What are the genetic changes related to Winchester syndrome ?
Winchester syndrome is caused by mutations in the MMP14 gene (also known as MT1-MMP). This gene provides instructions for making a protein called matrix metallopeptidase 14, which is found on the surface of cells. Matrix metallopeptidase 14 normally helps modify and break down various components of the extracellular matrix, which is the intricate lattice of proteins and other molecules that forms in the spaces between cells. These changes influence many cell activities and functions, including promoting cell growth and stimulating cell movement (migration). Matrix metallopeptidase 14 also turns on (activates) a protein called matrix metallopeptidase 2. The activity of matrix metallopeptidase 2 appears to be important for a variety of body functions, including bone remodeling, which is a normal process in which old bone is broken down and new bone is created to replace it.  Mutations in the MMP14 gene alter matrix metallopeptidase 14 so that less of the enzyme is able to reach the cell surface. As a result, not enough of the enzyme is available to break down components of the extracellular matrix and activate matrix metallopeptidase 2. It is unclear how a shortage of this enzyme leads to the signs and symptoms of Winchester syndrome. It is possible that a loss of matrix metallopeptidase 2 activation somehow disrupts the balance of new bone creation and the breakdown of existing bone during bone remodeling, causing a progressive loss of bone tissue. How a reduced amount of matrix metallopeptidase 14 leads to the other features of Winchester syndrome is unknown.