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. Method: 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. Discussion: These geneenvironment interactions are discussed. Geneenvironment interactions may explain the variety of behavioural and psychiatric phenotypes in triple X syndrome. Ongoing atypical development in adults is hypothesized. Conclusions: Geneenvironment 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. © 2012 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.