Linkage test (DNA based) - Copper toxicosis

Details about the disease

Copper toxicosis is a hereditary disease that leads to the build-up of dietary copper in the liver, causing illness and death.

Clinical signs

This disease does not typically show any signs in the earlier stages. Clinical effects of this disorder are commonly related to any effects associated with the liver such as weight loss, anorexia, depression, vomiting, weakness, lethargy (lack of energy) and dehydration.

As this disease progresses, the dog may encounter problems such as ecchymotic hemorrhages (bruising), and may cause melena (blood in the stool).

Without treatment, affected dogs develop liver disease and die, usually between 3 to 7 years of age.

How is it inherited?

Copper toxicosis is caused by the deletion in the gene COMMD1, but is possible that there are other genetic causes of copper toxicosis not yet identified.

The disease is described as an autosomal-recessive condition. This means that a dog must inherit two copies of an 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) will have no signs of the disease, but will be a carrier and may pass the gene on to any offspring.

What is a linkage test?

Most DNA tests identify whether your dog has a specific genetic mutation that causes a disease. Linkage tests do not do this, instead they find parts of unrelated DNA that are almost always inherited with the genetic mutation. Linkage tests may not be as precise as other DNA tests, but they can still be highly accurate. Laboratories will often estimate how accurate their test is. The accuracy of a linkage tests depends on the links between marker DNA and the actual mutation being maintained (i.e. them continuing to be inherited together).
Why do laboratories create linkage tests rather than regular DNA tests?

Laboratories may offer linkage tests for three main reasons:

  1. Sometimes scientists are unable to find the exact gene that causes a disease, but they are able to find sections of DNA that are somehow linked to, and inherited alongside it
  2. It may be technically difficult to find the mutation and it may be easier and cheaper to look at and determine linked markers instead
  3. The test for a particular genetic mutation is patented by a specific laboratory and may not allow others to offer this test, or may ask that they pay to offer it. In these circumstances some laboratories may create a linkage test so that they can offer the test to their clients

Which laboratories test for this condition?

A list of laboratories that offer a copper toxicosis linkage tests can be found below.

Other laboratories offer a standard DNA test for copper toxicosis that identifies if a dog has the section of DNA that can cause this condition. Find out more about the COMMD1 DNA test.

Laboratories that send a copy of your dog's results straight to The Kennel Club, so you don't have to
Laboratories Contact details
Laboklin (UK) Phone: 0161 282 3066
Email: Laboklin Veterinary Diagnostic Laboratory
Web: www.laboklin.co.uk

Where will your dog's results be published?

DNA test results from these laboratories are sent directly to The Kennel Club and are recorded on to the dog's record in the registration database, and are published:

Breeding advice and what your dog's results mean

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 DNA testing information.

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.