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Genetic syndromes and other conditions

Angelman syndrome

A genetic disease that affects the nervous system. It causes delayed development, difficulty speaking and balance problems. Children laugh often and seem cheerful.

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 “Genetic syndromes and other conditions” 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?

In the brain, only the copy of the UBE3A gene that comes from the mother works. If this copy is lost or faulty, there is no working copy left in the brain. Most often, a small piece of the mother's chromosome 15 is missing. As a result, development, speech and movement are affected.

Which symptoms can occur?

Delayed development is usually noticed at 6 to 12 months of age.

  • Delayed development and learning difficulties
  • Very little or no speech
  • Balance and coordination problems when walking
  • Seizures (in most children)
  • A small head
  • Frequent laughing, getting excited easily, hand flapping
  • Sleep problems and sleeping little
  • Fair skin and hair, curvature of the spine (sometimes)

How is it diagnosed?

The disease is suspected when there is delayed development and the typical signs. The diagnosis is confirmed with a blood test. Genetic tests on the blood look for the missing chromosome piece or a change in the UBE3A gene. Most children are diagnosed between 9 months and 6 years of age.

Treatment and care

There is no approved treatment specific to the disease; research is ongoing. Seizures are controlled with medicines. Physiotherapy supports posture, balance and walking. Communication therapy helps children communicate using signs and visual aids. Behavioral therapy may also be recommended. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

It is usually not inherited. The change happens by chance at the start of pregnancy or when the egg or sperm cells are formed. Rarely, a gene change passed on from the mother is involved. This is why it is important to know which change is the cause. Genetic counselling helps to understand the risk in a new pregnancy.

Source: NHS: Angelman syndrome · MedlinePlus Genetics: Angelman syndrome

Key facts

How common is it?
Prevalence: 1-9 per 100 000 (Worldwide)
How is it inherited?
Not inherited
When does it usually start?
Infancy

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.

Guides related to this disease

  • Rare disease at school · Telling the school, medicines and emergency plan, inclusion and BEP, support education room, absences, LGS/YKS arrangements, peer bullying.

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 Angelman

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 10 active interventional studies for this disease. 3 are 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

Genetic syndromes and other conditions: 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:72 · ICD-11 LD90.0

Codes checked against WHO ICD-11 and Orphanet on October 7, 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.