prcd-Progressive Retinal Atrophy (PRA) in several dog breeds
Progressive retinal atrophy (PRA) as an inherited disease occurs in many dog breeds and also in different forms. The form of progressive rod-cone degeneration (prcd-PRA) is a photoreceptor degeneration in dogs with varying ages of onset. This genetic disorder causes the degeneration of retinal cells in the eye: firstly, rod cells are affected, thus leading to progressive night blindness. Secondly, degeneration of the cone cells results in complete blindness of the dog, even in full light situations during the day.
Age of onset of clinical symptoms is typically in early adolescence or early adulthood. However, the onset of the disease may vary among different dog breeds. Since diagnosis of retinal diseases in dogs may prove difficult, the genetic test on prcd-PRA helps to diagnose a specific disease and is also a useful tool for breeders to eliminate the mutated gene from the dog population.
The mutation and inheritance
The mutation in the PRCD gene which has been suggested to cause prcd-PRA has recently been published by the group of Gustavo D. Aguirre at the University of Pennsylvania, USA, and could be found in several dog breeds (see below). Prcd-PRA is inherited as an autosomal recessive trait. So there are three conditions a dog can be: it can be clear (genotype N/N or homozygous normal) meaning that it does not carry the mutation and will not develop the prcd-form of PRA. Since it also cannot pass the mutation onto its offspring, it can be mated to any other dog.
A dog which has one copy of the PRCD gene with the mutation and one copy without the mutation is called a carrier or heterozygous (genotype N/PRA); while it will not be affected by prcd-PRA, it can pass the mutation onto its offspring and should therefore only be mated to clear dogs. Dogs that develop this form of PRA have two PRCD gene copies with the mutation (genotype PRA/PRA or homozygous affected); they will always pass the mutated gene onto their offspring and should also be mated only to clear dogs.
prcd-PRA-Breeds
The prcd-PRA mutation has been found in the following dog breeds: Australian cattle dog, American Cocker Spaniel, American Eskimo, Chesapeake Bay Retriever, Chinese Crested, English Cocker Spaniel, Entlebuch Mountain dog, Kuvasz, Lapponian Herder, Labrador Retriever, Golden Retriever, Miniature Poodle, Nova Scotia Duck tolling Retriever, Portugese Waterdog, Schwedish Lapp dog, Finnish Lapp dog, Silky Terrier, Australian Stumpy tail cattle Dog , Toy Poodle and spanish waterdog.
We are not a breeding kennel