VCAN

The VCAN gene provides instructions for making a protein called versican. Versican is found in the extracellular matrix of many different tissues and organs. The extracellular matrix is the intricate lattice of proteins and other molecules that forms in the spaces between cells. Versican interacts with many of these proteins and molecules to facilitate the assembly of the extracellular matrix and ensure its stability.

Researchers have proposed several additional functions for versican. This protein likely helps regulate cell growth and division, the attachment of cells to one another (cell adhesion), and cell movement (migration). Studies suggest that versican plays a role in forming new blood vessels (angiogenesis), wound healing, inflammation, and preventing the growth of cancerous tumors. Versican also regulates the activity of several growth factors, which control a diverse range of processes important for cell growth.

Four different versions (isoforms) of the versican protein are produced from the VCAN gene. These isoforms (called V0, V1, V2, and V3) vary by size and by their location within the body.

Wagner syndrome - caused by mutations in the VCAN gene

At least six mutations in the VCAN gene have been found to cause Wagner syndrome. Some of these mutations can also cause a similar condition called erosive vitreoretinopathy, which is often considered a variant of Wagner syndrome. All of the identified VCAN gene mutations disrupt the way the gene's instructions are used to make versican. These mutations may decrease the production of versican isoforms V0 and V1 and increase the production of isoforms V2 and V3. Researchers believe that this imbalance of the versican isoforms is responsible for the vision problems experienced by people with Wagner syndrome. It is unknown why VCAN gene mutations seem solely to affect vision.