Progressive retinal atrophy due to rod-cone dysplasia type 1a (rcd1a) in the Sloughi. Progressive degeneration of retinal photoreceptors caused by a mutation in the PDE6B gene, distinct from the rcd1 mutation of the Irish Setter. It leads to progressive blindness.

Affects the Sloughi. Limited data on the exact carrier frequency in the population.

- Nyctalopia\n- Progressive retinal degeneration\n- Tapetal hyperreflectivity\n- Vascular attenuation\n- Progressive blindness

rcd1a was identified in the Sloughi as a form of PRA caused by a different mutation in the same PDE6B gene as the rcd1 of the Irish Setter. This showed that independent mutations in PDE6B can give rise to PRAs in unrelated breeds. The genetic test makes it possible to distinguish carriers from clear animals.

- Genotype breeding animals before mating\n- Do not mate carrier×carrier (25% risk of affected homozygotes); carrier×clear produces 0% affected and 50% carriers\n- An affected animal should not be bred; a carrier may be mated to a clear animal without producing affected offspring\n- Complementary annual ophthalmological examination (ECVO)

Although rcd1 and rcd1a affect the same gene (PDE6B), the mutations are different and the tests are specific to each breed. Confirmation requires a genetic test for the Sloughi rcd1a variant. Differentiate from other PRAs described in sighthounds.

1. Dekomien G et al. 2000. Generalized progressive retinal atrophy of Sloughi dogs is due to an 8-bp insertion in exon 21 of the PDE6B gene. Cytogenet Cell Genet 90:261-267. PMID: 11124530
2. OMIA:001669-9615 - Retinal atrophy, rod-cone dysplasia 1a. https://omia.org/OMIA001669/9615/