Embryology, Anencephaly

Anencephaly is a pathology of development characterized by a fetus that has no calvarium, with a lack of most or all of the fetus' brain tissue. Anencephaly belongs to a collective group known as neural tube defects (NTD) and is a result of the neural tube failing to close in its rostral end during fetal development. While the central nervous system (CNS) is developing in a fetus, the neural plate becomes folded and fused, creating the neural tube. Any disturbance to the process of neural tube closure can result in structural abnormalities collectively called neural tube defects. Anencephaly is one of the two main types resulting from the failure of closure of the rostral end of the neural tube. The other primary type is due to the failure of closure of the caudal end called spina bifida. The development of anencephaly is not believed to have one single origin but can be a result of many factors, including environmental and nutritional factors.