Friesian distichiasis
Summary
Distichiasis is a rare and relatively minor eyelash problem mainly affecting the beautiful Friesian horse breed. It happens when extra lashes grow from the wrong place on the eyelash line. Sometimes, this can cause pain and may lead to serious eye problems.
Distichiasis is caused by a mutant form of the ECA13 gene. Testing for this form of the gene can inform breeding choices, and help you know if your horse should have regular eye examinations to look out for signs of distichiasis.
Distichiasis requires two copies of the mutant ECA13 gene, one from each parent, to develop in horses. However, not all horses with two copies will develop the condition. Carriers (one copy) won't have distichiasis but can pass the gene on to offspring.
Gene or region and technical reference
Gene: ECA13 (causative). Reference: Hisey et al. (2020)
Reported alleles
n. Test developed using artificial DNA, animal controls.
DIS. Test developed using artificial DNA.
Panels: groups of tests that are often ordered together
This test is in the Friesian health & colour panel.
