TBX1 and coronary artery disorder: DGCR8, located within the 22q11.2 microdeletion syndrome region, encodes a subunit of the microprocessor complex involved in the biogenesis of microRNA, which plays an important role in global gene regulation.34 While the entire 22q11.2 cytoband is known to be associated with CHD, most research has focused on TBX1 and CRKL.10,18,23 However, previous studies have suggested that there may be a whole set of genes in the region contributing to these phenotypes, including DGCR8.