Golden Retriever-PRA 1 (GPRA1)

Description

Progressive Retinal Atrophy (PRA) is a category of genetic mutations that cause vision loss and blindness. Photoreceptor cells (light-sensing cells) in the retina begin to degenerate, typically progressing from a loss of night vision to complete blindness.

PRA affects many different dog breeds, and these mutations are breed-specific. In Golden Retrievers, two mutations have been identified (in addition to prcd-PRA) known as GR-PRA1 and GR-PRA2.

Both GR-PRA1 and GR-PRA2 are inherited autosomal recessive disorders. Autosomal recessive disorders are disorders that can be passed from either parent and require two copies of the gene to show symptoms. Because both GR-PRA1 and GR-PRA2 are recessive disorders, a dog must have two copies of the mutation in order for the disease to manifest. This means that a dog can have one copy of the mutation and not experience any signs or symptoms of GR-PRA1 or GR-PRA2. This dog would be known as a carrier. The carrier can then pass on either the normal gene or the mutated gene to any offspring. If two carriers are bred, there is a 25% per puppy that they will develop symptoms of GR-PRA1 or GR-PRA2.

References

Downs LM, Wallin-Hakansson B, Boursnell M, Marklund S, Hedhammar A, Truve K, Hubinette L, Lindblad-Toh K, Bergstrom T, Mellersh CS. A frameshift mutation in golden retriever dogs with progressive retinal atrophy endorses SLC4A3 as a candidate gene for human retinal degenerations. PLoS One. 2011;6(6):e21452. [PubMed: 21738669]