Progressive Retinal Atrophy in Irish SetterS
Progressive retinal atrophy (rcd1) Irish Setters is an early-onset disorder leading to night-blindness and eventually total blindness. Symptoms can occur as early as six weeks of age. The gene responsible, the β-subunit of rod cGMP phosphodiesterase, has now been identified and a DNA test devised. The disease shows an autosomal recessive mode of inheritance; therefore two copies of the defective gene, one inherited from each parent, have to be present for a dog to be affected by the disease. Individuals with one copy of the defective gene and one copy of the normal gene - called carriers - show no symptoms but can pass the defective gene onto their offspring. When two apparently healthy carriers are crossed, 25% (on average) of the offspring will be affected by the disease with a further 50% themselves being carriers.
We are now offering a DNA test for this disease distinguishing affected, carrier and normal individuals. The test probes directly the DNA of the β-subunit of rod cGMP phosphodiesterase gene and provides definitive information on the genetic status of this disease, giving breeders the information to eradicate the disease from their lines.
The test can not only diagnose setters affected with this disease but can also detect those dogs which are carriers, showing no symptoms of the disease but able to produce affected pups if mated to another carrier. It is important that carrier dogs are still bred with clear dogs, especially in the first few generations of a new DNA test being launched for a condition. Through this, breeders can capture the desired traits of the breeding dogs, and then, at a point in the future, if two dogs are genuinely comparable, can choose the clear dogs over the carriers.
DNA testing for progressive retinal atrophy (rcd1) is carried out under a screening scheme run with the Kennel Club. Results are made publicly available through the Kennel Club.
Tests can be ordered through our Webshop.