English Springer Spaniels and Dachshunds ONLY

What is PRA-CRD4/CORD1?

Progressive retinal atrophy, cone-rod dystrophy 4/cord1 (PRA-crd4/cord1) is an inherited eye disease affecting English Springer Spaniels and Dachshunds. PRA-crd4/cord1 occurs as a result of degeneration of both rod and cone type cells of the retina. Affected dogs can show symptoms of vision loss or have signs of retinal disease on veterinary ophthalmologic exam by 3 years of age. However, age of onset varies significantly in PRA-crd4/cord1 affected dogs. Mutations in the RPGRIP1 gene show incomplete penetrance meaning that not all dogs inheriting two copies of the mutation develop clinical disease.  A recent report from the laboratory of Dr. Keiko Miyadera at the University of Pennsylvania indicates that the age at onset is influenced by the presence or absence of two genetic two modifiers.  Although progression tends to be relatively slow, most affected dogs (especially those with an early age of onset) will progress to complete blindness.

Test Results

PRA-crd4/cord1 is an autosomal recessive disease.

Normal/Clear – This dog has tested normal/clear for the mutation associated with PRA-crd4/cord1. It can only transmit a normal gene to its offspring, and can be bred to a dog with any test result with no risk of producing affected offspring.

Carrier – This dog has tested as a carrier for the mutation associated with PRA-crd4/cord1. There is no evidence that carriers develop clinical signs of the disease. It may transmit either a normal or mutated gene to potential offspring. Carriers may be bred to normal/clear dogs with no risk of producing affected offspring. However, those offspring should be tested to determine their possible carrier status.

Affected – This dog has tested affected and is homozygous for the mutation associated with PRA-crd4/cord1.

Tests are ordered online through the secure area of the OFA website. Payment is accepted by credit card (MasterCard and VISA). The OFA administers all order handling. Upon receipt of an order, the OFA will send out the test kit which will include a Foam-Tipped Applicator card for DNA sample collection, along with sample collection instructions. Using the FTA card technology, owners can safely collect DNA samples at home. The collection process is non-invasive, and no veterinary appointment is necessary.

Samples are then sent to the University of Missouri College of Veterinary Medicine where the samples will be processed by the Small Animal Molecular Genetics Lab. Results will be forwarded to the OFA, and the OFA will issue the resulting report to the owner.

The fee for each test includes the test kit, laboratory processing, and subsequent registration in the OFA databases.