Genetic canine blindness nears elimination through the latest testing method
In a groundbreaking discovery, a team of scientists led by Katherine Stanbury from the University of Cambridge has identified a new genetic variant responsible for Progressive Retinal Atrophy (PRA) in English Shepherds. This condition, which affects over 100 breeds and is caused by multiple genetic variants, can lead to blindness in dogs.
PRA initially affects vision in dimmer lighting and can progress to full blindness. Unfortunately, there is currently no treatment for PRA. However, a DNA test has been developed to help dog parents identify English Shepherds with PRA early on, allowing for careful breeding practices to potentially eliminate the condition from the breed.
The team carried out whole genome sequencing on Shola, an English Shepherd, and her brother's DNA. Their research revealed that neither Shola nor her brother had genetic variants previously associated with PRA, suggesting the presence of a new variant.
Shola, who has had puppies, is fortunate that none of them are expected to develop PRA due to careful breeding practices. Her offspring have achieved remarkable feats, with one of her daughters completing mountain rescue training, and one of her sons serving as a therapy dog. One of Shola's offspring even saved a man's life.
The development of this DNA test is significant, as it can show whether dogs have two, one, or no copies of the variant. Dogs carrying one copy of the variant can still be bred from, but only with dogs who have no copies. This test will enable breeders to make informed decisions, potentially reducing the prevalence of PRA in English Shepherds.
The team plans to screen any dog affected by a genetic eye condition for the new variant, with the hope of identifying similar genetic variants in other breeds. This research could pave the way for further advancements in understanding and managing inherited eye conditions in dogs.
It's important to note that dogs do not rely on their eyesight as much as humans do. Their sense of smell is more important, and they can perceive some colors, primarily blues and yellows. However, they cannot distinguish reds and greens, which likely appear as grays or browns to them. This limited color vision does not affect their ability to live happy, fulfilling lives.
In conclusion, the discovery of this new genetic variant for PRA in English Shepherds is a significant step forward in understanding and managing inherited eye conditions in dogs. The development of a DNA test will enable breeders to make informed decisions, potentially reducing the prevalence of PRA in English Shepherds and other breeds.
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