A Correlational Study On 5-HTTLPR/rs25531 Polymorphisms, Life Events And Major Depressive Disorder

Object i ve:To analyze the correlation of 5-HTTLPR, single nucleotide polymorphisms (SNPs) rs25531 and major depressive disorder (MDD), as well as the relation between 5-HTTLPR/rs25531 polymorphisms and depression severity, each factor of HAMD. To explore the correlation between life events and MDD, also to investigate the influence of interaction between 5-HTTLPR/rs25531 polymorphisms and life events on MDD.Methods:250 patients, which meet the DSM-â…£diagnostic criteria for major depressive disorder, and 250 healthy controls were recruited in this case-control study with strictly selected standards. HAMD-17 was used to evaluate the severity of depression; LES was adopted to assess the depression severity of patients group. Peripheral blood of the patients was collected, and genomic DNA was extracted. Polymerase chain reaction (PCR) was used to amplify the target band and 5-HTTLPR genotypes were determined. The PCR products were digested by restriction enzyme and rs25531 polymorphisms were decided. SPSS 17.0 was used to do statistic analysis, the significant difference were set at P<0.05.Result:1. The 5-HTTLPR/rs25531 genotypes and allele frequency distribution had statistically significance between MD patients and controls (P<0.05). Genotype distribution in women, but not in men, had a significant statistically difference (P <0.05) between patients and controls. Univariate Logistic regression analysis showed a statistical significance between 5-HTTLPR LL genotypes and MDD. LL was the risk genotype, L was the risk allelic gene for MDD, but these correlations were only seen in women. There was a statistical significance between rs25531 LALA genotype and MDD, LALA as the risk genotype, LA as the risk allelic gene, but it also only existed in women. 2. The correlation between 5-HTTLPR/rs25531 and depression severityThe increase of HAMD scores, damping factor, Maier symptom factors, anxiety/somatization factor and core factor was related to rs25531. LALA was related to the increase of HAMD total score, Maier symptom factor, anxiety/ somatization factor and core factor, and S'S'was related to damping factors especially in women. LALA was only related to HAMD total score and anxiety/ somatization factors in men.3. The impact of life events on people with different 5 - HTTLPR/rs25531 genotypes had significant difference.5 - HTTLPR gene polymorphisms and life events had no correlation with the severity of depression, whereas the interaction between rs25531 polymorphisms and life events was related to the severity of depression.Conclusion:5 - HTTLPR LL genotype and rs25531 LALApolymorphism were the risk gene of depression in women, but not in men.5 - HTTLPR gene polymorphisms were unrelated to the severity of depression. The LALA polymorphism had correlation with the severity of depression and Maier, anxity/somatization, core symptom, and S'S' genotype related to the delayed symptoms in women. LALA polymorphism only related to the severity of depression and anxity/somatization symptoms in men. The interaction of rs25531 polymorphisms and life events were correlated with the severity of depression.