Progressive Retinal Atrophy, Progressive Rod-Cone Degeneration

General Information: Progressive Retinal Atrophy, progressive Rod-Cone Degeneration (PRA-prcd) represents a group of genetic disorders characterized by the gradual deterioration of the retina, affecting both rods and cones—the photoreceptor cells necessary for vision in low and bright light. Initially, affected dogs may exhibit night blindness due to rod degeneration, which typically begins to manifest between the ages of 3 to 5 years, although signs can appear earlier or later depending on the breed. As the condition progresses, dogs lose their peripheral vision and eventually their ability to see in bright light, leading to complete blindness. Symptoms such as changes in eye reflectivity and tapetal changes are often observable upon veterinary examination. The rate of progression can vary widely, with some dogs maintaining partial vision for years, while others may experience a rapid decline in sight.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Unlikely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing for Progressive Retinal Atrophy, Progressive Rod-Cone Degeneration (PRA-prcd) focuses on identifying mutations in the PRCD gene, which is crucial for diagnosing and managing this condition in breeding programs. This disorder follows an autosomal recessive inheritance pattern, meaning that a dog must inherit two mutated copies of the PRCD gene—one from each parent—to develop the disease. Dogs with one mutated gene (carriers) do not show symptoms but can pass the mutation to their offspring. Breeding strategies should ensure that carriers are not mated with other carriers, as this pairing has a 25% chance of producing affected offspring with each pregnancy. Testing is essential before breeding to help eradicate this mutation from the gene pool and prevent the birth of affected puppies. Breeders are advised to mate carriers only with non-carriers to avoid producing clinically affected dogs, thereby progressively reducing the disease's prevalence in future generations.