title: Association of schizophrenia with the rs821633 polymorphism in the DISC1 gene among Han Chinese.
abstract: BACKGROUND
  Previous studies report that various single nucleotide polymorphisms (SNP) in the Disrupted-in Schizophrenia 1 (DISC1) gene are closely associated with schizophrenia, but there are no studies that assess the relationship of age of onset of schizophrenia with these SNPs.
  
  
  OBJECTIVE
  Investigate the relationship between the rs821633 SNP in the DISC1 gene and the occurrence and age of onset of schizophrenia in Han Chinese.
  
  
  METHODS
  We used the TaqMan genotyping technology to examine the rs821633 SNP in the DISC1 gene among 315 individuals who developed schizophrenia prior to 19 years of age ('early-onset'), 407 individuals who developed schizophrenia when 19 years of age or older ('late-onset'), and 482 healthy controls. We used survival analyses to investigate the relationship between the rs821633(C) risk allele and the age of onset of schizophrenia.
  
  
  RESULTS
  Compared to the prevalence in healthy controls, the prevalence of the C/C genotype of rs821633 and of the C allele in rs821633 were significantly greater in individuals with early-onset schizophrenia (X (2)=7.17, df=1, p=0.007; X (2)=7.20, df=2, p=0.032) and significantly greater in individuals with late-onset schizophrenia (X (2)=5.36, df=1, p=0.022; X (2)=6.58, df=2, p=0.041). However, there were no significant differences in the prevalence of the C/C genotype or the C allele between individuals with early-onset and late-onset schizophrenia. Kaplan-Meier survival analyses found no significant association between the rs821633(C) risk allele and age of onset in schizophrenia.
  
  
  CONCLUSIONS
  We confirm the association of polymorphism in the rs821633 SNP in the DISC1 gene with schizophrenia among Han Chinese, but we found no association between the rs821633(C) risk allele and the age of onset in individuals with schizophrenia.
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Guoqin
authors.initials: G
authors.lastname: Hu
authors.affiliation: Mental Health Center of Hongkou District, Shanghai, China.
authors.forename: Chengqing
authors.initials: C
authors.lastname: Yang
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Minghuan
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Xiangqing
authors.initials: X
authors.lastname: Guo
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Chenxi
authors.initials: C
authors.lastname: Bao
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Si
authors.initials: S
authors.lastname: Jia
authors.affiliation: Mental Health Center of Hongkou District, Shanghai, China.
authors.forename: Ahong
authors.initials: A
authors.lastname: Xu
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Jie
authors.affiliation: Mental Health Center of Hongkou District, Shanghai, China.
authors.forename: Zuowei
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Yongguang
authors.initials: Y
authors.lastname: He
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Qinyu
authors.initials: Q
authors.lastname: Lv
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Shunying
authors.initials: S
authors.lastname: Yu
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Zhenghui
authors.initials: Z
authors.lastname: Yi
keywords: China; DISC1 gene; age of onset; schizophrenia; single nucleotide polymorphism; transmission disequilibrium test