, including a host of retinal disorders.
Retinoschisis is usually first detected in boys between 5 and 10 years of age when their vision problems cause reading difficulties. In a healthy eye, retinal cells secrete a protein called retinoschisin, or RS1, which acts like glue to connect the layers of the retina. Without it, the layers separate and tiny cysts form, devastating the vision and often leading to blindness in about 1 of every 5,000 boys.
UF researchers injected a healthy version of the human RS1 gene to the sub-retinal space of the right eyes of 15-day-old male mice, which, like boys with the disease, don't have the healthy gene to maintain the retina. In terms of disease development, the condition in the mice was roughly equivalent to retinoschisis in a 10-year-old boy.
Six months later, researchers looked at the interior of the eyes with a laser ophthalmoscope and found cyst formation was clearly evident in the untreated eyes, but the treated eyes appeared healthy. The eye's photoreceptor cells - the rods and cones that h
Source:University of Florida