The critical segment for the Langer-Giedion syndrome: 8q24.11----q24.12.

An 18-year-old intellectually normal male with characteristic features of the Langer-Giedion syndrome is reported. High resolution chromosome analysis showed a small deletion in the region of bands 8q24.11 and 8q24.12 in addition to an apparently balanced de novo translocation (2;9)(q21;q13). This finding provides additional information on the minimum deleted segment required to produce the Langer-Giedion syndrome and may indicate that deletions of this size or smaller are not necessarily associated with mental retardation.