From MedlinePlus Genetics
CLN11 disease is a disorder that primarily affects the nervous system. Individuals with this condition typically show signs and symptoms in adolescence or early adulthood. This condition is characterized by recurrent seizures (epilepsy), vision loss, problems with balance and coordination (cerebellar ataxia), and a decline in intellectual function.

Seizures in CLN11 disease often involve a loss of consciousness, muscle stiffness (rigidity), and generalized convulsions (tonic-clonic seizures).

Vision loss is gradual over time and is due to a condition called retinitis pigmentosa, which is caused by the breakdown of the light-sensitive layer at the back of the eye (retina). People with CLN11 disease can also develop clouding of the lenses of the eyes (cataracts) and rapid, involuntary eye movements (nystagmus).

Affected individuals can also develop muscle twitches (myoclonus), walking problems and falling (gait disturbance), and impaired speech (dysarthria). Over time, people with CLN11 disease develop short-term memory loss and loss of executive function, which is the ability to plan and implement problem-solving strategies and actions. They may also become irritable and impulsive. Some affected individuals experience visual hallucinations involving people or animals.

CLN11 disease is one of a group of disorders known as neuronal ceroid lipofuscinoses (NCLs). All of these disorders affect the nervous system and typically cause progressive problems with vision, movement, and thinking ability. The different NCLs are distinguished by their genetic cause. Each disease type is given the designation "CLN," meaning ceroid lipofuscinosis, neuronal, and then a number to indicate its subtype.  https://medlineplus.gov/genetics/condition/cln11-disease