New research shows that juvenile idiopathic epilepsy (JIE) is not genetically related to lavender foal syndrome (LFS), severe combined immunodeficiency (SCID) or other previously identified inherited conditions affecting the Arabian breed.

JIE, which is typically seen in Arabian foals between 2 days and 6 months of age, is characterized by “tonic/clonic” seizures that start with body-wide muscle stiffness and culminate in recumbency, rapid muscle contracture and loss of consciousness.

Foals can injure themselves during seizures, which may last a few seconds or several minutes. Seizures are followed by temporary blindness and/or disorientation. Some foals succumb to seizure-related problems, but most outgrow JIE within a year or 18 months.

JIE is an inherited epileptic disorder, so researchers at the University of California–Davis sought to determine whether it is associated with other genetic conditions found in Arabians. The researchers analyzed the DNA of 10 foals diagnosed with JIE to look for the mutations that cause LFS, SCID, cerebellar abiotrophy (CA) and occipitoatlantoaxial malformation (OAAM1). They found that the JIE foals did not have mutations for any of those conditions and, therefore, concluded there is no association between them.

Reference: “Investigation of known genetic mutations of Arabian horses in Egyptian Arabian foals with juvenile idiopathic epilepsy,” Journal of Veterinary Internal Medicine, November 2017

This article was originally published in EQUUS 486, March 2018