TBX1 and 22q11.2 deletion syndrome: DiGeorge syndrome (DGS) is usually caused by 22q11.2 deletion; the most common deletion includes loss of TBX1 gene which is an important transcription factor for the development of the heart, thymus, parathyroid glands, palate, and teeth: thus, haploinsufficiency of TBX1 is thought to be the greatest cause of the disorder [1, 2].