Breeds Affected: Frisian Waterdog
Samples Accepted: Blood, Buccal Swabs
Disease Information: Frisian Waterdog SCID-affected pups are usually clinically healthy at 6 weeks, but between 8-12 weeks of age SCID-affected pups rapidly develop diarrhea, unsteadiness, blindness, and epileptic seizures, leading to spontaneous death around 12 weeks.
Inheritance Information: SCID 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/scid The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/scid carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
scid/scid The dog is affected, and will not live long enough to reproduce.
– Carriers may be bred to normal animals (N/scid 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/scid x N/scid) is not recommended due to the possibility of 25% of the offspring being affected.
Test Information: This mutation test identifies a single base pair change in the RAG1 gene.
Verfuurden, B., Wempe, F., Reinink, P., van Kooten, PJ., Martens, E., Gerritsen, R., Vos, JH., Rutten, VP., Leegwater, PA: Severe combined immunodeficiency in Frisian Water Dogs caused by a RAG1 mutation. Genes Immun 12:310-3, 2011. Pubmed reference: 21293384. DOI: 10.1038/gene.2011.6.
Further information is available at the Online Mendelian Inheritance in Animals website.