Mutating Dachshund Genes May Help Cure Blindness In Humans

In a novel discovery scientists have come across mutations in genesdefine responsible for causing CRD in dogs. CRD is a rare eye disease in dogs as well as humans, and the discovery has opened new vistas of possible therapies in case the mutation can be linked to Human CRD too, of which the scientists are quite hopeful.

The gene mutation study was published in the august issue of the online publication – Genome Research.

The gene mutations have specifically been implicated in the dachshund breed of dogs, however they yet have to be seen in other breeds. The variation has been seen on chromosome 5, associated with cone-rod dystrophy specifically in wire haired dachshunds.

The CRD set of eye diseases are very rare and can run through families over generations. This disease in both humans as well as dogs is responsible for the continuous degeneration of the function of cone cells in the retina of the eye.

The retina is made up of two components – rods and cones. The rod cells help the peripheral vision; while the cone cells help us with our central vision (helping us read, see far away things and also see color). Rod cells affect the nighttime vision while the cone cells are there to help us with our daytime vision. Together they help the retina to receive images and transmit them to the brain.

Thus, with patients of CRD once the degeneration of the cone cells sets in, it initially effects the daytime vision and progresses on to take a more serious form, which is – total blindness.

But according to Dr. Robert Cykiert, associate professor of ophthalmology at New York University Langone Medical Center in New York City, the discovery of the gene has helped them pin point what was causing the degeneration, now it will be easier for them to figure out the defective proteins and treat the patients.

"The implications for dogs is that we have the possibility to reduce the frequency of this mutation in the population, and in this way immediately avoid new cases of CRD caused by this mutation," said senior study author Frode Lingaas, a professor at the Norwegian School of Veterinary Science in Oslo. "For humans, the study may help in the identification of the etiology of some cases of CRD, and the dog could also be an extremely valuable model for the development of new treatment schemes for CRD [including gene therapy]."

Researchers are hoping that they would be able to replace the faulty gene with a good gene protein in the future sometime using this model of gene therapy, thereby helping the restoration of vision in the dogs. For, if that works then gene therapy can be expected to be used for humans too in the future.

"It may not be the same mechanism in humans, but they think that it is," Cykiert said. "This is going to lead researchers in a direction where they know what to look for."

This work was supported by the Norwegian School of Veterinary Science.