Shprintzen-Goldberg craniosynostosis syndrome (SGS; MIM 182212) is an autosomal dominant disorder caused by mutations in the SKI gene. SGS displays considerable phenotypic overlap with Marfan syndrome (MFS; MIM 154700) and Loeys-Dietz syndrome (LDS; MIM 609192, 610168, 613795 & 614816) with the additional findings of intellectual disability, infantile muscular hypotonia, and craniosynostosis. The typical craniofacial features are: craniosynostosis, dolichocephaly, hypertelorism, down-slanting palpebral fissures, proptosis, malar hypoplasia, a high narrow palate, micrognathia and low set ears. The reported skeletal features are: arachnodactyly, pectus deformity, camptodactyly, joint hypermobilty / contractures and scoliosis. Cardiovascular findings may include: mitral valve prolapse and aortic root dilation. Other findings include: inguinal and umbilical hernia, minimal subcutaneous fat and hyperelastic skin. SKI is a proto-oncogene that represses transforming growth factor beta activity (TGF-β). Mutations in SKI are thought to lead to a loss of the suppression of the TGF-β signaling cascades.