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Genetic syndromes and other conditions

Williams syndrome

A developmental disease caused by a small missing piece of chromosome 7. Narrowing of the heart's blood vessels and mild or moderate learning difficulties are common. These children are usually very warm and sociable.

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?

A small piece containing 25 to 27 genes is missing from chromosome 7. One of the missing genes makes elastin, a protein that gives the blood vessels their flexibility. Because of this, there can be narrowing in the heart and blood vessels. Development, learning and behavior are also affected.

Which symptoms can occur?

Symptoms differ from person to person.

  • Narrowing of the aorta where it leaves the heart and narrowing of other blood vessels (common)
  • Mild or moderate learning difficulties, delayed development
  • A very warm, friendly personality; an interest in music
  • Attention problems and anxiety
  • A distinctive facial appearance; small, widely spaced teeth
  • Feeding problems in infancy and high calcium in the blood
  • High blood pressure and extreme sensitivity to sound
  • Short stature

How is it diagnosed?

The diagnosis is made with a blood test that shows the missing piece of chromosome 7. The heart and blood vessels are examined with echocardiography. Calcium is measured in the blood and urine, and blood pressure and the kidneys are checked.

Treatment and care

There is no treatment specific to the disease. Care is planned according to the symptoms. Narrowing of the heart and blood vessels is followed up; treatment is chosen according to how severe the narrowing is. High calcium is treated; extra calcium and vitamin D are not taken. Physiotherapy, developmental therapy and speech therapy help. It is recommended that care is coordinated by a genetics specialist. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

It is usually not inherited. The missing piece happens by chance when the egg or sperm is formed. There are no other affected family members. However, a person with Williams syndrome has a 50% chance of passing it to each child. Genetic counselling guides the family.

Source: MedlinePlus Genetics: Williams syndrome · MedlinePlus: Williams syndrome

Key facts

How is it inherited?
Autosomal dominant
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.

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 Williams

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 5 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:904

No separate ICD-11 code; WHO classifies this disease under: LD44.70

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.