Glossary

Screening Scheme Description

DNA test - Gonio
severe goniodysgenesis and glaucoma risk

Details about the disease

Primary glaucoma is a painful and blinding disease. This condition prevents the eye from properly draining fluid, causing a build-up of pressure.

Clinical signs

Pain, light sensitivity, red eyes, dilated pupils, blindness.

How it is inherited?

The disease is an autosomal recessive condition. With this test is means that a dog usually inherit two copies of the abnormal gene (one from its mother and one from its father) before its health is affected. A dog that inherits only one copy of the abnormal gene (from its mother or its father) is unlikely to have any signs of the disease, but will be a carrier and may pass the gene on to any offspring.

IMPORTANT NOTE ABOUT THE TEST

Whilst most DNA tests definitively identify the gene mutation that causes the disease, sometimes determining this can be difficult. In this case, the mutation identified is very strongly associated with severe goniodysgenesis (two copies of the gene were present in 9 of 11 affected dogs, and none of 56 unaffected dogs possessed two copies). However, although this association means it is very likely that the identified mutation is the cause of this disorder, it is not absolutely proven that this mutation is entirely and solely responsible for causing the condition, and so is described by the Kennel Club as a ‘very strong contender’ (for being the causal mutation). Despite not being absolutely definitive, this DNA test nevertheless will likely have considerable value in assisting breeding dogs free from the disease.

Because the identified mutation is a ‘very strong candidate’, rather than definitively proven as the only cause of disease, Border Collie breeders should continue to present their dogs for gonioscopy examinations under the British Veterinary Association (BVA)/Kennel Club (KC)/International Sheep Dog Society (ISDS) Eye Scheme. These eye examination results will provide further data which may assist in proving definitively that the candidate is (or is not) the cause of disease (and if not, in identifying the true cause).

Which laboratories test for this condition?

A list of laboratories and DNA tests can be found at the following link www.thekennelclub.org.uk/health/for-breeders/dna-testing-simple-inherited-disorders/worldwide-dna-tests/

How to responsibly breed from your DNA tested dog

If, once your dog is DNA tested, you would like to find out what their DNA test results mean, or how to select the right mate to avoid producing affected puppies, then please read our breeding advice and information on the following link http://bit.ly/2oSbtnn.

How to find out if a potential mate has been DNA tested

The Kennel Club’s “Health Test Results Finder” allows you to find the results of DNA tests carried out as part of official Kennel Club DNA testing schemes for any dog on the Kennel Club’s breed register. To access this free health tool, please follow this link http://bit.ly/1jyCFnc.

 


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