FAMILIAL X-LINKED MENTAL-RETARDATION AND ISOLATED GROWTH-HORMONE DEFICIENCY - CLINICAL AND MOLECULAR FINDINGS

We report on several members of a family with varying degrees of X-lin ked mental retardation (XLMR), isolated growth hormone deficiency (IGH D), and infantile behaviour but without other consistent phenotypic ab normalities, Male patients continued to grow until well into their twe nties and reached a height ranging from 135 to 159 cm, Except one, all female carriers were mentally normal; their adult height ranged from 159 to 168 cm, By linkage studies we have assigned the underlying gene tic defect to the Xq24-q27.3 region, with a maximum lod score of Z = 3 .26 at theta = 0.0 for the DXS294 locus, The XLMR-IGHD phenotype in th ese patients may be due to pleiotropic effects of a single gene or it may represent a contiguous gene syndrome. (C) 1996 Wiley-Liss, Inc.