Dogs Shed Light on Night Blindness Genes: Study

Beagles may help science sniff out a treatment for a rare inherited condition in humans that makes it impossible to see when lights are low.

In a study published in the journal PLOS One, scientists from Mie University Graduate School of Medicine, in Tsu, Japan, who worked in collaboration with the University of Pennsylvania, reported the discovery of the first canine form of the condition, called congenital stationary night blindness (CSNB).

Dogs born with the faulty DNA behave in the same way as affected humans.

“In bright light they can walk around and navigate easily, but in darkness they sort of freeze,” Penn School of Veterinary Medicine's Gustavo Aguirre, professor of medical genetics and ophthalmology, said in a press release. “It’s really very dramatic.”

The Japanese scientists, led by Mineo Kondo, chair of ophthalmology at Mie University, confirmed CSNB as cause of the dogs’ vision problems through electroretinography, a technique that measures the reaction of light-processing cells in the eye.

Efforts to pin down the DNA responsible for the condition in these dogs have not yet yielded results, but the scientists say they’ve ruled out some candidate genes. They’ve also identified patterns among dogs with and without the condition that will help direct future research.

Long term, scientists hope that what they learn from the Beagles will contribute to the development of a genetic therapy to help humans.

Previous research by Aguirre identified a gene for a similar condition in Briards, which led to a DNA test. Aguirre also made headlines in 2001 with a gene therapy that restored vision in a dog born blind. The AKC Canine Health Foundation has supported some of his research.