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Crouzon disease is characterized by craniosynostosis and facial hypoplasia. The estimated prevalence in the general population of Europe is 1 in 50,000. The craniosynostosis is variable but many sutures are usually involved. The facial dysmorphology is characterised by hypertelorism, exophthalmos, hypoplastic maxilla and mandibular prognathism. The synostosis is evolutive and is usually either not visible or only slightly visible at birth. It usually manifests by the age of 2 years and becomes progressively more severe. However, precocious and congenital forms have been reported in which hypoplasia of the upper maxilla is pronounced and leads to respiratory difficulties, and the exophthalmia is severe resulting in palpebral occlusion. These forms may represent a separate clinical entity. Hydrocephaly and involvement of the cerebellar tonsils are also frequently observed in Crouzon disease and may pose therapeutic problems. The disease is transmitted in an autosomal dominant manner and mutations in the fibroblast growth factor receptor gene (FGFR2) have been identified in 60% of the patients tested. A distinct form of Crouzon disease associated with acanthosis nigricans (a skin disorder characterized by pigmentation anomalies) has been reported and is caused by a specific mutation (ala391 to glu) in the transmembrane domain of another protein from the same family, FGFR3 (crouzon syndrome - acanthosis nigricans; see this term). Two thirds of patients with Crouzon disease have intracranial hypertension, which may lead to blindness. Interventions should be considered at diagnosis to prevent ophthalmological or cerebral complications. The surgical approach adopted needs to take into account the cranio-facial synostosis and hypertelorism, and should be adapted to each patient.
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