Genome-wide association study of Korean asthmatics: a comparison with UK
Background Although genome-wide association studies (GWAS) represent the
most powerful approach for identifying genes that influence asthma, no
studies have established the genetic susceptibility to asthma in the
Korean population. To identify genetic variants associated with adult
Korean asthmatics and compare them with the significant single
nucleotide polymorphisms (SNPs) of UK asthmatics from UK Biobank.
Methods Asthmatic patients were defined as having asthma if they were
diagnosed by a doctor or taking medications for asthma. Controls were
defined as having no asthma and chronic obstructive pulmonary disease.
We performed the quality controls, genotype imputation, GWAS, and
PrediXcan analysis. In GWAS, P value < 5×10-8 is considered
significant. We compared significant SNPs between Korean asthmatics and
UK asthmatics. Results A total of 1,386 asthmatic patients and 5,205
controls were analyzed. The SNP rs1770, located near human leukocyte
antigen (HLA)-DQB1, was the most significant SNP (P=4.5×10-10). In
comparison with 24 SNPs in GWAS of UK asthmatics, 6 SNPs were
significant with the same odds ratio direction, including signals
related to type 2 inflammation (e.g., IL1RL1, TSLP, and GATA3) and mucus
plugging (e.g., MUC5AC). HLA-DQA1 showed an opposite odds ratio
direction. HLA-DQB1 gene demonstrated significant imputed mRNA
expression levels for lung tissue and whole blood. Conclusions The SNP
rs1770 of HLA-DQB1 was the most significant SNP in Korean asthmatics.
There were similarities and discrepancies in genetic variants between
Korean and UK asthmatics. The GWAS of Korean asthmatics should be
replicated and compared with those of GWAS of other ethnicities.