Neuronal Ceroid Lipofuscinosis 2
Affected Genes: TPP1
Inheritance: Autosomal Recessive
Variant(canFam6):
chr21:29626933: 1 bp deletion G
Breed: Dachshund
Miniature Longhaired Dachshund
Miniature Smooth Dachshund
Miniature Wirehaired Dachshund
Standard Longhaired Dachshund
Standard Smooth Dachshund
Standard Wirehaired Dachshund
General Information: Neuronal Ceroid Lipofuscinosis 2 (NCL2) is a severe and early-onset lysosomal storage disorder that affects dogs, characterized by a rapid progression of neurological symptoms due to the accumulation of waste materials in brain cells. The disease is caused by a deficiency in the enzyme tripeptidyl peptidase 1 (TPP1), which is crucial for breaking down specific proteins within cells. As a result, affected dogs begin to show signs of neurological decline as early as nine months of age. Symptoms of NCL2 include a loss of learned behaviors, mental dullness, coordination issues (ataxia), vision loss, muscle weakness, abnormal gait, seizures, tremors, and aggressive behavior. Unfortunately, the disease progresses quickly, leading to severe debilitation and typically resulting in death by 12 months of age. Recognizing the early signs of NCL2 is critical for managing the affected dog's condition, although there is currently no cure or effective treatment to halt the progression of this devastating disease.
How to Read Your Dog's Test Results for this Genetic Variant:
Two Variants Detected: Dog Likely Affected
One Variant Detected: Dog Unlikely Affected
No Variants Detected: No Effect
Gene / Testing Information: Genetic testing for the TPP1 gene is essential to identify carriers of the mutation responsible for Neuronal Ceroid Lipofuscinosis 2 (NCL2) in dogs. This disease is inherited in an autosomal recessive manner, which means a dog must inherit two copies of the mutated gene, one from each parent, to develop the disease. Dogs carrying only one copy of the mutation (carriers) do not typically show symptoms but can pass the mutated gene to their offspring. When two carriers are bred, each puppy has a 25% chance of developing NCL2 and a 50% chance of being a carrier. Accurate genetic testing is crucial for responsible breeding practices to avoid mating two carriers, thereby reducing the risk of producing affected puppies. By ensuring that only non-carrier dogs are bred, breeders can help eliminate this severe condition from dog populations, ensuring healthier future generations. It is imperative for breeders to perform comprehensive genetic testing to maintain the health and well-being of their breeding lines and to prevent the spread of this fatal neurological disorder.
References:
Awano T, Katz ML, O'Brien DP, Sohar I, Lobel P, Coates JR, Khan S, Johnson GC, Giger U, Johnson GS. A frame shift mutation in canine TPP1 (the ortholog of human CLN2) in a juvenile Dachshund with neuronal ceroid lipofuscinosis. Mol Genet Metab. 2006 89(3):254-260.