[Association of hereditary hydrocephalus and holoprosencephaly]

An infant with alobar holoprosencephaly and hydrocephalus is reported. The mechanism of hydrocephalus (aqueductal stenosis) and the mother's previous history (2 boys from a first marriage still-born with hydrocephalus) suggest a X-linked hydrocephalus. The association of a holoprosencephaly with this hereditary hydrocephalus is discussed.