Ethnicity-Dependent Effects of Schizophrenia Risk Variants of the OLIG2 Gene on OLIG2 Transcription and White Matter Integrity

Hiroshi Komatsu, Hikaru Takeuchi, Yoshie Kikuchi, Chiaki Ono, Zhiqian Yu, Kunio Iizuka, Yuji Takano, Yoshihisa Kakuto, Shunichi Funakoshi, Takashi Ono, Junko Ito, Yasuto Kunii, Mizuki Hino, Atsuko Nagaoka, Yasushi Iwasaki, Hidenaga Yamamori, Yuka Yasuda, Michiko Fujimoto, Hirotsugu Azechi, Noriko KudoRyota Hashimoto, Hirooki Yabe, Mari Yoshida, Yuko Saito, Akiyoshi Kakita, Nobuo Fuse, Ryuta Kawashima, Yasuyuki Taki, Hiroaki Tomita

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


Previous studies have indicated associations between several OLIG2 gene single-nucleotide polymorphisms (SNPs) and susceptibility to schizophrenia among Caucasians. Consistent with these findings, postmortem brain and diffusion tensor imaging studies have indicated that the schizophrenia-risk-associated allele (A) in the OLIG2 SNP rs1059004 predicts lower OLIG2 gene expression in the dorsolateral prefrontal cortex (DLPFC) of schizophrenia patients and reduced white matter (WM) integrity of the corona radiata in normal brains among Caucasians. In an effort to replicate the association between this variant and WM integrity among healthy Japanese, we found that the number of A alleles was positively correlated with WM integrity in some fiber tracts, including the right posterior limb of the internal capsule, and with mean blood flow in a widespread area, including the inferior frontal operculum, orbital area, and triangular gyrus. Because the A allele affected WM integrity in opposite directions in Japanese and Caucasians, we investigated a possible association between the OLIG2 gene SNPs and the expression level of OLIG2 transcripts in postmortem DLPFCs. We evaluated rs1059004 and additional SNPs in the 5′ upstream and 3′ downstream regions of rs1059004 to cover the broader region of the OLIG2 gene. The 2 SNPs (rs1059004 and rs9653711) had opposite effects on OLIG2 gene expression in the DLPFC in Japanese and Caucasians. These findings suggest ethnicity-dependent opposite effects of OLIG2 gene SNPs on WM integrity and OLIG2 gene expression in the brain, which may partially explain the failures in replicating associations between genetic variants and psychiatric phenotypes among ethnicities.

Original languageEnglish
Pages (from-to)1619-1628
Number of pages10
JournalSchizophrenia Bulletin
Issue number6
Publication statusPublished - 2020 Nov 1


  • OLIG2 polymorphism
  • schizophrenia
  • white matter integrity/cerebral blood flow/OLIG2 gene expression/ethnic difference

ASJC Scopus subject areas

  • Psychiatry and Mental health


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