Agenesis of the corpus callosum and macrocephaly in siblings.

A brother and sister with developmental delay, relative macrocephaly and agenesis of the corpus callosum are described. The brother also had unilateral cerebellar hypoplasia and malrotation of the large bowel. Published cases of familial agenesis of the corpus callosum are reviewed and the value of ultrasonography in demonstrating agenesis of the corpus callosum in the neonate is emphasised.