- Labradoodle
- Labrador Retriever
Breeds Serviced
CT - Copper Toxicosis (Labrador Type)
Copper Toxicosis in the Labrador Retriever is similar to the disease found in other breeds in that it manifests itself as a build up of copper in the liver of affected animals. Unlike the disease seen in Bedlington Terriers, the Labrador form is not inherited as a strictly recessive trait. The mutant genes have an additive affect, so one copy of the mutation increases copper levels, and a second copy when present increases levels even further. This affect is somewhat more extreme in females than in males. We know very little of the frequency of the disease itself. It is an uncommon diagnosis, but that may be due to the fact that it is a relatively late onset disease (middle aged or older dogs) and may have variable, difficult to diagnose, symptoms. The mutation responsible for copper toxicosis in Labradors has been identified by researchers at the University of Utrecht. Our test is based on their findings.
The primary cause of copper toxicosis in Labrador Retrievers is a mutant form of ATP7B. Dogs that inherit two normal versions of the gene (one from each parent) will have normal levels of copper in their livers. Dogs that inherit one normal copy and one mutant copy will have somewhat elevated levels of copper in their liver, while those that inherit two mutant copies will have the highest levels. Generally speaking, it is those dogs with two mutant copies that are at the highest risk for the disease, although there have been some dogs reported that only had one copy and still had dangerously high copper levels.
The second gene involved in the Labrador disease is a mutated form of ATP7A. This is a "good" mutation which helps minimize the accumulation of copper in the liver. Since this gene is located on the X chromosome, the mutation is inherited as a sex-linked recessive. Males inherit only a single copy of the gene either normal or mutant from their mother, while females inherit two copies, one on the x chromosome of each parent. Therefore, males only need to inherit one copy of the mutant gene to help with their copper levels, while females need to inherit two. This is why females are more commonly diagnosed with the disease than males.
Since the frequency of the ATP7B CT mutation is relatively high, we do not recommend breeding completely away from it, but rather avoiding pairings that might produce two-copy offspring.
Result Types for the ATP7B CT mutation (copper storage disease)
0 copies of the CT mutation:Negative - Zero copies of the CT ATP7B mutation
1 copy of the CT mutation:
Positive (heterozygous) 1 copy of the CT ATP7B mutation
2 copies of the CT mutation:
Positive (homozygous) 2 copies of the CT ATP7B mutation
Result Types for the ATP7A (dampening mutation)
Males -
O copies:
Negative - Zero copies of the CT ATP7A Dampener Mutation
1 copy:
Positive (hemizygous) One copy of the CT ATP7A Dampener Mutation
Females -
0 copies:
Negative - Zero copies of the CT ATP7A Dampener Mutation
1 copy:
Positive (heterozygous) One copy of the CT ATP7A Dampener Mutation
2 copies:
Positive (homozygous) Two copies of the CT ATP7A Dampener Mutation
