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HelpOrder Code XYMF Known 45,X, Mosaicism Reflex Analysis, FISH, Whole Blood
Useful For
Detecting sex chromosome mosaicism in patients with a 45,X karyotype
Genetics Test Information
This test is only appropriate to detect low levels of sex chromosome mosaicism when a nonmosaic 45,X karyotype has been observed.
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
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.
Special Instructions
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
Known 45,X Mosaicism Reflex, FISHSpecimen Type
Whole bloodOrdering Guidance
This test does not detect other chromosomal or structural anomalies and is intended to be ordered after a complete chromosome analysis.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
A reason for testing must be provided. The laboratory will not reject testing if this information is not provided however an applicable indication for testing may be entered by Mayo Clinic Laboratories. Appropriate testing and interpretation may be compromised or delayed.
Specimen Required
Container/Tube:
Preferred: Green top (sodium heparin)
Acceptable: Lavender top (EDTA) or yellow top (ACD)
Specimen Volume: 4 mL
Collection Instructions
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
3. Other anticoagulants are not recommended and are harmful to the viability of the cells.
4. Cord blood is acceptable
Additional Information:
1. If the specimen does not grow in culture, you will be notified within 7 days of receipt.
2. Specimen cannot be frozen.
Specimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole blood | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
An interpretive report will be provided.
Method Description
This test is performed using a commercially available enumeration strategy probe set for the centromere regions of the X (DXZ1) and Y (DYZ3) chromosomes. The probe set is hybridized to the appropriate target areas, and 2 technologists independently analyze 250 interphase nuclei (500 total) 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(3):132-135)
Day(s) Performed
Monday through Friday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
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)
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)
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: