Many people with Muenke syndrome have a premature fusion of skull bones along the coronal suture, the growth line which goes over the head from ear to ear. Other parts of the skull may be affected as well. These changes can result in an abnormally shaped head, wide-set eyes, and flattened cheekbones. About 5 percent of affected individuals have an enlarged head (macrocephaly). Some people with Muenke syndrome have mild abnormalities of the hands or feet.
Hearing loss is present in about one third of patients.
While most people with this condition have normal intellect, developmental delay and learning disabilities have been reported.
The signs and symptoms of Muenke syndrome vary among affected people, and some findings overlap with those seen in other craniosynostosis syndromes. Between 6 percent and 7 percent of people with the FGFR3 gene mutation do not have any of the characteristic features of the disorder.