Affected Gene: NHEJ1
Transmission: Autosomal recessive with variable expression
Mutation: 7.8 kb deletion in the NHEJ1 gene. CanFam3.1 37 g.25698028_25705826del c.588+462_588+8260del
OMIA Link: 000218-9615

Breeds Recommended for Testing: Longhaired Collie, Smooth Collie, Border Collie, Australian Shepherd,  Shetland Sheepdog, Swiss White Shepherd, Miniature Australian Shepherd, Nova Scotia Duck Tolling Retriever, Lancashire Heeler

Symptoms:
Collie Eye Anomaly (CEA) is a hereditary eye disorder common in herding breeds. CEA presents with varying degrees of visual impairment, ranging from no visual deficit to complete blindness. Clinically, the disease results in poor development of the choroid and sclera, causing retinal issues.

References:
Parker, H.G., Kukekova, A.V., Akey, D.T., Goldstein, O., Kirkness, E.F., Baysac, K.C., Mosher, D.S., Aguirre, G.D., Acland, G.M., Ostrander, E.A.
Breed relationships facilitate fine-mapping studies: a 7.8-kb deletion cosegregates with Collie eye anomaly across multiple dog breeds.
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DOI: 10.1101/gr.6772807
Chang, HS., Mizukami, K., Yabuki, A., Hossain, MA., Rahman, MM., Uddin, MM., Arai, T., Yamato, O.
A novel rapid genotyping technique for Collie eye anomaly: SYBR Green-based real-time polymerase chain reaction method applicable to blood and saliva specimens on Flinders Technology Associates filter paper.
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Discrepancy in compliance between the clinical and genetic diagnosis of choroidal hypoplasia in Danish Rough Collies and Shetland Sheepdogs.
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Mizukami, K., Yabuki, A., Kohyama, M., Kushida, K., Rahman, M.M., Uddin, M.M., Sawa, M., Yamato, O.
Molecular prevalence of multiple genetic disorders in Border Collies in Japan and recommendations for genetic counselling.
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Novel insights into chorioretinal and juxtapapillary colobomas by optical coherence tomography.
Vet Ophthalmol, 2022. PubMed: 35092136
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