Progressive retinal Atrophy, progressive Rod-cone degeneration or PRA-prcd
Progressive retinal Atrophy, progressive Rod-cone degeneration, or PRA-prcd, is a disorder in which the cells in the retina of a dog degenerate and die. PRA is the dog equivalent of retinitis pigmentosa in humans. Most affected dogs will not show signs of vision loss until 3-5 years of age. Complete blindness can occur in older dogs. Progressive Rod-Cone Degeneration is a form of PRA known to affect over 40 different breeds.
The retina is a membrane located in the back of the eye that contains two types of cells known as photoreceptors. These cells take light coming into the eyes and relay it back to the brain as electrical impulses. These impulses are interpreted by the brain as vision. In dogs suffering from PRA-prcd, the photoreceptors begin to degenerate, causing an inability to interpret changes in light resulting in loss of vision. Rod cells, which are normally function in low-light, begin to degenerate first, leading to night-blindness. The cone cells, which normally function in bright-light or daytime conditions, will deteriorate next. This often leads to complete blindness over time.
PRA-prcd is inherited as an autosomal recessive disorder. A dog must have two copies of the mutated gene to be affected by PRA. A dog can have one copy of the mutation and not experience any symptoms of the disease. Dogs with one copy of the mutation are known as carriers, meaning that they can pass on the mutation to potential offspring. If they breed with another carrier, there is a 25% chance that the offspring can inherit one copy of the mutated gene from each parent, and be affected by the disease.
Test Is Relevant to the Following Breeds:
American Cocker Spaniel, American Eskimo Dog, Australian Cattle Dog, Australian Cobber dog Australian Shepherd, Australian Shepherd, Miniature & Toy, Australian Stumpy Tail Cattle Dog, Barbet, Bolonka Zwetna, Chesapeake Bay Retriever, Chinese Crested, Chihuahua, Cockapoo, Dwarf Poodle, English Cocker Spaniel, English Shepherd, Entlebucher Mountain Dog, Finnish Lapphund, Pembroke Welsh Corgi, German Spitz, Giant Schnauzer, Golden Retriever, Golden Doodle, Karelian Bear Dog, Kuvasz, Lab/Golden Cross, Labradoodle, Australian, Labradoodle/Goldendoodle Cross, Labrador Retriever, Lapponian Herder, Maltipoo, Markiesje, Miniature & Toy Poodle, Miniature American Shepherd, Moyen Poodle Norwegian Elkhound, Nova Scotia Duck Tolling Retriever, Portuguese Water Dog, Silky Terrier, Schipperke, Spanish Water Dog, Sprocker Spaniel, Standard Poodle, Swedish Jamthund, Swedish Lapphund, Yorkshire Terrier
Animal Genetics accepts buccal swab, blood, and dewclaw samples for testing. Sample collection kits are available and can be ordered at test now.
Animal Genetics UK offers DNA testing for PRA-prcd. The genetic test verifies the presence of the recessive PRA Gene and presents results as one of the following:
|prcd/prcd||Affected||The dog carries two copies of the mutant gene and is homozygous for PRA-prcd. This dog will be affected and will always pass on the defective gene to it's offspring.|
|prcd/n||Carrier||Both the normal and mutant copies of the gene detected. Dog is a carrier for the PRA-prcd mutation and can pass on a copy of the defective gene to its offspring 50% of the time.|
|n/n||Clear||Dog tested negative for the PRA-prcd gene mutation and will not pass on the defective gene to its offspring.|