Combination of the serotonin transporter and norepinephrine transporter gene promoter polymorphisms might influence harm avoidance and novelty seeking in healthy females

It has been demonstrated that the interaction between serotonin transporter (5HTT) and norepinephrine transporter (NET) functions affects each transporter function and behavior in studies using knockout mice model. In the present study, we examined the effects of the 5HTT and NET gene promoter polymorphisms on personality traits in 575 Japanese healthy subjects. The 5HTT (long/short, L/S) and NET (−3081 A/T) genotypes were identified by PCR methods, and personality traits were assessed by the Temperament and Character Inventory (TCI). Neither of the two polymorphisms affected any TCI dimension, but the interaction between them had significant effects on harm avoidance and novelty seeking in females. Subsequent analyses showed that the females with the combination of the SS genotype reducing 5HTT function and the TT genotype reducing NET function had higher harm avoidance and lower novelty seeking. The present study suggests that the combination of 5HTT and NET polymorphisms influences harm avoidance and novelty seeking in females.