Crouzon syndrome: phenotypic signs and symptoms of the postnatally expressed subtype

In a retrospective study, the characteristics of a group of patients (n = 9) with a postnatally expressed Crouzon syndrome were described. Although they do not always display the physical signs of craniosynostosis, such patients are highly at risk of developing symptoms secondary to multiple suture synostosis. By reviewing the hospital files, radiographs, and three-dimensional computed tomography scans of these patients, it was possible to describe the pattern of suture obliteration chronologically. Furthermore, certain phenotypic signs and symptoms such as skull shape and development of digital impressions, a bulge at the bregma, and intracranial hypertension were inventoried as well as patients' genotypes. Interestingly, ossification started at the lambdoid sutures in at least four patients and most likely in three additional ones. The coronal sutures were the last to ossify in at least three of the patients. Various skull shapes were encountered. Furthermore, all nine patients developed digital impressions, starting occipitally in eight of them. Seven patients developed a bulge at the bregma, and four of them exhibited intracranial hypertension. The genotype varied in our patients. To recognize patients with postnatal Crouzon syndrome as soon as possible, special attention must be paid to 1) occipital development of digital impressions and/or ossification of sutures, 2) development of a prominent bregma, 3) development of intracranial hypertension, and/or 4) progressive characteristic "crouzonoid" features. Such patients can be considered as representing a subtype of Crouzon syndrome. To prevent or treat intracranial hypertension and/or loss of vision, surgical intervention should be performed at the onset of progressive craniosynostosis between 1 and 2 years of age.