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Muenke syndrome is a condition characterized by premature closure of coronal suture of skull during development (coronal craniosynostosis), which affects the shape of the head and face. It may be uni- or bilateral. When bilateral, it is characterized by a skull with a small antero-posterior diameter (brachycephaly), often with a decrease in the depth of the orbits and hypoplasia of the maxillae. Unilateral closure of the coronal sutures leads to flattening of the orbit on the involved side (plagiocephaly). The intellect is normal. The extremities are affected in a variable manner: carpal-tarsal fusion is diagnostic when present but is not always present; brachydactyly, carpal bone malsegregation, or coned epiphyses may occur. Phenotypic overlap occurs with Pfeiffer, Jackson-Weiss and Saethre-Chotzen syndromes. The premature closure of coronal suture of skull occur in about 1 in 15,000 births. The diagnosis of Muenke syndrome is based on identification of a disease-causing mutation in the FGFR3 gene. In most cases there are no radiologic findings of hands and feet, which implies that all patients with coronal synostosis should be tested for the specific P250R mutation of the FGFR3 gene, inherited as an autosomal dominant condition and localized in 4p16.3. The P250R mutation seems present in about 75% of familial cases, vs in 17% of sporadic cases. The P250R mutation is more often retrieved in bilateral cases, it is associated with a more severe phenotype in females than in males. Treatment for craniosynostosis generally consists of surgery to relieve pressure on the brain and the cranial nerves. For some children with less severe problems, cranial molds can reshape the skull to accommodate brain growth and improve the appearance of the head. |