Williams syndrome: The genetic condition marked by extreme friendliness and empathy

A genetic condition sometimes described as the ‘opposite of autism’ is drawing attention for its striking personality traits — and the significant health risks that often accompany it.

Williams syndrome affects roughly one in every 7,500 people. Those with the condition are known for greeting strangers ‘like that person is a lifelong friend’, displaying unusual warmth, trust and empathy.

But beneath the engaging personality lies a complex medical reality.

A genetic deletion with lasting effects

Professor Jayneel Joshi, a paediatric and interventional cardiologist and chairperson of the Pediatric Cardiac Society of South Africa, said the condition has been recognised for about 45 years.

“It actually results from a spontaneously occurring deletion of some of the genes on one of the chromosomes,” she explained.

That deletion gives rise not only to the distinctive behavioural profile — children who are ‘very talkative and engaging and excessively empathetic’ — but also to characteristic facial features, as well as cardiac and neurological abnormalities.

Heart defects often lead to diagnosis

Joshi said many children are first diagnosed in a cardiology setting.

“In my practice as a paediatric cardiologist, we get to make the primary diagnosis on a lot of these patients because they present with a cardiac problem,” she said.

The most common issues involve narrowing or blockages of major blood vessels, including the aorta, which carries blood to the body, and the pulmonary arteries, which carry blood to the lungs.

Some cases require monitoring, while others may need intervention or even surgery.

“So certainly, there's a lot of other physical findings that go along with the personality issues,” she added.

Distinctive features and vulnerability

Beyond their outgoing personalities, children with Williams syndrome often have distinctive facial characteristics. Medical professionals look for features sometimes described as ‘elfin’, including a broad forehead, slightly larger ears and a small chin.

While their friendliness can be endearing, Joshi warned that it can also make them vulnerable.

“Children often have this stranger danger that kind of protects them from just walking away with anyone,” she said. “Unfortunately, children with Williams are excessively empathetic, and this really can make them a big target for someone who wants to take advantage of them.”

Many also experience developmental delays, cognitive challenges and anxiety. Despite being highly sociable, they often struggle to form long-term, meaningful relationships.

Life expectancy and adulthood

Life expectancy depends largely on the severity of associated health conditions, particularly heart defects.

“If the cardiac abnormalities were very mild, they would have a near-normal lifespan,” Joshi said. More severe abnormalities, however, can affect long-term prognosis.

She noted that most children have mild to moderate complications.

However, the condition can significantly affect long-term independence.

“Very complex careers would be extremely difficult for these patients,” she said, adding that many adults with Williams syndrome rely heavily on family support or structured environments.

While rare, Williams syndrome is not vanishingly so, and as awareness grows, experts say understanding both the warmth and the risks is key to protecting and supporting those who live with it.

For detailed information, listen to Joshi using the audio player below: