Association analysis between BDNF gene polymorphism and the anxiety symptoms of depressive disorder in Chinese Han population

Abstract

Oblectlve To explore the association of brain-derived neurotrophic factor(BDNF)gene polymorphism and the anxiety symptoms of depressive disorder in Chinese Han population.Methods A total of 458 depressive patients diagnosed by DSM-Ⅳ were admitted in the study.The severity of depression and anxiety were respectively assessed with 17-item Hamilton Depression Hating Scale(17-HAMD)and Hamilton Anxiety Scale (HAMA).Polymerase chain reaction(PCR)and DNA direct sequencing technique were used to detect the genetic polymorphism of the BDNF gene.The analyses of the quantitative trait were performed by UNPHASED(version 3.0).Results There were no significant differences between HAMA score and polymorphism of the BDNF gene rs6265(alleles:X2=1.947,P=0.163;genotypes:X2=2.184,P=0.336).An association between the polymorphism and the quantitative character of anxiety symptoms were observed in the allele(mental anxious factor:X2=4.908,P=0.027;anxious mood:X2=4.312,P=0.038),but not in the genotype.Other item score of HAMA was showed no association with polymorphism of the BDNF gene rs6265(P＞0.05).Conclusion The polymorphism in allele of BDNF gene may be associated with the anxiety symptoms of depressive patients.Polymorphism of the BDNF gene might constitute the appearance of the clinical manifestation-anxiety in depressive disorder.The result also suggests that the analysis of symptom phenotype may be more suitable for genetic study of depressive disorder. Key words: Depressive disorder; Anxiety; BDNF gene; Polymorphism