Golden Retriever PRA GR-PRA1 & GR-PRA2
Progressive Retinal Atrophy (PRA) in dogs is the canine equivalent of retinitis pigmentosa (RP) in humans and is characterized by vision loss due to degeneration of the photoreceptor cells in the retina. This degenerative disease eventually leads to complete blindness. PRA affects more than 100 dog breeds, and is caused by numerous mutations. One variant, prcd-PRA, only accounts for a very small proportion of PRA cases in the Golden Retriever breed. Two new causes of PRA in Golden Retrievers have been identified and are refered to as GR-PRA1 and GR-PRA2.
PRA-1 is a results of a frameshift mutation in SLC4A3 gene in golden retriever dogs with progressive retinal atrophy GR-PRA1. This variant was present in 56% of PRA cases in the Golden Retriever breed.
Research at AHT, in collaboration with scientists from at the Swedish University of Agricultural Sciences and Uppsala University, have identify have identified a recessive mutation that is associated with the development of a form of PRA in the Golden Retriever, known as GR_PRA2. Approximately 15% of known PRA cases in the breed. In addition GR_PRA2 has to date been identified in dogs from the USA, Canada, UK, Sweden and France.
Both GR_PRA1 and GR-PRA2 are inherited in an autosomal recessive manner. This means that both forms of the disease will occur only if two copies of the identical mutation are present; carriers of one copy of the either mutation do not show disease. By ensuring that at least one parent is Normal/Clear either variant then no affected offspring will be produced. See below for expected breeding outcomes when the GR-PRA1/GR-PRA2 genotype have been determined by DNA testing.
Animal Genetics accepts buccal swab, blood, and dewclaw samples for testing. Sample collection kits are available and can be ordered at test now.
Test Is Relevant To The Following Breeds:
- Golden Retriever
Animal Genetics UK offers DNA testing for Golden Retriever PRA GR-PRA1&2. The genetic test verifies the presence of the recessive PRA Gene and presents results as one of the following:
|PRA1/PRA1||Affected||The dog carries two copies of the mutant gene and is homozygous for GR-PRA1. This dog will be affected and will always pass on the defective gene to it's offspring.|
|PRA1/n||Carrier||Both the normal and mutant copies of the gene detected. Dog is a carrier for the GR-PRA1 mutation and can pass on a copy of the defective gene to its offspring 50% of the time.|
|n/n||Clear||Dog tested negative for the GR-PRA1 gene mutation and will not pass on the defective gene to its offspring.|
|PRA2/PRA2||Affected||The dog carries two copies of the mutant gene and is homozygous for GR-PRA2. This dog will be affected and will always pass on the defective gene to it's offspring.|
|PRA2/n||Carrier||Both the normal and mutant copies of the gene detected. Dog is a carrier for the GR-PRA2 mutation and can pass on a copy of the defective gene to its offspring 50% of the time.|
|n/n||Clear||Dog tested negative for the GR-PRA2 gene mutation and will not pass on the defective gene to its offspring.|