- X-linked juvenile retinoschisis (XLRS) is caused by changes in the RS1 gene. These changes cause abnormal function of the eye protein retinoschisin. Without normal retinoschisin, the layers of the retina split and vision is lost. Researchers want to try to introduce a healthy RS1 gene into eye cells, to see if this helps retinal cells make healthy retinoschisin. They will put the gene in a virus. The gene and virus package is known as a gene transfer vector (AAV-RS1 vector).