Collie Eye Anomaly (CEA)

 

Gene: NHEJ1

Transmission: Autosomal recessive (variable penetration)

For an autosomal recessive genetic disease an animal must have two copies of the mutation in question to be at risk of developing the disease.  Both parents of an affected animal must be carriers of at least one copy of the mutation.  Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.

Mutation: Deletion, NHEJ1 gene; del. 7,6 Kb, intron4-5

Medical system: Ocular

Breeds: American Foxhound, American Staffordshire Terrier/Amstaff, Anatolian Shepherd Dog, Australian Cattle Dog, Australian Kelpie, Australian Shepherd, Beagle, Bearded Collie, Border Collie, Boston Terrier, Boxer, Boykin Spaniel, Chihuahua, Chinook, Chow Chow, Collie, Collie - Rough, Collie - Smooth, Dalmatian, Doberman Pinscher, English Bulldog, English Shepherd, German Shepherd, Golden Retriever, Great Pyrenees, Hokkaido Dog, Koolie, Labrador Retriever, Lacy Dog, Lancashire Heeler, Lapponian Herder, Long-Haired Whippet, McNab Shepherd, Miniature American Shepherd, Miniature Australian Shepherd, Nova Scotia Duck Tolling, Old English Sheepdog, Parson Russell Terrier, Pembroke Welsh Corgi, Poodle - Miniature (Dwarf), Poodle - Standard, Rottweiler, Saint-Bernard, Schnauzer - Giant, Shetland Sheepdog, Siberian Husky, Silken Windhound, Toy Australian Shepherd, Treeing Walker Coonhound, Whippet, Yorkshire Terrier

Age of onset of symptoms: Young age

Colley eye anomaly, also known as choroidal hypoplasia, is a developmental eye disease that affects the choroid, the layer responsible for the blood supply to the retina of the eye.  Affected animals have a thinner choroid than normal.  In mild cases, no vision problems result, while in severe cases retinal detachment, and intraocular haemorrhage can lead to blindness. The degree of severity of this condition varies from one individual to another and is unfortunately not predictable, thus mildly affected parents can give birth to severely afflicted puppies.

 

References:

OMIA link: [0218-9615]

Donner J, Freyer J, Davison S, et al. (2023) Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs.  PLoS Genet. 19(2):e1010651. [pubmed/36848397]

Marelli SP, Rizzi R, Paganelli A, Bagardi M, et al. (2022) Genotypic and allelic frequency of a mutation in the NHEJ1 gene associated with collie eye anomaly in dogs in Italy. Vet Rec Open 9:e26. [pubmed/35127102]

Kucharczyk N, Cislo-Pakuluk A, Bedford P. (2019) Collie eye anomaly in Australian Kelpie dogs in Poland. BMC Vet Res 15:392. [pubmed/31684941]

Brown EA, Thomasy SM, Murphy CJ, Bannasch DL. (2018) Genetic analysis of optic nerve head coloboma in the Nova Scotia Duck Tolling Retriever identifies discordance with the NHEJ1 intronic deletion (collie eye anomaly mutation). Vet Ophthalmol 21:144-150. [pubmed/28702949]

Grosås S, Lingaas F, Prestrud KW, Ropstad EO. (2018) Compliance between clinical and genetic diagnosis of choroidal hypoplasia in 103 Norwegian Border Collie puppies. Vet Ophthalmol 21:371-375. [pubmed/29111596]

Fredholm M, Larsen RC, Jönsson M, et al. (2016) Discrepancy in compliance between the clinical and genetic diagnosis of choroidal hypoplasia in Danish Rough Collies and Shetland Sheepdogs. Anim Genet. 47(2):250-252. [pubmed/26732749]

Mizukami K, Yabuki A, Endoh D, et al. (2014) Investigation of parallel and simultaneous selection for collie eye anomaly and ivermectin toxicosis. Bet Rec 175:174. [pubmed/24939474]

Walser-Reinhardt L, Hassig M, Spiess B. (2009) Collie Eye Anomaly in Switzerland. Schweiz Arch Tierheilkd.151(12):597-603. [pubmed/19946851]

Munyard KA, Sherry CR, Sherry L. (2007) A retrospective evaluation of congenital ocular defects in Australian Shepherd dogs in Australia. Vet Ophthalmol. 10(1):19-22. [pubmed/17204124]

Parker HG, Kukekova AV, Akey DT, et al. (2007) Breed relationships facilitate fine-mapping studies: A 7.8-kb deletion cosegregates with Collie eye anomaly across multiple dog breeds. Genome Research 17:1562-1571. [pubmed/17916641]

Lowe JK, Kukekova, AV, Kirkness EF, et al. (2003) Linkage mapping of the primary disease locus for collie eye anomaly. Genomics 82(1):86-95. [pubmed/12809679]