2.1
Neuronal ceroid lipofuscinosis type 2 (CLN2) is a rare genetic disease caused by deficiency of the enzyme called tripeptidyl peptidase 1 (TPP1). It is 1 form of neuronal ceroid lipofuscinosis, also known as Batten disease. CLN2 is inherited as an autosomal recessive disorder, which means that both chromosome copies carry mutations in the CLN2 gene, and both parents are unaffected carriers. A deficiency of TPP1 results in abnormal storage of proteins and lipids in neurons and other cells. Accumulation of these proteins and lipids prevents the cells from functioning as they should.