Breeds Affected: Jack Russell Terrier
Samples Accepted: Blood, Buccal Swabs
Disease Information: SCID-affected Jack Russell Terriers (JRT) appeared normal until approximately 12 weeks of age, but died at 14-15 weeks of age. The exception were SCID-affected JRT vaccinated with modified live virus vaccines at 8 weeks, which died shortly after vaccination.
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 change in the PRKDC gene.
Bell, T.G., Butler, K.L., Sill, H.B., Stickle, J.E., Ramos-Vara, J.A., Dark, M.J.:Autosomal recessive severe combined immunodeficiency of Jack Russell Terriers Journal of Veterinary Diagnostic Investigation 14:194-204, 2002. Pubmed reference: 12033674.
Ding, Q., Bramble, L., Yuzbasiyan-Gurkan, V., Bell, T., Meek, K.: DNA-PKcs mutations in dogs and horses: allele frequency and association with neoplasia Gene 283:263-269, 2002. Pubmed reference: 11867233.
Further information is available at the Online Mendelian Inheritance in Animals website.