22q11.2 Deletion Syndrome

Overview

22q11.2 deletion syndrome is a genetic condition caused by a small missing piece of chromosome 22. It is one of the more common chromosomal conditions and has been known by several names, including DiGeorge syndrome and velocardiofacial syndrome, which are now recognized as part of the same condition.

Because the missing genetic material affects the development of several organs and systems, the syndrome can involve a wide range of features. These commonly include heart defects, immune system problems, low calcium levels, differences in the palate, feeding and speech difficulties, and developmental and learning challenges. The features and their severity vary greatly from person to person, so care is individualized and usually coordinated by a team of specialists.

Symptoms

The features of 22q11.2 deletion syndrome vary widely. Common ones include:

• Heart defects: Present in many affected children, ranging from mild to serious.
• Immune problems: A weakened immune system that increases the risk of infections.
• Low calcium: From underactive parathyroid glands, which can cause muscle cramps, jitteriness, or seizures.
• Palate differences: Such as a cleft palate or problems that cause a nasal-sounding voice and feeding difficulties.
• Developmental and learning differences: Delays, learning difficulties, and speech delay.
• Mental health and behavior: A higher risk of anxiety, attention difficulties, and certain other conditions.
• Other features: Distinctive facial features, kidney differences, and feeding problems.

Causes

22q11.2 deletion syndrome is caused by the loss of a small segment of genetic material from one copy of chromosome 22, at a location described as 22q11.2. The missing piece contains a number of genes important for the development of several organs, which explains the wide range of possible features.

In most people, the deletion happens by chance during the formation of egg or sperm cells or in early development, and there is no family history. In a minority of cases, the deletion is inherited from a parent who also has the condition, sometimes in a milder form. A parent with the deletion has a chance of passing it to each child.

Risk Factors

• Most cases occur by chance, without a family history
• Having a parent with the 22q11.2 deletion increases the chance of inheriting it
• There are no known behaviors or exposures during pregnancy that cause it

Genetic counseling can help families understand whether a deletion was inherited and the chance of recurrence.

Diagnosis

Diagnosis is confirmed with genetic testing, often prompted by characteristic features:

• Genetic testing: Specialized tests that detect the missing segment of chromosome 22 confirm the diagnosis; testing may be done before or after birth.
• Clinical evaluation: Recognizing a combination of features such as a heart defect, low calcium, immune problems, or palate differences.
• Additional assessments: Echocardiogram for the heart, immune testing, calcium levels, kidney imaging, and developmental evaluation.

Treatment

There is no cure, so treatment is directed at each affected system and coordinated by a team of specialists. Care may include:

• Heart care: Monitoring and, when needed, surgery to repair heart defects.
• Immune support: Monitoring immune function, taking precautions against infection, and guidance on vaccines.
• Calcium management: Calcium and vitamin D supplements and monitoring of calcium levels.
• Palate and feeding care: Surgery for cleft palate when present, plus feeding and speech therapy.
• Developmental and mental health support: Early intervention, school support, and care for anxiety, attention, or other concerns.
• Ongoing monitoring: Regular checks across systems throughout life.

When to See a Doctor

22q11.2 deletion syndrome is often identified in infancy, especially when a heart defect, low calcium, or palate difference is found, but milder cases may be diagnosed later. Talk to a doctor if a child has a combination of these features, frequent infections, or developmental delays, as genetic testing can confirm the diagnosis.

Seek prompt or emergency care for:

• Signs of a heart problem, such as rapid breathing, poor feeding, or a bluish color
• Seizures, muscle spasms, or jitteriness, which can signal low calcium
• Signs of a serious infection, such as high fever or difficulty breathing

Related Topics

Frequently Asked Questions

References

1. National Institutes of Health (NIH), Genetic and Rare Diseases Information Center (GARD).
2. MedlinePlus, U.S. National Library of Medicine. 22q11.2 deletion syndrome.
3. National Organization for Rare Disorders (NORD).
4. Centers for Disease Control and Prevention (CDC). Birth Defects.