RITSCHER-SCHINZEL (3C) SYNDROME - DOCUMENTATION OF THE PHENOTYPE

Ritscher-Schinzel syndrome or 3C (craniocerebello-cardiac) syndrome is characterized by cardiac defects, cerebellar vermis hypoplasia, and c ranial defects. Nineteen cases were reported previously; however, the full spectrum of this disorder has not been determined. We have evalua ted two unrelated males with this condition, Both had defects of the e ndocardial cushion and vermis hypoplasia with hypotonia. In addition, both had hypospadias, a previously undescribed finding of this disorde r. Review of the previously reported cases and those described herein demonstrate: 1) Although varying degrees of vermis hypoplasia are acco mpanied by hypotonia, delayed gross motor function improves with advan cing age leaving speech delay as the major neurodevelopmental handicap , 2) Two different types of cardiac anomalies occur: defects of the en docardial cushion ranging from anomalies of the mitral or tricuspid va lves to complete AV canal, and/or conotruncal defects, 3) Postnatal gr owth deficiency was seen in most patients in whom longitudinal informa tion was available. In our review of patients with vermis hypoplasia w e ascertained a patient diagnosed as having ''Joubert syndrome'' who h ad most findings of the Ritscher-Schinzel syndrome and several other p atients with ''Dandy-Walker syndrome'' who likely have had Ritscher-Sc hinzel syndrome, suggesting that Ritscher-Schinzel syndrome is more co mmon than has been appreciated. Careful search for the subtle facial c hanges characteristic of this disorder as well as coloboma, cleft pala te/bifid uvula, short neck, syndactyly, and hypoplasia of the nails is warranted when evaluating children with Dandy-Walker malformation wit h or without clinical signs of Joubert syndrome. (C) 1997 Wiley-Liss, Inc.