FISH Study: DiGeorge / VCF Syndrome (22q11.2)

Additional Information:

UFHPL Test #: 30075
UFHPL Epic order code: LAB5851

CPT Code(s):

  • 88271
  • 88273
  • 88291

Specimen Requirements:

Peripheral Blood: Collected aseptically in sodium heparin tubes (usually green-top tubes) and immediately rotated thoroughly to prevent clotting. For infants obtain approximately 2 cc and for children and adults obtain 5 – 7 cc.

Note: A separate blood sample is required if a concurrent CGH microarray study is desired. Do not freeze or fix samples in any manner contrary to the maintenance of cell viability. Maintain sample sterility; keep all specimens at room temperature; and deliver samples to the laboratory within 24 – 48 hours. Ship specimens at room temperature for overnight delivery.

  • Unacceptable Conditions:
    • Frozen specimens
    • Specimens greater than 48 hours old*
  • Stability (collection to initiation of testing):
    • Ambient: 24 – 48 hours*
    • Frozen: Unacceptable

* Cell viability of specimens requiring cell culture may be compromised in specimens more than 48 hours old upon receipt. Refrigeration at 2° – 8° C may assist when a delay is not preventable. Do not freeze or place specimens directly on ice.


This test is used to detect chromosome 22 long-arm deletions associated with multiple genetic conditions, including DiGeorge Syndrome, but have also been described with 22q11.2 deletion syndrome, CATCH-22, velo-cardio facial syndrome, Shprintzen syndrome and others.


Metaphase/Chromosome fluorescence in-situ hybridization (FISH) analyses; requires cell culture and a concurrent or previous routine karyotyping


10 – 28 days

Reference Values:

By report; interpretive