What is Williams Syndrome?

Williams Syndrome is a very rare developmental disorder caused by missing genes in an individual. Genes are tiny segments of DNA that control how cells function, such as telling them when to divide and grow. Each of us is born with two copies of about 100,000 different genes contained in each cell.

Williams Syndrome occurs in about one per 7,500 to 20,000 births. It is also known as Beuren Syndrome, Williams-Beuren Syndrome, WBS, WMS, and sometimes Early Hypercalcemia Syndrome with Elfin Facies.

It is usually diagnosed before age 4.

Who gets Williams Syndrome?

The cause of Williams Syndrome is not known. Most babies diagnosed with Williams Syndrome will have no known family connection. However, if a person with Williams Syndrome goes on to have children, his or her child has about a 50 percent chance of having the syndrome.

What are the causes of Williams Syndrome?

Williams Syndrome is caused by a missing series of genes on chromosome 7 in a person. (Chromosomes are long, thread-like molecules made of DNA and other proteins. Each chromosome is numbered [in humans, 1-46].) This area includes about 25 genes. It is still unclear which of the missing genes causes specific problems in Williams. Eight of the genes have known disease association. Researchers are still working on the association with the rest of the genes

What are the symptoms of Williams Syndrome?

Williams Syndrome causes a range of issues and symptoms for an individual. These are usually noticed by a parent or a doctor before a child turns four, though sometimes a child is not diagnosed until he or she has started school.

Symptoms are both physical and developmental. Not every child with Williams will have every symptom or problem. The more common symptoms include:

  • Elfin-like facial features, including an upturned nose and prominent lips
  • Mild-to-moderate intellectual disability
  • An abnormally small head
  • Sunken chest
  • Vertical skin folds, called epicanthal folds, that cover the inner corners of the eyes
  • Missing or small, widely spaced teeth
  • Speech delays
  • Trouble gaining weight as a baby
  • A height lower than expected
  • Scoliosis (curved spine)
  • Attention deficit disorder (ADD)
  • Developmental delays/not meeting developmental milestones
  • Very friendly, outgoing, trusting personality
  • Farsightedness
  • An unusual star-like pattern in the iris, called "stellate" (more prominent in those with blue or green eyes)

The most serious symptoms of Williams Syndrome include heart defects present at birth, including narrowed heart valves and blood vessels, and increased blood calcium levels in babies . These defects can include avalvular aortic stenosis, pulmonary stenosis, and pulmonary artery stenosis. Cardiac issues such as those listed are often the first sign that a child may have Williams Syndrome.

Many of the symptoms of Williams Syndrome occur in other diseases that are not Williams syndrome, and range from mild to serious. If you or someone else who is frequently around your child is concerned about these symptoms in your child, you should seek medical advice from your healthcare provider or pediatrician.

How is Williams Syndrome diagnosed?

A pediatrician will began an examination for Williams Syndrome by doing an external examination to look for physical characteristics of the disease. He or she may also order an EKG and ultrasound to check your child's heart for irregularities. He or she may check your child's blood pressure and kidneys for abnormalities. If the findings are concerning for Williams Syndrome, the pediatrician will refer you to a geneticist who can best help come up with a diagnosis and treatment plan for your child. The geneticist will perform a blood test to look for the missing genes that diagnose Williams Syndrome.

How is Williams Syndrome treated?

If it is found that your child has Williams Syndrome based on an examination and genetic test, the genetics team and your primary doctor will counsel you on what that means for the child and the family. While there is no cure for Williams Syndrome it is important to find and treat the different medical problems and symptoms that can occur with this disorder.

Certain steps can be taken to lessen symptoms. These include

  • Avoid taking extra calcium and Vitamin D to prevent higher blood calcium levels.
  • If heart problems are found, a heart doctor may be needed depending on what problems are found.
  • Special education programs and developmental and speech therapy can help deal with developmental delays.
  • Other treatments will be planned for your child on an individual basis, based on his or her symptoms.

What is the prognosis for Williams Syndrome?

Williams Syndrome cannot be cured, but many symptoms can be managed. It is important to seek a medical evaluation if you think your child may have Williams Syndrome. Early treatment and intervention can help with some developmental delays, and heart problems should be treated as soon as possible.

Many individuals with Williams Syndrome will not live to normal life expectancy due to complications of the disease.

Williams Syndrome is a very rare condition. It can help to discuss issues with experts and other families who are dealing with it. Resources for those with Williams Syndrome include the National Organization for Rare Disorders (www.raredisease.org).


  • National Institute of Neurological Disorders and Stroke. Williams Syndrome.. Accessed February 20, 2013.
  • National Organization for Rare Disorders. Williams Syndrome. www.rarediseases.org. Accessed February 20, 2013.
  • Ropper AH, Samuels MA. Chapter 38. Developmental Diseases of the Nervous System. In: Ropper AH, Samuels MA, eds. Adams and Victor's Principles of Neurology. 9th ed. New York: McGraw-Hill; 2009. www.accessmedicine.com. Accessed February 20, 2013.

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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 2/25/2013…#15174