A well-defined syndrome is described that consists of multiple nevoid basal cell carcinoma, multiple jaw cysts and rib anomalies, the most common of which are bifurcation, synostosis and partial agenesis. Less frequently palmar dyskeratosis, milia, mild mandibular prognathism, vertebral anomalies, frontal bossing, calcification of dura, shortened metacarpals, dystopia canthorum and congenital hydrocephalus have been seen, frequently enough in association with the triad to suggest they are part of the syndrome. Other signs such as mental retardation, agensis of corpus callosum, eye colobomata and pelvic calcification must wait for further case reports for evaluation of their significance. Inheritance is auto-somal dominant with poor penetrance and variable expressivity. The association of an anomaly of the No. 1 chromosome (Denver nomenclature) in 1 patient and several members of her family appears to be fortuitous but raises fascinating questions concerning the presence of an added chromosome segment without phenotypic expression. This may be identical to the finding described by Patau, et al. in patients with orodigitofacial dysostosis. The present authors suspect that the chromosome changes described in the latter syndrome may be foruitous as well.