Familial schizencephaly: further delineation of a rare disorder.

We report on two Somalian sibs with severe developmental retardation and spastic cerebral paresis. Both children have bilateral cerebral clefts in the Sylvian region with dilatation of the ventricles, absence of the septum pellucidum, and heterotopia. The diagnosis of familial schizencephaly was made. The occurrence of schizencephaly in two affected sibs supports a genetic basis for schizencephaly.