Williams Syndrome: Definition, Symptoms & Causes

Instructor: Artem Cheprasov

Artem has a doctor of veterinary medicine degree.

Learn about a genetic disorder called Williams syndrome. Find out which genes are effected, the traits they bring about, and the symptoms that can be common in this disorder.

What Is Williams Syndrome?

Despite an unfortunate genetic condition, there are people in this world who are considered to be the friendliest people in the world. Williams syndrome is a rare genetic disorder characterized by various physical and mental abnormalities including friendly personality, facial abnormalities, and heart problems.

Williams syndrome was independently described by German physician A.J. Beuren and New Zealand cardiologist John Williams in the 1960s. So if you see the term Williams-Beuren syndrome somewhere else just know that this term was eventually shortened to Williams syndrome and the two terms are synonymous.


This genetic syndrome stems from missing copies of at least 25 genes in chromosome number 7. And one of these genes codes for a very important protein called elastin.

Elastin, as the name kind of suggests, is elastic. In other words, it gives the connective tissues of your body the ability to spring back into shape after being deformed. For example, pinch your skin and stretch it away from your body a bit. Now let go. See how the skin bounced back into its original shape like a rubber band? That happens thanks to elastin.

Elastin is found in many other important structures besides the skin, including the blood vessels, heart, tendons, and ligaments.

Signs & Symptoms

Thus, without that ability to snap back into shape, those with Williams syndrome tend to have cardiovascular problems, flexible joints, stretchy skin narrowing of blood vessels, and even facial abnormalities.

A 21 and 28 year old with Williams syndrome. Note the stretchy appearance of the facial features.
williams syndrome

As a result of all the other missing genes, a person with Williams syndrome may have numerous other problems. They may have microcephaly, an abnormally small sized head, known for being a symptom of babies born to mothers with the Zika virus. 'Micro-' means small and '-cephalo-' means head. This occurs in about 33% of children with Williams syndrome. They may also have small teeth or missing teeth among other problems.

Almost all people with Williams syndrome have abnormal facial features, collectively called facial dysmorphology. Possible facial features include: wide mouth and full lips, widely spaced teeth, a flat nasal bridge, a short and upturned nose, and a long philtrum. The philtrum is the vertical groove between your lips and nose.

Cardiovascular problems like high blood pressure or supravalvular aortic stenosis may be an issue, the latter of which is the narrowing of the blood vessel that carries blood from the heart and to the rest of the body.

An noticeable symptom of Williams syndrome is having a very friendly, outgoing and non-judgmental personality. However, they may suffer from mental or psychological problems, such as mild to moderate intellectual disability or ADHD, attention deficit/hyperactivity disorder.

Other problems include:

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