Muenke syndrome occurs in about one in 30,000 births. Muenke syndrome is genetic. It is caused from a pro250Arg mutation in FGFR-3 on chromosome 4p. This is inherited in an autosomal dominant fashion. Muenke syndrome usually causes coronal suture craniosynostosis. It is believed to be the cause of about 10% of all cases of coronal suture craniosynostosis. It is the most newly discovered common syndromic craniosynostosis.
About 40 percent of boys with this syndrome have craniosynostosis involving both coronal sutures, and about 40% have it involving only one coronal suture. About 60% of girls with the syndrome have both coronal sutures closed, while 20% have only one coronal suture involved.
Children with Muenke syndrome have very few additional physical findings which makes it difficult to make this diagnosis from physical exam alone. These children rarely have flatness in the middle of the face or an underdeveloped upper jaw. Subtle changes in the bone of the hand are described as small “thimble-like” bones in the middle segment of their fingers. About 33% of patients with Muenke syndrome patients have learning delays. All patients have a characteristic pattern of hearing loss.
It is important to diagnose these patients because their skulls may not grow well, even after cranial vault remodeling surgery. They are five times more likely to need another operation to relieve increased pressure inside the skull, than patients with coronal suture craniosynostosis who do not have Muenke syndrome. It is important for these patients to be followed by the craniofacial team until they are fully grown to monitor for growth problems or signs of elevated pressure in the skull.