Chromosome FISH, Prenatal

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.

Performance of FISH testing in conjunction with routine cytogenetic analysis is recommended.

This test must be ordered using Cytogenetic test request form #43098 or through your ARUP interface. Specimen and completed test request form, including clinical indication, must be received within 48 hours of collection. Please submit the Patient History for Prenatal Cytogenetics form with the electronic packing list (https://ltd.aruplab.com/Tests/Pdf/65).