Here we present two confirmed cases of NCL in Alpenländische Dachsbracke dogs from different litters of the same sire with a different dam harboring the same underlying novel mutation in the CLN8 gene.
Although functions are defined for some of the soluble proteins that are defective in NCL (cathepsin D, PPT1, and TPP1), the primary function of the other proteins defective in NCLs (CLN3, CLN5, CLN6, CLN7, and CLN8) remain poorly defined.
A homozygous mutation in the orthologous mouse gene (Cln8) underlies the phenotype of a naturally occurring NCL model, the motor neuron degeneration mouse (mnd).
CLN8 mutation was first identified in Finnish patients, and the condition was named Northern Epilepsy (NE); however, the severe phenotype of the CLN8 gene was subsequently found outside Finland and named 'variant late-infantile' NCL.
Neuronal ceroid lipofuscinoses (NCL) comprise the most common group of childhood encephalopathies caused by mutations in eight genetic loci, CLN1-CLN8.