Objective: To identify a DNA marker for the copper toxicosis (CT) locus in Bedlington Terriers (BT).
Animals: 77 BT, of which 25 were affected. Diagnosis of affected or unaffected with CT was made in all cases by quantitative copper determinations on liver biopsy samples by use of established criteria.
Procedure: BT pedigrees segregating for CT were identified. Linkage studies were carried out using polymorphic microsatellite markers developed for the canine genome in these pedigrees. DNA was isolated from blood samples of pedigree members. Polymerase chain reaction was used to amplify and type alleles at 213 microsatellite loci in each dog, and findings were subjected to linkage analysis.
Results: One microsatellite marker was identified to be closely linked to CT with logarithm of odds score of 5.96 at a recombination fraction of zero.
Conclusions: Using the linked marker, it has become possible to distinguish affected, homozygous normal, and carrier dogs in some BT pedigrees.
Clinical relevance: In informative pedigrees where the marker is variable in the parents, it is possible to identify which dogs will require anticopper therapy and provide breeders with sound scientific advice about breeding strategies.