Genetic testing could eliminate hereditary blindness in dogs | Medical research

A mountain rescue dog who quit his duties after losing his eyesight helped scientists develop a test that could eradicate a genetic eye condition in his breed.

Shola the English Shepherd has an inherited eye disease called Progressive Retinal Atrophy (PRA), which causes the light-sensitive cells at the back of the eye to deteriorate, eventually leading to blindness.

PRA affects more than 100 dog breeds, can be caused by various genetic variants, and has no cure. For some breeds, symptoms do not appear until the dog is several years old, by which time they may have passed their genes on to puppies.

Kathryn Stanbury, the first author of the research at the University of Cambridge, said Shola was four years old when she began to struggle with her vision in dim light.

„She was sent to a veterinary ophthalmologist and they confirmed she had PRA,” Stanbury said. „Then it turned out her brother also had PRA.”

Stanbury and colleagues identified only the genetic variation responsible for the condition in English shepherds. £48 DNA test made to reveal Dogs have none, just one or two copies of the variant.

Although Stanbury said the variants that cause PRA are usually breed-specific, the team will now test any dog ​​with inherited eye disease for the new variant.

„If it appears in another species, we can track it down,” he said.

Research began when Shola and her brother were brought to the group’s attention by their concerned foster carer.

Writing in Jeans magazineStanbury and colleagues reported how they performed whole-genome sequencing on the siblings’ DNA, but found no genetic variants previously associated with PRA, suggesting a different variant was at play.

Through a series of analyzes using these genes, as well as data on the genetic structure of two English shepherds clear of PRA and 22 eye disease, the team identified the variant responsible.

They hope the DNA test will help owners identify English Shepherds with PRA early and avoid using them for breeding.

„You can still reproduce from a carrier [which has one copy of the variant]Unless you’re breeding with a clear dog,” Stanbury said, adding that the breed is relatively rare, especially in England, which is important given the genetic variation.

He said the team had tested the father of Shola’s offspring and could not produce PRA.

„Two of his daughters have completed mountain rescue training with Mountain Rescue England,” Stanbury said. „One of her sons is a therapy dog.”

In fact, a rescue dog recently saved a man’s life. „[The owners] „Know that none of those dogs are going to go blind and all that training will be wasted,” Stanbury said.