X-LINKED MENTAL-RETARDATION WITH ISOLATED GROWTH-HORMONE DEFICIENCY IS MAPPED TO XQ22-XQ27.2 IN ONE FAMILY

X-linked mental retardation (XLMR) includes distinct entities in which mental deficiency is either associated with specific abnormalities (s yndromal) or not (nonsyndromal), We report on the clinical, neuropsych ological, and laboratory findings and Linkage analysis in one family w ith XLMR and isolated growth hormone deficiency (IGHD), Mental retarda tion was associated in 3 males and 5 females with short stature, micro cephaly, and particular facial traits, i,e,, high curved forehead, mid face hypoplasia, and concave nasal bridge with nasal end of normal siz e and broad traits, Significant lod scores (Z(max) > 2) at a recombina tion fraction of theta = 0 were detected for 6 marker loci between DXS 178 (Xq22.1) and DXS292 (Xq27.2). This mapping region overlaps that of XLMR with IGHD, recently reported by Hamel et al, [1996: Am J Med Gen et 64:35-41] (Xq24-q27.3), and that of agammaglobulinemia with IGHD (X q21.33-q22.2). This observation may confirm the suspicion of a gene in volved in growth hormone regulation being localized in Xq, (C) 1998 Wi ley-Liss, Inc.