Canine Leukocyte Adhesion Deficiency CLAD Test Code 251
For breeds: Irish Setters and Irish Red & White Setters
Please note cheek swabs are not accepted for this test.
Technically known as Canine Leukocyte Adhesion Deficiency, this rare but devastating condition is an inherited fatal immunodeficiency disease. Pups that inherit two recessive genes for CLAD usually die early in life from multiple severe infections, even when treated with massive doses of antibiotics.
CLAD is related to the same disease in humans (LAD) and cattle (BLAD). So far, CLAD has been found only in Irish Setters. Research on the disease was carried out in England and Scandinavia, where the carrier rate is close to 12%. However, CLAD was first identified clinically in the United States.
Reliable identification of dogs that do not carry disease genes is the key to eliminating autosomal recessive diseases such as CLAD. As a mutation-based gene test, the OptiGen CLAD test unequivocally and specifically identifies normal dogs. Called "genetically clear," "noncarriers" or, more formally, "homozygous normals," such dogs can pass only the gene for normal leukocyte (white blood cell) function on to all their pups.
The test also identifies carriers (heterozygous dogs) with 100% accuracy. These carriers can be safely bred to "clears." Their recessive genes can only cause disease when matched with the recessive gene of another carrier. It isn't necessary to remove those carriers which are otherwise excellent dogs from the breeding population. But given the lethal nature of the disease, it is best to select against carriers who are not superlative dogs, so as to entirely eliminate the gene from a line within two or three generations.
Irish Red & White Setters – Testing for PRA and CLAD
The DNA-based genetic tests for the rcd1 form of Progressive Retinal Atrophy (PRA) and for Canine Leukocyte Adhesion Deficiency (CLAD) are identical for both Irish Setters and Irish Red & White Setters. The information given above on this page for Irish Setters therefore can be applied to Irish Red & Whites as well.
CLAD has been reported in Irish Red & Whites in Europe and recent screening done there for the CLAD mutation confirms that the mutation is in these lines. Out of 76 Irish Red & Whites screened, six were carriers with the CLAD mutation. (reported by Debenham, Millington, Kijas, Andersson and Binns, Journal of Small Animal Practice. Vol 43, February 2002.) Again, as more dogs are tested, an estimate of mutation frequency will be generated specifically for the US.
Registration with CERF of the DNA test results for Irish Red & White Setters is not addressed in the general guidelines of the IRWSA.