Polymorphisms of the COL9A2, AOAH and FRZB Genes in the Horse Genome and their Association with the Occurrence of Osteochondrosis

The aim of the study was to evaluate the chosen polymorphisms of the COL9A2, AOAH and FRZB genes and find their potential effect on the occurrence of osteochondrosis in Polish sport horses population. During two successive years, all 198 performance tested horses were checked for osteochondrosis. The health status of the horses was assessed based on 10 x-ray images of three joints: fetlock, hock and stifle, and scored on a 0-3 scale. The methodology of analysis of selected candidate genes using the PCR-RFLP technique was developed. The analysis of variance was performed to evaluate significance of the effect of the COL9A2, AOAH and FRZB genotype on the occurrence of osteochondrosis in individual joints. Fixed effects of breed, gender and training centre were taken into account in the analysis. The results showed a significant influence (P≤0.05) of the COL9A2 genotypes on the occurrence of osteochondrosis in fetlock and hock joints. Polymorphism of this gene, even not proved a causal mutation, appears to have effect on symptoms of the disease. In genes AOAH and FRZB there was no significant effect for investigated SNPs. Further analysis of the discussed genes/polymorphisms seems to be important.