Genome-Wide Association Analyses of Osteochondrosis in Belgian Warmbloods Reveal Candidate Genes Associated With Chondrocyte Development.
Authors: Drabbe Alize, Janssens Steven, Blott Sarah, Ducro Bart J, Fontanel Marie, Francois Liesbeth, Schurink Anouk, Stinckens Anneleen, Lindgren Gabriella, Van Mol Bram, Pille Frederik, Buys Nadine, Velie Brandon D
Journal: Journal of equine veterinary science
Summary
Belgian Warmbloods experience osteochondrosis at concerning prevalence rates (32%), yet genetic associations in this breed remain poorly characterised compared to others, prompting a genome-wide association study of 407 registered animals to identify candidate variants influencing disease susceptibility. Genotyping via the 670K Axiom Array and principal component analysis revealed significant associations (P < .01) on equine chromosomes 3, 12, and 18 for overall osteochondrosis status, though site-specific analyses of hock and stifle lesions failed to reach statistical significance. The candidate genes clustering within 500 kilobases of these significant single nucleotide polymorphisms point towards biological pathways governing cell differentiation and chondrocyte development—mechanisms directly relevant to the pathophysiology of cartilage and bone lesion formation. Whilst these findings offer valuable genomic markers for future breeding decisions and provide insight into the developmental processes underpinning disease, validation studies across additional cohorts and breeds will be necessary before implementing these variants into practical selection programmes. For practitioners involved in breeding, veterinary assessment, and management decisions, this research underscores the polygenic nature of osteochondrosis and suggests that targeted breeding strategies informed by genomic data may eventually reduce disease incidence in predisposed populations.
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Practical Takeaways
- •Belgian Warmblood breeders should be aware that osteochondrosis affects nearly one in three horses in the breed, making genetic testing for identified variants a potential breeding tool once validated
- •The identification of chondrocyte development pathways suggests that nutritional and developmental management during growth periods may interact with genetic predisposition to influence disease expression
- •Veterinary screening recommendations should consider Belgian Warmblood genetic risk factors, though further validation studies are needed before implementing SNP-based selection in breeding programs
Key Findings
- •Osteochondrosis prevalence in Belgian Warmbloods is 32.0%, indicating a significant disease burden in the breed
- •Genome-wide association analyses identified significantly associated SNPs on ECA 3, ECA 12, and ECA 18 for osteochondrosis status (P < .01)
- •Candidate genes near significant SNPs have functions related to cell differentiation and chondrocyte development, suggesting developmental mechanisms underlying osteochondrosis
- •No single SNPs reached significance for hock-specific or stifle-specific osteochondrosis, indicating site-specific genetic architectures may differ