Breeds Affected: Norwegian Elkhound
Samples Accepted: Blood, Buccal Swabs
Disease Information: Early retinal degeneration is characterized by abnormal photoreceptor development, followed by rapid degeneration of the retina noticeable upon exam at 10-12 weeks of age. Pups may show night blindness as early as 6 weeks of age, and affected dogs are normally completely blind by 12-18 months of age.
Inheritance Information: ERD is autosomal recessive, meaning that animals with two copies of this allele will be affected. Animals with one copy of the gene will be clinically-normal carriers.
The possible genotypes are:
N/N The dog is normal, and cannot produce affected offspring.
N/erd The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/erd carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
erd/erd The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to a N/erd carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/erd x N/N) without any risk of producing affected offspring. The offspring should be tested before breeding to determine if they are carriers or normal.
– Breeding two carriers (N/erd x N/erd) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (erd/erd) should not be used for breeding.
Test Information: This mutation test identifies a SINE insertion in exon 4 of the STK38L gene.
Goldstein, O., Kukekova, AV., Aguirre, GD., Acland, GM.: Exonic SINE insertion in STK38L causes canine early retinal degeneration (erd). Genomics:, 2010. Pubmed reference: 20887780. Doi: 10.1016/j.ygeno.2010.09.003.
Further information is available at the Online Mendelian Inheritance in Animals website.