title: Association of tryptophan hydroxylase-2 polymorphisms with oppositional defiant disorder in a Chinese Han population.
abstract: BACKGROUND
  Oppositional defiant disorder (ODD) is a behavioral disorder of school-age population. It is well known that 5-HT dysfunction is correlated with impulsivity, which is one of the common characteristics of ODD. The enzyme tryptophan hydroxylase-2 (TPH-2) synthesizes 5-HT in serotonergic neurons of the midbrain raphe. The purposes of this study were to investigate the potential association of TPH-2 polymorphisms with susceptibility to ODD in a Han Chinese school population.
  
  
  METHODS
  Four polymorphisms (rs4570625, rs11178997, rs1386494 and rs7305115) of the TPH-2 gene were analyzed by using polymerase chain reaction and DNA microarray hybridization in a case-control study of 276 Han Chinese individuals (124 ODD and 152 controls).
  
  
  RESULTS
  In single marker analyses,there was a significant difference in the genotype (χ2= 4.163, P = 0.041) and allele frequency (χ2= 3.930, P = 0.047) of rs1386494 between ODD and control groups. Haplotype analyses revealed higher frequencies of haplotypes TA (rs4570625-rs11178997), TAG (rs4570625-rs11178997-rs1386494), TAA (rs4570625-rs11178997-rs7305115) and TAGA (rs4570625-rs11178997-rs1386494-rs7305115), but lower frequencies of haplotypes GA (rs4570625-rs11178997) and GAG (rs4570625-rs11178997-rs1386494) in ODD compared to control groups.
  
  
  CONCLUSIONS
  These findings suggest the role of these TPH-2 gene variants in susceptibility to ODD. Some haplotypes might be the risk factors for Chinese Han children with ODD, while others might be preventable factors.
authors.affiliation: Department of Psychiatry, The Second Affiliated Hospital of Xinxiang Medical University (Psychiatric hospital of Henan province, China), Xinxiang, 453002, Henan, China.
authors.forename: Chang-Hong
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Department of Psychiatry, The Second Affiliated Hospital of Xinxiang Medical University (Psychiatric hospital of Henan province, China), Xinxiang, 453002, Henan, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Psychiatry, The Second Affiliated Hospital of Xinxiang Medical University (Psychiatric hospital of Henan province, China), Xinxiang, 453002, Henan, China.
authors.forename: En-Zhao
authors.initials: EZ
authors.lastname: Cong
authors.affiliation: Department of Psychiatry, The Second Affiliated Hospital of Xinxiang Medical University (Psychiatric hospital of Henan province, China), Xinxiang, 453002, Henan, China.
authors.forename: Gai-Ling
authors.initials: GL
authors.lastname: Xu
authors.affiliation: Department of Psychiatry, The Second Affiliated Hospital of Xinxiang Medical University (Psychiatric hospital of Henan province, China), Xinxiang, 453002, Henan, China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Lv
authors.affiliation: Department of Psychiatry, The Second Affiliated Hospital of Xinxiang Medical University (Psychiatric hospital of Henan province, China), Xinxiang, 453002, Henan, China.
authors.forename: Ying-Li
authors.initials: YL
authors.lastname: Zhang
authors.affiliation: Department of Psychiatry, The Second Affiliated Hospital of Xinxiang Medical University (Psychiatric hospital of Henan province, China), Xinxiang, 453002, Henan, China.
authors.forename: Qiu-Fen
authors.initials: QF
authors.lastname: Ning
authors.affiliation: Department of Psychiatry, The Second Affiliated Hospital of Xinxiang Medical University (Psychiatric hospital of Henan province, China), Xinxiang, 453002, Henan, China.
authors.forename: Ji-Kang
authors.initials: JK
authors.lastname: Wang
authors.affiliation: Department of Psychiatry, The Second Affiliated Hospital of Xinxiang Medical University (Psychiatric hospital of Henan province, China), Xinxiang, 453002, Henan, China. niehuiyao@163.com.
authors.forename: Hui-Yao
authors.initials: HY
authors.lastname: Nie
authors.affiliation: Department of Child and Adolescent, Public Health College, Zhengzhou University, 100 Kexue Road, Zhengzhou, 450001, Henan, China. liyanzzu2009@126.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
mesh_terms: D000293:Adolescent; D044466:Asian People / Q000235:genetics; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000201:enzymology* / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D002681:China; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies / Q000379:methods; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D020641:Polymorphism, Single Nucleotide; D014365:Tryptophan Hydroxylase / Q000235:genetics* / Q000378:metabolism
chemical_list: C494784:TPH2 protein, human; D014365:Tryptophan Hydroxylase
keywords: Oppositional defiant disorder; Single nucleotide polymorphisms; Tryptophan hydroxylase-2 gene