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Genetic syndromes and other conditions

Prader-Willi syndrome

A genetic disease present from birth. In infancy there is muscle floppiness and difficulty feeding. In childhood a hunger that is never satisfied begins, which can lead to excess weight.

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

Orphanet has a guideline for emergency doctors for this disease (language: Spanish, French, Italian). See on Orphanet

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?

Prader-Willi syndrome is a genetic disease that is present from birth. A gene region on chromosome 15 does not work properly. In infancy, there is muscle floppiness and difficulty feeding. In childhood, an insatiable hunger begins; this can lead to excess weight.

Which symptoms can occur?

Symptoms change with age.

  • Muscle floppiness and difficulty sucking in infancy (common)
  • Strong urge to overeat in childhood (common)
  • Delayed development and mild or moderate learning disability (common)
  • Short stature; small hands and feet (common)
  • Behaviors such as temper tantrums, stubbornness and skin picking (common)
  • Delayed or incomplete puberty (common)
  • Squint and curvature of the spine (common)

How is it diagnosed?

The diagnosis is made with a genetic test. If there is marked muscle floppiness in infancy, the test may be considered. The test examines the region on chromosome 15 and the cause of the problem.

Treatment and care

In infancy, methods that make feeding easier are used. In childhood, access to food is carefully managed and physical activity is encouraged. Growth hormone treatment can contribute to height and muscle build. Behavioral, educational and hormone support are also part of care. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

Prader-Willi syndrome is often not inherited; it occurs by chance. In most families, the chance of it happening again is less than 1%. With rare causes the risk can be higher; that is why finding the cause and genetic counselling are important.

Source: MedlinePlus Genetics – Prader-Willi syndrome · NHS – Prader-Willi syndrome · GeneReviews – Prader-Willi Syndrome

Key facts

How common is it?
Prevalence: 1-9 per 100 000 (Worldwide) · Birth prevalence: 1-9 per 100 000 (Worldwide)
When does it usually start?
Before birth, Newborn period

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.

We could not find a patient association specific to this disease.

For all rare diseases: Nadir Hastalıklar Federasyonu

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 Prader-Willi

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 18 active interventional studies for this disease. 9 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:739 · ICD-11 LD90.3

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.