3C syndrome (Orphanet_7), first reported in 1987 by Ritscher and Schinzel, is characterized by the association of cardiac malformation, cerebellar hypoplasia and cranial dysmorphism. Cardiac malformations include defects of the endocardial cushion ranging from anomalies of the mitral or tricuspid valves to a complete atrioventricular canal, and/or conotruncal defects, and are the most important prognostic factor in the syndrome. Cranial features include relative macrocephaly, bulging forehead, prominent occiput, large anterior fontanel, ocular hypertelorism, depressed nasal bridge, downslanting palpebral fissures, cleft palate and bifid uvula. Multiple malformations are inconsistently associated with this syndrome. Also known as: Craniocerebellocardiac dysplasia, Ritscher-Schinzel syndrome.