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What Is Williams Syndrome?

Williams syndrome is a disorder that causes developmental delays, learning problems (like trouble with space and numbers), and heart and blood vessel problems. But kids who have it usually have good verbal skills, are friendly and social, and may enjoy music-related activities.

What Are the Signs & Symptoms of Williams Syndrome?

Williams causes distinctive facial features, such as:

  • a broad forehead (wider at the hairline than just above the eyes)
  • a short, upturned nose
  • abnormal pattern of the iris (the eye)
  • a wide mouth
  • a small chin

Kids might also have:

  • small, widely spaced teeth, crooked or missing teeth
  • low muscle tone and flexible joints
  • a hoarse or low voice

By age 2, most children show signs of developmental delays (doing things such as walking or talking much later than average). Socially, they might tend to keep eye-to-eye contact longer than most people find comfortable and have little, if any, fear of strangers.

What Causes Williams Syndrome?

Children who have Williams syndrome are born with it. The condition happens because genes in a small piece of 7 are missing (deleted). Some deletions are longer than others. Children with longer deletions tend to have more severe symptoms than those with shorter ones.

This happens by chance. Nothing that parents did or didn’t do caused the condition.

What Problems Can Happen With Williams Syndrome?

The missing genes in Williams syndrome can affect the making of a protein called elastin. Elastin helps make arteries (blood vessels that carry blood from the heart to the body) and skin strong, stretchy, and flexible.

Without elastin, arteries may be weak and narrow, especially those that carry blood to the heart, kidneys, and intestines.

It can also cause supravalvular aortic stenosis (SVAS). This is a narrowing of the aorta, the main artery carrying blood from the heart to the body. It can cause shortness of breath, chest pain, and heart failure.

Less often, children with Williams syndrome might have an blocked tear duct, strabismus, high blood pressure, hypercalcemia (too much calcium in the blood), and frequent ear infections.

How Is Williams Syndrome Diagnosed?

How a newborn looks might lead the doctor to check for Williams syndrome. But some babies don’t have the unusual facial features, so doctors might not suspect a problem.

In most cases, doctors first consider Williams syndrome if a child has a developmental delay, teeth problems, or other symptoms around age 2. They’ll do an exam and ask for an evaluation by a genetics specialist along with genetic testing.

How Is Williams Syndrome Treated?

Williams syndrome can affect almost every part of the body. To get the best possible treatment, kids need regular care from a team of pediatric specialists that includes:

  • ophthalmology (eyes)
  • audiology (hearing)
  • otolaryngology (ENT; ear, nose, throat)
  • genetics
  • cardiology (heart)
  • gastroenterology (swallowing, digestion, and bowel function)
  • endocrinology (hormone and mineral balance)
  • nephrology (kidneys)
  • behavioral and developmental psychology

Some kids also need care from specialists in:

If possible, kids should get care at a special clinic dedicated to children with Williams syndrome.

What Else Should I Know?

Kids with Williams syndrome usually have trouble with:

  • numbers, so math is often a problem
  • spatial concepts, so they might often get lost, have trouble drawing, or not be able to do a simple jigsaw puzzle
  • language skills development, though most eventually achieve average skills 

As part of what experts sometimes call the “Williams personality,” kids often:

  • enjoy interacting and talking, but can have trouble making friends
  • are socially uninhibited (which can be awkward for others)
  • enjoy and respond emotionally to music 

Some people with Williams syndrome can hold simple jobs, but will need help with their day-to-day lives, even in adulthood.

Obesity and diabetes are common problems, so nutritional planning is important.

Anesthesia can be risky, so if a child needs surgery, it’s best to have it done in a hospital that has experience in treating kids with Williams syndrome.

How Can Parents Help?

There’s no cure for Williams syndrome, but treatments and therapies can help with many of the problems it causes. Getting help early is the best way to help your child reach their full potential. Work with the care team, and take your child to see medical specialists, speech therapists, physical and occupational therapists, and education specialists as recommended.

It can help to connect with other families of kids with Williams syndrome. Ask your care team about local groups. You also can find more information and support online at:

Medically reviewed by: Gul H. Dadlani, MD
Date reviewed: August 2023