A chromosomal region on ECA13 is associated with maxillary prognathism in horses.
Authors: Signer-Hasler Heidi, Neuditschko Markus, Koch Christoph, Froidevaux Sylvie, Flury Christine, Burger Dominik, Leeb Tosso, Rieder Stefan
Journal: PloS one
Summary
# Editorial Summary: Chromosomal Region Associated with Maxillary Prognathism in Horses Maxillary prognathism (overshot jaw) remains the most common hereditary head morphology variation in horses, with significant consequences for dental wear and occlusion; this genome-wide association study sought to identify the genetic basis of the condition to support breeding decisions and potentially inform understanding of the trait across species. Researchers conducted a case-control analysis comparing 96 horses with maxillary prognathism against 763 controls, all genotyped using a 50k SNP array, and employed mixed-model analysis to account for genomic relationships and population stratification. Two SNPs located at the distal end of equine chromosome 13 (ECA13) achieved genome-wide significance after Bonferroni correction, identifying a previously unknown genomic region associated with the condition. Notably, no established prognathism candidate genes exist within this region, suggesting the authors have localised a novel genetic locus that may illuminate the complex polygenic architecture of jaw development not only in horses but potentially in humans and other livestock species. These findings provide a foundation for future functional studies and offer equine breeding programmes a testable genetic marker that could contribute to selection strategies aimed at reducing this malocclusion trait.
Read the full abstract on PubMed
Practical Takeaways
- •Genetic testing for the ECA13 SNP markers could potentially identify carrier animals and inform breeding decisions to reduce maxillary prognathism prevalence
- •This hereditary condition affects tooth wear and jaw function—breeders should prioritize selection against these genetic variants when evaluating breeding stock
- •The identification of this genomic region provides a foundation for further research into the specific gene responsible, which may enable more targeted preventive strategies in breeding programs
Key Findings
- •Two SNPs on chromosome ECA13 reached genome-wide significance for association with maxillary prognathism in horses (96 cases, 763 controls)
- •Maxillary prognathism is the most common hereditary head morphology variation in horses
- •The significant genomic region does not contain known prognathism candidate genes, suggesting a novel gene involvement
- •Findings may have translational relevance for understanding prognathism genetics in humans and other livestock species