More than 320 mutations in the COL3A1 gene cause the ‘Vascular Type’ of Ehlers-Danlos Syndrome (EDS). Only a few of these mutations have been seen in more than one family. The mutations alter the structure and production of type III procollagen molecules. As a result, a large percentage of type III collagen molecules are assembled incorrectly or the amount of type III collagen is greatly reduced.
As per research, these changes affect tissues which are normally rich in this type of collagen such as the skin, blood vessels, and internal organs. Lack of sufficient type III collagen causes the signs and symptoms of ‘Vascular Ehlers-Danlos Syndrome’.