Craniosynostosis represents a defection of the skull caused by early fusion of 
one or more cranial sutures. The shape alteration of the cranial vault varies, 
depending on the fused sutures, so that compensatory growth occurs in dimensions 
not restricted by sutures. Craniosynostosis can be divided into two main groups: 
syndromic and nonsyndromic. Nonsyndromic craniosynostosis is typically an 
isolated finding that is classified according to the suture(s) involved. 
Syndromic craniosynostosis is associated with various dysmorphisms involving the 
face, skeleton, nervous system and is usually accompanied by developmental 
delay. In the last 15 years, research on craniosynostosis has progressed from 
the description of gross abnormalities to the understanding of the genetic basis 
of certain cranial deformities. Mutations in the genes encoding fibroblast 
growth factor receptors 1, 2 and 3 (FGFR-1, FGFR-2, FGFR-3), TWIST and MSX2 
(muscle segment homebox 2) have been identified in certain syndromic 
craniosynostosis. The molecular basis of many types of syndromic 
craniosynostosis is known and diagnostic testing strategies will often lead to a 
specific diagnosis. Although the clarification of a genetic lesion does not have 
a direct impact on the management of the patient in many cases, there is a 
significant benefit in providing accurate prenatal diagnosis. This review 
summarizes the available knowledge on cranisynostosis and presents a graduated 
strategy for the genetic diagnosis of these craniofacial defects.