Is 22q11 DiGeorge Syndrome hereditary?

22q11 DiGeorge Syndrome is a genetic condition caused by a microdeletion on chromosome 22, but it is hereditary in only about 10% of cases. In the vast majority of instances, the deletion occurs as a de novo (spontaneous) event in the developing embryo, meaning it is not inherited from either parent.

Is 22q11 DiGeorge Syndrome hereditary?

While 22q11 DiGeorge Syndrome is defined as a genetic disorder, it is important to distinguish between "genetic" and "hereditary." A genetic condition arises from changes in DNA, but a hereditary condition is passed down from parent to child. In approximately 90% of cases, 22q11 DiGeorge Syndrome is caused by a de novo mutation, meaning the genetic change happens randomly during the formation of reproductive cells or early embryonic development. Only about 10% of individuals with this syndrome have inherited the deletion from an affected parent.

What is the inheritance pattern of 22q11 DiGeorge Syndrome?

When 22q11 DiGeorge Syndrome is passed down through a family, it follows an autosomal dominant inheritance pattern. This means that an affected parent has a 50% chance of passing the 22q11.2 deletion to each of their children. Because the clinical presentation of this syndrome can be highly variable—even among family members—a parent may have very mild symptoms and remain undiagnosed until they have a child with more severe manifestations of 22q11 DiGeorge Syndrome.

How is 22q11 DiGeorge Syndrome diagnosed and tested?

Genetic testing is the gold standard for confirming a diagnosis. Because the deletion is often too small to be seen on a standard karyotype, clinicians use specialized molecular testing. The following methods are commonly utilized to identify the underlying genetic cause:

• Chromosomal Microarray (CMA): The current clinical standard to detect the 22q11.2 deletion.


• Fluorescence In Situ Hybridization (FISH): A targeted test used when there is a high clinical suspicion of 22q11 DiGeorge Syndrome.


• MLPA (Multiplex Ligation-dependent Probe Amplification): Another reliable method for identifying copy number variants in the 22q11.2 region.

What is the role of genetic counseling for families?

Genetic counseling is vital for families affected by 22q11 DiGeorge Syndrome. A genetic counselor can perform a detailed family history analysis to determine if the deletion is de novo or inherited. For parents who have had one child with the syndrome, counseling helps determine the recurrence risk for future pregnancies. If a parent is found to carry the deletion, prenatal diagnosis options, such as amniocentesis or chorionic villus sampling (CVS), can be discussed for future family planning. Currently, over 215 members within the DiseaseMaps community have shared their experiences, highlighting the value of connecting with others who have navigated these complex genetic questions.

Next steps

• Consult with a board-certified clinical geneticist to discuss testing and recurrence risks.


• Request a referral to a genetic counselor to review your family history and testing options.


• Connect with the DiseaseMaps community to learn from the 215+ individuals currently sharing their experiences with 22q11 DiGeorge Syndrome.


• Visit the International 22q11.2 Foundation for specialized resources and clinical guidance.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

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


• Orphanet: 22q11.2 deletion syndrome (ORPHA: 567).


• OMIM (Online Mendelian Inheritance in Man): 22q11.2 Deletion Syndrome (Entry #188400).


• The International 22q11.2 Foundation: Patient and family resources.