Muenke syndrome is the most common craniosynostosis syndrome, occurring in approximately 1 in 30,000 births. It primarily affects the bones of the skull.
Cause of Muenke syndrome
Muenke syndrome is caused by a specific mutation in the FGFR3 gene, called the P250R mutation. In most cases, this mutation arises randomly or by chance. We do not yet fully understand what causes this mutation. However, it does not appear that the mutation occurs as a result of something either parent does or fails to do. Most parents who have a baby with Muenke syndrome likely have normal genes.
Children with Muenke syndrome can pass the condition on to their children, however. The mutation is passed in an autosomal dominant fashion, meaning that only one copy of the gene needs to be passed on for the new baby to have this syndrome. In practical terms, autosomal dominant inheritance means that there is a 50-50 chance of a parent with Muenke syndrome having a baby that also has this condition. Anyone with Muenke syndrome who wishes to have children should consider meeting with a geneticist in order to discuss the risks and make a thoughtful, informed decision.
Children with Muenke syndrome characteristically have fusion of one or both of the coronal sutures. The coronal sutures are specialized expansion joints in the skull which allow rapid growth of the front part of the skull in the first years of life. In 70% of cases, children with Muenke syndrome present with both coronal sutures fused. In the remainder of cases, only one of the sutures will generally be involved. Fusion of one or both of the coronal sutures leads to restricted skull growth and a very characteristic skull shape.
In addition to coronal craniosynostosis, a small number of children with this syndrome may also have sensorineural hearing loss.
Most often, the diagnosis of Muenke syndrome is suspected based on the abnormal skull shape and a diagnosis of coronal craniosynostosis. The suspected diagnosis is confirmed by a blood test to check for the P250R base substitution mutation in the FGFR3 gene. It is our current recommendation that all children with coronal craniosynostosis see a geneticist to evaluate for Muenke syndrome.
The treatment of Muenke syndrome is focused on correction of the abnormal skull shape and mirrors the treatment of non-syndromic coronal craniosynostosis. Although the timing of surgery can be highly individualized, surgical correction of the bicoronal craniosynostosis is most often done between 6 and 12 months of age. Surgery is usually performed through a scalp incision that lies concealed within the hair of the head. Your craniofacial surgeon will work in concert with a pediatric neurosurgeon in order to safely remove the bones of the skull. Then, the craniofacial surgeon reshapes and repositions those bones to give a more normal skull shape.