A related syndrome, Craniofrontonasal syndrome (OMIM 304110), which presents in females as FND is caused by mutations of EFNB1. Acromelicfrontonasal dysplasia (OMIM 603671) is a distinctive and rare form of FND caused by deficiency of ZSWIM636,38,45–49. Here, EFNB1 is linked to Craniofrontonasal dysplasia.