One child in every two thousand born suffers from a condition in which the separate bones of the skull fuse together prematurely, so that the skull is unable to grow. This occurs because the normal growth mechanism in the sutures between the skull bones is genetically damaged. The aim of this project is to understand the normal growth mechanism in the skull, and to determine how it is altered in these genetic conditions, so that it may become possible to reactivate growth in the sutures when it has stopped prematurely.