Williams Syndrome (WS) and Supravalvar Aortic Stenosis (SVAS) DNA and Tissue Bank

Study Summary

Williams syndrome is a rare genetic disorder occurring in 1:8000-12,000 individuals. It is caused by the deletion of 25-27 coding genes, including elastin (ELN) on the 7th human chromosome. Haploinsufficiency for these genes leads to the features of the condition, including: * Distinctive facial features; * Characteristic vascular problems including hypertension, focal vascular stenosis, (when present in the aorta this is referred to as SVAS), vascular stiffness and differences in heart rate variability; * Endocrine abnormalities including hypercalcemia, hypothyroidism, and early puberty; * Metabolic concerns with colic and failure to gain weight in infancy and obesity and early glucose intolerance in adulthood; * Characteristic neurocognitive profile comprised of cognitive impairment, high sociality with concurrent social awkwardness, difficulty with visual-spatial tasks, relative strengths in speech, and lack of social fear; * Anxiety and chronic pain in adulthood Most individuals with WS carry the same basic deletion on Chromosome 7q11.23. However, each feature may present as mild or more severe in any given individual. Variation in the presence and severity of these vascular phenotypes remains unexplained. The supravalvar aortic stenosis (SVAS) phenotype is caused by haploinsufficiency for elastin. This can come about due to the WS deletion (as above) or due to heterozygous variation in elastin (ELN) gene itself in this region. When this protein is reduced, connective tissues lose its strength, flexibility, and overall support. When this happens in the aorta, it may cause vascular narrowing that presents as shortness of breath, chest pain, and even heart failure if left untreated. Narrowing also occurs in other vessels especially the pulmonary and renal arteries. Changes in non-vascular elastic tissues such as the skin and lungs also occur. As in WBS, phenotypic variation also occurs in people with ELN gene changes--This variability remains unexplained despit

Conditions Studied

Study Locations (3)