title: Fragile X expression studied by clonal analysis and somatic cell hybridization.
abstract: The expression of the fragile site on the X chromosome was examined in euploid somatic cell hybrids to determine if a normal genome could complement the abnormal genome and suppress fragile X expression. Fibroblasts from the patient showed the fragile X in 8% to 12% of cells, and fibroblasts from the normal individual showed no fragile X expression. Six fibroblast clones from the patient showed a variable frequency of fragile X expression (from 6.6% to 12%), suggesting that the fragile X is not expressed in a clonal fashion. Three clones from the normal individual did not show the fragile X. Four hybrid clones showed the fragile X in 5.6%, 4.0%, 7.0%, and 4.0% of cells, respectively, indicating that fragile X expression is not completely suppressed by the normal genome.
mesh_terms: D002478:Cells, Cultured; D002999:Clone Cells; D005260:Female; D005796:Genes; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics; D006801:Humans; D006822:Hybrid Cells / Q000502:physiology; D008607:Intellectual Disability / Q000235:genetics; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D008677:Metaphase; D012729:Sex Chromosome Aberrations / Q000235:genetics; D012730:Sex Chromosomes / Q000502:physiology*; D012867:Skin / Q000166:cytology*; D014960:X Chromosome / Q000502:physiology*
chemical_list: D005954:Glucosephosphate Dehydrogenase