<unk>  is a cephalic disorder  in which there is the partial or total absence of the brain. It is an open neural tube defect occurs when the rostral (head) end of the neural tube fails to close resulting in the absence of a major portion of the brain, skull and spinal cord. Children with this disorder are born without a forebrain, the largest part of the brain consisting mainly of the cerebral hemispheres which is responsible for higher cognitive functions and cerebellum which control balance and movement. However, hindbrain is developed. The remaining brain tissue is often exposed - not covered by bone or skin.
Anencephaly
Hydranencephaly
Megalencephaly
Schizencephaly
Lissencephaly
Holoprosencephaly
Spina bifida
Encephalocele