DiGeorge syndrome

DiGeorge syndrome, or 22q11.2 deletion syndrome, is a syndrome caused by the deletion of a small segment of chromosome 22. The symptoms are caused by the lack of those genes. 
The symptoms often include congenital heart problems, facial features, infections, developmental delay, learning problems and cleft palate. Other conditions include kidney problems, hearing loss and autoimmune disorders such as rheumatoid arthritis or Graves disease.
DiGeorge syndrome is due to the deletion of 30 to 40 genes in the middle of chromosome 22 at a location known as "22q11.2". About 90% of cases occur due to a new mutation during early development, while 10% are inherited from a person's parents. 
The condition is autosomal dominant: only one affected chromosome is needed for the condition to occur. Diagnosis is suspected based on the symptoms and confirmed by genetic testing.
Although there is no cure, treatment can improve symptoms. This often includes efforts to improve the function of the many organ systems involved. Long-term outcomes depend on the symptoms present and the severity of the heart and immune system problems. With treatment, life expectancy may be normal.
DiGeorge syndrome occurs in about 1 in 4,000 people. The syndrome was first described in 1968 by American physician Angelo DiGeorge. In late 1981, the underlying genetics were determined.