title: Mapping of hepatic expression quantitative trait loci (eQTLs) in a Han Chinese population.
abstract: BACKGROUND
  Elucidating the genetic basis underlying hepatic gene expression variability is of importance to understand the aetiology of the disease and variation in drug metabolism. To date, no genome-wide expression quantitative trait loci (eQTLs) analysis has been conducted in the Han Chinese population, the largest ethnic group in the world.
  
  
  METHODS
  We performed a genome-wide eQTL mapping in a set of Han Chinese liver tissue samples (n=64). The data were then compared with published eQTL data from a Caucasian population. We then performed correlations between these eQTLs with important pharmacogenes, and genome-wide association study (GWAS) identified single nucleotide polymorphisms (SNPs), in particular those identified in the Asian population.
  
  
  RESULTS
  Our analyses identified 1669 significant eQTLs (false discovery rate (FDR) < 0.05). We found that 41% of Asian eQTLs were also eQTLs in Caucasians at the genome-wide significance level (p=10⁻⁸). Both cis- and trans-eQTLs in the Asian population were also more likely to be eQTLs in Caucasians (p<10⁻⁴). Enrichment analyses revealed that trait-associated GWAS-SNPs were enriched within the eQTLs identified in our data, so were the GWAS-SNPs specifically identified in Asian populations in a separate analysis (p<0.001 for both). We also found that hepatic expression of very important pharmacogenetic (VIP) genes (n=44) and a manually curated list of major genes involved in pharmacokinetics (n=341) were both more likely to be controlled by eQTLs (p<0.002 for both).
  
  
  CONCLUSIONS
  Our study provided, for the first time, a comprehensive hepatic eQTL analysis in a non-European population, further generating valuable data for characterising the genetic basis of human diseases and pharmacogenetic traits.
authors.affiliation: Department of General Surgery, Shanghai First People's Hospital, Medical College, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Wang
authors.forename: Huamei
authors.initials: H
authors.lastname: Tang
authors.forename: Mujian
authors.initials: M
authors.lastname: Teng
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Li
authors.forename: Jianguo
authors.initials: J
authors.lastname: Li
authors.forename: Junwei
authors.initials: J
authors.lastname: Fan
authors.forename: Lin
authors.initials: L
authors.lastname: Zhong
authors.forename: Xing
authors.initials: X
authors.lastname: Sun
authors.forename: Junming
authors.initials: J
authors.lastname: Xu
authors.forename: Guoqing
authors.initials: G
authors.lastname: Chen
authors.forename: Dawei
authors.initials: D
authors.lastname: Chen
authors.forename: Zhaowen
authors.initials: Z
authors.lastname: Wang
authors.forename: Tonghai
authors.initials: T
authors.lastname: Xing
authors.forename: Jinyan
authors.initials: J
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.forename: Shuyun
authors.initials: S
authors.lastname: Wang
authors.forename: Xiao
authors.initials: X
authors.lastname: Peng
authors.forename: Shengying
authors.initials: S
authors.lastname: Qin
authors.forename: Yongyong
authors.initials: Y
authors.lastname: Shi
authors.forename: Zhihai
authors.initials: Z
authors.lastname: Peng
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics*; D020869:Gene Expression Profiling; D005828:Genetics, Population; D055106:Genome-Wide Association Study; D006801:Humans; D008099:Liver / Q000502:physiology*; D008297:Male; D010597:Pharmacogenetics; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D044465:White People / Q000235:genetics
keywords: Clinical genetics; Genetics; Genome-wide; Molecular genetics