24 genes behind short-sightedness identified
London, Feb 11 : Scientists have identified as many as 24 new genes behind short-sightedness (myopia), a major cause of blindness and visual impairment worldwide.
Chris Hammond, professor of genetic epidemiology at the King's College London, who led the study, said: "We already knew that myopia - or short-sightedness - tends to run in families. But until now, we knew little about the genetic causes."
"This study reveals for the first time a group of new genes that are associated with myopia and that carriers of some of these genes have a 10-fold increased risk of developing the condition," adds Hammond, the journal Nature Genetics reports.
Researchers from Europe, Asia, Australia and the US collaborated under the Consortium for Refraction and Myopia (CREAM), according to a King's College statement.
They analysed genetic and refractive error data of over 45,000 people from 32 different studies, and found 24 new genes for this trait, and confirmed two previously reported genes.
Thirty percent of Western populations and up to 80 percent of Asians suffer from myopia. Interestingly, the genes did not show significant differences between the European and Asian groups.
Myopia is caused by the longer length of the eye, causing the light to focus in front of the retina rather than on it, resulting in a blurred image. This fault be corrected with glasses, contact lenses or surgery.