Dandy-Walker malformation and polydactyly: a possible expression of hydrolethalus syndrome.

Hydrolethalus syndrome consists of hydrocephalus, polydactyly, micrognathia, midcranial malformations, visceral abnormalities and perinatal lethality. It was first described in Finland, and only a few other cases outside Scandinavia are known. We report the first Hungarian patient who displayed many signs of the syndrome but had no cleft lip and visceral abnormalities. This observation suggests the existence of oligosymptomic hydrolethalus syndrome, and suggests that Dandy-Walker malformation with polydactyly may be a manifestation of the hydrolethalus syndrome.