What are the genetic changes related to megalencephaly-capillary malformation syndrome ?
MCAP is caused by mutations in the PIK3CA gene, which provides instructions for making the p110 alpha (p110) protein. This protein is one piece (subunit) of an enzyme called phosphatidylinositol 3-kinase (PI3K), which plays a role in chemical signaling within cells. PI3K signaling is important for many cell activities, including cell growth and division (proliferation), movement (migration) of cells, and cell survival. These functions make PI3K important for the development of tissues throughout the body, including the brain and blood vessels.  PIK3CA gene mutations involved in MCAP alter the p110 protein. The altered subunit makes PI3K abnormally active, which allows cells to grow and divide continuously. Increased cell proliferation leads to the overgrowth of the brain, blood vessels, and other organs and tissues characteristic of MCAP.