Australian racing greyhound

Chronic superficial keratitis (CSK) is a progressive inflammatory condition of the eye (cornea) that can cause discomfort and blindness. Differential disease risk across dog breeds strongly suggests that CSK has a genetic basis. In addition to genetic risk, the occurrence of CSK is exacerbated by exposure to ultraviolet light. Genome-wide association analysis considered 109 greyhounds, 70 with CSK and the remainder with normal phenotype at an age over four years. Three co-located variants on CFA18 near the 5' region of the Epidermal Growth Factor Receptor (EGFR) gene were associated with genome-wide significance after multiple-test correction [(BICF2P579527, CFA18:5,954,402, praw=1.765e-07, pgenome= 0.017); (BICF2P1310662, CFA18:5,963,278, praw=4.09e-07, pgenome= 0.040); (BICF2P160719, CFA18:5,973,238, praw= 4.09e-07, pgenome= 0.040)] (canFam3.1). Of the top 10 associated markers, eight were co-located with the significantly associated markers on CFA18. The associated haplotype on CFA18 is protective for the CSK condition. EGFR is known to play a role in corneal healing, where it initiates differentiation and proliferation of epithelial cells that in turn signal the involvement of stromal keratocytes to commence apoptosis. Further val-idation of the associated variants is required prior to their use in genetic testing for breeding programs