A lethal and previously undescribed syndrome in 3 siblings with hypoplasia of the corpus callosum is described from the Istituto Materno-Infantil de Pernambuco, and Laboratorio de Genetica, Universidade Federal de Pernambuco, Recife, PE, Brazil. The combination of anomalies, probably inherited as an autosomal recessive trait, included corpus callosum hypoplasia, microcephaly, severe mental retardation, preauricular skin tag, campodactyly (fixed flexion of one or more fingers), growth retardation, and recurrent bronchopneumonia. The children lived for 10, 23 and 32 months. At autopsy in 2 patients, the brain weighed approx 500 gms and showed marked hypoplasia of the corpus callosum, aqueductal stenosis, enlarged 3rd and 4th ventricles, widened cavum septi pellucidi, and diffuse degenerative changes with astrocytosis. The literature on anomalies associated with callosal defects is reviewed. 
COMMENT. Congenital callosal defects occur alone or with other brain anomalies, e.g. septum pellucidum defect, hydrocephalus, porencephaly, polymicrogyria, and cerebellar hypoplasia. Mental retardation, seizures, and failure to thrive are commonly associated, but the callosal defect itself may be asymptomatic. At least 4 distinct syndromes include callosal agenesis as a major component: Aicardi (with infantile spasms, hypsarrhythmia, chorioretinal lacunae and coloboma), Schinzel acrocallosal syndrome (with macrocephaly, and Polydactyly), Anderman's syndrome (with anterior horn cell disease), and Shapiro syndrome (with recurrent hypothermia). (See Ped Neur Briefs, March 1988;2:17).