Septopreoptic holoprosencephaly

A rare subtype of holoprosencephaly characterized by midline fusion limited to the septal and/or preoptic regions of the telencephalon without a significant frontal neocortical fusion. Midline craniofacial malformations are generally mild and include solitary median maxillary incisor and pyriform sinus stenosis. Other reported manifestations include language delay, learning difficulties, and behavioral disorders. Imaging reveals abnormal fornix, absent or hypoplasic anterior corpus callosum, and unpaired anterior cerebral artery.