Mapping cerebellar abiotrophy in Australian Kelpies.

An autosomal recessive form of cerebellar abiotrophy occurs in Australian Kelpie dogs. Clinical signs range from mild ataxia with intention tremor to severe ataxia with seizures. A whole-genome mapping analysis was performed using Affymetrix Canine SNP array v2 on 11 affected and 19 control dogs, but there was no significant association with disease. A homozygosity analysis identified a three megabase region likely to contain the disease mutation. The region spans 29.8-33 Mb on chromosome 3, for which all affected dogs were homozygous for a common haplotype. Microsatellite markers were developed in the candidate region for linkage analysis that resulted in a logarithm of odds score suggestive of linkage. The candidate region contains 29 genes, none of which are known to cause ataxia.