COL3A1

The COL3A1 gene provides instructions for making a component of collagen. Collagens form a family of proteins that strengthen and support many tissues in the body. Type III collagen is found in tissues such as the skin, lungs, intestinal walls, and the walls of blood vessels. The COL3A1 gene produces the components of type III collagen, called pro-alpha1(III) chains. Three copies of this chain combine to make a molecule of type III procollagen. These triple-stranded, rope-like procollagen molecules must be processed by enzymes outside the cell to remove extra protein segments from their ends. Once these molecules are processed, the collagen molecules arrange themselves into long, thin fibrils. Within these fibrils, the individual collagen molecules are cross-linked to one another. These cross-links result in the formation of very strong mature type III collagen fibrils, which are found in the spaces around cells.

Ehlers-Danlos syndrome - caused by mutations in the COL3A1 gene

More than 320 mutations that cause the vascular type of Ehlers-Danlos syndrome have been identified in the COL3A1 gene. 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. Researchers believe that these changes affect tissues that 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.