Agenesis of the corpus callosum was found in 7 of 135 children (aged 3 months to 15 years) with structural cerebral defects on MRI. All 7 showed dysmorphic features, psychomotor retardation, and neurologic abnormalities, and 6 had epilepsy (infantile spasms in 3). Causal factors in 4 children were partial trisomy of chromosome 13, partial duplication on the long arm of chromosome 10, Aicardi’s syndrome, and intracranial bleeding in the fetus due to injury. Dandy-Walker malformation was also present in one other patient. 
COMMENT. Agenesis of the corpus callosum occurs as part of chromosomal syndromes, trisomy 8, 13, 18, or 21, and with X-linked syndromes, especially Aicardi’s syndrome. It may be associated with other brain malformations, and it sometimes accompanies various inborn errors of metabolism, Exogenous factors such as intracranial bleeding and infection may also be involved in etiology.