The goal of this observational natural history study is to better characterize development, transition to adulthood, health and behavior of individuals diagnosed with Williams syndrome (WS) or carrying other variants of 7q11.23 chromosome and to build a DNA and tissue biobank with samples donated by affected individuals. The study has multiple arms focused on different aspects of WS. Participants with genetic diagnosis of WS or other variants of 7q11.23 and their family members are eligible to participate. Study participants may participate in one or multiple arms of the study:

1. Natural History Genotype-Phenotype Study to test the hypothesis that health, behavior, and developmental variability observed in WS is determined by genetic factors and to characterize those genetic changes. Participants of all ages are eligible to participate. Either a blood or saliva sample is required for participation.
2. Biobank: the research team is building a biobank enabling the development of new laboratory tools and models to study WS and test new treatment approaches. A blood sample is required for participation. Participants of all ages are eligible to participate.
3. Development arm of the study aims to delineate the development of language, cognition, personality, literacy and mathematics skills, and adaptive behavior from very early childhood through adulthood in individuals who have WS or Dup7. The purpose of this study also includes determining the predictors of specific aspects of development (e.g., word reading ability, language ability, spatial ability) for individuals with WS or Dup7. Affected individuals of all ages are eligible to participate.
4. Transition to Adulthood study aims to understand how young adults with WS make a successful transition out of high school into adulthood and to help them in this journey by providing a comprehensive psychosocial transition coupled with a medical transition plan. Individuals ages 14-25 years old are eligible to participate. Study requires three in person visits.
5. Health Outcomes, Resilience, Independence, and Executive functioning in Neurodevelopment (HORIZON) aims to characterize physical, mental health, cognitive, social, adaptive, aging, and quality of life outcomes for adults with WS, stress and resilience for caregivers, and the interplay between caregiver stress and resilience with outcomes for adults with WS.
6. Sleep and Activity Study aims to expand knowledge on sleep difficulties experienced by individuals with WS and to better understand the connection between sleep, activity (movement through the day), prescribed medications and other traits in WS.

Inclusion Criteria:

• clinical and/or molecular diagnosis of Williams syndrome (WS)
• biological parents or siblings of individuals diagnosed with WS
• molecular diagnosis of 7q11.23 duplication syndrome (Dup7)
• molecular diagnosis of another abnormality in the 7q11.23 region

Exclusion Criteria:

- No diagnosis of abnormalities in the 7q11.23 region, while not being a biological relative of affected individuals

Individuals with a clinical and/or molecular diagnosis of Williams Syndrome, 7q11.23 duplication syndrome, or another abnormality in the 7q11.23 region and their relatives

A limited and de-identified dataset may be available to other researchers

2027

Investigators studying Williams syndrome or Dup7 will be welcomed to apply for de-identified limited data set and/or biospecimen. Final decision on sharing will be made by the research committee at the Armellino Center of Excellence.