3C syndrome

3C syndrome, sometimes called Ritscher-Schinzel syndrome, is a very rare condition defined by a triad of heart defects, underdevelopment of the cerebellum and cranial dysmorphism, the three Cs of its name. The heart defects, often involving the endocardial cushion, are the most important factor in diagnosis and can include atrioventricular canal defects, malformed valves and conotruncal anomalies such as tetralogy of Fallot. Facial and skull features vary and can include low-set ears, a prominent forehead and occiput, wide-set eyes and cleft palate, and about three quarters of affected children have Dandy-Walker malformation with hydrocephalus. It is an autosomal recessive disease caused by mutations at 8q24.13, the locus of the gene for the protein strumpellin. Outcome depends chiefly on the severity of the cardiac defects, and many children die in infancy. It occurs in fewer than one birth per million but is far more common in one remote First Nations community in Manitoba.