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POAG Norwegian Elkhound Type
| Acronym: | POAG |
| Gene: | ADAMTS10 |
| Mutation: | c.1159G>A |
| Inheritance: | Autosomal recessive |
| Sample type: | CHS (Cheek Swab), WBE (Whole Blood EDTA) |
Genetics and characteristics
POAG Norwegian Elkhound Type is a genetic optic neuropathy characterized by elevated intraocular pressure. Forms of glaucoma can be differentiated as primary or secondary glaucoma. Primary glaucoma is characterized by its onset without any other ocular cause, while secondary glaucoma appears when another cause is present, which triggers glaucoma. Primary glaucoma is one of the most common causes of vision loss in dogs and also humans. A most common characteristic of POAG is an elevated intraocular pressure, which is caused by the blockage of the aqueous humor outflow, as a result of the shallow anterior chamber as well as the obstruction of the iris-trabecular meshwork in the iridocorneal angle of the eye.
In Norwegian Elkhound dogs, POAG symptoms usually develop in middle-aged or elderly dogs, but the actual disease onset can be also much earlier. It is common that peripheral vision is affected as well. With the disease progression, the narrowing of the ciliary cleft is noticed, which contributes to the elevation of the intraocular pressure, and can lead to the subluxation of the lenses as well. As the atrophy of the optic nerve progresses, vision deterioration becomes worse. Retina remains to seem unaffected until the later stages of the disease.
Primary open angle glaucoma in the Norwegian Elkhound is caused by a missense mutation in the ADAMTS10 gene. The disorder is inherited as an autosomal recessive disorder. Healthy parents of an affected dog are obligate heterozygotes and therefore carry one mutant allele. Heterozygotes are carriers and show no symptoms. At conception, each cub has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.
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:
Ahonen, S. J., Kaukonen, M., Nussdorfer, F. D., Harman, C. D., Komaromy, A. M. et al (2014): A Novel Missense Mutation in ADAMTS10 in Norwegian Elkhound Primary Glucoma. PloS ONE 9(11): e111941. doi;10.1371/journal.pone.0111941