Crouzon syndrome

Crouzon syndrome, also known as craniofacial dysostosis type I or Crouzon craniofacial dysostosis, is a genetic disorder characterized by the premature fusion of certain skull bones (craniosynostosis). This early fusion prevents the skull from growing normally and affects the shape of the head and face. It is one of the most common craniosynostosis syndromes and is caused by mutations in the FGFR2 (fibroblast growth factor receptor 2) gene on chromosome 10. Approximately 30–60% of cases arise from de novo (new) mutations, with the remainder inherited from an affected parent. The hallmark features of Crouzon syndrome involve the craniofacial skeleton. Premature fusion of the coronal and sometimes other cranial sutures leads to brachycephaly (short, broad skull) or other abnormal head shapes. Midface hypoplasia (underdevelopment of the middle portion of the face) results in shallow orbits with proptosis (bulging eyes), a beaked nose, and relative mandibular prognathism (prominent lower jaw). Patients frequently experience dental malocclusion and a high-arched or cleft palate. Ocular complications include exposure keratitis due to proptosis, strabismus, and occasionally optic nerve compression leading to vision loss. Conductive hearing loss occurs in a significant proportion of patients due to middle ear anomalies or external auditory canal atresia. Elevated intracranial pressure is a serious concern and can develop due to restricted skull growth, potentially causing headaches, papilledema, and cognitive impairment if untreated. Importantly, intelligence is typically normal in Crouzon syndrome, though developmental delays can occur if raised intracranial pressure is not managed. Treatment of Crouzon syndrome is primarily surgical and requires a multidisciplinary approach involving craniofacial surgeons, neurosurgeons, ophthalmologists, otolaryngologists, orthodontists, and speech therapists. Early cranial vault remodeling surgery may be necessary to relieve intracranial pressure and reshape the skull. Midface advancement procedures, such as Le Fort III osteotomy or distraction osteogenesis, are often performed during childhood or adolescence to correct midface hypoplasia, improve airway patency, and protect the eyes. Obstructive sleep apnea is common and may require intervention including adenotonsillectomy, CPAP, or tracheostomy in severe cases. Hearing aids or surgical correction may be needed for hearing loss. Long-term follow-up is essential, as multiple staged surgeries are typically required throughout growth and development.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Crouzon syndrome