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HelpTest Code MDSDF Myelodysplastic Syndrome (MDS), Diagnostic FISH, Varies
Ordering Guidance
Chromosome analysis is recommended as first-tier testing; order either CHRBM / Chromosome Analysis, Hematologic Disorders, Bone Marrow, or CHRHB / Chromosome Analysis, Hematologic Disorders, Blood. This second-tier test should only be ordered if chromosome analysis is not successful, as it does not increase the sensitivity for detection of myelodysplastic syndrome (MDS) for classic abnormalities (ie, -5/5q-, -7/7q-). If this test is ordered concurrently with a chromosomal study (CHRBM or CHRHB), testing will be held pending the results of the chromosome test. If the chromosome results are complete and informative, this test will be canceled. If the chromosome results are complete and normal, this test will be canceled. If a complete chromosome study is not achieved (<20 metaphases), this test will proceed. If an ambiguous abnormality (may include nonclonal abnormality or unresolved structural abnormality) is observed and targeted MDS probes could be useful in characterizing the abnormality, this test will be canceled and reordered with appropriate probes as MDSMF / Myelodysplastic Syndrome (MDS), Specified FISH, Varies.
This test should not be used to screen for residual MDS. If the patient is being treated for known abnormalities, MDSMF / Myelodysplastic Syndrome (MDS), Specified FISH, Varies is the more appropriate test order.
This test is intended for instances when the entire MDS fluorescence in situ hybridization (FISH) panel is needed as a second-tier test. If limited MDS FISH probes are preferred, order MDSMF.
If this test is ordered in conjunction with AMLAF / Acute Myeloid Leukemia (AML), FISH, Adult, Varies or AMLPF / Acute Myeloid Leukemia (AML), FISH, Pediatric, Varies, it will be canceled and reordered as MDSMF to avoid duplicate FISH probe testing.
At follow-up, targeted MDS FISH probes can be evaluated based on the abnormalities identified in the diagnostic study. Order MDSMF / Myelodysplastic Syndrome (MDS), Specified FISH, Varies and request specific probes or abnormalities.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
1. A reason for testing should be submitted 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. If this information is not provided, an appropriate indication for testing may be entered by Mayo Clinic Laboratories.
2. A pathology and/or flow cytometry report may be requested, if not received, by the laboratory to optimize testing and aid in interpretation of results.
Specimen Required
Submit only 1 of the following specimens:
Preferred:
Specimen Type: Bone marrow
Container/Tube:
Preferred: Yellow top (ACD)
Acceptable: Green top (heparin) or lavender top (EDTA)
Specimen Volume: 2 to 3 mL
Collection Instructions:
1. It is preferable to send the first aspirate from the bone marrow collection.
2. Invert several times to mix bone marrow.
3. Send bone marrow in original tube. Do not aliquot.
Acceptable:
Specimen Type: Blood
Container/Tube:
Preferred: Yellow top (ACD)
Acceptable: Green top (heparin) or lavender top (EDTA)
Specimen Volume: 6 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood in original tube. Do not aliquot.
Useful For
Detecting a neoplastic clone associated with the common chromosome abnormalities seen in patients with myelodysplastic syndromes or other myeloid malignancies using a laboratory-designated probe set algorithm
Evaluating specimens in which standard cytogenetic analysis is unsuccessful
Testing Algorithm
This test includes a charge for the probe application, analysis, and professional interpretation of results for 6 probe sets (12 individual fluorescence in situ hybridization probes). Additional charges will be incurred for all reflex or additional probe sets performed.
Panel includes testing for the following abnormalities using the probes listed:
-inv(3) or t(3;3), RPN1/MECOM
-5/5q-, D5S630/EGR1
-7/7q-, D7S486/D7Z1
+8, D8Z2/MYC
-17p-, TP53/D17Z1
-20/20q-, D20S108/20qter
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.
In the absence of RPN1::MECOM fusion, when an extra MECOM signal is identified, reflex testing using the MECOM/RUNX1 probe set will be considered at the laboratory’s discretion to identify a potential t(3;21)(q26.2;q22) rearrangement. Laboratory discretion may be influenced by available karyotype results.
In the absence of RPN1::MECOM fusion, when an extra RPN1 signal is identified, reflex testing using the PRDM16/RPN1 probe set will be considered at the laboratory’s discretion to identify a potential t(1;3)(p36;q21) rearrangement. Laboratory discretion may be influenced by available karyotype results.
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
MDS, Diagnostic FISHSpecimen Type
VariesSpecimen Minimum Volume
Blood: 2 mL
Bone Marrow: 1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Clinical Information
Myelodysplastic syndromes (MDS) primarily occur in the older adult population and have a yearly incidence of 30 in 100,000 in persons older than 70 years of age. These disorders are typically associated with a hypercellular bone marrow and low peripheral blood counts, and with significant morbidity and mortality. The eventual clinical outcome for patients with MDS relates to either bone marrow failure or transformation to acute myeloid leukemia. MDS can be either primary (de novo) or secondary (due to previous treatment with alkylating or etoposide chemotherapy, with or without radiation).
Cytogenetic studies can provide confirmatory evidence of clonality in MDS and can be used to provide clinical prognostic or diagnostic information. Clonal cytogenetic abnormalities are more frequently observed in cases of secondary MDS (80% of patients) than in primary MDS (40%-60% of patients). The common chromosomal abnormalities associated with MDS include: inv(3), -5/5q-, -7/7q-, +8, and 20q-. These abnormalities can be observed singly or in concert. In addition, t(1;3) and t(3;21) are more frequently associated with secondary MDS.
Conventional chromosome analysis is the gold standard for identification of the common, recurrent chromosome abnormalities in MDS; however, some of the subtle rearrangements associated with secondary MDS can be missed.
Reference Values
An interpretive report will be provided.
Interpretation
A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal reference range for any given probe.
The absence of an abnormal clone does not rule out the presence of a neoplastic disorder.
Cautions
This test is not approved by the US Food and Drug Administration, and it is best used as an adjunct to existing clinical and pathologic information.
Bone marrow is the preferred specimen type for this fluorescence in situ hybridization test. If bone marrow is not available, a blood specimen may be used if there are neoplastic cells in the blood specimen (as verified by a hematopathologist).
Method Description
This test is performed using commercially available and laboratory-developed probes. Deletion or monosomy of chromosomes 5, 7, trisomy of chromosome 8, and deletion or rearrangement of chromosomes 17 and 20 are detected using enumeration strategy probes. Dual-color, dual-fusion fluorescence in situ hybridization (D-FISH) strategy probe sets are used to detect inv(3), t(3;21), and t(1;3). For the enumeration probe sets, 100 interphase nuclei are scored; 200 interphase nuclei are scored when D-FISH probes are used. Results are expressed as the percent abnormal nuclei.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
88271 x 12, 88275 x 6, 88291-FISH Probe, Analysis, Interpretation; 6 probe sets
88271 x 2, 88275-FISH Probe, Analysis; each additional probe set (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| MDSDF | MDS, Diagnostic FISH | Obsolete |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 614278 | Result Summary | 50397-9 |
| 614279 | Interpretation | 69965-2 |
| 614280 | Result Table | 93356-4 |
| 614281 | Result | 62356-1 |
| GC121 | Reason for Referral | 42349-1 |
| GC122 | Specimen | 31208-2 |
| 614282 | Source | 31208-2 |
| 614283 | Method | 85069-3 |
| 614284 | Additional Information | 48767-8 |
| 614285 | Disclaimer | 62364-5 |
| 614286 | Released By | 18771-6 |