Progressive Retinal Atrophy Progressive Rod-Cone Degeneration
Turnaround: 3-5 days
US: $45.00 | UK: £40.00
Breeds: Akita, Aussiedoodle, Australian Cattle Dog, Australian Labradoodle, Australian Mix, Australian Shepherd, Australian Shepherd/Border Collie, Bernedoodle, Biewer Terrier, Bolognese, British Labrador Retriever, Cavalier King Charles Spaniel, Chesapeake Bay Retriever, Chihuahua, Chinese Crested, Cockapoo, Cocker Spaniel, Double Doodle, English Cocker Spaniel, English Shepherd, Fox Terrier, Giant Schnauzer, Golden Retriever, Goldendoodle, Gordon Setter, Jack Russell Terrier, Labradoodle, Labrador Retriever, Maltipoo, Miniature American Shepherd, Miniature Australian Shepherd, Miniature Poodle, Miniature Schnauzer, Mixed Breed (Dog), Nova Scotia Duck Tolling Retriever, Parson Russell Terrier, Poodle, Portuguese Podengo Pequeno, Puli, Rat Terrier, Russell Terrier, Schipperke, Silky Terrier, Spanish Water Dog, Standard Poodle, Standard Schnauzer, Toy Australian Shepherd, Toy Poodle, Wire Fox Terrier, Yorkiepoo, Yorkshire Terrier, Newfypoo, American Hairless Terrier, Lowchen, Norwegian Elkhound, Australian Stumpy Tail Cattle Dog, Clumberdoodle, Cavapoo, Russian Tsvetnaya Bolonka, Miniature Goldendoodle, American Morkshire Terrier, Volpino Italiano, Scotch Collie, Poochon, Sheepadoodle, Entlebucher Mountain Dog, Peruvian Inca Orchid, Akita Inu, Miniature Bernedoodle, Miniature Golden Retriever, Goldador, Pudelpointer, Bordoodle, Corgipoo, King Charles Bernedoodle
Description
Progressive Rod-Cone Degeneration, or PRA-prcd, is a form of Progressive Retinal Atrophy (PRA) in which the cells in the dog’s retina in the eye degenerate and die. PRA for dogs is similar to 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 photoreceptor cells. 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 to “create” images. In dogs suffering from PRA-prcd, the photoreceptor cells begin to degenerate, causing an inability to see changes in light. This results in a loss of vision. Rod cells, which normally function in low-light or nighttime conditions, begin to degenerate first. This leads 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 a period of time.
PRA-prcd is inherited as an autosomal recessive disorder. Autosomal recessive disorders are disorders that can be passed from either parent and require two copies of the gene to show symptoms. 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 their 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.
References
Moody JA, Famula TR, Sampson RC, Murphy KE. Identification of microsatellite markers linked progressive retinal atrophy in American Eskimo Dogs. Am J Vet Res. 2005 Nov;66(11):1900-2. [PubMed: 16334947]
Zangerl B, Goldstein O, Philp AR, Lindauer SJ, Pearce-Kelling SE, Mullins RF, Graphodatsky AS, Ripoll D, Felix JS, Stone EM, Acland GM, Aguirre GD. Identical mutation in a novel retinal gene causes progressive rod-cone degeneration in dogs and retinitis pigmentosa in humans. Genomics. 2006 Nov; 88(5):551-63. [PubMed: 16938425]
Possible Results
| Genotype | Description |
|---|---|
| n/n | Negative: Dog is negative for the mutation associated with prcd-PRA. |
| n/P | Carrier: Dog is a carrier of the PRA-prcd mutation. Dog will not be affected by PRA-prcd but may pass the mutation to offspring. |
| P/P | Affected: Dog has two copies of the prcd-PRA mutation. Dog will develop prcd-PRA and will always pass on a copy of the mutation to offspring. |