Craniofrontonasal syndrome occurs when the EFNB1 gene is mutated in heterozygous or hemizygous state. As it is located on Xq13.1, it is a Dominant X-linked disorder. Contrary as expected, heterozygous females are more severely affected than hemizygous males by a mechanism called cellular interference. Affected females will present with midline defects, a severe hypertelorism, a grooved nasal tip and unilateral or bilateral coronal craniosynostosis, as well as some other extracranial features.
EFNB1