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