Introduction (about PRA and testing).

In Abyssinian & Somali and some Ocicat breeds, an inherited late-onset blindness condition is characterized by progressive degeneration of the photoreceptors (rods and cones) in the retina. A single-nucleotide polymorphism designated "rdAc" in the CEP290 gene produces a defective protein which is associated with progressive retinal atrophy (PRA) in these breeds. Cats affected with this form of PRA have normal vision at birth, with degeneration first detected by electroretinographic exam at about seven months. By ages 3-5, affected cats are completely blind. There is no treatment available for the condition. The disease is inherited as an autosomal recessive; two copies of the mutation are present in affected cats. Carriers, cats that have one copy of the mutation, are not affected and have normal vision.

The VGL offers a DNA test for the rdAc mutation in CEP290 to assist owners and breeders in identifying normal, affected and carrier cats. The test uses DNA collected from buccal swabs avoiding invasive blood collection. Breeders can use this test as a tool to avoid breeding carriers together which would produce 25% affected offspring.