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Test Code SCTF Sex Chromosome Determination, FISH, Tissue

Useful For

Identifying the sex chromosome complement in paraffin-embedded tissues

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
_I099 Interphases, 25-99 No, (Bill Only) No
_I300 Interphases, >=100 No, (Bill Only) No
_IL25 Interphases, <25 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
_PBCT Probe, +2 No, (Bill Only) No

Testing Algorithm

This test includes a charge for application of the first probe set (2 fluorescence in situ hybridization probes) and professional interpretation of results.

 

Additional charges will be incurred for 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.

 

Appropriate ancillary probes may be performed at consultant discretion to render comprehensive assessment. Any additional probes will have the results included within the final report and will be performed at an additional charge.

Method Name

Fluorescence In Situ Hybridization (FISH)

Reporting Name

Sex Chromosome, FISH, Ts

Specimen Type

Tissue


Ordering Guidance


This test does not include a pathology consultation. If a pathology consultation is required, order PATHC / Pathology Consultation and the appropriate fluorescence in situ hybridization (FISH) test will be ordered and performed at an additional charge.

 

This testing is not appropriate for distinguishing tissue from the same gender, as in a same-sex transplant or potential tissue mix-up between 2 male patients or 2 female patients.

 

This evaluation can be more complicated in a post-transplant neoplastic evaluation and may not produce a confirmatory result.



Shipping Instructions


Advise Express Mail or equivalent if not on courier service.



Necessary Information


1. A reason for testing and a pathology report are required in order for testing to be performed. Send information with specimen. Acceptable pathology reports include working drafts, preliminary pathology or surgical pathology reports.

 

2. If a transplant has been performed, provide organ (ie, bone marrow, heart, lung, kidney, etc) and gender of donor information when sending the specimen.



Specimen Required


Submit only 1 of the following specimens:

 

Specimen Type: Tissue

Preferred: Tissue block

Collection Instructions: Submit a formalin-fixed, paraffin-embedded (FFPE) tumor tissue block. Blocks prepared with alternative fixation methods may be acceptable; provide fixation method used.

 

Acceptable: Slides

Collection Instructions: Four consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin (H and E)-stained slide.


Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Tissue Ambient (preferred)
  Refrigerated 

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Genotypically normal females possess 2 X chromosomes (XX); genotypically normal males possess 1 X chromosome and 1 Y chromosome (XY). Determining the sex chromosome complement in a tissue specimen can be used to:

-Identify opposite sex-donor cells post-transplant

-Help resolve cases of suspected sample mix-up

Reference Values

An interpretive report will be provided.

Interpretation

An interpretive report will be provided.

Cautions

This test is not approved by the U.S. Food and Drug Administration and it is best used as an adjunct to existing clinical and pathologic information.

 

Fixatives other than formalin (eg, Prefer, Bouin's) may not be successful for FISH assays, however non-formalin-fixed samples will not be rejected.

 

Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.

Method Description

The test is performed using a commercially available enumeration strategy probe set for the X centromere (DXZ1) and Y centromere (DYZ3). Formalin-fixed, paraffin-embedded tissues are cut at 5 microns and mounted on positively charged glass slides. The selection of tissue and the target areas on the hematoxylin and eosin (H and E)-stained slide is performed by a pathologist. Using the H and E-stained slide as a reference, target areas are etched with a diamond-tipped etcher on the back of the unstained slide to be assayed. The probe set is hybridized to the appropriate target areas and 2 technologists each analyze 50 interphase nuclei (100 total) with the results expressed as the percent of XX (female) or XY (male) nuclei.(Unpublished Mayo method)

Day(s) Performed

Monday through Sunday

Report Available

7 to 10 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed using an analyte specific reagent. Its performance characteristics were 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

88271 x 2, 88291-DNA probe, each (first probe set), Interpretation and report

88271 x 2-DNA probe, each; each additional probe set (if appropriate)

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

88271 x 2-DNA probe, each; coverage for sets containing 4 probes (if appropriate)

88271 x 3-DNA probe, each; coverage for sets containing 5 probes (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
SCTF Sex Chromosome, FISH, Ts 87436-2

 

Result ID Test Result Name Result LOINC Value
52077 Result Summary 50397-9
52079 Interpretation 69965-2
52078 Result 87436-2
CG733 Reason for Referral 42349-1
CG734 Specimen 31208-2
52080 Source 31208-2
52081 Tissue ID 80398-1
52082 Method 85069-3
54575 Additional Information 48767-8
53840 Disclaimer 62364-5
52083 Released By 18771-6