Langer-Giedion syndrome with and without del 8q. Assignment of critical segment to 8q23

Summary Two patients with typical Langer-Giedion or trichorhino-phalangeal type II syndrome are reported. One had an apparently normal karyotype. The second had an intercalary del 8q23. Attention is drawn to the severe bone defects seen in the latter and observations from the literature are discussed. The critical segment is assigned to band 8q23. The syndrome may result in a number of cases from a visible deletion, and in other instances from a more conventional gene mutation, although the molecular mechanism is uncertain.