Neuronal ceroid lipofuscinosis 5 (golden retriever type) is an inherited lysosomal storage disease affecting dogs. Affected dogs lack adequate activity of a specific Enzyme necessary for normal cellular metabolism. As a result, there is an abnormal accumulation of waste compounds primarily in the cells of the nervous system, leading to a range of neurological symptoms. Affected dogs usually present around 12 to 14 months of age with progressive neurological disease beginning with restlessness and changes in behavior. Around this age, loss of coordination, balance issues, or difficulty climbing stairs may also become apparent and may be more pronounced when excited. The disease progresses to include severe incoordination, wide-based stance, tremors, anxiety, agitation, persistent circling or pacing, loss of response to learned commands or behaviors, snapping at air (called “fly-biting”), blindness, aggression, and seizures. Affected dogs typically die or are humanely euthanized by 2 to 3 years of age.
Genetic testing of the CLN5 gene will reliably determine whether a dog is a genetic Carrier of neuronal ceroid lipofuscinosis 5 (golden retriever type). Neuronal ceroid lipofuscinosis 5 (golden retriever type) is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the CLN5 gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Dogs that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
Gilliam D, Kolicheski A, Johnson GS, Mhlanga-Mutangadura T, Taylor JF, Schnabel RD, Katz ML. Golden Retriever dogs with neuronal ceroid lipofuscinosis have a two-base-pair deletion and frameshift in CLN5. Mol Genet Metab. 2015 Jun-Jul;115(2-3):101-9. doi: 10.1016/j.ymgme.2015.04.001.
Meiman EJ, Kick GR, Jensen CA, Coates JR, Katz ML. Characterization of neurological disease progression in a canine model of CLN5 neuronal ceroid lipofuscinosis. Dev Neurobiol. 2022 Apr 15.