title: [Fragile X syndrome and mental retardation].
abstract: BACKGROUND
  Fragile-X syndrome is characterized by the presence of a fragile site (gap) on Xq 27.3 and the transcriptional inhibition of a mRNA protein-binding gene called FMR-1. Neuropsychological features include cognitive impairment, attention deficit disorder with and without hyperactivity, and impairment of visuospatial functions, language and frontal executive functions. In the present paper, other cytogenetic and phenotype characteristics, associate disorders, neurological and neuroimaging studies are revised.
  
  
  METHODS
  We describe two siblings that illustrate the pattern of neurocognitive and behavioural trends of the Fragile X syndrome, and sex differences.
  
  
  CONCLUSIONS
  These two cases emphasize the need for performing a cytogenetic diagnostic in patients with mental retardation, of unknown etiology, and with a familiar history of mental retardation.
authors.affiliation: Departamento de Psiquiatría y Psicobiología Clinica, Universidad de Barcelona, España.
authors.forename: A
authors.initials: A
authors.lastname: Estévez-González
authors.forename: C
authors.initials: C
authors.lastname: Roig
authors.forename: S
authors.initials: S
authors.lastname: Piles
authors.forename: M
authors.initials: M
authors.lastname: Pineda
authors.forename: C
authors.initials: C
authors.lastname: García-Sánchez
mesh_terms: D000328:Adult; D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D005260:Female; D005600:Fragile X Syndrome / Q000150:complications*; D006801:Humans; D008607:Intellectual Disability / Q000150:complications*; D008297:Male; D010641:Phenotype