SERPINE2 and holoprosencephaly: SNX6, a member sorting nexin family, has not been definitively linked to craniofacial disorders, however multiple studies have suggested it as a candidate gene for holoprosencephaly, the most common developmental field defect in patterning of the human prosencephalon and associated craniofacial structures (Kamnasaran et al., 2005; Segawa et al., 2007).