SMITH, Lemli, and Opitz, in 1964,1reported three patients with mental retardation and a distinctive pattern of multiple congenital anomalies. Subsequently, seven additional patients have been described.2-5 Although four patients with this syndrome have died, no autopsy has been performed upon a patient in whom the diagnosis was made prospectively. Smith et al,1recorded the autopsy findings of a deceased sibling of one of their patients who was said to have, in retrospect, similar features. The only distinctive finding was a small brain which was histologically normal. This report describes an additional patient with this syndrome, includes the radiologic and postmortem findings, and reviews the previous ten cases. Report of a Case A white male infant of Jewish extraction was born January 1966 when his mother was 19 years old and his father 22 years old. There were no previous pregnancies. Gestation was nine months and the