Dandy-Walker malformation was first described by Dandy and Blackfan in 1914.
The part of the brain located between the two cerebellar hemispheres called cerebral vermis becomes partially or completely absent. Other key features include an enlargement of the fourth ventricle (one of four connected cavities in the brain) and cyst formation near the internal base of the skull. The three features form a triad.
It is a genetically sporadic disorder. Dandy-Walker syndrome occurs one in every 25,000 live births. Females are mostly affected.
An increase in size and pressure occurs in the fluid spaces surrounding the brain.