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Test Code CHRAF Chromosome Analysis, Amniotic Fluid

Useful For

Prenatal diagnosis of chromosome abnormalities, including aneuploidy (ie, trisomy or monosomy) and balanced rearrangements

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
_ML15 Metaphases, <15 No, (Bill Only) No
_M15 Metaphases, 15 No, (Bill Only) No
_MG14 Metaphases, >15 No, (Bill Only) No
_COL1 Colonies, 1-5 No, (Bill Only) No
_COL6 Colonies, 6+ No, (Bill Only) No
_KTG1 Karyotypes, >1 No, (Bill Only) No
_STAC Ag-Nor/CBL Stain No, (Bill Only) No

Testing Algorithm

This test is not appropriate as a first-tier test for detecting gains or losses of chromosomal material in pregnancies with 1 or more major structural abnormalities.

 

This test includes a charge for cell culture of fresh specimens and professional interpretation of results. Analysis charges will be incurred for total work performed, and generally include 2 banded karyograms and the analysis of 20 metaphase cells. If no metaphase cells are available for analysis, no analysis charges will be incurred. If additional analysis work is required, additional charges may be incurred.

Method Name

Cell Culture followed by Chromosome Analysis

Reporting Name

Chromosomes, Amniotic Fluid

Specimen Type

Amniotic Fld


Ordering Guidance


This test should be performed for prenatal diagnostic purposes only. A chromosomal microarray (CMAP / Chromosomal Microarray, Prenatal, Amniotic Fluid/Chorionic Villus Sampling) is recommended, rather than chromosomal analysis, to detect clinically relevant gains or losses of chromosomal material in pregnancies with 1 or more major structural abnormalities. Chromosomal microarray can also be considered, rather than chromosome analysis, for patients undergoing invasive prenatal diagnostic testing with a structurally normal fetus.

 

Portions of the specimen may be used for other tests, such as measuring markers for neural tube defects (eg, AFPA / Alpha-Fetoprotein, Amniotic Fluid), molecular genetic testing, biochemical testing, and fluorescence in situ hybridization testing (including PADF / Prenatal Aneuploidy Detection, FISH). If additional molecular genetic or biochemical genetic testing is needed, order CULAF / Culture for Genetic Testing, Amniotic Fluid so amniocyte cultures may be set up specifically for the use in these tests.



Shipping Instructions


Advise Express Mail or equivalent if not on courier service.



Necessary Information


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



Specimen Required


Specimen Type: Amniotic fluid

Submission Container/Tube: Centrifuge tube

Specimen Volume: 20 to 25 mL

Collection Instructions:

1. Optimal timing for specimen collection is during 14 to 18 weeks of gestation, but specimens collected at other weeks of gestation are also accepted.

2. Discard the first 2 mL of amniotic fluid.

3. If ordering with PADF / Prenatal Aneuploidy Detection, FISH, submit a minimum of 14 mL.

4. If ordering with CMAP / Chromosomal Microarray, Prenatal, Amniotic Fluid/Chorionic Villus Sampling, submit a minimum of 24 mL.

5. If ordering with both PADF and CMAP, then submit a minimum of 26 mL.

Additional Information:

1. Unavoidably, about 1% to 2% of mailed-in specimens are not viable.

2. If the specimen does not grow in culture, the client will be notified within 7 days of receipt.

3. Bloody specimens are undesirable.

 

Specimen Type: Fetal body fluid

Container/Tube: Sterile tube

Specimen Volume: Entire specimen

Additional Information:

1. If the specimen does not grow in culture, the client will be notified within 7 days of receipt.

2. Clearly indicate on tube and paperwork that specimen is fetal body fluid.


Specimen Minimum Volume

The following are the minimum volumes when only this test is ordered:
Amniotic fluid: 12 mL
Fetal body fluid: See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Amniotic Fld Refrigerated (preferred)
  Ambient 

Reject Due To

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

Reference Values

An interpretative report will be provided.

Day(s) Performed

Monday through Friday

Report Available

10 to 14 days

Performing 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

88235, 88291-Tissue culture for amniotic fluid or chorionic villus cells, Interpretation and report

88269 w/modifier 52-Chromosome analysis, in situ for amniotic fluid cells, <6 colonies, 1 karyotype with banding (if appropriate)

88269-Chromosome analysis, in situ for amniotic fluid cells, 6 or greater colonies, 1 karyotype with banding (if appropriate)

88267, 88285-Chromosome analysis, amniotic fluid or chorionic villus, greater than 15 cells, 1 karyotype with banding (if appropriate)

88267 w/modifier 52-Chromosome analysis, amniotic fluid or chorionic villus, <15 cells, 1 karyotype with banding (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CHRAF Chromosomes, Amniotic Fluid 62351-2

 

Result ID Test Result Name Result LOINC Value
52297 Result Summary 50397-9
52299 Interpretation 69965-2
52298 Result 82939-0
CG765 Reason for Referral 42349-1
CG766 Specimen 31208-2
52300 Source 31208-2
52302 Method 85069-3
52301 Banding Method 62359-5
54640 Additional Information 48767-8
52303 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:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

Secondary ID

35243