Know Your Disease: Infantile Neuronal Ceroid Lipofuscinosis(INCL)
What is Infantile Neuronal Ceroid Lipofuscinosis?
Infantile neuronal ceroidlipofuscinosis (INCL) is a rare genetic disorder, in which certain lipids i.e. ceroid and lipofuscin accumulate abnormally within the nerve cells (neurons) of the brain as well as other tissues of the body. This may result in the progressive breakdown of certain areas of the brain in addition to neurological impairment.
All forms of NCL affect around 1 in 100,000 individuals worldwide. NCLs are more
common in Finland, where approximately 1 in 12,500 individuals are affected..
Genetics and risk:?
INCL is caused by the mutation in CLN1 (NCL1), the gene encoding the enzyme palmitoyl
protein thioesterase 1 (PPT1). PPT1 removes certain long-chain fatty acids from
proteins, which helps break down the proteins. Since INCL is an autosomal recessive
disorder, the child needs to receive the abnormal gene from both parents in order
to show any clinical symptoms.
If an individual receives one normal gene and another
gene for the disease, the person will only be a carrier for the disease The risk
for both carrier parents to pass the defective gene and have an affected child is
25% with each pregnancy The risk to have a child who is a carrier like the parents
is 50% with each pregnancy There is a 25% chance that a child will be completely
normal The risk is the same for males and females.
Signs and symptoms:?
Children develop normal motor skills during the 1 st year, but the slowdown in head
growth and decreased muscular tone are detectable after the age of 6 months. Loss
in control of bodily movements and clumsiness develop along with irritability, sleep
disturbance and visual failure, leading to a rapid developmental deterioration during
the 2 nd year.
Genetic testing may aid in the accurate diagnosis of the disorder and assist in
prenatal diagnosis (before birth) as well as carrier determination.Both prenatal and post-natal diagnosis include the PPT enzyme assay (to detect the deficient activity
of PPT enzyme) followed by DNA studies (to reveal the mutation). Prenatal diagnosis
includes a method called chorionic villus sampling (use of placental tissues) and
amniocentesis (use of the amniotic fluid).
There is no known specific treatment to halt or reverse the symptoms of INCL. Seizures (fits) can sometimes be reduced or controlled withChildhood NCLs such as INCL should be considered
in infants or children who begin to experience developmental regression
and seizure along with increasing visual impairment.
anticonvulsant drugs, and other medical problems
can be treated appropriately as they arise. Simultaneously, physical
and occupational therapy may help patients retain their function as long as possible.
Support and encouragement can help patients and families cope with the profound
disability and dementia caused by NCLs. Often, support groups enable affected children,
adults, and families to share common concerns and experiences.
Early diagnosis of INCL is important for
counseling the affected families about future
Santavuori Disease: National Organization For Rare Disease. Available online at:
2016. 2 Infantile Neuronal CeroidLipofuscinosis: Genetic Home Reference. Available
online at: https://ghr.nlm.nih.gov/condition/infantile-neuronal- ceroid-lipofuscinosis#diagnosis.
Last accessed in April 2016. 3 Batten Disease Fact Sheet: National Institute of
Neurological Disorders and Stroke. NIH. Available online at: http://www.ninds.nih.gov/disorders/batten/detail_ba
tten.htm. Last accessed in April 2016.