Craniosynostosis

Craniosynostosis, premature fusion of the coronal, sagittal, metopic, and=or lambdoidal sutures, may be primary or secondary to a wide range of poorly characterized genetic, nutritional, toxicological, and mechanical influences. Craniosynostosis also can be found when intracranial contents are markedly reduced, such as when patients are overshunted and sutures subsequently override and fuse or in cases of severe cerebral atrophy. The condition may be “isolated,” involving a single suture, or “complex,” involving multiple sutures. Approximately 100 different forms have been described. The manifestations have been classified as “nonsyndromic” and “syndromic.” The latter have been linked to several chromosomes. Defects in fibroblast growth factor receptor (FGFR) genes have been identified by several groups. Apert, Pfeiffer, Jackson-Weiss, and Crouzon syndrome associate with mutations in FGFR genes. However, pathophysiology may be heterogenous because clinical features are not always associated with specific mutations (1).