Neuronal Ceroid-Lipofuscinosis (TPP1-Related) (TPP1)
Neuronal ceroid-lipofuscinosis (TPP1-related) is an autosomal recessive neurodegenerative disorder that is caused by pathogenic variants in the gene TPP1. While it is found in different ethnicities around the world, it is more prevalent in individuals from Newfoundland, Canada due to the presence of a founder mutation. Most TPP1-caused neuronal ceroid-lipofuscinosis results in the late infantile form, in which symptoms begin between 2 and 4 years of age. Clinical features include progressive visual loss and neurologic symptoms, including seizures, ataxia, cerebral atrophy, and developmental regression. Affected individuals do not survive beyond adolescence. Rarely, patients may be diagnosed with a later-onset form. It is not currently possible to predict the age of disease onset based on the patients genotype.
For information about carrier frequency and residual risk, please see the residual risk table.