National Organization for Rare Disorders, Inc. It is possible
that the main title of the report Anencephaly is not the name
you expected. Anencephaly is a term that refers to the
incomplete development of the brain, skull, and scalp and is
part of a group of birth defects called neural tube defects
(NTD). The structure which will become the neural tube is
supposed to fold and to close together (to form a tube) during
the third and fourth weeks of pregnancy. From this neural tube,
the brain and spinal cord of the embryo develop. Neural tube
defects happen when the neural tube does not close as expected.
Anencephaly occurs when the end of the neural tube that would
have developed into the brain does not close properly, resulting
in the failure of the development of major portions of brain,
skull and scalp. Other neural tube defects, such as spina
bifida, form when the neural tube does not close properly in a
different part of the neural tube. Infants with anencephaly are
born without the front part of the brain