Normal craniofacial development is a precisely coordinated process involving the modelling of a framework supporting the tissues of the head, in particular the brain. Craniosynostosis, a common birth defect with an incidence of 1:2500, is characterised by the premature fusion of cranial sutures that disturbs this natural framework. This results in dramatic dysmorphology of the skull and face, sometimes accompanied by several additional functional abnormalities. Clinical and genetic studies have identified multiple forms of human craniosynostosis, and many are associated with mutations within FGF-related signalling pathways. Crouzon syndrome is a form of coronal craniosynostosis and midfacial hypoplasia without malformations in the extremities. Crouzon syndrome makes up to 4.5% of all craniosynostosis patients and mutations in the FGFR2 gene have been shown to be causative. Other syndromes associated with mutations in FGFR2 (Pfeiffer, Jackson-Weiss and Antley-Bixler) are considered to be part of the phenotypic spectrum of Crouzon-like syndromes. Research into this debilitating disease is carried out at the Institute of Child Health, in close collaboration with Great Ormond Street Hospital, as part of a wider research program into craniofacial birth defects. The main aims of this research are to: * Improve the molecular diagnosis of Crouzon-like syndromes. * Expand the fundamental knowledge on how impaired FGF signaling contributes to craniofacial birth defects. * Translate novel findings into relevant, clinical treatment strategies to enhance or replace current approaches for the treatment of craniosynostosis syndromes.