Neuronal Ceroid Lipofuscinosis Tibetan Terrier type (NCL)
Neuronal ceroid lipofuscinosis Tibetan terrier type (NCL) is an autosomal recessive genetic disease. It belongs in a group of neurodegenerative disorders called Neuronal ceroid lipofuscinoses (NCLs), also known as the Batten disease. It results from excessive accumulation of lipopygments in body’s tissue. This caused by lack one of several enzymes necessary for the lipopygments normal breakdown. The lipopygments are called lipofuscin, also known as autofluorescent lysosomal storage bodies, and they appear fluorescent when examined under blue or ultraviolet light. Autofluorescent lysosomal storage bodies are made of fats and proteins. The lipopygment lipofuscin in case of Neuronal ceroid lipofuscinosis builds up in the neural cells and some organs, such as liver, spleen, kidneys etc. This storage causes neuronal loss, cortical atrophy, and cerebellar and retinal degeneration resulting in seizures, progressive deterioration of cognition (dementia), motor function impairment (involuntary movements, myoclonus, ataxia, spasticity) and blindness.
NCL has been described in humans and various animals, such as sheep and dogs. They all share symptoms that include a progressive loss of mental and physical nervous system functions. Neuronal ceroid lipofuscinosis Tibetan terrier type is characterized with a progressive neurodegeneration that results in severe neurological impairment and premature death. NCL affected dogs, in first months appear as normal. The age when the disease starts to display depends on disease’s type. Up till now, 7 forms of NCL have been identified in dogs. NCL is documented in following dog breeds: Dachshund, English setter, Australian shepherd, American bulldog, Tibetan terrier, Border collie, Polish owczarek nizinny (Polish lowland sheepdog), Chihuahua and Labrador retriever. AnimaLabs offers genetic testing for Neuronal ceroid lipofuscinosis Tibetan terrier type (NCL).
Neuronal Ceroid Lipofuscinosis Tibetan Terrier type (NCL) genetics
Since neuronal ceroid lipofuscinosis Tibetan terrier type (NCL) is an autosomal recessive disease, the inheritance pattern is following: the healthy parents of a cub with an autosomal recessive form of NCL are obligate heterozygotes, and therefore carry one mutant allele. Heterozygotes have no symptoms. At conception, each cub has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.
Defected genes for autosomal recessive disease can be passed for many generations without affected individuals occurring until two carriers are bred to one another. The only way to find out if there is a chance of getting an affected puppy is to do genetic testing. Since the severity of this group of diseases, genetic testing for Neuronal ceroid lipofuscinosis Tibetan Terrier type (NCL) is highly recommened.