FETAL ALCOHOL SYNDROME - The most common cause of defective cerebral development in industrialized nations, affecting 1 in 700 live births in the United States. This clinical syndrome results from the direct toxic effects of alcohol on the developing fetus. Growth retardation, mental retardation, small brain, and heart valve lesions are common. Infants can be identified by close set eyes, small head, small nasal bridge, reduction in the vermilion border of the upper lip, eye folds, and small teeth.