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22q11.2 Deletion Syndrome

Alternate test name

DiGeorge Syndrome (DGS), Velocardiofacial Syndrome (VCFS), Shprintzen Syndrome

Gene name / Alternate gene name
  • 29 genes within the 22q11-13 region
Lab area
Genome Diagnostics - Molecular Genetics
Method and equipment
Deletion/duplication analysis via MLPA
Expected turn-around time
Pregnancy/STAT: 2-3 weeks Routine: 4-6 weeks
Specimen type

Blood; extracted DNA is not accepted for this test.

For details about specimen requirements, please refer to: Specimen Types & Requirements (PDF).

Specimen requirements

5-10 mL EDTA
0.5 mL EDTA (neonate)

Storage and transportation

Room Temperature

For details about specimen requirements, please refer to: Specimen Type and Requirements

DNA extracted at an external lab is not accepted for MLPA testing.

Special requirements

Special Instructions for Genome Diagnostics Samples

If sample shipment >48 hours, ship on ice.

Shipping information
The Hospital for Sick Children
Division of Genome Diagnostics
555 University Avenue, Black Wing, Room 3416
Toronto, ON
M5G 1X8
Phone: 416-813-7200 ext. 2
Hours: Monday to Friday, 8 a.m. to 4:30 p.m.
Off hours: Please send to Rapid Response Laboratory, 555 University Avenue, Room 3642
Email Molecular Lab:
Email Cytogenetics:
Background and clinical significance

22q11DS is one of the most common genetic causes of learning disabilities and mild intellectual delay, with an incidence of 1 per 4,000 live births. Individuals with 22q11.2 deletion syndrome (22q11DS), also known as DiGeorge syndrome or Velo-Cardio-Facial syndrome, have a number of physical and cognitive clinical features in common, such as congenital heart defects, learning difficulties and characteristic facial features although not everyone with 22q11DS has all of the features or is affected to the same degree of severity.


22q11.2 deletion syndrome is caused by deletion of a small part of chromosome 22 at a location designated 22q11.2. The disorder is an autosomal dominant condition and so an individual is affected with 22q11DS when a deletion is present on one of their two copies of chromosome 22. An individual with a 22q11.2 deletion has a 50% chance of transmitting the chromosome 22 with the deletion to a child. Most patients (~90%) with 22q11DS are new occurrences (deletion is not inherited) while ~10% of individuals with 22q11.2 deletion syndrome have inherited the deletion from a parent.

Approximately 90% of individuals with 22q11DS have a “common” 3 Mb deletion that remove of over 40 genes detectable with chromosome FISH analysis. The remaining patients have smaller deletions that are nested within the 3 Mb common deletion region and a few patients with deletions outside this region. To date no correlation has been found between the size or extent of the deletion and the severity of the clinical phenotype. Molecular testing for 22q11DS involves the determination of the copy number of the genes in the 22q11 region to define the relative start and end point of the deletion (see Figure 1 below).

See related information sheet 22q11.2 Deletion Syndrome

Disease condition

22q11.2 Deletion Syndrome

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