All
 C16 Congenital, Hereditary, and Neonatal Diseases and Abnormalities D009358 +
 C16.131 Abnormalities D000013 +
 C16.131.666 Nervous System Malformations D009421 +
 C16.131.666.680 Neural Tube Defects D009436 +
 C16.131.666.680.196 Anencephaly D000757 
 C16.131.666.680.291 Arnold-Chiari Malformation D001139 
 C16.131.666.680.488 Encephalocele D004677 
 C16.131.666.680.598 Meningocele D008588 
 C16.131.666.680.610 Meningomyelocele D008591 
 C16.131.666.680.800 Spinal Dysraphism D016135 +