Progressive Retinal Atrophy (PRA rdAc) (Abyssinian)

Quick Summary

This progressive retinal atrophy is an inherited late-onset blindness condition seen in Abyssinian, Somali, and some Ocicat and other breeds. Affected cats have normal vision at birth that slowly degenerates to blindness.

Phenotype: Cats affected with this form of blindness have normal vision at birth, with degeneration first detected at about seven months of age. Vision loss progresses slowly and is variable, with most cats becoming blind at about 3-5 years of age.

Mode of Inheritance: Autosomal recessive

Alleles: N = Normal, rdAc = Progressive retinal atrophy (CEP290 mutation-associated)

Breeds appropriate for testing: Abyssinian, American Curl, American Wirehair, Balinese, Bengal, Colorpoint Shorthair, Cornish Rex, Javanese, Munchkin, Ocicat, Oriental Longhair, Oriental Shorthair, Peterbald, Savannah Cat, Siamese, Singapura, Somali, and Tonkinese.

Explanation of Results:

  • Cats with N/N genotype do not have CEP290/rdAc progressive retinal atrophy and cannot transmit this progressive retinal atrophy variant to their offspring.
  • Cats with N/rdAc genotype do not have CEP290/rdAc progressive retinal atrophy, but are carriers. They will transmit this progressive retinal atrophy variant to 50% of their offspring. Matings between two carriers are predicted to produce 25% kittens affected by this CEP290/rdAc form of progressive retinal atrophy.
  • Cats with rdAc/rdAc genotype will have CEP290/rdAc progressive retinal atrophy, an untreatable condition leading to eventual blindness. They will transmit this progressive retinal atrophy variant to all of their offspring.
Price

$40 one test per animal

Also available as part of the following packages:

Additional Details

In Abyssinian, Somali, and some Ocicat breeds, an inherited late-onset blindness condition has been identified and is characterized by progressive degeneration of the photoreceptors (rods and cones) in the retina. This disease has been designated "rdAc". Cats affected with this form of blindness have normal vision at birth, with degeneration first detected by electroretinographic (ERG) exam at about seven months of age. Vision loss progresses slowly and is variable, with most cats becoming blind by usually 3-5 years of age. There is no treatment available for the condition. This is an autosomal recessive condition, thus the disease is not associated with sex and two copies of the mutation are required for the cats to lose their vision. Carriers, cats that have one copy of the mutation, are not affected and have normal vision.

A single nucleotide mutation in the gene called CEP290 produces a defective protein which is associated with this progressive retinal atrophy (PRA) in the cat. In addition to Abyssinian, Somali and Ocicat, a survey of 43 cat breeds showed presence of the CEP290 mutation in many other breeds including, American Curl, American Wirehair, Bengal, Balinese/Javanese, Colorpoint Shorthair, Cornish Rex, Munchkin, Oriental Shorthair, Peterbald, Siamese, Singapura and Tonkinese. The high frequency of the CEP290 mutation in Siamese (about 33%) and related breeds (Oriental Shorthair, Balinese/Javanese, Colorpoint Shorthair, Peterbald) poses a significant health risk in the Siamese breed group.

A different form of blindness called “rod cone dysplasia”, or “Rdy” has also been identified in Abyssinian and Somali cats.

To assist owners and breeders in identifying affected and carrier cats, the VGL offers DNA tests for the two mutations known to cause the two different forms of PRA in cats - rdAc (CEP290) and Rdy (CRX). Breeders can use these tests as tools to avoid breeding two carriers of rdAc which would produce 25% affected offspring, or to test for the presence of “Rdy” in the CRX gene of suspected affected cats.

Since both forms of blindness are found in the Abyssinian breed, all associated breeds may have a concern for these diseases. A novel form of blindness occurs in the Bengal cat, and a separate causative mutation has been identified (a genetic test for the Bengal-specific PRA is available here). However, since Bengal cats have had Abyssinian breedings in their ancestry, genetic testing for rdAc and Rdy may also be warranted in some Bengal lines.

 

Note: The test offered on this page only detects the mutation in the CEP290 gene known to cause "rdAc" progressive retinal atrophy in Abyssinian, Somali, Ocicat and other breeds mentioned above. To view the DNA test for the mutation in the CRX gene (Rdy), click here.
Turnaround Time
2-6 business days
Type of Sample

Species

Cat

Type of Test

Results Reported As
Test Result CEP290 PRA-rdAc Status
N/N Normal. Cat does not have rdAc mutation.
N/rdAc Carrier. Cat has one copy of rdAc mutation. Breedings between carriers will be expected to produce 25% affected kittens.
rdAc/rdAc Affected.
References

Menotti-Raymond, M., David, V.A., Schäffer, A.A., Stephens, R., Wells, D., Kumar-Singh, R., O'Brien, S.J., & Narfström, K. (2007). Mutation in CEP290 discovered for cat model of human retinal degeneration. Journal of Heredity, 98(3), 211-220. doi: 10.1093/jhered/esm019

Menotti-Raymond, M., David, V.A., Pflueger, S., Roelke, M.E., Kehler, J., O'Brien, S.J., & Narfström, K. (2009). Widespread retinal degenerative disease mutation (rdAc) discovered among a large number of popular cat breeds. The Veterinary Journal, 186(1), 32-38. doi: 10.1016/j.tvjl.2009.08.010

Menotti-Raymond, M., Deckman, K.H., David, V., Myrkalo, J., O'Brien, S.J., & Narfström, K. (2010). Mutation discovered in a feline model of human congenital retinal blinding disease. Investigative Ophthalmology & Visual Science, 51(6), 2852-2859. doi: 10.1167/iovs.09-4261