X linked recessive inheritance of agenesis of the corpus callosum.

A 2-year-old boy with psychomotor retardation, congenital unilateral ptosis, bilateral adducted thumbs, weakness of upper limbs, and Hirschsprung's disease (aganglionosis), with complete agenesis of the corpus callosum and hypoplasia of the inferior vermis and cerebellum is reported. His 24-year-old maternal uncle, with severe psychomotor retardation but none of the other physical problems, also has agenesis of the corpus callosum demonstrated by CT scan. The implications for antenatal diagnosis are discussed.