A submicroscopic deletion of chromosome 22q11.2 has been identified in the majority of patients with the DiGeorge, velocardiofacial, and conotruncal anomaly face syndromes, and in some patients with the Opitz G/BBB and Cayler cardiofacial syndromes. ... The Philadelphia story: the 22q11.2 deletion: report on 250 patients Genet Couns. 1999;10(1 ....