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Publication
Predisposição genética para o comportamento agressivo de uma população portuguesa
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Abstract(s)
Estudos têm demonstrado que fatores genéticos e ambientais influenciam em conjunto uma variedade de comportamentos, incluindo o comportamento agressivo. A base genética da agressividade é, porém, ainda na atualidade, pouco compreendida.
Os genes candidatos mais promissores no que diz respeito ao estudo genético do comportamento agressivo codificam componentes que estão envolvidos nos sistemas dopaminérgico e serotoninérgico Os sistemas de serotonina (5HT) e dopamina (DA) interagem a nível neurofisiológico, e o comprometimento do sistema de 5HT pode levar à desregulação do sistema de DA.
A hipótese subjacente ao presente estudo afirma que determinados genótipos aumentam a tendência para o comportamento agressivo. Para testar esta hipótese, foi utilizada uma população de estudantes universitários com idades entre os 18 e 35 anos. Foram escolhidos seis polimorfismos, localizados em cinco genes (rs28363170 do SLC6A3, rs4795541 e STin2 do SLC6A4, rs6311 do HTR2A, dVNTR do MAOA e rs4680 do
COMT). Os genótipos dos indivíduos amostrados foram identificados por PCR ou PCRRFLP, e os perfis genotípicos obtidos foram cruzados com os perfis resultantes de um instrumento de avaliação psicológico, desenvolvido pelo departamento de Psicologia do instituto Egas Moniz, e preenchido pelos voluntários.
Relativamente ao polimorfismo rs28363170 do gene SLC6A3, indivíduos com o genótipo 9R/9R reportaram os menores valores de neuroticismo, abertura à experiência, raiva e agressividade reativa e os maiores valores de amabilidade, enquanto que os indivíduos com o genótipo 10R/10R reportaram os maiores valores de
conscienciosidade, extroversão e hostilidade. Já no que concerne o polimorfismo rs4795541 do gene SLC6A4, os indivíduos heterozigóticos ID reportaram os menores valores de hostilidade, agressão física, agressividade reativa e instrumental, e os maiores valores de conscienciosidade e abertura à experiência, enquanto que os homozigóticos DD obtiveram os maiores valores de neuroticismo e os menores valores de extroversão.
O tamanho reduzido da amostra, porém, impediu que se obtivessem resultados estatisticamente significativos.
Studies have shown that genetic and environmental factors jointly influence a variety of behaviours, including aggressive behaviour. The genetic basis of aggressiveness is, however, still poorly understood today. The most promising candidate genes for the genetic study of aggressive behaviour encode components that are involved in the dopaminergic and serotonergic systems. The serotonin (5HT) and dopamine (DA) systems interact at a neurophysiological level, and the compromise of the serotonin system can lead to deregulation of the dopamine system. The hypothesis underlying the present study states that certain genotypes increase the tendency for aggressive behaviour. To test the hypothesis a population of university students aged between 18 and 35 years was used. Six polymorphisms were chosen, localized on five genes (rs28363170 of SLC6A3, rs4795541 and STin2 of SLC6A4, rs6311 of HTR2A, dVNTR of MAOA and rs4680 of COMT). The genotypes of the volunteers were identified by PCR or PCRRFLP, and the genotypic profiles were crosschecked with the profiles provided by the psychological assessment instrument, developed by the Psychology department of the Egas Moniz Institute, and filled in by the volunteers. Regarding the rs28363170 polymorphism of the SLC6A3 gene, individuals with the 9R/9R genotype reported the lowest values of neuroticism, openness to experience, anger and reactive aggression and the highest values of agreeableness, while individuals with the 10R/10R genotype reported the highest values of conscientiousness, extraversion and hostility. As for the rs4795541 polymorphism of the SLC6A4 gene, ID heterozygous individuals reported the lowest values of hostility, physical aggression, reactive and instrumental aggression and the higher values of conscientiousness and openness to experience, while homozygous DD had the highest values of neuroticism and the lowest values of extraversion. The small sample size, however, prevented statistically significant results from being obtained.
Studies have shown that genetic and environmental factors jointly influence a variety of behaviours, including aggressive behaviour. The genetic basis of aggressiveness is, however, still poorly understood today. The most promising candidate genes for the genetic study of aggressive behaviour encode components that are involved in the dopaminergic and serotonergic systems. The serotonin (5HT) and dopamine (DA) systems interact at a neurophysiological level, and the compromise of the serotonin system can lead to deregulation of the dopamine system. The hypothesis underlying the present study states that certain genotypes increase the tendency for aggressive behaviour. To test the hypothesis a population of university students aged between 18 and 35 years was used. Six polymorphisms were chosen, localized on five genes (rs28363170 of SLC6A3, rs4795541 and STin2 of SLC6A4, rs6311 of HTR2A, dVNTR of MAOA and rs4680 of COMT). The genotypes of the volunteers were identified by PCR or PCRRFLP, and the genotypic profiles were crosschecked with the profiles provided by the psychological assessment instrument, developed by the Psychology department of the Egas Moniz Institute, and filled in by the volunteers. Regarding the rs28363170 polymorphism of the SLC6A3 gene, individuals with the 9R/9R genotype reported the lowest values of neuroticism, openness to experience, anger and reactive aggression and the highest values of agreeableness, while individuals with the 10R/10R genotype reported the highest values of conscientiousness, extraversion and hostility. As for the rs4795541 polymorphism of the SLC6A4 gene, ID heterozygous individuals reported the lowest values of hostility, physical aggression, reactive and instrumental aggression and the higher values of conscientiousness and openness to experience, while homozygous DD had the highest values of neuroticism and the lowest values of extraversion. The small sample size, however, prevented statistically significant results from being obtained.
Description
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Keywords
Agressividade Polimorfismos Serotonina Dopamina