title: Association analysis of putative cis-acting polymorphisms of interleukin-19 gene with schizophrenia.
abstract: BACKGROUND
  Genome-wide association studies (GWAS) and gene expression analyses have revealed that single nucleotide polymorphisms (SNPs) associated with multifactorial diseases, such as schizophrenia, are significantly more likely to be associated with expression quantitative trait loci (eQTL). It was recently suggested that an immune system imbalance plays an important role in the pathogenesis of schizophrenia. Interleukin-19 is a novel cytokine that may play multiple roles in immune regulation and various diseases.
  
  
  METHODS
  We selected eight tag SNPs in the eQTL of the IL-19 gene. Seven of the SNPs are putative cis-acting SNPs. Then, we conducted a case-control study using two independent samples. The first sample comprised 567 schizophrenia patients and 710 controls, and the second sample comprised 677 schizophrenia patients and 667 controls.
  
  
  RESULTS
  We identified the TGAA haplotype as being significantly associated with schizophrenia (p=0.0036 and corrected p=0.0264), although a combined analysis of the TGAA haplotype with the replication samples exhibited a nominally significant difference (p=0.022 and corrected p=0.235).
  
  
  CONCLUSIONS
  These results suggest that the IL-19 gene might slightly contribute to the genetic risk of schizophrenia. Thus, further research on the association of eQTL SNPs with schizophrenia is warranted.
authors.affiliation: Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okazaki
authors.affiliation: Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan. Electronic address: hishipon@med.kobe-u.ac.jp.
authors.forename: Akitoyo
authors.initials: A
authors.lastname: Hishimoto
authors.affiliation: Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Sasada
authors.affiliation: Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Mouri
authors.affiliation: Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Shiroiwa
authors.affiliation: Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Noriomi
authors.initials: N
authors.lastname: Eguchi
authors.affiliation: Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Woraphat
authors.initials: W
authors.lastname: Ratta-Apha
authors.affiliation: Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Otsuka
authors.affiliation: Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Nunokawa
authors.affiliation: Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Naoshi
authors.initials: N
authors.lastname: Kaneko
authors.affiliation: Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Shibuya
authors.affiliation: Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Someya
authors.affiliation: Department of Neuropsychiatry, Kinki University School of Medicine, Osaka, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Shirakawa
authors.affiliation: Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sora
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics / Q000523:psychology; D016022:Case-Control Studies; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007378:Interleukins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D040641:Quantitative Trait Loci / Q000235:genetics; D012559:Schizophrenia / Q000235:genetics*
chemical_list: C421250:IL19 protein, human; D007378:Interleukins
keywords: Haplotype; IL-19; SNP; Schizophrenia; eQTL