Association between serotonin transporter gene polymorphisms and non-lesional temporal lobe epilepsy in a Chinese Han population

Serotonin (5-hydroxytryptamine, 5-HT) influences the cortical and subcortical excitatory/inhibitory balance and participates in the pathophysiological processes of epilepsy. The serotonin transporter (5-HIT) is the most important factor in serotonin inactivation. We tested whether 5-HIT polymorphisms are involved in the pathogenesis of epilepsy in Chinese Han population. We did not find a significant difference in the frequencies of genotypes and alleles in the 5-HIT gene-linked polymorphic region (5-HTTLPR) in patients with non-lesional temporal lobe epilepsy and normal controls (P > 0.05). Frequencies of the 5-HIT intron 2 variable number tandem repeat (5-HTTVNTR) 12/12 genotype and allele 12 were higher in the patients with non-lesional temporal lobe epilepsy than normal controls (P < 0.01). The odds ratio of affecting non-lesional temporal lobe epilepsy was 1.435 (95% CI, 1.096-1.880) in patients carrying allele 12 (P < 0.05). Although the 5-HTTLPR may not be a genetic locus of non-lesional temporal lobe epilepsy in Chinese Han population, allele 12 in the 5-HTTVNTR may correlate with non-lesional temporal lobe epilepsy. The Stin2.12 allele and 12/12 genotype could be predisposing to non-lesional temporal lobe epilepsy.