Agenesis of corpus callosum: clinical description and etiology.

In 135 children (aged 3 months to 15 years) with structural defects of the central nervous system found on magnetic resonance imaging, agenesis of the corpus callosum was evident in 7. The etiology of agenesis of the corpus callosum has been established in four children: partial trisomy of chromosome 13, partial duplication of the long arm of chromosome 10, Aicardi's syndrome, and intracranial bleeding during the fetal period as a result of injury. Agenesis of the corpus callosum coexisted with a Dandy-Walker malformation in one other patient, which suggests a genetic etiology. In spite of these variable etiologies, dysmorphic features were identified in all seven patients, as was psychomotor retardation. Epileptic seizures had occurred in six patients, and all manifested abnormalities on neurologic examination.