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23215 Prenatal Aneuploidy Detection, FISH (PADF)

Prenatal Aneuploidy Detection, FISH (PADF)
Test Code: AFPADSO
Synonyms/Keywords

Ambiguous Genitalia
FISH For Prenatal Aneusomy
Trisomy 13 (Patau Syndrome)
Trisomy 18 (Edwards Syndrome)
Trisomy 21 (Down Syndrome)
Turner Syndrome, FISH
XXY, XXX, or XYY
Prenatal aneuploidy

Amnio Aneuploidy FISH SO (PADF)

AF PADSO

Test Components

 Prenatal Aneuploidy Detection, FISH

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.

Useful For
Screening for chromosomal aneuploidies of chromosomes 13, 18, 21, X, and Y in prenatal specimens
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
Submit only 1 of the following specimens:
​ ​ ​ ​ ​ ​
Amniotic fluid​ Amniotic fluid container​ ​ 20-25 mL​ 2 mL​ ​
Acceptable:
Chorionic villi
​		 15-mL tube containing 15 mL of transport media​ ​ 20-30 mg​ 2 mg​ ​
Collection Processing Instructions

​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.

Amniotic fluid:

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. Provide gestational age at the time of amniocentesis.
2. Discard the first 2 mL of amniotic fluid.
3. Place the tubes in a refrigerate/ambient mailer.
4. Fill remaining space with packing material.
Additional Information:
1. Unavoidably, about 1% to 2% of mailed-in specimens are not viable.
2. Bloody specimens are undesirable.
3. If the specimen does not grow in culture, you will be notified within 7 days of receipt.
4. Results will be reported and also telephoned or faxed, if requested.
 
Chorionic villi:
 
1. Collect specimen by the transabdominal or transcervical method.
2. Transfer chorionic villi to a Petri dish containing transport medium.
3. Using a stereomicroscope and sterile forceps, assess the quality and quantity of the villi and remove any blood clots and maternal decidua.
 
Specimen Minimum Volume:
Amniotic Fluid: 2 mL; Chorionic Villi: 2 mg; If ordering in conjunction with other testing: If ordered with CHRAF: 12 mL; with CHRCV: 12 mg; with CMAP: 12 mL or 12 mg; with CHRAF/CHRCV and CMAP: 26 mL or 26 mg
 
Specimen Stability Information
Specimen Type Temperature
Varies​ Refrigerated (preferred)​
​ Ambient ​
Rejection Criteria

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

Interference

The use of these probes has been approved by the Food and Drug Administration as a stand-alone test. However, we recommend that complete chromosome analysis (CHRAF / Chromosome Analysis, Amniotic Fluid or CHRCV / Chromosome Analysis, Chorionic Villus Sampling) or chromosomal microarray (CMAP / Chromosomal Microarray, Prenatal, Amniotic Fluid/Chorionic Villus Sampling) 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:

-Inadequate amount of specimen may not permit adequate analysis

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

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

-Transport time should not exceed 2 days

-Contamination by maternal cells may interfere with attempts to culture cells and may cause interpretive problems

Performing Laboratory Information
Performing Location Day(s) Test Performed Report Available Methodology/Instrumentation
Mayo Clinic Laboratories​
 Monday through Friday​ 3  to 4 days​
Fluorescence In Situ Hybridization (FISH)​
Reference Lab
Mayo Clinic Laboratories
Test 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 the 5 chromosomes analyzed by this test. Therefore, aneuploidy of chromosomes 13, 18, 21, X, and Y accounts for 81% to 95% of major chromosome anomalies in liveborn infants.

Techniques to detect aneuploidy include standard chromosome analysis and FISH. Standard chromosome analysis from amniotic fluid cells or chorionic villi requires 5 to 9 days for culture, harvest, and analysis. FISH, which uses DNA probes and can be performed on cultured and uncultured cells, can rapidly detect aneuploidy of 13, 18, 21, X, and Y in uncultured amniotic fluid cells or chorionic villi. FISH-based analysis may be helpful in medically urgent evaluations of newborn infants suspected to have aneuploidy of any of these chromosomes.

Ordering Guidance:

This test does not detect aneuploidy of chromosomes other than 13, 18, 21, X, or Y. This test does not detect other chromosomal or structural anomalies.

Low levels of mosaicism involving chromosomes 13, 18, 21, X, or Y may not be detected by this procedure.

