Epigenetic Approach to Asthma Diagnosed using Korean Differentiation- Category in Traditional Korean Medicine

Asthma is a serious disease around the world. It is caused by genetic and environmental factors. Epigenetics is the study of heritable changes in gene expression without changes of deoxyribonucleic acid (DNA) sequences. The gene expression change is due to methylation on DNA. Traditional Korean Medicine (TKM) uniquely classifies patients with asthma according to their symptoms. The present study is investigated to find a novel epigenetic marker of diagnosis for Korean asthma patients using Korean differentiation syndrome category in TKM. We recruited 62 patients with asthma from departments of respiratory medicine in hospitals. They are classified by symptom diagnosis and questionnaire to the deficiency syndrome (DS) group and excess syndrome (ES) group. And their DNA was extracted from peripheral blood. To investigate novel epigenetic markers on classification by Korean differentiation syndrome category, methylation analysis was performed using next generation sequencing (NGS), Agilent SureSelect Human Methyl-Seq which is a tool from Agilent Technologies company. In analysis of differential methylated epigenetic markers between the DS group and the ES group, total of 8 sites in exon region in [meprin (a cell surface glycoprotein), A5 antigen (a developmentally-regulated cell surface protein), and receptor protein-tyrosine phosphatase mu domain containing glycosylphosphatidylinositol anchor 1] (MDGA1) gene were considered to be closely associated with differentiation syndrome category in Korean asthma patients. The methylation within MDGA1 gene could be regarded as an epigenetic candidate marker for Korean differentiation syndrome category in Korean asthma patients.