Equine Cerebellar Abiotrophy (CA) is a debilitating degenerative condition of the cerebellar portion of the brain which results in a severe lack of coordination. The degree of severity can vary among individual horses, but most affected horses are euthanized before adulthood, due to the hazard they present to themselves and others, and the current inability to treat or cure the condition.
Breeding experiments conducted at UC Davis indicate that CA is the result of an autosomal recessive gene mutation. Autosomal means the disorder is not sex linked (both sexes can be affected) and recessive means both parents must contribute the “CA gene” in order to have an affected foal (this is the same mode of inheritance as SCID and LFS).
Research conducted at the UC Davis Veterinary Genetics Laboratory (VGL) by Drs. Leah Brault and Cecilia Penedo has identified a mutation that is associated with CA. This potential causative mutation involves 2 overlapping candidate genes that are undergoing further study.
This is an important finding, as it moves the currently available CA test from a marker based screening test to a more fully developed DNA test. The availability of this test continues to help diagnose the defect in suspect foals and to help owners identify carriers in their breeding stock. The true value of testing is to help guide breeders in making safe mating selections, with the goal to never produce a CA affected foal.
The Arabian Horse Foundation has provided additional funding to the VGL to incorporate whole genome scanning into the project, to further validate the location of the CA gene in the horse.