AbstractTwo infants with a striking pattern of associated malformations including agnathia, situs inversus, renal agenesis and ectopia, and multiple vertebral and rib abnormalities are described. It appears that these two infants represent a previously unrecognized malformation association that involves far more than developmental arrest of the mandibular arch. It is conceivable that a single defect at a very early stage in development could account for the multiple manifestations seen.