NKX2-5 and coronary artery disorder: However, although NKX2-5 has been extensively studied among different CH populations, including Chinese [13], Japanese [16], Brazilian [31,32], Czech [39], Dutch [40], and Iranian [41] patients, no fully penetrant pathogenic genotype has been found to condition CH-TD [40], with or without CHD [38,39,40], nor is TD a characteristic feature of patients with CHD attributable to NKX2-5 defects [40].