Genetics of Equine Reproductive Diseases.

This research article discusses the current limitations in genetic testing to understand and diagnose equine reproductive disorders, citing a need for better collaboration among geneticists, clinicians, breeders, and owners to facilitate research progress.

Understanding Equine Reproductive Disorders

• Equine reproductive disorders are said to be genetically diverse and complex. This means that such disorders can have multiple genetic causes, which can vary widely between individual cases.
• The genetic tests currently available can provide limited insight into potential causes or susceptibilities to these disorders. These tests primarily encompass cytogenetic analysis, a technique used to visualize chromosomes to detect any abnormalities, and testing for the presence of a susceptibility gene, FKBP6. A susceptibility gene is one that indicates a higher likelihood of developing a disease, but does not guarantee its occurrence.

Current Genetic Testing Approaches

• The first step in genetic testing for equine reproductive disorders involves cytogenetic analysis. This involves examining the horse’s chromosomes to identify any anomalies and determine if these might be contributing to a reproductive disorder.
• The only known gene associated with potential susceptibility to stallion subfertility— a condition characterized by a failure to achieve pregnancy in a timely manner—is FKBP6. Testing for this gene serves as the only specific genetic test available for stallion reproductive disorders

Challenges and Future Perspectives

• Despite the ongoing improvements in the field of equine genomics—the study of the horse’s complete set of DNA, including all of its genes—the current state of genetic testing for equine reproductive disorders still leaves much to be desired. This is largely because subfertile phenotypes—visible physical traits or conditions resulting from the expression of certain genes—are not conducive to collecting large samples or extensive family trees, both of which can be crucial for genetic research.
• In addition, the exact clinical causes behind many instances of equine reproductive disorders remain elusive. Therefore, to foster progress in this research field, the study advocates for increased cooperation and dialogue between the various stakeholders in the equine breeding industry, namely geneticists, clinicians, breeders, and owners.