Progressive retinal atrophy (PRA) is a genetic condition fou…
Progressive retinal atrophy (PRA) is a genetic condition found in certain dog breeds; its is particularly prevalent in Entlebucher Mountain Dogs. PRA is characterized by the bilateral degeneration of the retina (in the eye) causing progressive vision loss culminating in blindness. The condition is inherited as an autosomal recessive trait. Two Entlebucher Mountain Dogs, both carriers, have a pup with PRA. What is the probability that their next two pups will not have PRA?