() as a Novel Candidate Biomarker Gene for Suicidal Behavior.

It has been previously shown that the serotonin and dopamine neurotransmitter systems might influence the predisposition to suicidal behavior. This study aims to estimate the contribution of 11 polymorphisms in the genes (), , , , (), , , , and to suicidal behavior and severity of symptoms of depression and anxiety in the Russian population. The study was performed on 100 patients with repeated suicide attempts and 154 controls. We first found an association between () 40 bp VNTR locus and suicidal behavior. This association was significant; when using the codominant ( = 0.006), dominant ( = 0.001), overdominant ( = 0.004), and log-additive ( = 0.004) models, LL genotype played a protective role (OR = 0.48, 0.29-0.82, = 0.005). Difference in the distribution of rs4680 genotypes was significant in the codominant ( = 0.04), dominant ( = 0.013), and log-additive ( = 0.02) models, and AA genotype might protect against suicide (OR = 0.49, 0.26-0.91, = 0.025). SLC6A4 5-HTTLPR + rs25531 locus was significant in the recessive model ( = 0.024), and also affected the severity of symptoms of depression ( = 0.044) and personal anxiety ( = 0.029). Our results suggest that allelic variants of , , and genes might be considered as risk factors for suicidal attempts.