Juvenile idiopathic epilepsy in Arabian horses is not a single-gene disorder

Valued for their temperament, beauty, athletic ability, and exhibition in the show ring, Arabian horses are an important component of the horse industry. Juvenile idiopathic epilepsy (JIE), a seizure disorder, is most often reported in Arabian foals from birth to 6 months of age. Affected foals exhibit tonic-clonic seizures lasting as long as 5 min and risking secondary complications like temporary blindness and disorientation. Some foals outgrow this condition, while others die or suffer lifelong complications if not treated. Previous work suggested a strong genetic component to JIE and proposed JIE to be a single-gene trait. In this work, we conducted a genome wide association study (GWAS) in 60 cases of JIE and 120 genetically matched controls, identifying loci suggesting JIE is not caused by a single locus. Coat color (chestnut, gray) phenotypes were used as positive control traits to assess the efficacy of GWAS in this population. Future work will attempt to future define candidate regions and explore a polygenic mode of inheritance.

Automated summary

Arabian horses are valued for their temperament, beauty, athletic ability, and exhibition in the show ring, making them an important part of the horse industry. Juvenile idiopathic epilepsy (JIE) is a seizure disorder that primarily affects Arabian foals from birth to 6 months of age. A genome wide association study (GWAS) was conducted, suggesting that JIE is not caused by a single gene and potentially has a polygenic mode of inheritance. The study also used coat color phenotypes as positive control traits to assess the effectiveness of GWAS in this population.