Craniofrontonasal syndrome (CFNS; MIM #304110) is a rare craniofacial disorder characterized by hypertelorism, a broad nasal root with a bifid nasal tip, orofacial clefting, and genital malformations caused by pathogenic variants in the X-linked gene EFNB1 (MIM *300035). Here, EFNB1 is linked to craniofrontonasal syndrome.