Klinefelter's syndrome (karyotype 47,XXY) and schizophrenia-spectrum pathology.

Klinefelter's syndrome, characterised by a 47,XXY chromosomal pattern, has largely been associated with physical abnormalities. Here, we report high levels of schizophrenia-spectrum pathology in 32 men with this syndrome in comparison with 26 healthy controls. This may have implications for treatment of have implications for treatment of Klinefelter's syndrome and suggests that the X chromosome may be involved in the aetiology of schizophrenia.