Introduction
Asthma is a common chronic inflammatory disease of the airways resulting from the interaction of genetic susceptibility with environmental exposures across the life course1. Both genetic and environmental factors contribute to disease risk, with genetic factors accounting for 35–95% of the susceptibility to progress asthma2. Genetic risk factors may be useful in classifying the endotypes of asthma, and genetic studies allow a structured means of understanding the causes of asthma as well as verifying targets that can be used to treat the disease3. Some studies on the genetic associations with asthma have been conducted, and genome-wide association studies (GWAS) represent the most powerful approach for identifying genes that influence asthma4.
The results of GWASs have highlighted the importance of genetic variants in, or near, genes that are implicated in asthma. Previous studies have reported 41 regions associated with asthma, providing novel insight into disease biology3,5,6. However, few GWAS have been performed for populations of racial and ethnic minorities. Several studies have reported significant differences in the allele frequencies of the variants and genetic architecture between European and Asian populations7. These suggest that genetic associations with asthma do not consistently replicate across studies because of the heterogeneity of populations. Therefore, GWAS using different ethnic populations are needed for a better understanding of the genetic basis of asthma.
Although many recent GWAS have reported the association of multiple loci with asthma risk, the effect of genetic variation on asthma susceptibility in the Korean population has not been elucidated. For the Korean population, some studies have performed simple replication analysis and reported the results of GWAS for aspirin exacerbated respiratory disease (AERD)8,9. However, no studies have confirmed the genetic susceptibility of asthma using GWAS in the Korean population. Therefore, the aim of this study was to (1) identify genetic variants associated with adult asthmatics in the Korean population, and (2) evaluate whether significant single nucleotide polymorphisms (SNPs) in the UK Biobank are specifically correlated with those in Korean asthmatics.