Deutsch
Hrvatski
Русский
Português
Collie Eye Anomaly (CEA)
| Acronym: | CEA, CH |
| Gene: | NHEJ1 |
| Mutation: | c.588+462_588+8260del7799bp |
| Inheritance: | Autosomal recessive |
| Sample type: | CHS (Cheek Swab), WBE (Whole Blood EDTA) |
Genetics and characteristics
Collie eye anomaly (CEA) is a complex hereditary ocular disorder that is characterized by regional hypoplasia of choroids, the highly vascularized layer of the eye that supplies blood and nutrients to the retina. Occasionally, tortuous retinal vessels and multiple retinal folds are also observed. The clinical symptoms can vary greatly among affected dogs within one breed, between parent and offspring, and within a litter. No medical treatment for the disease is available. CEA is widespread in dogs, with a prevalence of 65–97% for rough and smooth collies, while the prevalence in Border collies is lower. CEA is also recognized in all herding dogs or breeds that are derived from classic herding breeds.
CEA inheritance is autosomal recessive with variable expression and pleomorphism (wide range in the clinical expression of the defect). Some mildly to moderately CEA-affected dogs appear to retain their normal vision function throughout their life. Severely affected individuals, particularly those with colobomas, can develop retinal detachments leading to blindness. In these cases, subretinal and pre-retinal neovascularization and intraocular hemorrhage can occur.
Results Reported As
Test Result |
Interpretation of test result |
CLEAR |
Tested mutation was not detected in animal with „clear“ result. Animal tested as clear has wild-type allele in homozygous state (i.e. two pairs of healthy alleles). It will not develop disease caused by tested mutation.* It will pass only wild-type allele to its offspring. |
CARRIER |
Tested mutation was detected in animal with „carrier“ result. Animal tested as carrier has one wild-type and one mutation allele, it is in heterozygous state. It will not develop disease caused by tested mutation.* It can pass wild-type or mutation allele to its offspring. |
AFFECTED |
Tested mutation was detected in animal with „affected“ result. Animal tested as affected has two copies of mutation alleles affecting the gene. It is likely the animal will experience a genetic disorder due to this mutation.** It will pass only mutation allele to its offspring. |
*Test excludes only tested mutation but not possible unknown mutations or factors that can lead to similar condition/symptoms.
** Potential unknown mutations or multiple other factors can possibly affect the likelihood of experiencing a genetic disorder.
References:
Dostál, J., Horák, P., Hrdlicová, A., and Stratil, A. (2010). Simplified PCR analysis of a mutation in the NHEJ1 gene causing Collie eye anomaly in some dog breeds. Czech Journal of Animal Science 55, 346–350.
Lowe, J.K., Kukekova, A.V., Kirkness, E.F., Langlois, M.C., Aguirre, G.D., Acland, G.M., and Ostrander, E.A. (2003). Linkage mapping of the primary disease locus for collie eye anomaly☆. Genomics 82, 86–95.