Dandy-Walker syndrome, also known as Dandy-Walker anomaly or Dandy-Walker malformation, presents with a series of anomalies in the posterior cranial fossa, including the fourth ventricle, the medullary pool of the cerebellum, and the cerebellar earthworms, with some patients having dilated lateral ventricles and about 1/3 having hydrocephalus. The incidence of Dandy-Walker anomalies is approximately 1:25,000-1:30,000 and is the cause of 4-12% of fetal hydrocephalus. Dandy-Walker anomalies may be part of a Mendelian genetic disorder (monogenic genetic disorder) and chromosomal abnormalities. The etiology is mainly related to chromosomal abnormalities, teratogenic agents, alcoholism, maternal diabetes mellitus, etc.