title: Twelve families with fragile X(q27).
abstract: Through a community study of boys requiring special education for the severely mentally retarded, 12 families were ascertained in which the fragile X was found to be segregating. By assiduous follow up of these families, it was found that in only four of them could male transmission be ruled out from the grandparents' or great grandparents' generation and that the segregation ratios are disturbed.
mesh_terms: D002478:Cells, Cultured; D003582:Cytogenetics; D005260:Female; D005600:Fragile X Syndrome / Q000235:genetics*; D006580:Genetic Carrier Screening; D006801:Humans; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D010375:Pedigree; D012729:Sex Chromosome Aberrations / Q000235:genetics*