Williams syndrome

What is Williams syndrome?

Williams syndrome is a developmental disorder caused by a microdeletion on the long arm of chromosome 7. This deletion encompasses ~25 genes, including Elastin and LIM-kinase1. Many individuals with Williams syndrome have congenital heart defects such as supravalvar aortic stenosis (SVAS), hernias, and/or other connective tissue disorders. These problems result from the hemizygous deletion of the Elastin gene. Young children with Williams syndrome almost always show developmental delay. About 75% of older children and adults have intellectual disability.

Williams syndrome is characterized by a distinctive pattern of cognitive strengths and weaknesses. The verbal short-term memory ability of individuals with Williams syndrome is typically above the level expected for their level of general cognitive ability. Language abilities are at or slightly above the level expected for general cognitive ability. Visuospatial constructive abilities (e.g., writing, drawing, pattern construction) are well below the level expected for general cognitive ability. The hemizygous deletion of the LIM-kinase1 gene contributes to the extreme difficulty individuals with Williams syndrome have with visuospatial construction.

Williams syndrome also involves a distinctive personality profile. Individuals with Williams syndrome typically are overly friendly, sensitive to other people's feelings, have a strong desire to please others, and are very talkative. Many individuals with Williams syndrome indiscriminately approach strangers. This behavior, combined with a tendency to wander, creates a potentially dangerous situation unless close supervision is provided. Anticipatory anxiety is a problem for many individuals with Williams syndrome, as are unexpected changes in routines. Phobias, especially those involving certain loud or sudden noises, also are common. A large proportion of children and adolescents with Williams syndrome have attention deficit hyperactivity disorder (ADHD); some have inattention and others both inattention and hyperactivity (combined type). People with Williams syndrome typically are limited in their general reasoning abilities. Hence, they may not fully consider the implications of their actions. In many cases, the expressive language skills of individuals with Williams syndrome mask these reasoning difficulties; individuals with Williams syndrome may seem to understand more than they actually do.

This description does not adequately capture how delightful individuals with Williams syndrome can be. Many children with Williams syndrome can light up a room with their smiles and their positive approach to others.

Recent publication

We have recently published an article providing an overview of our research with children with Williams syndrome. This article includes suggestions for speech and language intervention. Click here to view this publication.

Our research focus/interests

Our research is focused on the language, cognitive, social, and personality development of children with Williams syndrome. We are particularly interested in the relations between language and cognitive development. and in early language and social-communicative development. We also study reading development in children and adolescents with Williams syndrome. Because our research is concerned with development, many of our studies involve our following the same children over many years. At the University of Louisville, we collaborate with Dr. Janet Woodruff-Borden on a study of anxiety in children with Williams syndrome and Dr. Cara Cashon on studies of infants and toddlers with Williams syndrome, with a focus on face processing and early language and conceptual development.

We have several collaborations with colleagues at other universities; some of these projects also involve faculty at the University of Louisville.

  • Dr. Colleen Morris (University of Nevada School of Medicine): Genotype/phenotype relations in Williams syndrome. This project includes medical aspects of Williams syndrome as well as cognitive and behavioral aspects.
  • Dr. Lucy Osborne (University of Toronto): Molecular genetics of Williams syndrome.
  • Dr. Karen Berman (National Institute of Mental Health): Neuroimaging studies of children and adults with Williams syndrome who have normal intelligence. This project focuses on identifying the brain bases for some of the most distinctive characteristics of individuals with Williams syndrome, including difficulties with visuospatial construction, overly friendly approach to strangers (social disinhibition), and non-social specific phobias.
  • Dr. Bonnie Klein-Tasman (University of Wisconsin-Milwaukee): Socio-communicative difficulties of children with Williams syndrome.
  • Dr. Jeffrey Marler (Ohio State University): Auditory memory and hearing ability of children with Williams syndrome. Dr. Fred Wightman and Dr. Doris Kistler (University of Louisville) also collaborate on these studies.


If you are interested in learning more about our work and/or in participating in our research, please email Dr. Mervis at cbmervis@louisville.edu (please put "Williams syndrome" on the subject line) or call us at (502) 852-4638.

Most of our current studies are focused on:

  • Infants between the ages: 6 - 16 months
  • Children between the ages: 5 1/2 - 7 years

As always, we particularly appreciate the continued participation of families who have been involved in our research for several years.

For more Information

If you are interested in finding out more about Williams syndrome, please visit the Williams Syndrome Association website.