PhD defence J.M.G. (Joyce) Florisson

Craniosynostosis most commonly occurs sporadically as an isolated defect and commonly involves one suture. Syndromic craniosynostosis typically involves multiple sutures synostosis as part of a larger constellation of associated anomalies. This thesis focuses on several aspects of craniosynostosis syndromes.

In the group of craniosynostosis patients without a known genetic mutation all children are analyzed and different genetic mutations are found. With linkage analysis a family with an MSX2 mutation and the associated phenotype is describes. In two other patients we found a deletion which causes craniosynostosis and a microcephaly.

The causes of intracranial pressure such as venous hypertension are evaluated. We focused at the relation between the diameter of the jugular foramen and the presence of papilledema These findings confirm an abnormal venous system which may predispose to an elevated ICP.

Not only genetics and elevated intracranial pressure may contribute to the known developmental and psychological problems in craniosynostosis patients, but also intrinsic brain abnormalities may contribute. We investigated whether architectural alterations exist in the white matter of the brain. 

We investigated white matter alterations in syndromic craniosynostosis patients. With diffusion tensor inmaging studies in operated and unoperated craniosynostosis patients we found an abnormal white matter fiber organization. Because there is no effect of surgery and impact of intracranial hypertension is minimized in these young patients, our results strongly suggest an intrinsic factor, most likely as the genetic mutation itself as its cause.

Due to corona, the PhD defences do not take place publicly in the usual way in the Senate Hall of the Professor Andries Querido Room. The candidates will defend their dissertation either in a small group or online.