Agenesis of the corpus callosum and limbic malformation in Apert syndrome (type I acrocephalosyndactyly).

Agenesis of the corpus callosum and malformation of limbic structures are described in a patient with Apert syndrome, a disorder characterized by acrocephaly, severe syndactyly, and often, mental retardation. Including the present case, malformation of the corpus callosum and/or limbic structures apparently has been reported in a total of ten patients with the syndrome. Complete or partial agenesis of the corpus callosum was found in six patients, septal defects in three, and arhinencephaly and ammonic hypoplasia in one. Since malformation or limbic structures are, to our knowledge, a consistent feature of agenesis of the corpus callosum, it seems that limbic abnormalities could be important for the pathogenesis of mental retardation not only in Apert syndrome, but also in other acallosal patients.