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FISH, Prenatal Screen

Test code(s) 14604X

This assay detects numerical abnormalities of chromosomes 13, 18, 21, X, and Y (eg, trisomy 13, trisomy 18, trisomy 21 [Down syndrome], sex chromosome abnormalities such as Turner syndrome and Klinefelter syndrome, and triploidy).

  1. Aneuploidy of chromosomes other than 13, 18, 21, X, and Y
  2. Structural chromosome abnormalities
  3. Low-level mosaicism

While FISH results have been reported to be concordant with traditional chromosome analysis results in the vast majority of cases, there have been a few instances of discrepant results. The American College of Medical Genetics recommends that irreversible therapeutic action should not be taken based on the results of FISH analysis alone (Am J Hum Genet. 1993;53:526-527).

This FAQ is provided for informational purposes only and is not intended as medical advice. A clinician’s test selection and interpretation, diagnosis, and patient management decisions should be based on his/her education, clinical expertise, and assessment of the patient.

Document FAQS.59 Version: 0
Effective 05/30/2012 to present