Previously we had posted how a group of researchers had started to work down towards identifying the exact changes in genetic code (SNP's) that made a horse, in this case warmbloods, have a prevalence towards 'heaves' or recurrent airway obstruction (RAO) as it is more formally termed. The process starts with identifying groups of horses afflicted with the disease, and those that are not, and then bringing the focus down from a genome wide study towards identification of mutations within genes that cause the disease.
In a paper released today on Animal Genetics, it seems that the same researchers previously discussed have done exactly that and mapped RAO down to a single mutation. In their initial screen and a subsequent screen of an independent sample, the SNP BIEC2-224511 showed the strongest association with RAO in the unrelated horses. The T allele at this SNP was associated with RAO both in the family and the unrelated horses. While this is in warmbloods, this is no doubt interesting news to the thoroughbred community as well. Independent validation by other groups and in other breeds of horses could allow for widespread genetic testing for this disease.