The frequency of the canine leukocyte adhesion deficiency (CLAD) allele within the Irish Setter population of Australia

To determine the frequency of the 107G-->C canine leukocyte adhesion deficiency (CLAD) mutation in Irish Setters from the Australian breeding population.

Genomic DNA was isolated from 87 Irish Setter blood samples and a region of the beta-2 integrin gene (ITGB2), encompassing the mutation, was amplified using real-time Polymerase Chain Reaction (PCR). Two fluorescently labelled probes were hybridised to the fragment, and fluorescence resonance energy transfer (FRET) was used to detect the 107G-->C mutation responsible for CLAD.

Three new heterozygotes were identified among 87 healthy Irish Setters from Australia. All originated from a litter sired by a known heterozygote. A total of seven heterozygotes have now been identified in 92 dogs (7.6%), representing over 90% of all major breeding stock in five Australian states. Two of the heterozygotes were recently imported adult dogs and the others were their offspring.

The frequency of the 107C allele in the Australian population of Irish Setters is lower than that in Europe. Selective breeding programs should be adopted to eliminate the mutant allele presently in two breeding lines.