A study team at the University of California has discovered a genetic risk factor for the most common forms of cancer affecting horses’ eyes in three additional breeds.

Click here to follow a link to read an abstract from the study.
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In summary
Work by Margo Crausaz and fellow researchers focused on a variant of the damage-specific DNA binding protein 2 (DDB2) gene.

It was previously identified as a causal recessive genetic risk factor for the development of ocular squamous cell carcinoma (SCC) within Haflingers, Belgian Draft horses, and Rocky Mountain Horses, but not in the Appaloosa or Arabian breeds.

This study aimed to evaluate three cases of ocular SCC in additional breeds and determine if DNA testing for the DDB2 variant in warmblood horses and Connemara ponies is warranted. Histopathology confirmed ocular SCC in all three cases and DNA testing confirmed each horse was homozygous for the DDB2 risk factor.

Given the low observed allele frequencies in both the Holsteiner and Belgian Warmblood breeds and that the case under investigation was a Warmblood cross-bred, evaluating additional SCC affected Warmbloods is warranted to fully determine the importance of DDB2 genotyping as a risk factor in Warmblood breeds.