AIM:To describe the clinical characteristics with genetic lesions in a Chinese family with Crouzon syndrome. METHODS: All five patients from this family were included and received comprehensive ophthalmic and systemic examinations.Direct sequencing of the FGFR2 gene was employed for mutation identification.Crystal structure analysis was applied to analyze the structural changes associated with the substitution. RESULTS: All patients presented typical Crouzon features,including short stature,craniosynostosis,mandibular prognathism,shallow orbits with proptosis,and exotropia.Intrafamilial phenotypic diversities were observed.Atrophic optic nerves were exclusively detected in the proband and her son.Cranial magnetic resonance imaging implied a cystic lesion in her sellar and third ventricular regions.A missense mutation,FGFR2 p.Cys342 Trp,was found as disease causative.This substitution would generate conformational changes in the extracellular Ig-III domain of the FGFR-2 protein,thus altering its physical and biological properties.CONCLUSION: We describe the clinical presentations and genotypic lesions in a Chinese family with Crouzon syndrome.The intrafamilial phenotypic varieties in this family suggest that other genetic modifiers may also play a role in the pathogenesis of Crouzon syndrome. METHODS: All five patients from this family were included and received comprehensive ophthalmic and systemic examinations. Direct sequencing of the FGFR2 gene was employed for mutation identification. Crystal structure analysis was applied to analyze the structural changes associated with the substitution. RESULTS: All patients presented with typical Crouzon features, including short stature, craniosynostosis, mandibular prognathism, shallow orbits with proptosis, and exotropia. Intrafamilial phenotypic diversities were observed. Atrophic optic nerves were exclusively detected in the proband and her son. Magnetic magnetic resonance imaging implied a cystic lesion in her sellar and third ventricular regions. A missense mutation, FGFR2 p. Cys342 Trp, was found as disease causative. This substitution would generate conformational changes in the extracellular Ig -III domain of the FGFR-2 protein, thus alt ering its physical and biological properties. CONCLUSION: We describe the clinical presentations and genotypic lesions in a Chinese family with Crouzon syndrome. The intrafamilial phenotypic varieties in this family suggest that other genetic modifiers may also play a role in the pathogenesis of Crouzon syndrome.