Genetics Northern California

22q11.2 deletion

What is 22q11.2 deletion syndrome?
How common is 22q deletion syndrome?
What causes 22q11.2 deletion syndrome?
How is 22q11.2 deletion syndrome diagnosed?
Can 22q11.2 deletion syndrome be diagnosed during pregnancy?
How is 22q11.2 deletion syndrome treated?
Where can I get more information about 22q11.2 deletion syndrome?

What is 22q11.2 deletion syndrome?
22q11.2 deletion syndrome is a genetic condition that can affect many parts of the body and may also include learning and behavior issues. This condition has also been called velocardiofacial syndrome (VCFS) and diGeorge syndrome (DGS).

Medical concerns
    - Many different medical concerns are seen with this condition. The most common ones include:
    - Heart defects     
    - Cleft palate (an opening in the roof of the mouth)
    - Immune deficiencies
    - Calcium imbalance
    - Feeding and swallowing problems
    - Intestinal problems

Learning and behavior in 22q11 deletion syndrome
There is a wide range of learning abilities in individuals with this condition. Language is often delayed and there can also be delays in motor milestones, like sitting and walking. Behavior concerns are common and may include social fears, anxiety disorder, attention deficit disorder (ADD), and autism. Mental illness can also be part of this condition and affects about 1 in 4 adults with 22q11.2 deletion syndrome.

How common is 22q11.2 deletion syndrome? 
It is estimated that one in every 3,000 to 6,000 newborns has 22q11.2 deletion syndrome. However, it may be more common than that. The features of this condition are extremely variable, so the diagnosis may be missed in some people.

What causes 22q11.2 deletion syndrome? 
Individuals with 22q11.2 deletion syndrome are missing a small amount of genetic information from chromosome 22. Since there are usually two copies of chromosome 22 (one from each parent) that means a person with this condition only has half the usual amount. The size of the deletion (missing piece) can vary and does not predict the severity of the condition. This condition is usually NOT inherited. Most deletions happen as a random event when an egg or sperm is formed. A small percentage of individuals inherit the 22q11.2 deletion from a parent. A person with this condition has a 50% chance of passing this condition to their offspring.

How is 22q11.2 deletion syndrome diagnosed? 
22q11.2 deletion syndrome is diagnosed in individuals by testing a blood sample with a test called chromosomal microarray (CMA). This test can determine the size of the deletion and which genes are involved. The deletion is usually too small to see by standard chromosome studies using a microscope (karyotype).

Can 22q11.2 deletion syndrome be diagnosed during pregnancy? 
This condition can be diagnosed during pregnancy by using a chromosomal microarray on a sample from a developing baby. The sample can be taken by a prenatal diagnostic test, such as CVS or amniocentesis.

Ultrasound may find birth defects that could be part of 22q11.2 deletion syndrome, like certain heart defects. A diagnostic test would still be needed to confirm the diagnosis. There is a new prenatal screening test that can look for this condition using a blood sample from a pregnant woman. However, this test is not yet routinely offered or recommended due to the high rate of false alarms.

How is 22q11.2 deletion syndrome treated? 
There is no cure or treatment to replace the missing genetic material in individuals with this condition. Medical care is arranged based on individual need and could involve many different specialists. Individuals may receive care from a craniofacial team, especially when a cleft palate is present. This team generally includes specialists in genetics, plastic surgery, maxillofacial surgery, speech, audiology, otolaryngology, developmental pediatrics, neurology, nursing and orthodontics. There may be other medical concerns that are followed by specialists outside the craniofacial clinic. These specialists might include endocrinology, immunology, psychiatry and cardiology. Guidelines for medical care for both children and adults have been published.

Where can I get more information about 22q11.2 deletion syndrome? 
Genetics Home Reference: 22q11.2 deletion syndrome - General information about 22q11.2 deletion syndrome provided by the National Library of Health. Also includes links to many related sites.

Genetic and Rare Diseases Information Center: 22q11.2 deletion syndrome – Broad overview of the condition with links to many sites.

Chromosome 22 Central – Support for disorders of chromosome 22
22q (The International 22q11.2 Deletion Syndrome Foundation) - This site includes information about 22q11.1 deletion syndrome and support resources for families.

Last reviewed: December 20, 2017

Last updated: December 20, 2017

Reviewed by: Kimberly Barr, LCGC