Iniencephaly is a rare neural tube defect involving dysmorphic spine and abnormal fusion of the portion of the occipital skull with the back. it results in extreme fixed head retroflexion. [pmid:33294089]

Iniencephaly is a rare type of cephalic disorder characterised by three 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 invariably occurs within a short time. The disorder was first described by Étienne Geoffroy Saint-Hilaire in 1836...