A new malformation syndrome is described in a pair of sibs and 3 sporadic patients. The characteristic manifestations are radial aplasia or hypoplasia, absence of thumbs, absent or hypoplastic patellae, dislocations of joints, unusual face, cleft or highly arched palate, diarrhea in infancy, small stature, and normal intelligence. Recessive inheritance seems the most plausible cause. The acronym RAPADILINO syndrome is proposed.