X-linked pachygyria and agenesis of the corpus callosum: evidence for an X chromosome lissencephaly locus.

A family of 5 affected male infants in 2 generations with an X-linked pattern of inheritance is described. All affected infants manifested intractable seizures, severe psychomotor retardation, growth failure, microphallus, and death during infancy. Three of the affected patients had radiological studies that demonstrated findings consistent with pachygyria-agyria and agenesis of the corpus callosum. We believe that this family represents a form of X-linked pachygyria-agyria (lissencephaly) that has not been described previously and suggests a locus for lissencephaly on the X chromosome.