22q11.2 deletion syndrome, which has several presentations including DiGeorge syndrome (DGS), DiGeorge anomaly, velo-cardio-facial syndrome, Shprintzen syndrome, conotruncal anomaly face syndrome, Strong syndrome, congenital thymic aplasia, and thymic hypoplasia is a syndrome caused by the deletion of a small piece of chromosome 22. The deletion occurs near the middle of the chromosome at a location designated q11.2 i.e. , on the long arm of one of the pair of chromosomes 22. It has a prevalence estimated at 1:4000. The syndrome was described in 1968 by the pediatric endocrinologist Angelo DiGeorge.