ARUP's Laboratory Test Directory

Chromosome FISH, Prenatal : 2002297
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Time Sensitive
[ image for: Patient History for Prenatal Cytogenetics]
Patient History for Prenatal Cytogenetics


Mnemonic: CHR FISHP

Methodology: Fluorescence in situ Hybridization
Performed: Sun-Sat
Reported: 1-3 days
Specimen Required: Collect: Amniotic fluid.

Specimen Preparation: Do not freeze or expose to extreme temperatures. Transport 30 mL amniotic fluid in sterile centrifuge tubes. (Min: 15 mL)

Storage/Transport Temperature: Room temperature.

Remarks: Specimen and completed test request form, including clinical indication, must be received within 48 hours of collection.
It is recommended that FISH be performed in conjunction with routine cytogenetic analysis.
This test must be ordered using Cytogenetic test request form #43097 or through your ARUP interface. Submit the Patient History for Cytogenetic (Chromosome) Studies form with the electronic packing list (available at available at http://www.aruplab.com/genetics/forms.php).

Unacceptable Conditions: Frozen specimens. Bloody specimens.

Stability (collection to initiation of testing): Ambient: 48 hours; Refrigerated: 48 hours; Frozen: Unacceptable
Reference Interval:
By report
Interpretive Data: Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com
Note: Fluorescence in situ hybridization (FISH) is performed for aneuploidy of chromosomes X, Y, 13, 18, and 21.

The FISH analysis does not detect structural chromosome abnormalities, mosaicism, and other numerical chromosome abnormalities (excluding X, Y, 13, 18, and 21). In addition, false-positive or negative results, as well as maternal cell contamination, have been demonstrated in prenatal FISH analysis. The American College of Medical Genetics recommends that irreversible therapeutic action should not be initiated on the basis of FISH results alone.

A processing fee will be charged if this procedure is canceled at the client's request, after the test has been set up, or if the sample integrity is inadequate to allow culture growth.
CPT Code(s): 88271 x5; 88275; 88291
Cross References: Chromosome Analysis (Chromosome FISH, Prenatal)