11/17/2024
⚠️Recently Embark has updated their testing to test for the ATP7B mutation as well as ATP7A and RETN genes.
⁉️After researching ourselves and contacting other breeders about this updated Testing for Copper Toxicosis this is what we have found:
✅ATP7B mutations are classically associated with copper toxicosis in breeds like Labrador Retrievers and Bedlington Terriers. However, copper storage disease in Dobermans is not linked to an ATP7B mutation. Instead, Dobermans often suffer from idiopathic copper-associated hepatopathy, which does not yet have an identified genetic mutation or gene like ATP7B tied to it.
In Dobermans, copper-related liver disease is believed to result from an abnormality in copper metabolism or excretion, but the precise genetic cause remains unknown. While genetic testing is available for ATP7B mutations in other breeds, Dobermans diagnosed with copper-associated Hepatopathy typically require liver biopsies to confirm excessive copper accumulation and may benefit from treatment with copper-chelating agents and a low-copper diet.
Research continues to identify specific genetic factors involved in Dobermans’ copper metabolism, so the gene(s) responsible for this condition may still be discovered.
Another breeder emailed the Genetics team at Gensol to ask about their position on this matter. In their response to that email, the Geneticist stated that Gensol does not recommend purchasing only this specific test for Dobermans as it is not accurate for our specific breed.
There is one gene that Geneticists have identified the COMMD1 Gene. It does play a role in the Doberman, but there are limited panels that look for it. At this time, it is in the research and collecting data for the analysis stage.
✳️At this time, we recommend everyone to just be mindful of this and check their food for copper content, etc.; our vet says she has no concerns for our dogs developing it at this point as we feed a good kibble and our dogs have not had any signs or symptoms of having an issue.
❕Please do your research on copper toxicity and speak with your vet to see if they have any recommendations as well.
🔗So What is Copper Toxicosis?
Copper Toxicosis is an accumulation of copper in the liver. Affected dogs have difficulty excreting excess copper from their liver, which allows copper to build up until the liver eventually begins failing. Multiple genetic and environmental (particularly dietary) factors also contribute to the development of this condition.
Clinical signs can range from none to severe, including imweight loss, vomiting, jaundice, fluid-filled abdomen, and neurologic signs. Females are more impacted than males. Adult onset is typically between 2 and 7 years of age. Copper Toxicosis is definitively diagnosed through liver biopsy and copper quantification
ATP7B (Accumulating variant)
The mode of inheritance for ATP7B is incomplete dominance, meaning that one or two copies of this gene can cause the disorder. However, it is incompletely penetrant, which means not all dogs with one or two copies of the variant will develop the disease. Dogs with one copy have a significantly lower disease risk than dogs with two copies.
ATP7A (Attenuating variant)
The mode of inheritance for ATP7A is complex (X-linked). This variant has been shown to decrease copper accumulation in dogs with one or two copies of the ATP7B variant. The ATP7A gene is most beneficial in males with one copy. Females with one copy likely have less benefit than females with two copies. It is not completely protective in either s*x. Dogs with one or two copies of the ATP7A variant but no copies of ATP7B will not have copper levels low enough to pose any health risk.
Copper Toxicosis (Attenuating)
The RETN variant is considered beneficial and may be best described as a helpful modifier of the harmful copper toxicosis variant ATP7B. The RETN variant may help mitigate some of the symptoms of dogs with variants at ATP7B. Dogs with the RETN variant have not been observed to have any beneficial or harmful complications if they have two copies of the normal ATP7B variant.
Information about Testing for Copper Toxicosis:
ATP7B mutations are classically associated with copper toxicosis in breeds like Labrador Retrievers and Bedlington Terriers. However, copper storage disease in Dobermans is not linked to an ATP7B mutation. Instead, Dobermans often suffer from idiopathic copper-associated Hepatopathy, which does not yet have an identified genetic mutation or gene like ATP7B tied to it.
In Dobermans, copper-related liver disease is believed to result from an abnormality in copper metabolism or excretion, but the precise genetic cause remains unknown. While genetic testing is available for ATP7B mutations in other breeds, Dobermans diagnosed with copper-associated Hepatopathy typically require liver biopsies to confirm excessive copper accumulation and may benefit from treatment with copper-chelating agents and a low-copper diet.
Research continues to identify specific genetic factors involved in Dobermans’ copper metabolism, so the gene(s) responsible for this condition may still be discovered.
