Transcription factor 21 gene polymorphism in patients with coronary artery disease Waleed Abdou Hamed,1 Ghada E Hamoda,2 Sally M El-Hefnawy,2 Eman M Abd El-Gayed2 1Cardiology Department, 2Biochemistry Department, Faculty of Medicine, Menoufia University, Shebin El-Kom, Egypt Background: CAD is the most common type of heart disease and the leading cause of death in both men and women. Transcription factor 21 (TCF21) is required for normal epicardial development and regulates epicardium-derived cell (EPDC) differentiation into smooth muscle and fibroblast lineages.Objectives: The aim of this study was to investigate the distribution of TCF21 (12190287G/C) gene polymorphism in patients with CAD and its association with other clinical and laboratory variables in these patients.Patients and methods: This study was carried out in 100 patients with CAD, and 50 healthy subjects served as controls. All studied subjects underwent laboratory investigations, including measurement of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), creatinine kinase-MB (CK-MB), troponin I (TnI) and genotyping of TCF21 (12190287G/C) gene using the TaqMan Allelic Discrimination assay technique.Results: Serum creatinine, TC, TG, LDL-c, CK-MB and TnI were significantly higher in patients with CAD than in the control group. There was a statistically significant difference regarding genotype frequency of TCF21 (12190287G/C) polymorphism between the two studied groups, with the highest frequency of GG genotype among the control group, while CC genotype had the highest frequency in the patient group. C allele was more frequent in the patient group, while G allele was more frequent in the control group.Conclusion: CC genotype and C allele of TCF21 (12190287G/C) polymorphism are considered as genetic risk factors for CAD; these findings could have an impact on the future preventive and management protocols in this group of patients. Keywords: coronary artery disease, transcription factor, gene polymorphism