Breeds Affected: Norfolk Terrier
Samples Accepted: Blood, Buccal Swabs
Disease Information: Epidermolytic hyperkeratosis causes areas of skin to be thick and darkened. It is also very fragile.
Inheritance Information: Epidermolytic Hyperkeratosis 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/eh The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/eh carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
eh/eh The dog is affected, and if bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/eh carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/eh 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/eh x N/eh) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (eh/eh) should not be used for breeding.
Test Information: This test identifies a single base change in the KRT10 gene.
Credille, KM., Barnhart, KF., Minor, JS., Dunstan, RW.: Mild recessive epidermolytic hyperkeratosis associated with a novel keratin 10 donor splice-site mutation in a family of Norfolk terrier dogs. Br J Dermatol 153:51-8, 2005. Pubmed reference: 16029326. DOI: 10.1111/j.1365-2133.2005.06735.x
Further information is available at the Online Mendelian Inheritance in Animals website.