MAPPING OF SIMPSON-GOLABI-BEHMEL SYNDROME TO XQ25-Q27

Simpson - Golabi - Behmel syndrome (SGBS) is an X-linked gigantism syn drome characterized primarily by a coarse facies and somatic overgrowt h which we have observed to be associated with an increased risk for e mbryonal tumors. Genetic linkage analysis for two SOBS kindreds in whi ch X linked dominant inheritance was observed has been conducted for t he X chromosome. The closest linkage to SGBS was observed for the Xq26 locus HPRT (Z max = 7.45, theta max = 0.00). SGBS-Xq marker recombina tions map the disease locus to the DXS425 - DXS1123 interval on Xq25 - q27. This maps the disease locus to a region known to contain a previ ously characterized chromosomal translocation breakpoint found in a yo ung girl with somatic overgrowth. This observation may have implicatio ns for the cloning of the SGBS gene.