How is 22q11 DiGeorge Syndrome diagnosed?

TL;DR: 22q11 DiGeorge Syndrome is primarily diagnosed through specialized genetic testing, specifically a chromosomal microarray (CMA) or fluorescence in situ hybridization (FISH) to detect a deletion on chromosome 22. Because the condition presents with a wide spectrum of symptoms—ranging from cardiac defects to immune deficiencies—it is often identified by a multidisciplinary team of specialists following the clinical suspicion of systemic physical or developmental differences.

How is 22q11 DiGeorge Syndrome clinically diagnosed?

The diagnostic journey for 22q11 DiGeorge Syndrome often begins when a physician notices a pattern of clinical features, such as distinct facial characteristics, heart defects, or recurrent infections. Because the phenotype is so variable, there is no single "look" for the syndrome. Clinicians typically look for a combination of the "CATCH-22" features: Cardiac defects, Abnormal facies, Thymic hypoplasia, Cleft palate, and Hypocalcemia. When these are observed, a referral to a clinical geneticist is the gold standard for confirming a diagnosis of 22q11 DiGeorge Syndrome.

What specific tests confirm 22q11 DiGeorge Syndrome?

Confirmation of 22q11 DiGeorge Syndrome requires molecular genetic testing to identify the microdeletion on the long arm of chromosome 22. The following tests are commonly utilized in the diagnostic process:

• Chromosomal Microarray (CMA): The current first-line diagnostic test, which provides high-resolution analysis to detect missing or duplicated segments of DNA.


• FISH (Fluorescence In Situ Hybridization): A targeted test that specifically looks for the deletion in the 22q11.2 region; while highly accurate, it does not detect other chromosomal abnormalities.


• Echocardiogram: Used to identify structural heart anomalies, which occur in approximately 75% of individuals with 22q11 DiGeorge Syndrome.


• Immunological Panel: Blood tests to measure T-cell counts and function, assessing the impact of thymic hypoplasia.


• Serum Calcium Levels: Monitored to detect hypoparathyroidism, a common endocrine manifestation of the condition.

Why is the diagnostic odyssey so challenging?

For many of the 215 members in our DiseaseMaps community, the "diagnostic odyssey" is a source of profound frustration. Because 22q11 DiGeorge Syndrome can mimic other conditions like autism spectrum disorder, developmental delay, or isolated congenital heart disease, families often spend years visiting various specialists before a genetic cause is identified. It is normal to feel exhausted by this process; please know that your search for answers is valid. If your primary care provider is unfamiliar with the syndrome, do not hesitate to request a referral to a clinical geneticist or a center specializing in rare pediatric conditions.

Which specialists are involved in the diagnosis?

Diagnosing 22q11 DiGeorge Syndrome is a team effort. You will likely interact with a clinical geneticist, who coordinates the testing, as well as pediatric cardiologists, immunologists, and endocrinologists. Because the condition is multisystemic, differential diagnosis is vital to rule out other syndromes with overlapping features, such as CHARGE syndrome or VACTERL association. Working with a coordinated team ensures that no symptom is overlooked and that your care is managed holistically.

Next steps

• Request a referral to a board-certified clinical geneticist to discuss genetic testing options.


• Gather your family’s medical history to provide your specialist with a comprehensive health timeline.


• Connect with the 215 members on DiseaseMaps.org to learn how others navigated their diagnostic journey.


• Consult the International 22q11.2 Foundation for a list of clinical centers of excellence in your region.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment from a qualified healthcare provider.

References

• NIH Genetic and Rare Diseases Information Center (GARD): 22q11.2 deletion syndrome entry.


• Orphanet: Rare disease database, 22q11.2 deletion syndrome profile.


• OMIM (Online Mendelian Inheritance in Man): DiGeorge Syndrome (#188400).


• The International 22q11.2 Foundation: Clinical resources and patient support data.