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.
Clinical signs typically emerge before 5 months of age, with some cases having detectable clinical signs present before weaning. Clinical signs are progressive and include ataxia (uncoordinated movements), hypermetria (exaggerated movements), intention tremors, head tremors, and blindness. Progression of clinical signs can lead to an inability to swallow, stand, and walk. The prognosis is grave.
Upon initial observation of clinical signs, affected dogs should be closely monitored to assess welfare and devise a supportive care treatment plan. Due to the rapidly progressive nature of the disease, affected pups are often euthanized for welfare reasons.
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 NAD mutation can be safely bred with a clear dog with no copies of the NAD mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the NAD 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 NAD mutation could develop due to a different genetic or clinical cause.
All coordinates reference CanFam3.1
Tsuboi, M., Watanabe, M., Nibe, K., Yoshimi, N., Kato, A., Sakaguchi, M., … Nakayama, H. (2017). Identification of the PLA2G6 c.1579G>A missense mutation in papillon dog neuroaxonal dystrophy using whole exome sequencing analysis. PLoS ONE, 12(1), 1–17. View the article