- Poster presentation
- Open Access
Gene-environment interaction and personality/behaviour
© The Author(s) 2006
Published: 28 February 2006
Genes and environment interact to form an individual's personality. Abnormal or extreme behaviour could thus be explained by hereditary factors in combination with poor environmental conditions, as shown by Caspi et al., 2002 and replicated e.g. by Foley et al., 2004.
Materials and methods
The MAO-A and 5-HTT genes are two key players in the regulation of serotonin turnover within the brain. Functional variations in the promoter regions allow for division of both these genes into a short and a long allele proven to exert low and high transcriptional activities, respectively (Sabol et al., 1998; Lesch et al., 1996). AP-2ß is a transcription factor of importance for development and maintenance of, among other structures, the monoamine brain-stem nuclei. An AP2ß gene polymorphism has been shown to be associated with personality and monoamine turnover (see Damberg, 2005).
The results were in the same direction for all behavioural phenotypes/disorders, showing that genotype is dependent on psychosocial factors for penetration. The short MAO-A allele interacted with psychosocial factors with regard to risk for criminal activity (60% of the variance) and destructive behaviour when drunk. With regard to 5-HTT genotype, heterozygous subjects reporting Bad family relations showed a 13 fold increased risk for high intoxication frequency. Increased anorectic problems were seen in individuals carrying the short allele, if in interaction with Bad family relations (p = 0.009). AP-2 genotype interacted significantly with psychosocial environment with regard to risk for criminality, alcohol intake as well as depressive symptoms in girls.
In conclusion, genotype and a wide variety of psychosocial factors interact significantly, above what would be expected from simple additive effects, to precipitate a variety of behavioural and psychiatric disorders. Background, methods and some results are to be found in ref 1–4
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