Crouzon twins with cloverleaf skull malformations.

We describe unique monozygotic twins with Crouzon's disease and cloverleaf-shaped skull deformities who have been closely followed since birth. Their abnormal skull shapes were identified during antenatal ultrasound examination. The twins had gross exophthalmos and hydrocephalus with papilledema, so early calvarial decompression surgery was required. Although born to healthy parents of normal appearance, a third cousin of the twins had a milder form of Crouzon's disease, and there was a family history of high-arched palate on the twins' paternal side. Because Crouzon's disease is an uncommon condition and the cloverleaf skull shape is unusual in patients with Crouzon's disease, identical twins with this constellation of deformities must be exceptionally rare.