DiGeorge Syndrome (also known as 22q11.2 Deletion Syndrome, and formerly Velocardiofacial Syndrome) is a syndrome caused by the deletion of a small segment (microdeletion) of chromosome 22. It is the most common microdeletion syndrome in humans. This microdeletion is also responsible for a 20 to 30 times increased risk for schizophrenia, which equates to 1 in 4 individuals developing schizophrenia. Thus, 22q11.2 deletion is considered to be the first true molecular genetic subtype of schizophrenia. In addition, individuals often have congenital heart problems, facial dysmorphia, developmental delay, learning problems, and cleft palate. Renal impairment, hearing loss, infections, and autoimmune disorders are also common.