CLN2 Disease

About CLN2 Disease

CLN2 (late infantile neuronal ceroid lipofuscinosis type 2) disease is an ultra-rare and rapidly progressing pediatric brain disorder¹ and one of the most common forms of neuronal ceroid lipofuscinosis, a group of inherited disorders collectively known as Batten disease.^2,3 Children with CLN2 disease produce deficient levels of the enzyme TPP1 (tripeptidyl peptidase 1). Without enough of this enzyme, children are unable to dispose of all the wastes normally metabolized in their cell’s lysosomes. The wastes accumulate in organs, particularly the brain and retina, contributing to the loss of cognitive, motor and visual functions.

CLN2 disease is autosomal recessive, meaning both parents of an affected child have a specific mutation on their TPP1 gene. Parents are usually asymptomatic carriers. If both parents carry the mutation, there is a 25 percent chance that their child will have CLN2 disease.^1,4

Signs and Symptoms

Seizures are the most common symptom that brings children to medical attention between ages of 2–4. Oftentimes, children can have a history of language delay. Symptoms typically do not present until age 3, at which point children who were previously healthy and developing normally can suddenly experience seizures and language delays. The condition rapidly progresses to dementia, the loss of the ability to walk and talk, and blindness. By age 6, most affected children will be completely dependent on families and caregivers. Tragically, these children typically die between the ages of 8 and 12.