Craniosynostosis: A rare complication of pycnodysostosis.

Uncommon features of rare genetic disorders are often poorly known, as the likelihood of having them reported is low. We describe a 7-year-old boy with clinical and radiological diagnosis of pycnodysostosis, and c.436G>C (p.G146R) mutation in CSTK). He developed intracranial hypertension that required surgical decompression. Despite patent fontanels, the cause of the intracranial hypertension was identified to be a combination of coronal and metopic craniosynostoses. Intracranial hypertension and craniosynostosis have only been reported once in pycnodysostosis, which is on the contrary characterized by delayed closure of the sutures and persistence of open fontanels. Our observation confirms that intracranial hypertension represents a rare but life-threatening complication of pycnodysostosis. We strongly suggest including systematic examination of fundus oculi and monitoring of OFC in the systematic clinical follow-up of these patients.