Stargardt Disease

General Information: Stargardt Disease is a genetic eye condition in dogs caused by the degeneration of rod and cone photoreceptor cells in the retina. These cells are crucial for vision in both dim and bright light. Dogs affected by this condition typically show signs of vision loss before the age of 10, including dilated pupils and decreased response to light. A veterinary eye exam may reveal changes in the reflectivity and appearance of the tapetum, a structure behind the retina, as well as thinning of the retinal blood vessels. While dogs with Stargardt Disease may not completely lose their vision, they often experience significant vision impairment, especially in well-lit environments. This condition has been specifically identified in Labrador Retrievers.

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 the ABCA4 gene can determine whether a dog is a carrier of Stargardt Disease. This condition is inherited in an autosomal recessive manner, meaning a dog must inherit two copies of the mutated gene (one from each parent) to be affected. Carrier dogs, with only one copy of the mutation, do not show symptoms but can pass the gene to their offspring. When two carriers are bred, each puppy has a 25% chance of being affected by Stargardt Disease and a 50% chance of being a carrier. Because symptoms do not appear until adulthood, genetic testing should be performed before breeding to prevent producing affected puppies. Breeding known carriers to each other is not recommended. Dogs that do not carry the mutation have no increased risk of having affected pups.