Early pregnancy loss (EPL) remains one of the greatest challenges in equine reproductive health as it is very common and in a remarkable 60-80% of cases the underlying cause is not identified. As a result, veterinarians are left with very few options to reduce its occurrence. Our research laboratory has focused on identifying novel underlying lethal genetic variants of the early equine conceptus, with our recent discovery of aneuploid EPLs (loss or gain or a chromosome) explaining 20% of clinical cases of EPL (Shilton et al, 2020), the highest contributing single pathology described to date. In our follow up preliminary studies, we have identified triploid EPLs (gain of an extra haploid set of chromosomes) that are similarly common, found in an additional 35% of EPLs, suggesting that these two disorders together could account for up to half of all EPLs. Significant gaps remain in our understanding of both the clinical characteristics and mechanisms that underpin these ploidy aberrations key to progress. The overarching goal of this project is to characterize the origins and clinical characteristics of equine triploid and aneuploid aberrations thus providing specific key targets for the development of novel diagnostic tests and interventional approaches that aim to reduce the occurrence of EPL in the mare, and provide veterinarians with clinical tools for these common reproductive conditions.

This study will determine how common genetic disorders of the early equine embryo occur as well as identify how they present to veterinarians and key factors that increase their risk.