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HelpTest ID NADF Newborn Aneuploidy Detection, FISH
Useful For
Screening for chromosomal aneuploidies of chromosomes 13, 18, 21, X, and Y in newborn peripheral blood specimens
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 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
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
Newborn Aneuploidy Detection, FISHSpecimen Type
Whole bloodSpecimen Required
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.
3. Advise Express Mail or equivalent if not on courier service.
4. Cord blood is acceptable.
Specimen Minimum Volume
1 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.Clinical Information
Approximately half of clinically recognizable spontaneous abortions have a major chromosomal anomaly.
Up to 95% of chromosomal abnormalities diagnosed prenatally involve aneuploidy (gain or loss of whole chromosome) of chromosomes 13, 18, 21, X, and Y.
In liveborn infants, about 8/1,000 have a major chromosome anomaly, of which 6.5/1,000 involve aneuploidy of 1 of these 5 chromosomes.
Diagnosis of chromosomal disorders can be performed by chromosome analysis of uncultured blood, standard chromosome study, and the technique utilizing FISH based on interphase cells. Standard chromosome analysis takes 3 to 10 days and analysis from uncultured newborn blood is often unsatisfactory and labor-intensive. FISH based methods facilitate rapid diagnosis of aneuploidy and may be helpful in medically urgent evaluations of newborn infants suspected to have aneuploidy of any of these chromosomes.
This test does not detect chromosomal aneuploidies other than 13, 18, 21, X, and Y or any structural anomaly that does not result in gain of these chromosomes.
Low levels of mosaicism involving chromosomes 13, 18, 21, X, or Y may not be detected by this assay.
Reference Values
An interpretive report will be provided.
Interpretation
An interpretive report will be provided.
Cautions
The use of these probes has been approved by the FDA as a stand-alone test. However, we recommend that a complete chromosome analysis (CHRCB / Chromosome Analysis, Congenital Disorders, Blood) or chromosomal microarray (CMACB / Chromosomal Microarray, Congenital, Blood) be performed in conjunction with this FISH test. In cases where the FISH analysis is normal, a chromosome analysis or chromosomal microarray allows for the potential identification of more complex abnormalities and the less common numeric abnormalities of other chromosomes. In cases where the FISH study is abnormal, chromosome analysis can determine whether the abnormality is due to aneuploidy or a complex structural abnormality, allowing for recurrence risk information for the family.
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
Clinical Reference
1. Jalal SM, Law ME: Detection of newborn aneuploidy by interphase fluorescence in situ hybridization. Mayo Clin Proc 1997;72:705-710
2. Cassidy SB, Allanson JE: Management of Genetic Syndromes. Second edition. Hoboken, NJ, John Wiley and Sons, 2005, p 557
3. Sheets KB, Crissman BG, Feist CD, et al: Practice guidelines for communicating a prenatal or postnatal diagnosis of Down syndrome: recommendations of the national society of genetic counselors. J Genet Couns 2011;20:432-444
Method Description
This test is performed using probes for the centromere regions of chromosome X (DXZ1), Y (DYZ3), and 18 (D18Z1), and locus-specific probes for 13q14 and 21q22. For each probe set, 2 technologists each analyze 50 interphase nuclei (100 total). Aneuploidy of chromosomes 13, 18, 21, X, and Y is reported.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
3 to 4 daysTest 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
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)Â Â Â Â Â Â Â Â
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| NADF | Newborn Aneuploidy Detection, FISH | 57318-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 51930 | Result Summary | 50397-9 |
| 51932 | Interpretation | 69965-2 |
| 54552 | Result | 57318-8 |
| CG694 | Reason for Referral | 42349-1 |
| 51933 | Specimen | 31208-2 |
| 51934 | Source | 31208-2 |
| 51935 | Method | 85069-3 |
| 51931 | Additional Information | 48767-8 |
| 53862 | Disclaimer | 62364-5 |
| 51936 | Released By | 18771-6 |
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: