Muenke Syndrome [Q75.0]
Dr. med. Imma Rost, Dipl.-Biol. Christina Sofeso
It was only in 1996 that, as a consequence of molecular genetic diagnostics, the autosomal dominant Muenke syndrome was defined as an independent craniosynostosis syndrome. The frequency is estimated to be 1 in 30,000. The coronary suture is usually affected, causing brachycephaly, midface hypoplasia, an outward-sloping eyelid axis and ptosis. Some carriers do not display any sings or symptoms of craniosynostosis, only those of macrocephaly. Some patients suffer from reduced hearing; approximately the same number has a developmental delay. Some have minor abnormalities of the hands, such as brachydactyly and clinodactyly. Some of these signs, for example cone-shaped epiphyses or abnormal middle phalanges, can only be detected during radiological examination.
The Muenke syndrome is caused only by the mutation FGFR3-P250R in the gene for the fibroblast growth factor receptor 3. Before this homogeneous etiology was known, patients had either been diagnosed with one of the other above-mentioned syndromes or with the unspecific craniosynostoses. This fact alone suggests a considerably variable expressivity.