Objective: This study is purposed to explore the relationship between aggressively driving behavior and functional polymorphism in the promoter region of the monoamine oxidase-A (MAOA) gene.
Methods: A total of 348 automobile drivers were investigated with Deffenbacher's driver anger scale, driving vengeance questionnaire (DVQ) and driver aggression behavior questionnaire. Eighty-eight drivers were selected as more, medium and less aggressive group, each. Polymerase chain reaction (PCR) and 2.5% agarose gel electrophoresisi were adopted to detect the polymorphism of functional 30 bp-uVNTR in the promoter region of the X-chromosomal MAOA gene and their frequencies of varied genotypes were estimated.
Results: Two alleles with 3 and 4 repeats of 30 bp-uVNTR were detected in the drivers. Among the more aggressive group, number of the allele with 3 repeats of 30 bp-uVNTR (63/88) was significantly more than that with 4 repeats (25/88) (chi(2) = 10.21, P < 0.01), and number of the allele with 4 repeats of 30 bp-uVNTR was more in the less aggressive group, indicating that persons with allele of 3 repeats of 30 bp VNTR were more aggressive in their driving than those with 4 repeats.
Conclusions: Aggressively driving behavior in drivers possibly related to their functional MAOA-uVNTR polymorphism. Effect of the gene on aggressively driving behavior should be further studied.