Complete absence of rib ossification, micrognathia and ear anomalies: extreme expression of cerebro-costo-mandibular syndrome?

We describe a newborn with complete absence of ossification of the ribs, extreme micrognathia, absence of external ear canals and the inner ears, and diminished mobility in the upper extremities. It is suggested that this represents an unusually severe expression of the cerebro-costo-mandibular syndrome. Some developmental genes that may have played a role in the pathogenesis are briefly reviewed.