For rapid detection of aneuploidy involving chromosomes 13, 18, 21, X, and Y. If the FISH results are abnormal, the specimen will reflex to chromosome analysis for mechanism determination. If the FISH results are normal, the specimen will reflex to genomic microarray.
If reflexed: 1-2 weeks required for chromosome analysis or microarray
- Patient Preparation
- 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.
- Unacceptable Conditions
- Bloody specimens.
- Ambient: 48 hours; Refrigerated: 48 hours; Frozen: Unacceptable
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
Maternal Cell Contamination: For maternal cell contamination studies in the event that FISH is normal and testing is reflexed to genomic microarray, please submit maternal blood and order Microarray Genomic, Maternal Confirm (ARUP test code 2002369) accompanied by a test request form for the mother (this test is performed at no charge). For questions regarding ordering please contact ARUP's genetic counselor at (800) 242-2787 ext. 2141.
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.
The chromosome analysis studies involve culturing of living cells; therefore, turnaround times given represent average times which are subject to multiple variables.
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.
Specimen and completed test request form, including clinical indication, must be received within 48 hours of collection. This test must be ordered using Cytogenetic test request form #43098 or through your ARUP interface. Submit the Patient History for Prenatal Cytogenetics form with the electronic packing list (http://ltd.aruplab.com/Tests/Pdf/65).
|Component Test Code*||Component Chart Name||LOINC|
|0097779||Chromosome FISH, Prenatal||55192-9|
- amniotic fluid
- ARRAY FE
- CHR AF
- Common trisomy FISH panel
- Down syndrome
- multiple congenital anomalies
- PN FISH
- prenatal FISH
- Trisomy 13
- Trisomy 18
- Trisomy 21
- Turner syndrome