The identification of genetic variants associated with risk of developing glaucoma is reported in three independent studies published online this week in Nature Genetics. These findings may lead to better diagnostic tools or therapies for glaucoma.
Glaucoma is a group of eye disorders that cause progressive damage to the optic nerve and can lead to permanent blindness. Though high inner eye pressure is a common risk factor for developing glaucoma, people with normal eye pressure can also develop the disease.
In one study, Zhenglin Yang and colleagues find variants near two genes, ABCA1 and PMM2, which are associated with glaucoma risk, with or without high inner eye pressure, in individuals from China and Singapore. Both genes have been previously implicated in other eye disorders, but not glaucoma. In a second study, Puya Gharahkhani and colleagues identify variants near three genes, including ABCA1, that are associated with glaucoma risk in Australians and Americans of European descent. A third study by Christopher Hammond and colleagues combines genetic data from 18 populations, including people of Asian and European descent, and also identifies ABCA1 as a risk gene for both high inner eye pressure and glaucoma. Two other genetic variants were also linked to both of these conditions in this last study.
ABCA1 is a major regulator of cellular cholesterol and lipid levels. Previous studies have found that this gene is expressed at higher than normal levels in the blood of glaucoma patients, and therefore this may represent a promising drug target.