X-linked mental retardation with variable stature, head circumference, andtesticular volume linked to Xq12-q21

Clinical and molecular studies are reported on a family with X-linked menta l retardation (XLMR) in which there are eight affected males in three gener ations. Although the males have somatic manifestations, these are variable and in most cases do not allow clear distinction of affected and unaffected males, Affected males are shorter and have a smaller head circumference. S everal also have a sloping forehead (5/8), hearing loss (3/8), cupped ears (2/8), and small testes (4/6), An LOD score of 4.41 with zero recombination was obtained at locus DXS1166 in Xq13.2. This family highlights the diffic ulty in classifying XLMR conditions as either nonsyndromic or syndromic bec ause of the variable somatic manifestations observed in the affected males. Am. J. Med Genet. 85:223-229, 1999. (C) 1999 Wiley-Liss, Inc.