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Test Code FISHD FISH, DiGeorge, Velocardiofacial (VCFS)

Specimen Required

5 mL whole blood collected in a sodium heparin (green-top) tube

Specimen Minimum Volume

1 mL whole blood. 5 mg CVS

Specimen Stability

Room temperature: See instructions Refrigerated: See instructins Frozen: See instructions

Rejection Due To

Received frozen

Method Name

Fluorescence in situ Hybridization (FISH)


If this test is ordered on blood without routine G-band chromosome analysis, a Tissue Culture charge will be added, (CPT code: 88230). If results are not possible, the test order may be canceled and replaced with a Cytogenetics Communication.

Collection Container / Tube

Preferred: Sodium Heparin (green-top)
Other Acceptable Container: Sterile container 5 mg CVS in culture media, Whole blood collected in: sodium heparin (royal blue-top), or sodium heparin lead-free (tan-top) tube

Transport / Storage Conditions

Room temperature

Special Instructions

Clinical history and reason for referral are required with test order.
3-5 mL whole blood collected in sodium heparin tube; or 5 mL amniotic fluid collected in sterile container or 5 mg CVS in culture media.
Specimen viability decreases during transit. Send specimen to testing lab for viability determination. Do not freeze. Do not reject.

Reference Values

See Laboratory Report

Day(s) Performed

Set up: Mon-Sat; Report available: 6 days

CPT Codes

88271, 88273

Clinical Reference

This test is used to detect microdeletions of chromosome 22q11 associated with DiGeorge, Velocardiofacial (VCFS) syndrome, using FISH (fluorescence in situ hybridization).

Clinical indications to perform this test prenatally include a previous child with a 22q11.2 deletion or DiGeorge/velocardiofacial syndrome, an affected parent with a 22q11.2 deletion, and in utero detection of a conotruncal cardiac defect (Genet Med. 2001;3(1):14-8).