For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.
At risk dogs are highly likely to show signs of this disease in their lifetime.
Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.
The first signs of NCL8 are usually observed at the age of 1 to 2 years. The clinical signs include ataxia (uncoordinated movements), behavioral changes, vision loss, and epileptic seizures. NCL8 is a progressive condition. The lifespan of affected dogs is rarely over two years of age due to severity of the clinical signs.
Treatment is supportive care, however, due to the progressive nature of the condition, clinical signs typically lead to euthanasia on welfare grounds.
There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.
This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to occur. A carrier dog with one copy of the NCL8 mutation can be safely bred with a clear dog with no copies of the NCL8 mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the NCL8 mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the NCL8 mutation could develop due to a different genetic or clinical cause.
All coordinates reference CanFam3.1
Guo, J., Johnson, G. S., Brown, H. A., Provencher, M. L., da Costa, R. C., Mhlanga-Mutangadura, T., … Katz, M. L. (2014). A CLN8 nonsense mutation in the whole genome sequence of a mixed breed dog with neuronal ceroid lipofuscinosis and Australian shepherd ancestry. Molecular Genetics and Metabolism, 112(4), 302–309. View the article