Test Overview

Test Methodology

Fluorescence In Situ Hybridization (FISH)

Test Usage

FISH testing is intended to determine inheritance of an abnormal Chromosomal Microarray Analysis result on a child/proband (CMA testing available from the MMGL Molecular Genetics Laboratory). FISH analyses of peripheral blood samples from both parents of a patient with a CMA aberration are recommended to determine whether the abnormality occurred de novo or was inherited from a carrier parent. Identifying the origin of the aberration (de novo or parental) allows a better assessment of the probability that the aberration is pathogenic, promotes improved diagnosis of disease (or risk of disease), allows a more precise calculation of recurrence risk, and facilitates more accurate and appropriate counseling.

Reference Range*

Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details

Days Test Performed

Monday - Friday, 8:00am - 4:00pm

Soft Order Code


MiChart Code

Cytogenetics, FISH for CMA-detected Abnormality, Peripheral Blood



Chromosomal Microarray Confirmation
FISH Confirmation, Parental Sample
CMA Confirmation
Parental Analysis of Chromosomal Microarray Result
Array Analysis, Parental Sampl
Parent Analysis of CMA Result
Parental FISH
FISH Analysis, Prntl Shadow
Cytogenetics, FISH for CMA Abn
Aberrant CMA confirmation by FISH
Aberrant Chromosomal Microarray (CMA) Confirmation by FISH

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Specimen Requirements

Offsite Collection Instructions

Please notify MLabs Client Services Center prior to sending specimen. Requests for this test will be accepted if the CMA test was performed for the child/proband at the University of Michigan MMGL Molecular Genetics Laboratory. Collect specimen in a green top (sodium heparin) tube. Invert the tube several times to prevent clotting. Send the specimen intact at room temperature within 24 hours of collection. DO NOT CENTRIFUGE. Clotted or hemolyzed specimens are unacceptable. Include the proband's CMA information specified, as follows: Proband name, U of M registration number, chromosome abnormality (deletion or duplication), size, band, beginning and ending nucleotide numbers.

Rejection Criteria

Clotted or hemolyzed specimen, or specimen over 48 hours old.

Normal Volume

5 mL whole blood

Minimum Volume

2 mL whole blood

Additional Information

For additional information on FISH for CMA-detected Abnormality, contact the UMHS/MLabs Cytogenetics Laboratory. Chromosome Analysis (cpt codes 88230 and 88262) will be performed if indicated. By ordering this test the clinician acknowledges that additional reflex testing will be performed and billed at a separate additional charge if indicated.

Billing Information

Fee Codes

CPT Code

88230, 88271, 88273 (deletion) or 88275 (duplication)

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