Childhood Dementia NCL


NCL is the acronym for Neuronal Ceroid Lipofuscinosis, a metabolic disorder which leads to the progressive death of nerve cells. NCL is the most common form of childhood dementia. The destruction of neurons leads to blindness, loss of mental ability, loss of motor function, epilepsy and premature death.

For the 700 children in Germany affected by NCL this means that they will lose the ability both to think and to act. In the final stages of the disease, even the vital life-sustaining functions fail to be maintained.


NCL manifests itself in different forms dependent upon the genetic defect. Our foundation focuses primarily on the juvenile form (jNCL), the most common one.

You will find some information about:

Forms | Causes | Onset and Development | Diagnostics 





NCL involves the mutation of one of fourteen different NCL genes. Therefore different subtypes of NCL exist. These differentiate themselves primarily by the age at which symptoms appear and in the speed with which the disease progresses. Most forms first show symptoms during childhood, but adults are also affected. All forms of child and youth NCL are autosomal recessively inherited. Adult NCL can also appear in dominant inheritance. The one thing that all forms share is that they are currently incurable.


The most common forms of NCL in Germany.


Form of  NCL                                    

Onset of Disease


Affected gene

Infantile (INCL)

6-24 months

Cessation and following degeneration of psychomotor development, muscular hypotonia, later epilepsy, atrophy (deterioration) of cerebral tissue.


Late-infantile (LINCL)

2-4 years

Seizures and ataxia (loss of motor co-ordination), later brain atrophy and dementia


Juvenile (JNCL)

5-10 years

Loss of sight, loss of motor and cognitive functions, epilepsy, dementia.


A list of the genetic spectrum of all forms of NCl can be found here.



JNCL is caused by an error in genetic material, which is a recessive gene. The affected gene lies on chromosome 16. This genetic mutation leads to fat like material collecting in the nerve cells because the natural metabolising protein is defective. The cells cannot clean themselves of pollutants of energy production and become dirty and later die. The eyes are the first affected organ leading to blindness - , followed shortly after by the brain.  


You can find further information about the defective protein Cln3 here.


Onset and Development


In their first year of lives, children with jNCL develop completely normally. The first signs generally appear with gradual loss of sight beginning around the age of six. Glasses are useless in the prevention of the destruction of the retina. Eye sight diminishes quickly and on average will lead to complete blindness in one to two years.


Around the age of eight the first signs of mental deterioration appear. Next follows unexpected difficulties with abstract thought such as mathematics. Because the children must live in full awareness of the disease it often leads to dramatic personality changes.


From the age of eleven, speech becomes difficult. At the age of thirteen the ability to hold a conversation is often completely gone. Alongside this (at around the age of ten), there are the first sights of movement loss. The development of juvenile NCL leads to the child becoming dependent on a wheelchair. A further symptom is epilepsy which usually sets in around the age of ten.

Seizures increase in frequency and strength as the disease progresses. This can lead to cardiological problems. By the time the child is twenty the disease will have reached a stage where it has affected every part of the body. The NCL patient will lose all control of theirbodilyfunctions (bladder, bowel). Difficulty swallowing mean that it is problematic to ensure sufficient fluids and nutrition. Death is caused by dehydration or respiratory paralysis.

Around one in every 100,000 new-borns is affected by juvenile NCL (jNCL). There are currently around 700 children in Germany affected by NCL, around 70,000 worldwide.

This German - English translation was done by the translators Tizzy Mann, Andrea Murphy, Kate Humby and Marcia Neff for the PerMondo initiative that involves providing free translations for NGOs. PerMondo is sponsored and run by the translation agency Mondo Agit.