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Test ID: CMAFF Chromosomal Microarray (CMA) Familial Testing, FISH

Useful For

Determining the inheritance pattern of copy number changes previously identified by chromosomal microarray analysis in a patient and aiding in the clinical interpretation of the pathogenicity of the copy number change

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
_PBCT Probe, +2 No, (Bill Only) No
_PADD Probe, +1 No, (Bill Only) No
_PB02 Probe, +2 No, (Bill Only) No
_PB03 Probe, +3 No, (Bill Only) No
_ML10 Metaphases, 1-9 No, (Bill Only) No
_M30 Metaphases, >=10 No, (Bill Only) No
_IL25 Interphases, <25 No, (Bill Only) No
_I099 Interphases, 25-99 No, (Bill Only) No
_I300 Interphases, >=100 No, (Bill Only) No

Testing Algorithm

If the copy number change identified in a patient is below the level of resolution of FISH analysis, CMA studies will be required. In this circumstance, this test will be cancelled and CMACB / Chromosomal Microarray, Congenital, Blood will be performed.


This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results. Additional charges will be incurred for application of all reflex probes performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.

Method Name

Fluorescence In Situ Hybridization (FISH)

Reporting Name

CMA Familial Testing, FISH

Specimen Type

Whole blood

Ordering Guidance

This test is used to confirm the presence of a specific copy number change in a family member after it has been identified by chromosomal microarray (CMA) testing in a patient previously tested at Mayo Clinic Laboratories. All family member studies will be charged unless otherwise specified in the proband report.


Consultation with the laboratory is required prior to submitting a specimen when the initial patient (proband) was tested elsewhere. Whenever possible, family member testing should be performed by the original testing laboratory. If this is not possible, call 800-533-1710 and ask to speak with a laboratory genetic counselor to determine if testing will be accepted. Failure to contact the laboratory prior to ordering may result in test cancellation.

Shipping Instructions

Advise Express Mail or equivalent if not on courier service.

Necessary Information

Completion of the Family Member Phenotype Information for Genomic Testing form is required. The use of parental testing for the evaluation of uncertain copy number variants requires parental phenotypic information.


Clinical information on the family member being tested is essential for appropriate test interpretation and must be provided by the ordering clinician.

Specimen Required

Specimen Type: Whole blood

Container/Tube: Green top (sodium heparin)

Specimen Volume: 4 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Other anticoagulants are not recommended and are harmful to the viability of the cells.

Additional Information: Provide the name of the child (originally tested family member) on the request form. If testing was performed outside of Mayo Clinic Laboratories, consultation with the laboratory is required prior to ordering this test.

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Ambient (preferred)

Clinical Information

Chromosomal microarray (CMA) is a method for detecting copy number changes (gains or losses) across the entire genome. When copy number changes are identified in a patient, parental studies are sometimes necessary to assess their clinical significance. Changes that are inherited from clinically normal parents are less likely to be clinically significant in the patient and de novo changes are more likely to be pathogenic.


To identify familial copy number changes in parents of previously tested patients, fluorescence in situ hybridization testing is utilized. the parental results will provide the context for interpretation of the patient's CMA results.

Reference Values

An interpretive report will be provided.


An interpretive report will be provided.

Clinical Reference

1. Shaffer LG, Kashork CD, Saleki R, et al: Targeted genomic microarray analysis for identification of chromosome abnormalities in 1500 consecutive clinical cases. J Pediatr. 2006 Jul;149(1):98-102

2. Baldwin EL, Lee JY, Blake DM, et al: Enhanced detection of clinically relevant genomic imbalances using a targeted plus whole genome oligonucleotide microarray. Genet Med. 2008 May;10:415-429

Day(s) Performed

Monday through Friday

Report Available

9 to 28 days

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

88271x2, 88291-DNA probe, each (first probe set), Interpretation and report

88271x2-DNA probe, each; each additional probe set (if appropriate)

88271x1-DNA probe, each; coverage for sets containing 3 probes (if appropriate)

88271x2-DNA probe, each; coverage for sets containing 4 probes (if appropriate)

88271x3-DNA probe, each; coverage for sets containing 5 probes (if appropriate)

88273 w/modifier 52-Chromosomal in situ hybridization, less than 10 cells (if appropriate)

88273-Chromosomal in situ hybridization, 10-30 cells (if appropriate)

88274 w/modifier 52 Interphase in situ hybridization, <25 cells, each probe set (if appropriate)

88274-Interphase in situ hybridization, 25 to 99 cells, each probe set (if appropriate)        

88275-Interphase in situ hybridization, 100 to 300 cells, each probe set (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CMAFF CMA Familial Testing, FISH In Process


Result ID Test Result Name Result LOINC Value
52405 Result Summary 50397-9
52406 Result 62356-1
54644 Nomenclature 62378-5
52407 Interpretation 69965-2
CG781 Reason For Referral 42349-1
52408 Specimen 31208-2
52409 Source 31208-2
52410 Method 85069-3
55129 Additional Information 48767-8
53403 Disclaimer 62364-5
52411 Released By 18771-6
Mayo Clinic Laboratories | Genetics and Pharmacogenomics Catalog Additional Information: