Inclusion Criteria:

• We will recruit individuals with people with WS, SVAS or other WS region variation conditions (cases) and demographically similar control (unaffected) participants.
• Children or adults with WS must:
• * be between the ages of 3 and 85
• * have a presumed or confirmed diagnosis of WS (genetic testing is not performed in this research study).
• * have a parent/guardian available to provide consent and assist in answering medical questions
• * not be pregnant
• Children or adults with SVAS must:
• * be between the ages of 3 and 85
• * have clinical features suggestive of SVAS or an SVAS-like condition OR have no clinical features of SVAS or an SVAS-like condition but have genetic testing results that imply affected status (SVAS has decreased penetrance). No genetic testing will be done as part of this protocol.
• * have a parent/guardian available to provide consent and assist in answering medical questions if they are a minor (not applicable to adults)
• Children or adults with WS region gene changes:
• * be between the ages of 3 and 85
• * have clinical or research genetic testing that reports gene variation in a non-ELN gene in the WS region.
• * have a parent/guardian available to provide consent and assist in answering medical questions if they are a minor or if they have cognitive impairment that would impede their ability to consent on their own behalf.
• Children or adults participating in the study as part of control group must:
• * be between the ages of 3 and 85
• * not have clinical features or genetic profile suggestive of WS, SVAS or an SVAS-like condition. No genetic testing will be performed in this research study.
• * have a parent/guardian available to provide consent and assist in answering medical questions if they are a minor (not applicable to adults)