For the first time, researchers have found that dogs too can be afflicted with a form of night blindness that is seen in humans, including one of Indian-origin.
People with congenital stationary night blindness, or CSNB, have normal vision during the day but find it difficult or impossible to distinguish objects in low light.
This rare condition is present from birth and can seriously impact quality of life, especially in locations and conditions where artificial illumination is not available.
The new discovery of a form of CSNB in dogs and subsequent hunt for the genetic mutation responsible may one day allow for the development of gene therapy to correct the dysfunction in people as well as dogs, the study said.
Working in collaboration with Japanese scientists, Gautami Das, a postdoctoral researcher at the University of Pennsylvania in the US, and colleagues found out about a unique population of beagles with night-vision problems.
The dogs had been bred by a Japanese pharmaceutical company and displayed behaviors characteristic of night blindness. "In bright light they can walk around and navigate easily, but in darkness they sort of freeze," said Gustavo Aguirre from University of Pennsylvania.
All the affected dogs showed signs that were characteristic of CSNB, specifically a type known as Schubert-Bornschein complete CSNB, which is also seen in humans. While the gene responsible for these dogs' condition remains a mystery, the researchers believe a genome-wide approach by means of whole-genome sequencing will narrow their hunt.
The gene may represent a novel one not previously associated with CSNB, or a new manner in which the mutation can cause disease. Once the researchers find it, they can begin development of a gene therapy approach to treating the condition. The findings were reported in the journal PLOS ONE