Abstract

Background: The serotonin transporter (5HTT) is a protein locating on the presynaptic neuron membrane. The genes coding for 5HTT has 6 separate families, of which, SLC6A4. Polymorphism in the promoter region of SLC6A4 (5HTTLPR) has been shown to correlate with personality traits. This study aimed to compare the L and S alleles of 5HTTLPR in healthy people and patients with severe depression in the Ilam province, Iran. Methods: In this study, 198 patients with depression and 100 volunteers enrolled. The DNA of samples was extracted and PCR was performed. After electrophoresis, PCR product was identified on 2 gel electrophoresis to distinguish SS, LS and LL bands. Finally, data were analyzed using chi-square and logistic regression. Results: The frequency of analysis of 5HTTLPR alleles in healthy subjects and patients was as follows: In healthy group genotypes were LS 44, LL 49, SS 7 and in the patient group were LS 39.9, LL 23.7, and SS 36.4. Further analysis showed that the frequency of genotypes in patients was significantly associated with psychological trauma (P = 0 .001). Our results also showed that S/S genotype was associated with a 6.2 fold onset of depression. Conclusion: The results of this study showed that the health status of individuals was significantly correlated with the frequency of SS genotype that was higher in the patient group. © 2020 Elsevier B.V.