Test Catalog

Test Id : XYMF

Known 45,X, Mosaicism Reflex Analysis, FISH, Whole Blood

Useful For
Suggests clinical disorders or settings where the test may be helpful

Detecting sex chromosome mosaicism in patients with a 45,X karyotype

Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request

Only appropriate to detect low levels of sex chromosome mosaicism when a nonmosaic 45,X karyotype has been observed.

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial 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
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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 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.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

Fluorescence In Situ Hybridization (FISH)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Known 45,X Mosaicism Reflex, FISH

Aliases
Lists additional common names for a test, as an aid in searching

Turner syndrome mosaicism

XY mosaicism

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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 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.

Specimen Type
Describes the specimen type validated for testing

Whole blood

ORDER QUESTIONS AND ANSWERS

Question ID Description Answers
CG668 Reason for Referral

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Provide a reason for referral with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.

 

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.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

2 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

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

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

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

Useful For
Suggests clinical disorders or settings where the test may be helpful

Detecting sex chromosome mosaicism in patients with a 45,X karyotype

Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request

Only appropriate to detect low levels of sex chromosome mosaicism when a nonmosaic 45,X karyotype has been observed.

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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 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.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

This test is appropriate for use in individuals with a karyotype of 45, X.

 

Ullrich-Turner syndrome (UTS), also called Turner syndrome, is a genetic disorder associated with the apparent loss of a sex chromosome. Routine cytogenetic methods have identified 3 types of chromosomal abnormalities in UTS patients: loss of an entire X chromosome (45,X), structural X chromosome abnormalities, and mosaicism with an X or Y abnormality. In mosaicism, 2 or more populations of cells with different karyotypes are present (eg, 45,X/47,XXX).

 

The incidence of UTS is approximately 1 in 3,000 newborn girls. Many of these patients demonstrate the 45,X karyotype. About 30% to 50% are mosaic, with either a 45,X/46,XX karyotype or a structurally abnormal X chromosome. Fewer than 15% of patients with UTS appear to have mosaicism with a 46,XY cell population or a Y chromosome rearrangement.

 

Identifying the mosaic status of patients with UTS is of clinical importance because phenotypic expression and clinical management are dependent upon the karyotype result. Patients with a Y chromosome have a 15% to 25% increased risk of gonadoblastoma.

 

Failure to identify an XY signal pattern does not rule out the possibility of <0.6% Y chromosome mosaicism.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

An XX clone is confirmed when > or =1.0% cells display with 2 X chromosome signals. An XY clone is confirmed when > or =0.6% cells display a 1 X and 1 Y signal pattern.

 

Females with a 45,X/46,XX karyotype have no increased risk of gonadoblastoma and generally have a more moderate expression of Turner syndrome features than females with a nonmosaic 45,X karyotype. The presence of a Y chromosome confers increased risk of gonadoblastoma.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Because this FISH test is not approved by the U.S. Food and Drug Administration, it is important to confirm X or Y chromosome mosaicism by other established methods, such as clinical history or physical evaluation.

 

Interfering factors

-Cell lysis caused by forcing the blood quickly through the needle

-Use of an improper anticoagulant or improperly mixing the blood with the anticoagulant

-Excessive transport time

-Inadequate amount of specimen may not permit adequate analysis

-Improper packaging may result in broken, leaky, and contaminated specimen during transport.

-Exposure of the specimen to temperature extremes (freezing or > 30 degrees C) may kill cells and interfere with attempts to culture cells

-In prenatal specimens, a bloody specimen may interfere with attempts to culture cells and contamination by maternal cells may cause interpretive problems

Supportive Data

In a group of 22 patients with a nonmosaic 45,X karyotype by conventional cytogenetics, we have identified 3 (14%) patients with a mosaic X/XX result using FISH analysis. These results were confirmed by analysis of additional metaphase cells. Of the 3 patients, 2 have an iso(X) chromosome and 1 has what appears to be a structurally normal X chromosome.

 

The potential of maternal cells in the peripheral circulation of newborn females with a 45,X/46,XX karyotype result was investigated. Thirty specimens from newborn males (<2 days old) were tested, and based on the analysis of 500 interphase nuclei from each specimen, no XX cells were identified in any specimen, suggesting a low likelihood of maternal cells in newborn specimens.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Canto P, Kofman-Alfaro S, Jiminez AL, et al: Gonadoblastoma in Turner syndrome patients with nonmosaic 45,X karyotype and Y chromosome sequences. Cancer Genet Cytogenet 2004;150:70-72

2. Wiktor A, Van Dyke, DL: FISH analysis helps identify low-level mosaicism in Ullrich-Turner syndrome patients. Genet Med 2004;6:132-135

3. Sybert VP, McCauley E: Turner syndrome. N Engl J Med 2004;351:1227-1238

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

This test is performed using commercially available probes for the centromere regions of the X (DXZ1) and Y (DYZ3) chromosomes. A total of 500 interphase nuclei (250 each by 2 technologists) are examined to determine the sex chromosome complement.(Wiktor A, Van Dyke DL: FISH analysis helps identify low level mosaicism in Ullrich-Turner syndrome patients. Genet Med 2004;6:132-135)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

7 to 9 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Amniotic Fl. (remaining supernatant/whole fluid aliquots): Discarded 14 days after report. Blood: 4 weeks. Products of Conception (identifiable fetal tissue): Cremated quarterly after results reported. All Other Specimens: Discarded when results reported.

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

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)

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)        

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
XYMF Known 45,X Mosaicism Reflex, FISH 87436-2
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
51844 Result Summary 50397-9
51846 Interpretation 69965-2
54537 Result 62356-1
CG668 Reason for Referral 42349-1
51847 Specimen 31208-2
51848 Source 31208-2
51849 Method 85069-3
54451 Additional Information 48767-8
51850 Released By 18771-6
55279 Disclaimer 62364-5

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports