Infantile autism in twins.

A pair of MZ male twins concordant for early infantile autism (E.I.A.) is presented. A distinction is drawn between E.I.A. and infantile psychosis (I.P.) with associated mental retardation as a guide to prognosis and the necessity to provide suitable social training and education. The relevance of aetiology is discussed, and the importance of abnormal ante-natal history and delivery status, even in cases with strong genetic predisposition, is noted.