Atopic dermatitis in West Highland white terriers is associated with a 1.3-Mb region on CFA 17

Canine atopic dermatitis (AD) is an allergic inflammatory skin disease that shares similarities with AD in humans. Canine AD is likely to be an inherited disease in dogs and is common in West Highland white terriers (WHWTs). We performed a genome-wide association study using the Affymetrix Canine SNP V2 array consisting of over 42,800 single nucleotide polymorphisms, on 35 atopic and 25 non-atopic WHWTs. A gene-dropping simulation method, using SIB-PAIR, identified a projected 1.3 Mb area of association (genome-wide P=6x10(-5) to P=7x10(-4)) on CFA 17. Nineteen genes on CFA 17, including 1 potential candidate gene (PTPN22), were located less than 0.5 Mb from the interval of association identified on the genomewide association analysis. Four haplotypes within this locus were differently distributed between cases and controls in this population of dogs. These findings suggest that a major locus for canine AD in WHWTs may be located on, or in close proximity to an area on CFA 17.