Crouzon Syndrome (Congenital Craniofacial Dysostosis): from the Clinical Case to the Review of Craniosynostosis

Crouzon disease or Crouzon syndrome (CS) is a rare congenital anomaly that is caused by intrauterine premature closure of the coronal, sagittal and lambdoid sutures causing abnormal growth of the skull. It is considered an ultra-rare (ultra-orphan) disease, with an incidence of 1/50,000-60,000 neonates. We present the case of a 78-year-old woman with CS who presented congenital craniosynostosis with turricephaly, hypertelorism, external strabismus with bilateral exophthalmos and blindness (due to atrophy of the optic nerve of the right eye), maxillary hypoplasia, hearing loss, narrow palate, mandibular prognathism, malocclusion with crossbite, anosmia, parrot-beak nose, thin upper lip and facial asymmetry. It is a genetic disease with autosomal dominant inheritance, complete penetrance and variable expressivity. It is caused by mutations in the FGFR2 gene (chromosomal locus 10q25-10q26). From 30 to 60% of the cases are sporadic because they are new mutations (de novo mutations). The prenatal diagnosis of this entity is difficult, since the early welding of the sutures generally begins after birth. The diagnosis is fundamentally clinical, which must be complemented with imaging studies. Appropriate genetic counseling is necessary. In the future, with advances in clinical genetics, most craniosynostoses could be avoided if we incorporate the genetic study of the different genes involved (already known) to carrier screening. For this, it is necessary to promote assisted reproduction techniques (preimplantation genetic diagnosis). The cases that correspond to de novo mutations cannot be avoided through these strategies. Regarding treatment, an early diagnosis is required to plan a highly specialized surgery that allows the remodeling of the skull and face so as to achieve good aesthetic and functional results, and avoid some of the auditory and visual complications. In this article we review the embryology of the skull, craniosynostosis, and more specifically of CS.