CLN2 disease is an inherited disorder that primarily affects the nervous system. The signs and symptoms of this condition typically begin between ages 2 and 4. The initial features usually include recurrent seizures (epilepsy) and difficulty coordinating movements (ataxia). Affected children also develop muscle twitches (myoclonus) and vision loss. CLN2 disease affects motor skills, such as sitting and walking, and speech development. This condition also causes the loss of previously acquired skills (developmental regression), intellectual disability that gradually gets worse, and behavioral problems. Individuals with this condition often require the use of a wheelchair by late childhood and typically do not survive past their teens.