© 2007 The Royal College of Psychiatrists
Correspondence |
X-chromosome abnormality and schizophrenia
Bennekom, The Netherlands. Email: maarten.otter{at}fitternet.nl
EDITED BY KIRIAKOS XENITIDIS and COLIN CAMPBELL
Van Rijn et al (2006) concluded that their findings suggested a link between an X chromosomal abnormality and liability to schizophrenia which might be useful in the search for the genetic aetiology. Moreover they stated that a crucial role for X chromosome abnormalities in this context has been proposed by Lishman (1998). In 1966 Hambert described a group of 75 XXY men, of whom 17 had hallucinations, 21 paranoid ideas, 9 `megalomanic ideas' and 5 `short periods of mania-like disorder'. Penrose (1966) claimed that `the effects of sex chromosomal disorders are more noticeable in relation to alterations in character and stability than to intellectual loss. Olanders (1975), working in the same research group as Hambert and Penrose, reported 16 women with schizophrenia among 31 with triple X syndrome. Olanders' own psychiatric investigation of these women revealed many with paranoid symptoms who did not meet his strict criteria for schizophrenia. He described a paranoid syndrome in 8, hallucinations in 4, confusion in 3 and catatonic symptoms in 2.
Van Rijn et al discuss the relationship between an extra X chromosome and psychosis through the `decreased cerebral lateralisation' hypothesis. Netley & Rovet (1982) reviewed data which point to diminished cerebral cell numbers owing to lower mitotic rates which also result in the lower dermal ridge counts. I think that a lower cerebral cell number could give rise to decreased cerebral lateralisation, but this needs further investigation.
In my opinion, Van Rijn et al present no new data but have rediscovered what was known for a long time.
REFERENCES
- Hambert, G. (1966) Males with Positive Sex Chromatin. An Epidemiologic Investigation Followed by Psychiatric Study of Seventy-Five Cases. Akademiförlaget.
- Lishman, W. A. (1998) Endocrine diseases and metabolic disorders. In Organic Psychiatry: The Psychological Consequences of Cerebral Disorder (ed. W. A. Lishman), pp. 526 -527. Blackwell Science.
- Netley, C. & Rovet, J. (1982) Verbal deficits in children with 47,XXY and 47,XXX karyotypes: a descriptive and experimental study. Brain and Language, 17, 58-72.[CrossRef][Medline]
- Olanders, S. (1975) Other psychiatric findings. In Females with Supernumerary X Chromosomes. A Study of 39 Psychiatric Cases, pp. 91-104. Scandinavian University Books.
- Penrose, L. S. (1966) The contribution of
mental deficiency research to psychiatry. British Journal of
Psychiatry, 112, 747
-755.
[Free Full Text] - Van Rijn, S., Aleman, A., Swaab, H., et al
(2006) Klinefelter's syndrome (karyotype 47, XXY) and
schizophrenia-spectrum pathology. British Journal of
Psychiatry, 189, 459
-460.
[Abstract/Free Full Text]
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