Saethre-Chotzen Syndrome (SCS) [Q75.0]
Dr. med. Imma Rost, Dr. rer. nat. Christoph Marschall
The autosomal dominant Saethre-Chotzen syndrome belongs to the family of the craniosynostoses. Usually, the coronal suture is affected; the consequence is brachycephaly or plagiocephaly in the case of unilateral fusion. A low frontal hairline, ptosis, hypertelorism and midfacial hypoplasia as well as small, posteriorly rotated ears are frequently seen. The extremities occasionally show brachydactyly and partial snydactyly, especially between the 2nd and the 3rd finger, as well as broadening of the big toe, sometimes with fissures of the distal phalanx. Mental development is normal in most cases. However, like in other craniosynostosis syndromes, there is a risk of raised intracranial pressure. There is a high degree of variation, even among carriers of the same mutation within one family. The signs and symptoms overlap with other craniosynostosis syndromes to a great extent, especially with the Muenke syndrome.
SCS is caused by mutations in the TWIST1 gene, which encodes a transcription factor that, among other things, plays an important role in the development of mesodermal structures. Numerous different mutations – including entire deletions – have been found in the TWIST1 gene.