Breeds Affected: Irish Setter, Irish Red & White Setter
Samples Accepted: Blood, Buccal Swabs
Disease Information: CLAD, also known as Leukocyte Adhesion Deficiency I, usually presents in early puppyhood, often before the age of 12 weeks. Pups exhibit recurrent infections, slow wound healing without pus, low body weight and lack of appetite, lameness, enlarged longbone growth plates, and fever. Affected pups normally die around 6 months of age.
Inheritance Information: CLAD 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/clad The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/clad carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
clad/clad The dog is affected. Although it is unlikely to live long enough to be reproduce, if bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/clad carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/clad 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/clad x N/clad) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (clad/clad) should not be used for breeding.
Test Information: This mutation test identifies a single base change in the ITGB2 gene, which codes for CD18.
Kijas, J.M.H., Bauer, T.R., Gafvert, S., Marklund, S., Trowald-Wigh, G., Johannisson, A., Hedhammar, A., Binns, M., Juneja, R.K., Hickstein, D.D., Andersson, L.: A missense mutation in the beta-2 integrin gene (ITGB2) causes canine leukocyte adhesion deficiency Genomics 61:101-107, 1999. Pubmed reference: 10512685. DOI: 10.1006/geno.1999.5948.
Further information is available at the Online Mendelian Inheritance in Animals website.