Researchers have identified five genetic variants that increase the risk of becoming nearsighted the longer a person stays in school. A team led by Jeremy Guggenheim of Cardiff University, UK, published these results on November 17 in an open access journal. PLOS Genetics.
Myopia is associated with a number of eye diseases, making it the leading cause of permanent vision loss in the elderly. However, people often become myopic in childhood, and the condition appears to be the result of a combination of genetics, too little time spent outdoors, and years of education. Genetic studies have identified more than 450 genetic variants associated with an increased risk of myopia, but some increase the risk specifically in people with lifestyle factors. In the new study, researchers used genetic and health data from more than 340,000 participants of European descent. They conducted a genome-wide study to identify genetic variants that make people more susceptible to developing myopia when combined with intensive schooling.
The study found five genetic variants that progressively increased people’s risk of developing nearsightedness the more time they spent in school – especially for people who had a university-level education. Three of these variants were previously unknown, while two were found in studies of East Asian cohorts, where about 80% of children become myopic. For comparison, in the West, myopia develops in about 30% of children. The researchers said the findings provide new insight into the biological pathways that cause myopia, but more research is needed to understand how these pathways interact with lifestyle factors to cause the condition.
Guggenheim adds, “Myopia not only requires the use of glasses or contact lenses, but is also the leading cause of vision loss that cannot be corrected. Building on our previous research linking education and myopia, the new study identifies 5 genes associated with the development of myopia, the effects of which are amplified by additional years spent in education.”
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