title: The psychiatric phenotype in triple X syndrome: new hypotheses illustrated in two cases.
abstract: BACKGROUND
  Triple X syndrome (47,XXX or trisomy X) is a relatively frequent cytogenetic condition with a large variety of physical and behavioural phenotypes.
  
  
  METHODS
  Two adult patients with a triple X karyotype are described.
  
  
  RESULTS
  Their karyotype was unknown until some years ago. What these patients have in common is that they were diagnosed with a broader autism phenotype, they were sexually abused, they suffer from psychotic illness and they show challenging behaviour, suicidality and a decline in occupational capacity.
  
  
  CONCLUSIONS
  These gene-environment interactions are discussed. Gene-environment interactions may explain the variety of behavioural and psychiatric phenotypes in triple X syndrome. Ongoing atypical development in adults is hypothesized.
  
  
  CONCLUSIONS
  Gene-environment interactions and ongoing atypical development in adults should be taken into account in research concerning the psychiatric phenotype of developmental disorders, especially those involving triple X syndrome.
authors.affiliation: Department of Child & Adolescent Psychiatry, Eleos, Ede, The Netherlands. maarten.otter@filternet.nl
authors.forename: Maarten
authors.initials: M
authors.lastname: Otter
authors.forename: Constance T R M
authors.initials: CT
authors.lastname: Schrander-Stumpel
authors.forename: Robert
authors.initials: R
authors.lastname: Didden
authors.forename: Leopold M G
authors.initials: LM
authors.lastname: Curfs
mesh_terms: D000328:Adult; D001321:Autistic Disorder / Q000235:genetics / Q000523:psychology; D041321:Chromosomes, Human, X / Q000235:genetics; D002658:Developmental Disabilities / Q000235:genetics / Q000523:psychology; D059647:Gene-Environment Interaction; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics / Q000523:psychology; D008875:Middle Aged; D010641:Phenotype; D012729:Sex Chromosome Aberrations; D058533:Sex Chromosome Disorders of Sex Development / Q000235:genetics / Q000523:psychology*; D012742:Sex Offenses / Q000523:psychology; D014314:Trisomy / Q000235:genetics