Congenital heart abnormalities (e.g., tetralogy of Fallot, hypoplastic left heart, transposition of great vessels), ear abnormalities, cleft palate, mental retardation, up-slanted eyebrows, and genital abnormalities (e.g., hypospadias, hypertrophic clitoris). Cause is maternal ingestion of trimethadione or paramethadione during pregnancy; 2/3 newborns exposed in utero develop defects.