What is "iniencephaly"

n. A cephalic disorder characterized by spina bifida and spinal retroflexion

Iniencephaly, a term derived from the Greek word "inion" for nape of the neck, is a rare type of cephalic disorder that was first described by Étienne Geoffroy Saint-Hilaire in 1836. Those afflicted with the disorder all share 3 common characteristics: a defect to the occipital bone, spina bifida of the cervical vertebrae and retroflexion (backward bending) of the head on the cervical spine. Stillbirth is the most common outcome, with a few rare examples of live birth, after which death almost invariably occurs within a short time.