An X-linked developmental disorder that is more severe in heterozygous females than in hemizygous males. Females have frontonasal dysplasia, craniofacial asymmetry, CRANIOSYNOSTOSIS; bifid nasal tip, grooved nails, wiry hair, and thoracic skeleton abnormalities; males typically show only HYPERTELORISM. It is caused by mutations in the EPHRIN-B1 (EFNB1) gene. OMIM: 304110
Date introduced: August 25, 2010