|a neural tube defect, characterized by the total or partial absence of the cranial vault and the covering skin, the brain being missing or reduced to a small mass. Most cases are stillborn, although some infants have been reported to survive for a few hours. In most cases autopsy findings reveal absence of adrenal glands. Anencephaly is likely to be multifactorial, the result of gene-environment interactions. Familial cases with a seemingly autosomal recessive mode of inheritance have been described but most cases are sporadic. Folic acid and zinc deficiencies, as well as maternal obesity, have been shown to be risk factors.
- LA00.1 Iniencephaly - a rare form of neural tube defect in which a malformation of the cervico-occipital junction is associated with a malformation of the central nervous system. The cardinal features are occipital bone defect, partial or total absence of cervicothoracic vertebrae, fetal retroflexion of the head and characteristic absence of the neck. It is associated with malformations of the central nervous (spina bifida and/or anencephaly), gastrointestinal (omphalocele) and cardiovascular systems.
- LA00.2 Acephaly
- LA00.3 Amyelencephaly - Amyelencephaly is the absence of both the brain and spinal cord.
LA01 Cephalocele - failure of the skull to correctly close during the antenatal period. This condition is characterized by herniation of the meninges. This condition may present with herniation of brain, or developmental delay. Confirmation is through observation of herniated meninges by imaging.