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Lysosomal storage diseases

CLN2 disease (neuronal ceroid lipofuscinosis type 2)

An inherited disease that begins in childhood and affects the brain. It often starts with seizures between the ages of 2 and 4. Over time, the ability to walk, speak and see is lost; it is a progressive disease that shortens life.

Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source

Prepare an emergency card

This page is translated from the Turkish original.

This disease is followed through the “Lysosomal storage diseases” group.

Understanding the disease

This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.

What happens in this disease?

The body cannot make enough of an enzyme called TPP1. Because of this, certain substances build up in the cells. This build-up damages nerve cells. It is a disease that progresses over time and shortens life.

Which symptoms can occur?

In the classic type, symptoms begin between 2-4 years of age. Later-onset types progress more slowly.

  • Seizures; often the first symptom
  • Delayed speech
  • Clumsiness and problems with coordination of movement
  • Muscle jerks
  • Over time, loss of walking and speaking skills
  • Vision loss
  • Decline in learning skills, and behavior problems

How is it diagnosed?

When delayed speech, clumsiness and seizures occur together, the doctor may suspect this disease. For the diagnosis, enzyme activity is measured in the blood. A genetic test shows the changes in the two copies of the gene. A brain wave test (EEG) and brain imaging help with the diagnosis.

Treatment and care

There is an enzyme replacement therapy in which the missing enzyme is given directly into the brain. Medicines are used for the seizures. In care, neurology, physical therapy, nutrition and comfort (palliative) care teams work together. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

The disease is passed on through recessive inheritance. The child receives one changed gene from the mother and one from the father. The mother and father are often healthy carriers. Genetic counselling is recommended for brothers and sisters and for future pregnancies.

Source: MedlinePlus Genetics — CLN2 disease · Orphanet — CLN2 disease · Orphanet Journal of Rare Diseases (2021) — Guidelines on the diagnosis, clinical assessments, treatment and management for CLN2 disease patients

Key facts

How common is it?
Prevalence: <1 per 1 000 000 (Worldwide)
How is it inherited?
Autosomal recessive
When does it usually start?
Infancy
Gene(s) involved
TPP1

These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.

You are not alone: patient associations in Türkiye

Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.

For all rare diseases: Nadir Hastalıklar Federasyonu

Links checked on October 8, 2026.

Support and help

Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.

News about CLN2

Clinical trials (ClinicalTrials.gov)

A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.

This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.

Questions you can ask your doctor

  • Could this trial be suitable for us?
  • If we take part, how would current treatment and check-ups be affected?
  • Where does the trial take place, and how are travel and accommodation handled?
  • What happens if we want to leave the trial?

ClinicalTrials.gov lists 3 active interventional studies for this disease. 1 is recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.

Selected records (studies with a site in Türkiye first):

See all studies on ClinicalTrials.gov · Joining clinical trials

Lysosomal storage diseases: other news

Medical codes (for talking with your doctor and finding sources)

These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.

Orphanet code: ORPHA:228349

No separate ICD-11 code; WHO classifies this disease under: 5C56.1 (Neuronal ceroid lipofuscinosis)

Codes checked against WHO ICD-11 and Orphanet on October 6, 2026.

This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.

The information on these pages is for general information only and does not replace medical advice. Talk to your doctor about diagnosis and treatment decisions. In an emergency in Türkiye, call 112.

Every update is based on an open source and labeled with its level of evidence. No advertising and no drug brand names. Our scientific principles

This page was translated from Turkish by the Doktorclub editorial team.