Reference Range Information
An interpretive report will be provided.
Interpretation
​An interpretive report will be provided.
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​88291 ​ 1 Interpretation and report​ ​
88271 ​ ​2 DNA probe, each (first probe set) ​
​88271 ​ ​2 DNA probe, each; each additional probe set  ​if appropriate
​88271 ​ ​1 ​DNA probe, each; coverage for sets containing 3 probes if appropriate
​88271 ​ ​2 DNA probe, each; coverage for sets containing 4 probes if appropriate
​88271 ​ ​3 DNA probe, each; coverage for sets containing 5 probes if appropriate
​88274 ​ ​1 w/modifier 52-Interphase in situ hybridization, <25 cells, each probe set ​if appropriate
​88274 ​ ​1 Interphase in situ hybridization, 25 to 99 cells, each probe set ​if appropriate
​88275 ​ ​1 Interphase in situ hybridization, 100 to 300 cells, each probe set if appropriate
Synonyms/Keywords

Ambiguous Genitalia
FISH For Prenatal Aneusomy
Trisomy 13 (Patau Syndrome)
Trisomy 18 (Edwards Syndrome)
Trisomy 21 (Down Syndrome)
Turner Syndrome, FISH
XXY, XXX, or XYY
Prenatal aneuploidy

Amnio Aneuploidy FISH SO (PADF)

AF PADSO

Test Components

 Prenatal Aneuploidy Detection, FISH

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.

Ordering Applications
Ordering Application Description
COM Amnio Aneuploidy FISH SO (PADF)
​Cerner ​Amnio Aneuploidy FISH SO (PADF)
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
Submit only 1 of the following specimens:
​ ​ ​ ​ ​ ​
Amniotic fluid​ Amniotic fluid container​ ​ 20-25 mL​ 2 mL​ ​
Acceptable:
Chorionic villi
​		 15-mL tube containing 15 mL of transport media​ ​ 20-30 mg​ 2 mg​ ​
Collection Processing

​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.

Amniotic fluid:

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. Provide gestational age at the time of amniocentesis.
2. Discard the first 2 mL of amniotic fluid.
3. Place the tubes in a refrigerate/ambient mailer.
4. Fill remaining space with packing material.
Additional Information:
1. Unavoidably, about 1% to 2% of mailed-in specimens are not viable.
2. Bloody specimens are undesirable.
3. If the specimen does not grow in culture, you will be notified within 7 days of receipt.
4. Results will be reported and also telephoned or faxed, if requested.
 
Chorionic villi:
 
1. Collect specimen by the transabdominal or transcervical method.
2. Transfer chorionic villi to a Petri dish containing transport medium.
3. Using a stereomicroscope and sterile forceps, assess the quality and quantity of the villi and remove any blood clots and maternal decidua.
 
Specimen Minimum Volume:
Amniotic Fluid: 2 mL; Chorionic Villi: 2 mg; If ordering in conjunction with other testing: If ordered with CHRAF: 12 mL; with CHRCV: 12 mg; with CMAP: 12 mL or 12 mg; with CHRAF/CHRCV and CMAP: 26 mL or 26 mg
 
Specimen Stability Information
Specimen Type Temperature
Varies​ Refrigerated (preferred)​
​ Ambient ​
Rejection Criteria

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

Interference

The use of these probes has been approved by the Food and Drug Administration as a stand-alone test. However, we recommend that complete chromosome analysis (CHRAF / Chromosome Analysis, Amniotic Fluid or CHRCV / Chromosome Analysis, Chorionic Villus Sampling) or chromosomal microarray (CMAP / Chromosomal Microarray, Prenatal, Amniotic Fluid/Chorionic Villus Sampling) 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:

-Inadequate amount of specimen may not permit adequate analysis

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

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

-Transport time should not exceed 2 days

-Contamination by maternal cells may interfere with attempts to culture cells and may cause interpretive problems

Useful For
Screening for chromosomal aneuploidies of chromosomes 13, 18, 21, X, and Y in prenatal specimens
Test Components

 Prenatal Aneuploidy Detection, FISH

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.

Reference Range Information
An interpretive report will be provided.
Interpretation
​An interpretive report will be provided.
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Report Available Methodology/Instrumentation
Mayo Clinic Laboratories​
 Monday through Friday​ 3  to 4 days​
Fluorescence In Situ Hybridization (FISH)​
Reference Lab
Mayo Clinic Laboratories
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​88291 ​ 1 Interpretation and report​ ​
88271 ​ ​2 DNA probe, each (first probe set) ​
​88271 ​ ​2 DNA probe, each; each additional probe set  ​if appropriate
​88271 ​ ​1 ​DNA probe, each; coverage for sets containing 3 probes if appropriate
​88271 ​ ​2 DNA probe, each; coverage for sets containing 4 probes if appropriate
​88271 ​ ​3 DNA probe, each; coverage for sets containing 5 probes if appropriate
​88274 ​ ​1 w/modifier 52-Interphase in situ hybridization, <25 cells, each probe set ​if appropriate
​88274 ​ ​1 Interphase in situ hybridization, 25 to 99 cells, each probe set ​if appropriate
​88275 ​ ​1 Interphase in situ hybridization, 100 to 300 cells, each probe set if appropriate
For most current information refer to the Marshfield Laboratory online reference manual.