<unk>  is an extremely rare autosomal recessive genetic disorder that is part of the neuronal ceroid lipofuscinosis (NCL) family of neurodegenerative disorders. It is caused by the accumulation of lipopigments in the body due to a deficiency in tripeptidyl peptidase I as a result of a mutation in the TPP1 gene. Symptoms appear between ages 2 and 4 and consist of typical neurodegenerative complications: loss of muscle function (ataxia), drug resistant seizures (epilepsy), apraxia, development of muscle twitches (myoclonus), and vision impairment. This late-infantile form of the<unk>  progresses rapidly once symptoms are onset and ends in death between age 8 and teens. The prevalence of<unk>  is unknown, however NCL collectively affects an estimated 1 in 100,000 individuals worldwide.<unk>  is related to late-infantile Batten<unk>  and LINCL, and is under the umbrella of neuronal ceroid lipofuscinosis.
Jansky–Bielschowsky disease
Camurati–Engelmann disease
Achondrogenesis type 2
Achondrogenesis type 1B
Hermansky–Pudlak syndrome
Metaphyseal chondrodysplasia Schmid type
Jansen's metaphyseal chondrodysplasia
Keppen–Lubinsky syndrome