What are the Facial Features of Williams Syndrome?

Yes, Williams syndrome does cause distinctive facial features. Historically, older medical literature sometimes described these specific physical traits as having an “elfin” appearance ^[1]. However, modern patient advocates discourage this term, preferring to focus on the specific physical traits themselves. It is also important to remember that you or your child will still look a lot like other members of your family. The unique facial features are caused by the genetic deletion that defines the condition ^[2]. While these traits are subtle in infancy, they typically become more apparent as a person grows ^[3].

Key Facial Features

Individuals with Williams syndrome often share several distinctive physical traits:

• Broad forehead: The forehead may appear wider than average ^[3].
• Stellate iris: A unique, star-like (stellate) pattern often appears in the colored part of the eye (the iris). This is especially visible in individuals with lighter-colored eyes, such as blue or green ^[4].
• Periorbital fullness: There is often a subtle puffiness or fullness around the eyes ^[3].
• Full cheeks: Children, in particular, often have prominent, full cheeks ^[3].
• Short nose with a broad tip: The nose is typically shorter with a slightly wider or bulbous tip ^[3].
• Wide mouth with full lips: The mouth is often wide, accompanied by prominently full lips ^[5].
• Long philtrum: The vertical groove between the base of the nose and the top lip is often longer and smoother than average ^[3].

How Features Change Over Time

In infancy, the facial features of Williams syndrome can be very subtle ^[3]. Babies often have periorbital fullness and very full cheeks, giving them a delicate appearance. As a child transitions from infancy to older childhood, adolescence, and eventually adulthood, their face will naturally lengthen ^[3]. As this happens, the distinctive traits—such as the full lips, wider mouth, and broad forehead—tend to become more pronounced or noticeable ^[2][3].

Why Do These Features Occur?

Williams syndrome is caused by a missing piece of genetic material (a microdeletion) on chromosome 7 ^[6]. This missing region contains several genes responsible for how the body grows and develops.

One of the missing genes is the ELN gene, which provides instructions for making a protein called elastin ^[2]. Elastin gives tissues in the body their stretchiness and strength. The loss of elastin, along with the loss of other nearby genes like BAZ1B that help guide early bone and facial development, leads to the specific facial structure and connective tissue differences seen in the syndrome ^[2][7].

Importantly, this same lack of elastin is also responsible for the internal health risks associated with Williams syndrome, such as narrowed blood vessels and cardiovascular issues ^[2]. Because connective tissue affects the jaw and mouth, individuals may also develop specific dental differences, such as small or widely spaced teeth ^[5]. Early evaluation by a dentist or orthodontist familiar with connective tissue differences can help manage these oral health needs proactively ^[5][8].