Gene Variant Linked to Nearsightedness, But Only in Certain Kids
Scientists have found a gene that causes myopia, but only in patients who spend a lot of time in childhood reading or doing other "nearwork," according to a study published in PLOS Genetics.
Andrei Tkatchenko, MD, PhD, study lead author, noted that this is the "first known evidence of gene-environment interaction in myopia." A team of vision researchers from Columbia University examined a database of about 14,000 patients and discovered that those with a gene variant called APLP2 were 5 times more likely to develop myopia as a teen if they had read ≥1 hour daily during their childhood. No additional risk of developing myopia was seen in those with the gene variant that spent less time reading. The team believes the risk variant my increase the amount of APLP2 protein produced in the eye, which may cause excessive elongation of the eye.
Mice with little APLP2 protein present in the eye were less likely to develop myopia when exposed to a visual environment that mimicked reading. A therapy to reduce APLP2 levels would be most effective in young children before the eye starts to elongate but such therapy could take years to develop.
In the meantime, study authors concluded that spending time outdoors is the best way to lower children's risk of developing myopia. "When kids are in school, make sure they also spend at least two hours outdoors each day," Dr. Tkatchenko added.
For more information visit Columbia.edu.