CEA - Collie Eye Anomaly/Choroidal Hypoplasia

The Disease

Collie Eye Anomaly is an inherited disease with recessive mode of inheritance which results in abnormal development of the eye's choroid.The disease can be mild or servere, in the mild form of the disease, there is a thinning in the choroid layer of the eye but the dog's vision remains normal, however, dogs with the mild form of the disease can produce severly afected offspring.

In the Severe form of the disease, the dog can suffer serious loss of vision, Colobomas can be seen around and at the optic nerve head as outpouchings in the eye tissue layers. Colobomas may lead to secondary complications such as partial or complete retinal detachments and/or growth of new but abnormal blood vessels with bleeding inside the eye. The disease can affect one or both eyes and can lead to vision loss although this disease rarely lead to complete blindness.

Trait of Inheritance

CEA follows an autosomal recessive mode of inheritance.

                           

Clear

Genotype: N / N [ Homozygous normal ]

The dog is noncarrier of the mutant gene.

It is very unlikely that the dog will develop Collie Eye Anomaly (CEA) / Choroidal Hypoplasia (CH) Option 2 Optigen*. The dog will never pass the mutation to its offspring, and therefore it can be bred to any other dog.

Carrier

Genotype: N / CEA [ Heterozygous ]

The dog carries one copy of the mutant gene and one copy of the normal gene.

It is very unlikely that the dog will develop Collie Eye Anomaly (CEA) / Choroidal Hypoplasia (CH) Option 2 Optigen* but since it carries the mutant gene, it can pass it on to its offspring with the probability of 50%.

Carriers should only be bred to clear dogs.

Avoid breeding carrier to carrier because 25% of their offspring is expected to be affected (see table above).

Affected

Genotype: CEA / CEA [ Homozygous mutant ]

The dog carries two copies of the mutant gene and therefore it will pass the mutant gene to its entire offspring.

The dog is likely to develop Collie Eye Anomaly (CEA) / Choroidal Hypoplasia (CH) Option 2 Optigen* and will pass the mutant gene to its entire offspring.

 

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