Collie Eye Anomaly / CEA / choroidal hypoplasia (NHEJ1-related) - Dog

What does this test analyse?

This genetic test analyses the NHEJ1 deletion c.588+462_588+8260del used for Collie Eye Anomaly, CEA, choroidal hypoplasia, CEA/CH, Collie eye defect, Collie ectasia syndrome and scleral ectasia syndrome.

What does this mean for the dog?

CEA/CH is a congenital developmental disorder of the posterior part of the eye. The choroid under the retina may be underdeveloped. Severity varies: some dogs have little or no noticeable vision problem, while more severe forms can include coloboma, retinal detachment, eye haemorrhage and blindness. The DNA test shows whether the dog carries the tested NHEJ1 deletion.

Practical value of this test

• Breeders can distinguish clear dogs, carriers and dogs with two copies of the CEA/CH marker.
• The result helps avoid carrier x carrier matings and lowers the risk of puppies with genetic CEA/CH predisposition.
• The test supports targeted breeding selection in collie-type, herding and related breeds where this marker is used.
• For purchase, sale or breeding advice, the result shows whether the dog can pass on the CEA/CH deletion.
• Because the severity of eye changes can vary by dog and breed, the test is especially useful for clarifying genetic risk and breeding choices.

Inheritance and result

The marker is autosomal recessive. N/N means that the deletion was not detected. N/CEA means carrier. CEA/CEA means two copies of the NHEJ1 deletion and is reported as an affected genotype for the tested CEA/CH marker.