Based on the family presented and five others previously described, it can be concluded that the Grieg cephalopolysyndactyly syndrome is a fully penetrant autosomal dominant disease consisting of four variably expressed malformations: postaxial polydactyly (type B), preaxial polydactyly, syndactyly, and minor craniofacial abnormalities. This entity can be differentiated from other craniofacial-digital syndromes because of the absence of mental retardation, craniosynostosis, and brachydactyly.