This autosomal recessive disorder is designated Meckel syndrome type 7 (MKS7) based on the classic phenotypic triad of (1) cystic renal disease; (2) a central nervous system abnormality, and (3) hepatic abnormalities. According to these criteria, polydactyly is a variable feature. Dandy-Walker malformation can be the phenotypic manifestation of a central nervous system malformation in MKS. [From OMIM]