Fluorescence in situ Hybridization (FISH), Prenatal Aneuploid Evaluation, Chorionic Villus Sampling With Reflex to Microarray or Chromosome Analysis

TEST: 511625
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CPT: Contact CPT Coding Department at 800-222-7566, ext 6-8400.
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Synonyms

  • aCGH
  • CGH
  • Chromosome Analysis
  • CMA
  • CVS FISH
  • FISH, Prenatal
  • InSight FISH
  • Karyotype, Amniotic Fluid
  • Prenatal Aneuploid Evaluation
  • Prenatal FISH, Chorionic Villus Sampling
  • Prenatal Fluorescence in situ Hybridization
  • Prenatal Reveal
  • Rapid Interphase FISH
  • SNP Array
  • WGA

Special Instructions

Pertinent medical history and test request form must accompany request for chromosome analysis. Include name, age, gestational age, and indication for procedure. If abnormal FISH result, then reflex to chromosome karyotyping, if normal FISH result then reflex to microarray testing. A completed Informed Consent and Prenatal Chromosome SNP Microarray Questionnaire form should accompany specimens. Call 800-345-4363 to request form. Concurrent maternal contamination (MCC) studies are recommended.

Expected Turnaround Time

10 - 13 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Documents

For more information, please view the literature below.

SNP Microarray Prenatal POC Clinical Questionnaire

    Specimen Requirements

    Specimen

    Chorionic villi

    Volume

    20-30 mg

    Minimum Volume

    20 mg

    Container

    CVS transport tube available from the cytogenetic laboratory (call 800-345-4363); sterile specimen container with transport media.

    Collection

    Specimen is collected in syringe (transabdominal) or catheter (transcervical) and transferred by flushing with the media from the sterile container back into it. After collecting the specimen, wash with sterile saline solution (NaCl 0.95%) containing sodium heparin (two to three drops of sodium heparin in 10 mL of saline). Carefully transfer the specimen, into the CVS transport tube, using a sterile Pasteur pipette or a sterile fine needle forceps. Be sure to fill transport tubes completely with media. Samples from twin (multiple) pregnancies should be appropriately labeled and placed in separate transport containers with a separate request form for each twin.

    Storage Instructions

    Maintain specimen at room temperature and transport to the Cytogenetics Laboratory immediately. Do not freeze. Refrigerate if sterility is questioned or if sample cannot be shipped within 24 hours.

    Causes for Rejection

    No villi submitted or low volume in specimen; improper labeling; frozen or contaminated villi; specimen placed in fixative; wrong specimen or maternal decidual received

    Test Details

    Use

    FISH allows for rapid identification of common prenatal aneuploidy (specific for X, Y, 13, 18, 21). An abnormal result reflexes to karyotyping (G-band chromosome analysis). A normal FISH result reflexes to the SNP assay, which will detect chromosomal imbalances that could be associated with developmental delay/congenital anomalies. It provides detection of possible uniparental disomy of any chromosome, the percent and location of homozygosity, including the degree of identity by descent.

    Limitations

    FISH detects only the most common prenatal aneusomies. All abnormal FISH results should have cytogenetic confirmation. MCC studies are recommended. FISH will not detect balanced rearrangements and may not detect low level mosaicism. Extensive maternal cell contaminaton will limit the sensitivity of the assay. The SNP assay does not detect balanced rearrangements, low-level mosaicism (<10%), marker chromosomes that only contain heterochromatin or tetraploidy.

    The SNP assay does not detect balanced rearrangements, low-level mosaicism (<10%), marker chromosomes that only contain heterochromatin, or tetraploidy.

    Methodology

    Fluorescence in situ hybridization (FISH), Direct harvest of trophoblasts and in situ culture from enzymatic dissociated mesenchymal cells. An abnormal FISH result will reflex to cultured G-banded chromosome analysis. A normal FISH result will reflex to SNP microarray analysis, which is performed from uncultured cells using the Cytoscan® HD platform, which uses more than 743,000 SNP probes and 1,953,000 NPCN probes with a median spacing of 0.88 kb. If DNA yield on uncultured cells is inadequate, analysis will be performed on cultured cells. If cultures are needed, additional days will be required to complete testing.

    References

    Coppinger J, Alliman S, Lamb A, Torchia BS, Bejjani BA, Schafer LG. Whole-genome microarray analysis in prenatal specimens identifies clinically significant chromosome alterations without increase in results of unclear significance compared to targeted microarray. Prenatal Diagn. 2009 Dec; 29(12):1156-1166.19795450
    Schwartz S. Efficacy and applicability of interphase fluorescence in situ hybridization for prenatal diagnosis. Am J Hum Genet. 1993 May; 52(5):851-853.8488835
    Wapner R. A multicenter, prospective, masked comparison of chromosomal microarray with standard karyotyping for routine and higher risk prenatal diagnosis. Abstract 1. Am J Gyn. Supplement to Jan 2012.
    Ward BE, Gersen SL, Carelli MP, et al. Rapid prenatal diagnosis of chromosomal aneuploidies by fluorescence in situ hybridization: clinical experience with 4,500 specimens. Am J Hum Genet. 1993 May;52(5):854-865.8488836

    LOINC® Map

    Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
    511625 FISH CVS Rfx CMA or Chromo 510803 Cells Counted 64089-6
    511625 FISH CVS Rfx CMA or Chromo 510804 Cells Analyzed 64086-2
    511625 FISH CVS Rfx CMA or Chromo 510805 Cytogenetic Diagnosis 57318-8
    511625 FISH CVS Rfx CMA or Chromo 510958 Cytogenetic Interpretation 62365-2
    511625 FISH CVS Rfx CMA or Chromo 510807 Specimen Type 31208-2
    511625 FISH CVS Rfx CMA or Chromo 510959 Director Review: 72486-4
    511625 FISH CVS Rfx CMA or Chromo 511578 Reflex N/A
    511625 FISH CVS Rfx CMA or Chromo 512123 PDF 51967-8
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 510098 Chromosome Microarray 510216 Chromosome Microarray N/A
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 510098 Chromosome Microarray 510043 Specimen Type 31208-2
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 510098 Chromosome Microarray 510044 # of Genotyping Targets N/A
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 510098 Chromosome Microarray 510045 Array Type N/A
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 510098 Chromosome Microarray 510048 Diagnosis 48000-4
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 510098 Chromosome Microarray 510049 Interpretation 50398-7
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 510098 Chromosome Microarray 510061 Director Review 48672-0
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 510098 Chromosome Microarray 512123 PDF 51967-8
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 511579 Chromosome, Chorionic Villus 510052 Cells Counted 64089-6
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 511579 Chromosome, Chorionic Villus 510054 Cells Analyzed 64086-2
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 511579 Chromosome, Chorionic Villus 510055 Cells Karyotyped 64085-4
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 511579 Chromosome, Chorionic Villus 510056 GTG Band Resolution 64087-0
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 511579 Chromosome, Chorionic Villus 510057 Cytogenetic Diagnosis 33774-1
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 511579 Chromosome, Chorionic Villus 510989 Cytogenetic Interpretation 64088-8
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 511579 Chromosome, Chorionic Villus 511581 Specimen Type 31208-2
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 511579 Chromosome, Chorionic Villus 510991 Director Review: 48672-0
    Reflex Table for Reflex
    Order Code Order Name Result Code Result Name UofM Result LOINC
    Reflex 1 511579 Chromosome, Chorionic Villus 512123 PDF 51967-8

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