Last updated on June 2019

Impact of Elastin Mediated Vascular Stiffness on End Organs

Brief description of study


People with Williams Syndrome (WS) and supravalvular aortic stenosis (SVAS) have less elasticity in their blood vessels. This is called blood vessel stiffness. Blood vessels may have focal narrowings called stenoses or may just be globally more narrow.


Researchers want to see how blood vessel differences in people with Williams Syndrome and supravalvular aortic stenosis affect organs in the body including the heart, gut, kidneys, and brain.


People ages 3-85 who have WS or SVAS

Healthy volunteers ages 3-85

  • Participants will have yearly visits for up to 10 years. All participants will be offered the same tests.
  • Participants will give consent for the study team to review their medical records. If the participant is a child or an adult with WS, a parent or guardian will give the consent.
  • Participants will visit the NIH where they will have a physical exam and medical history. Based on their health history, participants will undergo a series of imaging tests and measures of blood vessel function over the course of 2-4 days. Tests of cognitive abilites will also be performed. Blood will be drawn and an IV may be placed for specific tests.

Detailed Study Description

Elasticity in the aorta buffers the body from damage due to pulsatile blood flow. Data from humans and mice show that with increasing age, vessels lose elasticity and become stiff. Vascular stiffness is associated with progressive cognitive impairment and dementia in aging adults, but little is known about the effects of early-onset/congenital vascular stiffness. Similarly, elastin-mediated arteriopathy in the form of stenosis has the potential to impact additional end organs such as the heart, lungs, gut, skeletal muscle and kidney causing feeding and exercise intolerance, as well hypertension. This study evaluates the impact of elastin arteriopathy and vascular stiffness on end organs.

Following consent, the investigators will work with the subjects and their caregivers to determine which tests are most appropriate for the patient based on their age/capabilities and preferences and may include:

  • testing of cognitive and neurobehavioral abilities as well as measures of general health and well being
  • undergo non-invasive measurements of vascular stiffness
  • undergo brain imaging by MRI
  • undergo echocardiogram
  • undergo ECG
  • undergo 24-hour ambulatory electrocardiogram monitor
  • undergo ultrasound imaging and flow studies of various vascular beds and tissues
  • undergo CT angiogram of relevant vessels
  • undergo non-invasive tissue oxygenation and endothelial functional assessment with near infrared spectroscopy (NIRS)
  • perform a 6 minute walk test
  • perform pulmonary function tests
  • receive an eye exam and Optical coherence tomography (OCT)
  • give blood/urine for relevant laboratories
  • evaluate biomechanical properties of skin
  • evaluate baseline fitness information using a fitness tracker
  • complete medica photography evaluating relevant features of the condition
  • receive a dental examination and dental photography

Additionally, the study will request permission to review the participant's medical records to obtain additional information about general and cardiovascular health. For individuals with supravalvular aortic stenosis (SVAS) or Williams syndrome (WS), the clinical report confirming the individuals diagnosis will be reviewed when available.

Clinical Study Identifier: NCT02840448

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Recruitment Status: Open

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