Primary open-angle glaucoma (POAG) affects 33 million individuals worldwide and is a leading cause of blindness. In a study of 54 families with autosomal dominantly inherited adult-onset POAG, we identified the causative gene on chromosome 10p14 and designated it OPTN (for "optineurin"). Sequence alterations in OPTN were found in 16.7% of families with hereditary POAG, including individuals with normal intraocular pressure. The OPTN gene codes for a conserved 66-kilodalton protein of unknown function that has been implicated in the tumor necrosis factor-alpha signaling pathway and that interacts with diverse proteins including Huntingtin, Ras-associated protein RAB8, and transcription factor IIIA. Optineurin is expressed in trabecular meshwork, nonpigmented ciliary epithelium, retina, and brain, and we speculate that it plays a neuroprotective role.

The RPE65 gene encodes the isomerase of the retinoid cycle, the enzymatic pathway that underlies mammalian vision. Mutations in RPE65 disrupt the retinoid cycle and cause a congenital human blindness known as Leber congenital amaurosis (LCA). We used adeno-associated virus-2-based RPE65 gene replacement therapy to treat three young adults with RPE65-LCA and measured their vision before and up to 90 days after the intervention. All three patients showed a statistically significant increase in visual sensitivity at 30 days after treatment localized to retinal areas that had received the vector. There were no changes in the effect between 30 and 90 days. Both cone-and rod-photoreceptor-based vision could be demonstrated in treated areas. For cones, there were increases of up to 1.7 log units (i.e., 50 fold); and for rods, there were gains of up to 4.8 log units (i.e., 63,000 fold). To assess what fraction of full vision potential was restored by gene therapy, we related the degree of light sensitivity to the level of remaining photoreceptors within the treatment area. We found that the intervention could overcome nearly all of the loss of light sensitivity resulting from the biochemical blockade. However, this reconstituted retinoid cycle was not completely normal. Resensitization kinetics of the newly treated rods were remarkably slow and required 8 h or more for the attainment of full sensitivity, compared with <1 h in normal eyes. Cone-sensitivity recovery time was rapid. These results demonstrate dramatic, albeit imperfect, recovery of rod-and cone-photoreceptor-based vision after RPE65 gene therapy. dark adaptation ͉ photoreceptor ͉ retinal degeneration ͉ retinoid cycle T he enzymatic pathway in the human eye that regenerates light-altered vitamin A molecules is known as the retinoid cycle of vision. Molecular defects in retinoid cycle genes can lead to inherited retinal diseases in man (1). The severity of visual disturbance in these diseases is thought to be related to how the mutation alters the biochemical activity and whether there is redundancy at the multiple biochemical steps of the cycle. A severe form of incurable childhood blindness, Leber congenital amaurosis (LCA), is caused by mutations in RPE65 (retinal pigment epithelium-specific protein, 65 kDa), the gene in the retinal pigment epithelium (RPE) that encodes the isomerase. This is the only known enzyme that catalyzes isomerization of all-trans-retinyl esters to 11-cis-vitamin A. In RPE65 deficiency, photoreceptor cells do not regenerate their visual pigment and vision is not sustained. Retinal anatomy also degenerates, but not entirely (2, 3).RPE65-deficient animals have been characterized, and proofof-principle studies using recombinant adeno-associated virus (AAV) vector delivery of RPE65 to RPE cells have described restoration of vision (2,(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). These studies provided the impetus for human safety studies of RPE65 gene replacement (trials NCT00481546, NCT00643747, NCT00516477, and NCT00422721, www.clinicaltri...

A glaucoma locus, GLC1A, was identified previously on chromosome 1q. A gene within this locus (encoding the protein myocilin) subsequently was shown to harbor mutations in 2-4% of primary open angle glaucoma patients. A total of 1703 patients was screened from five different populations representing three racial groups. There were 1284 patients from primarily Caucasian populations in Iowa (727), Australia (390) and Canada (167). A group of 312 African American patients was from New York City and 107 Asian patients from Japan. Overall, 61 different myocilin sequence variations were identified. Of the 61 variations, 21 were judged to be probable disease-causing mutations. The number of probands found to harbor such mutations in each population was: Iowa 31/727 (4.3%), African Americans from New York City 8/312 (2.6%), Japan 3/107 (2.8%), Canada 5/167 (3.0%), Australia 11/390 (2.8%) and overall 58/1703 (3. 4%). Overall, 16 (76%) of 21 mutations were found in only one population. The most common mutation observed, Gln368Stop, was found in 27/1703 (1.6%) glaucoma probands and was found at least once in all groups except the Japanese. Studies of genetic markers flanking the myocilin gene suggest that most cases of the Gln368Stop mutations are descended from a common founder. Although the specific mutations found in each of the five populations were different, the overall frequency of myocilin mutations was similar ( approximately 2-4%) in all populations, suggesting that the increased rate of glaucoma in African Americans is not due to a higher prevalence of myocilin mutations.