The genotype of human transcription factor AP-2beta is associated with platelet monoamine oxidase B activity.

Platelet monoamine oxidase B (MAO; EC 1.4.3.4.) activity is stable in the individual and is mainly genetically regulated. Levels of MAO-B in platelets have repeatedly been shown to be associated with personality traits. We have recently also demonstrated an association between the genotype of AP-2beta to a variety of personality traits as well as binge-eating disorder. In the present study we have analysed blood samples from 158 males and 64 females with regard to platelet MAO activity and genotype of transcription factor AP-2beta. In both sexes homozygotes for the long allele [CAAA](5) were significantly associated with low platelet MAO activity P<0.0001 (males) and P=0.0158 (females). This study represents a novel approach to increase the understanding about the molecular mechanisms for how the MAOB gene is regulated in blood cells and how this regulation is linked to personality traits.