22q11 Deletion Syndrome

What is 22q11 deletion syndrome?

22q11 deletion syndrome (also called 22q deletion syndrome or 22q DS) is a congenital condition that in many cases can involve congenital heart disease, abnormalities of the palate, facial irregularities, and speech and learning difficulties. Immune deficiencies and low calcium may be present in some cases. A smaller number of children with this condition can have feeding problems, kidney problems, hearing loss, growth hormone deficiencies, autoimmune disorders, seizures, or skeletal abnormalities.

There is a large range of differences among children with this condition. For some, only a few of the signs and symptoms may be present in a mild form. For others, more signs and symptoms may be present, or the signs and symptoms may be more severe.

This deletion is estimated to affect approximately 1 in 4,000 babies. It is the most common microdeletion syndrome. 

Before the cause of 22q11 deletion syndrome was discovered in the early 1990s, the majority of children with this syndrome were diagnosed with DiGeorge syndrome or velocardiofacial syndrome (also called Shprintzen syndrome). This deletion has also been detected in a number of cases of Conotroncal Anomaly Face Syndrome, Caylor Cardiofacial Syndrome, and Opitz G/BBB Syndrome. 

What causes 22q11 deletion syndrome?

22q Deletion Syndrome
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22q Deletion Syndrome is when genes are missing on a section of DNA strand in the q arm of Chromosome 22.
22q11 deletion syndrome is caused because a small piece of chromosome 22 is missing. This is called a deletion, or microdeletion. In a large majority of cases, the deletion is a new or spontaneous, but in a few cases, it is inherited in an autosomal dominant manner. That means if one parent has the deletion, a child has a 50% chance of having it too.

What heart conditions may be associated with 22q11 deletion syndrome?

In one study of 250 patients with this syndrome, 74% had a congenital heart condition. The most likely conditions were tetralogy of Fallot, interrupted aortic arch, ventricular septal defect, and truncus arteriosus.

What is the long-term outlook for children with 22q11 deletion syndrome?

Outcomes related to the congenital heart conditions that may be present in this syndrome depend on the individual heart condition involved. 

It is likely that the majority of children with this syndrome will experience some developmental delay or difficulty with learning. Adults with this condition are at greater risk than typically-developing individuals for developing psychiatric conditions, including schizophrenia.

For more information about 22q11 deletion syndrome, please ask to be referred to a genetic counsellor.

Fraser Golding, MD, FRCPC