Jansky-Bielschowsky disease

Jansky-Bielschowsky disease is an extremely rare inherited neurodegenerative disorder and belongs to the neuronal ceroid lipofuscinosis family. It follows an autosomal recessive pattern and is caused by a mutation in the TPP1 gene, which leaves the body deficient in the enzyme tripeptidyl peptidase I so that lipopigments build up in tissues. Symptoms usually begin between ages two and four and include loss of muscle coordination (ataxia), seizures that resist drugs, apraxia, muscle twitches (myoclonus) and loss of vision. This late-infantile form progresses quickly once symptoms start and leads to death between about age eight and the teenage years. Its exact prevalence is unknown, though the neuronal ceroid lipofuscinoses together affect an estimated one in 100,000 people. It is related to late-infantile Batten disease.