Test Code LABCOFISH CONSTITUTIONAL CYTOGENETICS, FISH, PRENATAL, ANEUVYSION
Ordering Notes
For questions about aneuploidy FISH testing email #UCM-Cytogenetics-Lab, or CytogeneticsLab@uchicagomedicine.org
Specimen and Container/Tube
Chorionic villus
Amniotic fluid
Volume
Chorionic villus: Preferred: >40 mg of villi devoid of blood clots and maternal decidua Minimum: 10 mg Amount needed by test: chromosome analysis: 15-20 mg; Aneuploidy FISH: 5 mg; SNP array (direct): 15-20 mg
Amniotic fluid: Preferred: >40ml fluid devoid of red blood cells or clots. Minimum: 30 mL
Amount needed by test: chromosome anlaysis: 10-15 mL, Aneuploidy FISH: 5 mL, AFP, CMV, Toxo, etc: 5 mL, SNP Array (direct): 15mL
Specimen Stability
Chorionic villus: Keep at room temperature if sample is delivered to the lab <24 hrs from collection. If transport delay is expected, keep at 4°C.
Amniotic fluid: Keep at room temperature if sample is delivered to the lab <24 hrs from collection. If transport delay is expected, keep at 4°C.
Note: Prolonged transport to the laboratory diminishes cell viability in cell culture.
Collection Instructions
Prior to collection of Chorionic Villus and Amniotic Fluid specimens: Call Cytogenetics at 773-702-6203 for collection containers and media as needed.
Specimen Handling and Transport Instructions
UCMC Onsite Instructions
Peripheral blood can be tubed directly to Cytogenetics via tube station #345
CVS, Amniotic fluid and Products of Conception: Call Cytogenetics at 773-702-6203 immediately after collection for sample pick up. Prenantal samples cannot be delivered in the tube station.
UCMC Offsite and UC MedLab Outreach Instructions
Chorionic Villus and Amniotic Fluid specimens: Arrange for independent courier to deliver specimens in provided collection tubes DIRECTLY to the Cytogenetics lab in Hyde Park. Notify the Cytogenetics lab at 773-702-6203 that a sample is being sent.
Rejection Criteria
Chorionic Villus: Specimens received >72 hours after collection
Amniotic Fluid: Specimens received >72 hours after collection
Reference Values
Results reported with current recommendations of the International Standing Committee on Human Cytogenomic Nomenclature (ISCN).
Turnaround Time
Chorionic villus: 2 days
Amniotic fluid: 2 days
Clinical Indications
Aneuploidy FISH (AneuVysion) is indicated for the rapid diagnostic confirmation of fetal aneuploidy following positive prenatal biochemical or non-invasive (NIPT) screen for chromosomes 13, 18, 21, X and Y; positive findings by ultrasound, or relevent family history.
Test Components
Direct cell harvest
slide preparation
FISH analysis
interpretive report
CPT Codes
88271
88275
Methodology
Fluorescence in situ hybridization (FISH)
Synonyms/Key Search Words
FISH
Additional Information
Test Limitations: AneuVysion does not detect structural chromosome abnormalities, mosaicism, and numerical abnormalities of chromosomes other than 13, 18, 21, X and Y. Aneuvysion cannot detect maternal cell contamination at low levels or when the fetus is female.
Last Review Date
4/17/2025