All of the fallowing are neural tube defects except –
Holoprosencephaly is a developmental disorder of the brain that results from defective cleavage of the prosencephalon. It is thus a malformation of cortical development and not a neural tube defect.
 
The major neural tube defect include:
Spina bifida occulta                     Anencephaly                        Diastematomyelea •
Meningocele                                  Dermal sinus                        Lipoma involving conus medullaris
Meningomyelocele                       Tethered cord
Encephelocele     Syringomyelia
Myelomeingocoele
Anencephaly
Encephalocele
Holoprosencephaly