GTR Home > Conditions/Phenotypes > Dandy-Walker syndrome


Dandy-Walker malformation is defined by hypoplasia and upward rotation of the cerebellar vermis and cystic dilation of the fourth ventricle. Affected individuals often have motor deficits such as delayed motor development, hypotonia, and ataxia; about half have mental retardation and some have hydrocephalus. DWM is a heterogeneous disorder. The low empiric recurrence risk of approximately 1 to 2% for nonsyndromic DWM suggests that mendelian inheritance is unlikely (summary by Murray et al., 1985). [from OMIM]

Clinical features

  • Truncal ataxia
  • Dilated fourth ventricle
  • Prominent occiput
  • Hydrocephalus
  • Nystagmus
  • Cleft palate
  • Abnormality of the urinary system
  • Elevated imprint of the transverse sinuses
  • Thinning and bulging of the posterior fossa bones
  • Posterior fossa cyst at the fourth ventricle
  • Dandy-Walker malformation
  • Tetralogy of Fallot
  • Frontal bossing
  • Encephalocele
  • Agenesis of cerebellar vermis
  • Partial absence of cerebellar vermis
  • Abnormality of the vertebrae
  • Cranial nerve paralysis
  • Aplasia/Hypoplasia of the corpus callosum
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