Retinal atrophy, Progressive rod-cone degeneration (PRCD) 

 

Gene: PRCD

Transmission: Autosomal recessive

For an autosomal recessive genetic disease, an animal must have two copies of the mutation in question to be at risk of developing the disease.  Both parents of an affected animal must be carriers of at least one copy of the mutation.  Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.

Mutation: Substitution, PRCD gene, c.5 G>A, p.(C2Y), exon1

Medical system: Ocular

Breeds: American Cocker Spaniel, American Eskimo Dog, American Hairless Terrier, American Staffordshire Terrier/Amstaff, Anatolian Shepherd Dog, Australian Cattle Dog, Australian Kelpie, Australian Shepherd, Barbet, Beagle, Bichon Frise, Biewer Terrier, Black Russian Terrier, Bolonka, Border Collie, Boston Terrier, Boxer, Boykin Spaniel, Bull Terrier, Cavalier King Charles Spaniel, Chesapeake Bay Retriever, Chihuahua, Chinese Crested, Chow Chow, Coton de Tulear, Dachshund Miniature Longhair/Shorthair, Dalmatian, English Cocker Spaniel, English Shepherd, English Springer Spaniel, Entlebucher Mountain Dog, Field Spaniel, Finnish Lapphund, Finnish Spitz, German Shepherd, German Shorthaired Pointer, Golden Retriever, Goldendoodle, Great Dane, Great Pyrenees, Havanese, Kai Ken, Karelian Bear Dog, Koolie, Kuvasz, Labrador Retriever, Lagotto Romagnolo, Lancashire Heeler, Lapponian Herder, Maltese Terrier, Manchester Terrier, Miniature American Shepherd, Miniature Australian Shepherd, Miniature Pinscher, Norwegian Elkhound, Nova Scotia Duck Tolling, Papillon / Continental Toy Spaniel, Pekingese, Pembroke Welsh Corgi, Plott Hound, Pomeranian, Poodle - Miniature (Dwarf), Poodle - Moyen, Poodle - Standard, Poodle - Toy, Portuguese Podengo, Portuguese Water Dog, Pug, Puli, Rat Terrier, Rottweiler, Russell Terrier, Saint-Bernard, Samoyed, Scandinavian Hound, Schnauzer - Giant, Schnauzer - Miniature, Shetland Sheepdog, Shiba Inu, Shih Tzu, Siberian Husky, Silky Terrier, Soft-coated Wheaten Terrier, Spanish Water Dog, Tibetan Terrier, Toy Australian Shepherd, Treeing Walker Coonhound, West Highland White Terrier, Xoloitzcuintli / Mexican Hairless, Yorkshire Terrier

Age of onset of symptoms:  3 to five years.

PRA refers to Progressive Retinal Atrophy, a family of genetic diseases that affect the vision of many dog breeds.  PRCD refers to Progressive Rod, Cone Degeneration which is a recessive, autosomal version of PRA that is seen in a number of dog breeds.  It is a late onset disease, with clinical signs of vision difficulties first becoming evident by 3 to 5 years of age although affected dogs can show abnormal electroretinogram profiles by 1.5 years of age.  Clinical signs of PRCD begin with night blindness due to degeneration of rod photoreceptor cells in the retina, followed by day blindness due to the degeneration of cone photoreceptor cells in the retina.  Although the progression of the disease is variable between dogs and between breeds, most affected dogs eventually go blind.

 

References:

OMIA link: [1298-9615]

Donner J, Freyer J, Davison S, et al. (2023) Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs.  PLoS Genet. 19(2):e1010651. [pubmed/36848397]

Motipally SI, Kolandaivelu S. (2023) Absence of PRCD leads to dysregulation in lipid homeostasis resulting in disorganization of photoreceptor outer segment structure. Adv Exp Med Biol 1415:389-394. [pubmed/37440062]

Trecenti-Santana AS, Guiraldelli GG, Albertino LG, et al. (2022) Allele frequency of SLC4A3 (PRA1), TTC8 (PRA2), and PRA-prcd mutations in golden retrievers in Brazil. Front Vet Sci 9:973854.  [pubmed/36325094]

Genetics Committee of the American College of Veterinary Ophthalmologists. (2021) The Blue Book: Ocular disorders presumed to be inherited in purebred dogs. 13th Edition.  [https://ofa.org/wp-content/uploads/2022/10/ACVO-Blue-Book-2021.pdf]

Allon G, Mann I, Remez L, et al. (2019) PRCD is concentrated at the base of photoreceptor outer segments and is involved in outer segment disc formation. Hum Mol Genet 28:4078-4088.  [pubmed/31628458]

Andrade LR, Caceres AM, Trecenti AS, et al. (2019) Allele Frequency of the C.5G>A Mutation in the PRCD Gene Responsible for Progressive Retinal Atrophy in English Cocker Spaniel Dogs. Animals (Basel) 9(10):844. [pubmed/31640229]

Spencer WJ, Arshavsky VY. (2019) PRCD Is a small disc-specific rhodopsin-binding protein of unknown function. Adv Exp Med Biol. 1185:531-535. [pubmed/31884666]

Palanova A. (2016) The genetics of inherited retinal disorders in dogs: implications for diagnosis and management.  Vet Med (Auckl). 7:41-51. [pubmed/30050836]

Spencer WJ, Pearring JN, Salinas RY, et al. (2016) Progressive Rod-Cone Degeneration (PRCD) Protein Requires N-Terminal S-Acylation and Rhodopsin Binding for Photoreceptor Outer Segment Localization and Maintaining Intracellular Stability. Biochemistry 55(36):5028-37. [pubmed/27509380]

Dostal J, Hrdlicova A, Horak P. (2011) Progressive rod-cone degeneration (PRCD) in selected dog breeds and variability in its phenotypic expression. Veterinarni Medicina. 56(5):243-47. [publicFiles/41402]

Zangerl B, Goldstein O, Philp AR, et al. (2006). Identical mutation in a novel retinal gene causes progressive rod-cone degeneration in dogs and retinitis pigmentosa in humans.  Genomics 88 :551-563. [pubmed/16938425]