Williams syndrome - associated with the ELN gene
The ELN gene is located in a region of chromosome 7 that is deleted in people with Williams syndrome. As a result of this deletion, people with Williams syndrome are missing one copy of the ELN gene in each cell. This loss reduces the production of elastin by half, which disrupts the normal structure of elastic fibers in many connective tissues. Large blood vessels with abnormal elastic fibers are often thicker and less resilient than normal. These vessels can narrow, increasing the resistance to normal blood flow and leading to serious medical problems.
In people with Williams syndrome, a loss of the ELN gene is associated with connective tissue abnormalities, such a joint problems and loose skin, and cardiovascular disease, particularly SVAS.