TBX1 and 22q11.2 deletion syndrome: TBX1 is considered a candidate gene of DGS/VCFS because haploinsufficiency of TBX1 leads to the typical phenotypes of DGS/VCFS, conotruncal anomaly face syndrome (OMIM #217095), and tetralogy of Fallot (OMIM #187500) (Table 3).