Association of Genetic Polymorphisms with Atopic Dermatitis, Clinical Severity and Total IgE: A Replication and Extended Study

PURPOSE: Atopic dermatitis (AD) is a common and chronic inflammatory skin disease affecting up to 20% of children and 3% of adults worldwide. Although previous reports including genome-wide association study (GWAS) approaches have identified several risk factors that appear to be associated with AD development, replication studies are lacking. In our current study, we replicated the associations between candidate susceptibility loci and AD. METHODS: A total of 885 Korean subjects (425 AD patients and 460 unaffected controls) were genotyped for 17 single nucleotide polymorphisms (SNPs) from previous GWASs and meta-analyses of AD and from immune-related genes. RESULTS: Several SNPs showed significant associations with AD in the case-control analysis (minimum P=0.005 at rs17389644), suggesting that these polymorphisms may be related to this disease. In addition, several SNPs showed significant signals (minimum P=0.004 at rs6473227) in severe AD compared to unaffected controls. In additional linear regression analysis, a few genotypes appeared to have potential effects on the SCORing AD (SCORAD) values (minimum P=0.003 at rs13361382 on TMEM232) and immunoglobulin E (IgE) levels (minimum P<0.0001 at rs4713555 near HLA-DRB1 and HLA-DQA1) in AD patients. CONCLUSIONS: Our replication and extended study provide additional supporting information on the genetic associations (especially, variants in TMEM232 and nearby to IL21 and HLA-DRB1/HLA-DQA1) related to AD, its clinical severity and IgE involvement.