We have over 20,000 different genes in the body. These genes are like instruction manuals for how to build a protein, and each protein has an important function that helps to keep our body working how it should. The COL3A1 gene makes a protein called type 3 collagen. Type 3 collagen works to strengthen and support many of the tissues in our bodies (primarily in the skin, lungs, intestines, and walls of our blood vessels).
If someone has a harmful change (called a pathogenic variant) in one of their COL3A1 genes, then their body does not make as much type 3 collagen as it should. Without enough type 3 collagen, these tissues in our bodies are not as strong and stable as they should be. This can lead different health conditions, such as the vascular form of Ehlers-Danlos syndrome, or familial thoracic aortic aneurysm and dissection.
Pathogenic variants in the COL3A1 gene are passed through a family in an autosomal dominant pattern, meaning that anyone who carries the variant has a 50% chance to pass it down to any children they have. Women and men both have the COL3A1 gene and have the same chances to inherit and pass down pathogenic variants.
Genetic testing for pathogenic variants in COL3A1 is currently available, but there are a few different ways to approach testing: