title : Identifcation of asthma-related genes using asthmatic blood eQTLs of Korean patients

Abstract : 

Background More than 200 asthma-associated genetic variants have been identifed in genome-wide association studies (GWASs). Expression quantitative trait loci (eQTL) data resources can help identify causal genes of the GWAS 

signals, but it can be difcult to fnd an eQTL that refects the disease state because most eQTL data are obtained from normal healthy subjects.

Methods We performed a blood eQTL analysis using transcriptomic and genotypic data from 433 Korean asthma patients. To identify asthma-related genes, we carried out colocalization, Summary-based Mendelian Randomization 

(SMR) analysis, and Transcriptome-Wide Association Study (TWAS) using the results of asthma GWASs and eQTL data. 

In addition, we compared the results of disease eQTL data and asthma-related genes with two normal blood eQTL data from Genotype-Tissue Expression (GTEx) project and a Japanese study.

Results We identifed 340,274 cis-eQTL and 2,875 eGenes from asthmatic eQTL analysis. We compared the disease eQTL results with GTEx and a Japanese study and found that 64.1% of the 2,875 eGenes overlapped with the GTEx 

eGenes and 39.0% with the Japanese eGenes. Following the integrated analysis of the asthmatic eQTL data with asthma GWASs, using colocalization and SMR methods, we identifed 15 asthma-related genes specifc to the Korean asthmatic eQTL data.

Conclusions We provided Korean asthmatic cis-eQTL data and identifed asthma-related genes by integrating them with GWAS data. In addition, we suggested these asthma-related genes as therapeutic targets for asthma. We envis‑

age that our fndings will contribute to understanding the etiological mechanisms of asthma and provide novel therapeutic targets.

Keywords Asthma, Expression quantitative trait loci, Genome-wide association study, Colocalization, Summarybased Mendelian Randomization, Transcriptome-wide association study