Progressive Retinal Atrophy (rcd1-PRA) in Sloughis
Progressive retinal atrophy (PRA) in the Sloughi is a late onset inherited rod-cone dysplasia that leads to visual impairment.
Phenotype: Dogs with this disease typically start showing signs of visual impairment between 2-3 years of age.
Mode of Inheritance: Autosomal recessive
Alleles: N = Normal, PRA = Progressive retinal atrophy (rcd1-PRA)
Breeds appropriate for testing: Sloughi
Explanation of Results:
Dogs with N/N genotype will not have this inherited form of progressive retinal atrophy and cannot transmit this variant to their offspring.
Dogs with N/PRA genotype will not be affected by this inherited form of progressive retinal atrophy, but are carriers. They may transmit this variant to 50% of their offspring. Matings between two carriers are predicted to produce 25% rcd1-PRA-affected puppies.
Dogs with PRA/PRA genotype are expected to develop this form of progressive retinal atrophy and will transmit this variant to all of their offspring.
Progressive retinal atrophy (PRA) in the Sloughi is a late onset inherited rod-cone dysplasia (type 1-rcd1) resulting from a mutation in phosphodiesterase 6B (PDE6B) enzyme. Dogs with this disease typically start showing signs of visual impairment between 2-3 years of age. The disease is inherited in an autosomal recessive fashion thus two copies are required for an animal to be affected with both sexes being equally affected. Carriers (dogs with one normal and one mutated PDE6B gene) are unaffected, but breeding two carriers together is expected to produce 25% affected offspring and 50% carriers.
Testing for Sloughi rcd1-PRA assists owners and breeders in identifying affected and carrier dogs. Breeders can use results from the test as a tool for selection of mating pairs to avoid producing affected dogs.
No copies of the rcd1-PRA mutation. Dog is normal.
1 copy of the rcd1-PRA mutation. Dog is a carrier.
Affected 2 copies of the rcd1-PRA mutation. Dog is affected.
Dekomien, G., Runte, M., Gödde, R., & Epplen, J.T. (2000). Generalized progressive retinal atrophy of Sloughi dogs is due to an 8-bp insertion in exon 21 of the PDE6B gene. Cytogenetics and Cell Genetics,90(3-4), 261-267. doi: 10.1159/000056785