Methylation and QTDT analysis of the 5-HT2A receptor 102C allele: analysis of suicidality in major psychosis.

Centre for Addiction and Mental Health, Department of Psychiatry, University of Toronto, 250 College Road, Toronto, Ontario, Canada.
Journal of Psychiatric Research (Impact Factor: 4.09). 10/2008; 43(5):532-7. DOI: 10.1016/j.jpsychires.2008.07.007
Source: PubMed

ABSTRACT Suicide is an act deliberately initiated and performed by a person with full knowledge that a fatal outcome is probable. The serotonin 2A (5-HT2A) receptor gene has been implicated in the pathogenesis of suicidal behaviour by a genetic association between the 5-HT2A T102C silent polymorphism and suicidality in patients with mood disorders and schizophrenia. However, a recent meta-analysis failed to confirm this association. We developed an improved quantitative assay for the measurement of allele-specific methylation of the 5-HT2A gene, and found that the methylation of the C allele in the pre-frontal cortex of heterozygous suicide victims (n=10) was not significantly different in comparison with the non-suicide group (n=10) (p=0.084). We also analyzed methylation of the C allele in white blood cell DNA from bipolar and schizophrenic attempters and found a significant difference in the schizophrenic attempters (p=0.00013) but not in the bipolar attempters (p=0.616). Because the 5-HT2A gene is subject to imprinting, the parent-of-origin may affect inheritance of suicidal behaviour. Thus, we examined the parental origin of specific alleles for genetic association in a genetic family-based sample of major psychoses in which information on suicidal behaviour was available. This result suggests that methylation of the 102C allele does not influence completed suicide.

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