FISH for 22q11.2 Del, VCF, DiGeorge
Test Mnemonic
DGEORG
CPT Codes
- 88271 - QTY (2)
- 88275 - QTY (1)
Aliases
- Catch 22 Syndrome
- FISH for DiGeorge Syndrome
- FISH for VCF
- Shprintzen Syndrome
- VCFS
- Velocardiofacial Syndrome
Performing Laboratory
Mayo Clinic Dpt of Lab Med & Pathology
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 5 mL | Whole blood | Sodium heparin (Green) | Ambient | Provide reason for referral with specimen. |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 30 mg | Chorionic Villus | Transport Medium | Refrigerated | ||
| 4 mm | Biopsy, skin | Sterile container | Refrigerated | Use Hank's balanced salt solution, Ringer's solution or normal saline in container. Do not handle specimen with hands. | |
| 20 - 25 mL | Fluid, amniotic | Sterile container | Refrigerated | Collect specimen in sterile syringe, discard first 2 mL and send remainder in sterile container. Collect during 14 - 18 weeks gestation. Provide gestational age at time of amniocentesis and reason for referral with specimen. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | Whole blood: 96 hours |
| Refrigerated | Whole blood: 96 hours |
| Frozen | Unacceptable |
Days Performed
Sun - Sat
Turnaround Time
3 - 8 days
Methodology
| Name | Description |
|---|---|
| Fluorescent In-Situ Hybridization (FISH) |
Reference Range
Special Info
Patients residing in New York State must sign an informed consent form. TESTING ALGORITHM: This test only includes a charge for professional interpretation of results and does not include charges for probe application or anlysis. Charges will be incurred for application of all probes applied. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cell are available for analysis, no analysis charges will be incurred.
Clinical Info
Useful for the detection of a submicroscopic deletion that has been associated with DGS, VCFS, and CATCH 22. Also may be useful to detect cryptic translocation involving 22q11.2. Any individual with a normal signal pattern in each metaphase is considered negative for this probe. This may be due to microdeletions outside the region tested by this probe, or point mutations or small deletions within the hybridization region.