title: Tryptophan hydroxylase 2 gene is associated with major depressive disorder in a female Chinese population.
abstract: BACKGROUND
  Previous candidate gene studies of major depressive disorder (MDD) have provided inconclusive evidence of association for genes with strong biological rationale for MDD. In this study, we aimed to investigate the association of tryptophan hydroxylase 2 gene with MDD and its treatment response in the Chinese Han population.
  
  
  METHODS
  Three hundred and sixty eight depressed patients who met DSM-IV criteria for major depressive disorder were recruited for the study. 371 normal controls were recruited from local community. Patients and normal controls were genotyped for TPH2 (rs4290270 and rs7305115) variants by polymerase chain reaction. Male and female subjects were analyzed separately.
  
  
  RESULTS
  No differences were found in the frequencies of the single alleles and genotypes of the tested polymorphisms between MDD patients and normal group. The frequency of the A-A haplotype was significantly higher in female MDD compared to healthy female controls (P<0.05). No significant association with treatment response was discovered in haplotype and single-marker analysis.
  
  
  CONCLUSIONS
  This study lacks a placebo control and we cannot definitively exclude the possibility that some patients in the responder group responded to the placebo effect alone.
  
  
  CONCLUSIONS
  The result suggests that TPH2 gene may have a gender dependent effect on susceptibility to MDD but not with its treatment response in Chinese Han population. Further studies are needed to replicate the association that we observed.
authors.affiliation: Department of Neurosis and Psychosomatic Diseases, Huzhou 3rd Hospital, Huzhou, Zhejiang, 313000, PR China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Shen
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Wu
authors.forename: Mingcai
authors.initials: M
authors.lastname: Qian
authors.forename: Xiaoquan
authors.initials: X
authors.lastname: Wang
authors.forename: Zhenghua
authors.initials: Z
authors.lastname: Hou
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Jushui
authors.initials: J
authors.lastname: Sun
authors.forename: Hua
authors.initials: H
authors.lastname: Zhong
authors.forename: Jianhong
authors.initials: J
authors.lastname: Yang
authors.forename: Min
authors.initials: M
authors.lastname: Lin
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.forename: Tiefeng
authors.initials: T
authors.lastname: Guan
authors.forename: Zhongxia
authors.initials: Z
authors.lastname: Shen
authors.forename: Yonggui
authors.initials: Y
authors.lastname: Yuan
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D044466:Asian People / Q000235:genetics*; D016022:Case-Control Studies; D002681:China; D003866:Depressive Disorder / Q000235:genetics; D003865:Major Depressive Disorder / Q000235:genetics* / Q000628:therapy*; D005260:Female; D056726:Genetic Association Studies; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D044382:Population Groups / Q000235:genetics; D016896:Treatment Outcome; D014365:Tryptophan Hydroxylase / Q000235:genetics*
chemical_list: C494784:TPH2 protein, human; D014365:Tryptophan Hydroxylase