Langer-Giedion syndrome /lang′ər zhēdē·ôN′/ [Leonard O. Langer, Jr., 20th-century American physician; A. Giedion, 20th-century Swiss physician] , an inherited disorder characterized by cognitive impairment, microcephaly, multiple outgrowths on the bones, characteristic facies with bulbous nose, sparse hair, cone-shaped epiphyses, loose redundant skin, joint laxity, and other anomalies.