22q11.2 deletion syndrome

22q11.2 deletion syndrome, also known as the DiGeorge syndrome or velocardiofacial syndrome, is a syndrome where a small portion of the chromosome 22 is lost and results in a variable but a recognisable pattern of physical and behavioral features.

Epidemiology

The estimated incidence is at ~ 1 in 4000-6000 live pregnancies .

Clinical presentation

CATCH 22 is the mnemonic to remember the chromosome and all the abnormalities.

Pathology

Genetics

There is a near-universal association with a deletion within chromosome 22q11.2. The majority of cases have de novo mutations. 22q11 deletions are associated with some types of conotruncal cardiac defects as well as conotruncal anomaly face syndrome .

Associations

Radiographic features

Temporal bone malformations are common: :

Brain and cerebrovascular malformations are common :

Cardovascular, particularly conotruncal, defects are usually the first imaging abnormality noted in these patients :

History and etymology

First described in 1968 by Angelo DiGeorge (1921-2009), an American physician.