PRA-rcd1a in Sloughi

PRA-rcd1a (rod-cone dysplasia) is a form of progressive retinal atrophy (PRA) with early onset of the disease. This specific form of PRA affects Sloughi.

PRA-rcd1a is hereditary eye defect. Photoreceptor degeneration starts in two weeks of age. Degeneration is completed by about 1 year when affected dog is totally blind.

PRa-rcd1a disease is caused by mutation c.2448_2449insTGAAGTCC of PDE6B gene (gene for β-subunit cGMP phosphodiesterase enzyme (PDE)).

PRA-rcd1a disease is incurable but it can be preceded. Genetic test can reveal normal individuals, carrier individuals or affected individuals. On the basis, a breeding program can be compiled to rcd1a defect excluding.

PRA-rcd1a is autosomal recessive inherited disease. That means the disease affects dogs with P/P (positive / positive) genotype only. The dogs with P/N (positive / negative) genotype are clinically without any symptom. They are genetically considered carriers of the disease (heterozygotes). In offspring of two heterozygous animals following genotype distribution can be expected: 25 % N/N (healthy non-carriers), 25 % P/P (affected), and 50 % N/P (healthy carriers). Because of high risk of producing affected offspring, mating of two N/P animals (carriers) can not be recommended.

.

References:

Miyadera, K., Acland, G.M., Aguirre, G.D.: Genetic and phenotypic variations of inherited retinal diseases in dogs: the power of within- and across-breed studies. Mamm Genome 23:40-61, 2012.