Abstract
OBJECTIVE: Genetic factors underlying different personality traits are not entirely understood, particularly how genes interact to modulate their effect. We studied 76 patients diagnosed with borderline personality disorder (BPD), characterized by extreme levels of personality traits, especially neuroticism (N), in which we genotyped two polymorphisms, the 5HTTLPR of the Serotonin transporter (SERT) gene, and the Val66Met of the Brain-derived neurotrophic factor (BDNF) gene. RESULTS: We found an association with SERT, where S-allele carriers had significantly higher levels of N than L-homozygous. Furthermore, we found that the protective effect of L-homozygosity is only evident on A-allele carriers of the BDNF Val66Met polymorphism. Genetic constitution in SERT and BDNF seems to be important in neuroticism, the most relevant personality trait on BPD.