- approximately 50%: DiGeorge Syndrome (OMIM 188400) [94] by 22q11.2 deletion of about 3 Mb interesting > 35 genes, among which the TBX-1 (T-box 1) gene involved in the development of heart, thymus, parathyroid glands, palate, face; note that the vast majority of infants with DiGeorge syndrome have "partial" DiGeorge anomaly, with low T cell counts but not the immunodeficiency of complete DiGeorge anomaly;. The gene discussed is TBX1; the disease is 22q11.2 deletion syndrome.