Chromosome FISH, Chorionic Villus with Reflex to Chromosome Analysis or Genomic Microarray

Casandra

Casandra Test Code AR99686Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 2011131CPT Codes 81229, 81265, 88235, 88269, 88271, 88275

Chromosome FISH, Chorionic Villus with Reflex to Chromosome Analysis or Genomic Microarray

Also known as: CVS F RFLX

Clinical Use

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Use

The primary clinical utility of this test is to rapidly detect aneuploidy involving chromosomes 13, 18, 21, X, and Y in chorionic villus samples. If the FISH results are abnormal, the test reflexes to chromosome analysis to determine the mechanism. In the case of normal FISH results, the specimen reflexes to genomic microarray analysis. This approach is valuable for prenatal diagnoses to identify potential chromosomal abnormalities early in pregnancy, aiding in clinical decision-making.

Special Instructions

Counseling and informed consent are recommended and necessary especially for New York patients before undergoing genetic testing. The test may incur additional charges if reflex analyses are performed. It is also critical that specimens are not placed in formalin and that they remain at room temperature until processed.

Limitations

This FISH test does not detect structural chromosome abnormalities, mosaicism, or non-standard numerical chromosome abnormalities beyond chromosomes 13, 18, 21, X, and Y. There is also a potential for false-positive or false-negative results. The test results should not be used as a sole basis for irreversible therapeutic decisions according to the American College of Medical Genetics guidelines. Reflex testing to chromosome analysis may yield additional insights, although chromosome analysis itself has its limitations in detecting small rearrangements or low-level mosaicism.

Test Details