22q11.2 Deletion Syndrome (DiGeorge Syndrome and Velo-Cardio-Facial Syndrome)

What is 22q11.2 deletion syndrome?

Chromosomes are structures found in almost every cell in the body. They contain DNA, which provides the instructions that help the body grow, develop and function. Most people have 23 pairs of chromosomes.

22q11.2 deletion syndrome (previously called DiGeorge syndrome or velo-cardio-facial syndrome) occurs when a small piece of chromosome 22 is missing. The term “22q11.2” refers to the specific location on chromosome 22 where the deletion occurs.

How is 22q11.2 deletion syndrome diagnosed?

A genetic test can detect a missing piece of chromosome 22. Chromosomal microarray is now commonly used, although fluorescence in situ hybridization (FISH) may also be used in some situations. This test can help determine whether a person has 22q11.2 deletion syndrome. If initial genetic testing does not find a deletion but symptoms strongly suggest the condition, additional genetic testing may be recommended.

What are the symptoms of 22q11.2 deletion syndrome?

Symptoms can vary from person to person and may be mild to severe. They can include:

• Congenital heart defects
• Autoimmune diseases
• Cleft palate
• Developmental delays and learning disabilities
• Behavioral, emotional or mental health conditions
• Distinctive facial features
• Feeding difficulties
• Hearing loss
• Speech problems
• Hypoparathyroidism (low levels of parathyroid hormone)
• Frequent infections
• Kidney abnormalities
• Scoliosis

If my child has 22q11.2 deletion syndrome, what is the risk for other children or family members?

22q11.2 deletion syndrome affects about 1 in 4,000 to 1 in 7,000 births. Most children with the condition are the first person in their family to be diagnosed with it. In these cases, the deletion usually occurs as a random event before birth, during the formation of the egg or sperm or early in fetal development. Because the deletion can be inherited, genetic testing is generally recommended for both parents after a child is diagnosed.

If a parent has 22q11.2 deletion syndrome, each pregnancy has a 50% (1 in 2) chance of inheriting the deletion. However, the signs and symptoms can vary widely, even among affected members of the same family.

If testing shows that neither parent has the deletion, the chance that another child will have 22q11.2 deletion syndrome is very low and similar to the risk in the general population.