title: X-linked mental retardation: transmission of the trait by an apparently unaffected male.
abstract: A pedigree is presented in which an apparently unaffected man transmitted the gene for X-linked mental retardation to at least four of his 12 daughters. None of his 12 sons was mentally retarded. These findings may be explained by a somatic mutation and germinal mosaicism in the father or by a half chromatid mutation in maternal gametes.
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009030:Mosaicism; D009154:Mutation; D010375:Pedigree; D012737:Sex Factors; D014960:X Chromosome