Male patient with a deformed head due to craniosynostosis. This congenital (present at birth) condition occurs when the joints of the skull (cranial sutures) fuse before the brain is fully formed. Often the cause is unknown, but it can be related to a genetic disorder. Surgery is needed to allow the brain to grow and correct the shape of the head. Without early diagnosis or treatment craniosynostosis can lead to developmental delays, cognitive impairment, impaired vision and headaches.