Copper Storage Disease in Labrador Retrievers: How Common Are the Genetic Variants?
Copper storage disease (copper toxicosis, CT) is a disorder of copper metabolism in which excess copper accumulates in the liver. This can cause chronic liver inflammation (hepatitis) and, over time, lead to severe liver damage. Since the disease often goes unnoticed for a long time, understanding genetic risk factors is particularly important.
What role do ATP7B and ATP7A play?
In Labrador Retrievers, two genes in particular influence the risk of copper accumulation:
- ATP7B: A variant in this gene increases the risk of copper accumulation in the liver. Dogs with two copies of the variant (CT/CT) have a higher genetic risk than heterozygous dogs (N/CT).
- ATP7A: A variant in this gene can partially mitigate copper accumulation. However, the protective effect is not complete and depends, among other factors, on sex and genotype.
How common are these variants in Labrador Retrievers?
Recent analyses of more than 1,000 Labrador Retrievers tested by LABOGEN each show the following genotype distributions:
ATP7B – risk-increasing variant
- 58% N/N: no risk variant detected
- 37% N/CT: one copy of the risk variant
- 5% CT/CT: two copies of the risk variant
This means that 42% of the dogs tested carry at least one copy of the ATP7B risk variant.
ATP7A – partially protective variant
- 50% N/N: no investigated modifying variant detected
- 28% N/CTm: one copy of the modifying variant
- 22% CTm/CTm: two copies of the modifying variant
Thus, at least one copy of the ATP7A variant was detected in 50% of the dogs tested.
Note: The distributions shown refer to the animals tested at LABOGEN and are not necessarily representative of the entire Labrador Retriever population. Due to X-linked inheritance, the ATP7A genotypes must be interpreted according to sex.
What do these results mean for breeding and preventive health care?
The results show that genetic variants affecting copper metabolism are common among the Labrador Retrievers studied. However, the presence of a risk variant does not necessarily mean that a dog will actually develop the disease.
Genetic testing helps to better assess genetic predisposition and can be used for both preventive health care and targeted breeding planning.
Detailed information about the disease, the significance of the various genotypes, and early detection and treatment can be found on our website:
