Test Code LAB1808 22q11.2 Del/Dup by MLPA
Clinical System Name
22q11.2 Deletion/Duplication test by MLPA
Description
Microdeletions/duplications in the 22q11.2 region cause a variety of disorders, including DiGeorge syndrome (DGS), velocardiofacial syndrome (VCFS) and cat eye syndrome (CES).
This test can be used to detect copy number changes (deletions and duplication) in the chromosome 22q11.2 region. Deletions in 22q11.2 occur in 1 in 4,000 live births and can cause a variety of clinical features including:
- Cardiac anomalies
- Palatal defects
- Learning difficulties
- Hypocalcemia
- Immune deficiency
- Atypical facial features
This test can also be used to detect rare copy number changes in the 10p14 region.
Sample Requirements
Note: For patients who have had a whole blood transfusion, wait 10 days post transfusion to draw for genetic testing. No wait time is necessary for blood or saliva collection if the patient received leuko-reduced red cells or plasma.
Specimen: Whole blood, cord blood
Container(s): Lavender/EDTA, Yellow/ACD A or B
Preferred Vol: 3 mL
Minimum Vol: 1 mL
Processing Instructions
Reject due to: Heparin
Spin: No
Aliquot: No
Temp: Refrigerate
Storage location: Molecular Genetics box in CPA refrigerator #2
Off-site collection: Refrigerate blood samples until ready to ship. Transport all sample types at room temperature via overnight shipping.
Stability
Specimen Type | Temperature | Time |
---|---|---|
Whole blood | Room temp | 3-5 days |
Whole blood | Refrigerated | 7 days |
Note: Whole blood samples > 7days may be submitted to be assessed by our lab for acceptability for testing.
Availability
STAT | Performed | TAT |
---|---|---|
Contact lab | Monday - Friday | 5-10 days |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Molecular Genetics Laboratory
Phone: 206-987-3872
Lab Client Services: 206-987-2617
Lab Genetic Counselor: LabGC@seattlechildrens.org
CPT Codes
81479 (updated 11/1/17)
Methodology
Method: Multiple ligation-dependent probe amplification (MLPA) of targeted regions on chromosome 22 and chromosome 10.
Limitations: More than 98% of individuals with 22q.11.2 deletion syndrome can be detected with this assay
Reference Range
Interpretive report will be provided
Requisition
Clinical Utility
Copy number changes in 22q.11.2 occur in 1 in 4,000 live births and can cause a variety of clinical features that include cardiac anomalies, palatal defects, learning difficulties, hypocalcemia, immune deficiency and atypical facial features. Other common names for this disorder include DiGeorge Syndrome and velocardiofacial syndrome (VCFS).
Special Instructions
Link to: 22q11.2 Deletion Syndrome GeneReviews
Link to: 22q Test Comparison Tool