DiGeorge syndrome Dr Trisha Macnair DiGeorge syndrome is an inherited condition where several different genes are lost. This can result in health problems of varying degrees.

In this article

What causes it? Who's affected?

What are the symptoms? What's the treatment?

Di George syndrome is an inherited condition that lies at the more severe end of a spectrum of syndromes (also known as CATCH22 or 22q11.2 deletion syndrome) that occur when a part of the DNA on chromosome 22 is missing. Several different genes are lost, resulting in a collection of different features, including problems with the immune system, congenital heart defects and abnormalities of the parathyroid glands.

Although 90 per cent of cases of DiGeorge may now be attributed to a 22q11.2 deletion, other chromosome defects have been identified, for example, on chromosome ten or 18.

DiGeorge syndrome affects about one in 4,000 births.

In most cases, 22q11.2 deletion is a new mutation (there's no family history), but DiGeorge may be passed on in an autosomal dominant fashion. In some families, several members are affected.

Babies with DiGeorge syndrome are born with a variety of different problems, some or all of which may be present to varying degrees.

The parathyroid glands in the neck may have failed to develop, leading to low levels of calcium in the blood. This can result in muscle spasms (tetany) and seizures.

The thymus gland may also be underdeveloped or absent, resulting in a deficiency of an important type of immune cell known as the T lymphocyte.

Infections (seldom life-threatening) and autoimmune disease (such as haemolytic anaemia, inflammatory bowel disease and juvenile rheumatoid arthritis) are common.

There are often heart defects, particularly affecting the large vessels that lead out of the heart.

There may be a typical facial appearance with a small jaw, small, low-set ears with abnormal folds, unusual eyes, small mouth, a rather bulbous nose and square nasal tip, and hypernasal speech with a cleft palate.

Short stature and variable mild to moderate learning difficulties are also common.

Sometimes the syndrome won't be detected until later in infancy, especially when problems are mild.

DiGeorge syndrome can't be cured, but treatment of problems such as low calcium, surgery for heart problems and thymus cell transplants to restore the immune system can reduce complications. Educational support and help for the family is vital.

Antenatal diagnosis, usually using CVS or amniocentesis, is possible especially when there's a family history or abnormalities on ultrasound scanning. Postnatal diagnosis is also available for those at risk of passing on the condition.

This article was last medically reviewed by Dr Rob Hicks in January 2008