Our goal with the Williams syndrome (WS) and Supravalvular Aortic Stenosis (SVAS), deoxyribonucleic acid (DNA) and Tissue Bank is to collect enough samples from individuals with this rare condition to ask questions about the genes that cause the many WS and SVAS related phenotypes, and to determine the genetic and environmental changes that modify the severity of disease from person to person. In addition, we would like to learn more about the natural history of these conditions and if there are environmental or genetic signatures that are associated with symptom presence.