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Chromosome Analysis, Amniotic Fluid With Reflex to SNP Microarray (Reveal®)

Test Number 052104
Test number copied
CPT

Contact CPT coding department at 800-222-7566, ext 6-8400.
Synonyms
  • Karyotype, Amniotic Fluid With Reflex to Microarray

Test Details

Methodology

In situ cell culturing of amniocytes to investigate numerical and/or structural chromosome abnormalities. A normal chromosome analysis will reflex to SNP microarray analysis using the Cytoscan® HD Accel platform which uses 743,000 SNP probes and 2,029,441 NPCN probes with a median spacing of 0.818 kb.

Result Turnaround Time

7 - 11 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.

Clinical Questionnaire for Prenatal SNP Microarray

Use

The chromosome analysis determines fetal karyotype. A normal chromosome analysis will reflex to a high-resolution SNP microarray analysis targeting 2.8 million copy-number and allele-specific genome sites. 

The SNP assay will detect chromosomal imbalances that could be associated with developmental delay/congenital anomalies. It provides possible detection of uniparental disomy of any chromosome, the percent and location of homozygosity, including the degree of identity by descent. 

 

Special Instructions

Pertinent medical findings must accompany request.

If prior NIPT studies have been performed, include copy of the report.

Limitations

Although the overall culture success rate is reported as >99%, culture failure can result. Reasons include (but are  not limited to) lack of amniocytes in the fluid and contamination of the fluid with bacteria or yeast. For the SNP assay it does not detect balanced rearrangements, low-level mosaicism (<10%), marker chromosomes that only contain heterochromatin or tetraploidy.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Custom Additional Information

Additional biochemical or molecular tests may be performed on the cultured amniocytes.

Fetal loss rate is considered to be 0.5% at 14 to 18 week sampling and 2% to 3% at 10 to 13 weeks.1 Chorionic villus sampling (CVS) may be safer than early amniocentesis for early prenatal diagnosis of cytogenetic abnormalities.2,3

The risk of miscarriage with CVS is 1% to 1.5%, but the risk of maternal infection appears to be higher with CVS than with amniocentesis.4 Cytogenetic analyses using such samples allow for early gestational testing based on a 10- to 11-week placental biopsy and a five-day cytogenetic study. Most failures are due to an inappropriate biopsy containing only maternal decidua. Chromosomal aberrations were found in 4.6% of fetuses in women older than 38 to 40 years. Trisomy 21 was the most common abnormality (62%). Klinefelter syndrome (11%), Edwards syndrome, and trisomy 18 (11%) were the next most frequent in the cases of advanced maternal age.

Prenatal diagnosis is possible for more than 1000 inherited diseases. Most are inherited in an autosomal recessive manner. Antenatal diagnosis using gene probes has become available for cystic fibrosis, muscular dystrophy, sickle cell anemia, hemophilia, and many other genetic abnormalities. This can be done from either cultured amniotic fluid cells or chorionic villus sampling.5

Specimen Requirements

Specimen

Amniotic fluid, fetal urine or cystic hygroma fluid

Volume

15-20 mL (20-30 mL for early amniocentesis)

Minimum Volume

5 mL (Minimum volume may delay results due to fewer cells available for culture.)

Container

Sterile plastic conical tube

Collection Instructions

Discard first 2 mL of fluid aspirated to avoid maternal cell contamination. Specimen is collected in a 20 mL sterile syringe and transferred aseptically to sterile tubes to be transported to Labcorp. Test request form is completed and accompanies specimen and miscellaneous slip to the laboratory. Samples from twin (multiple) pregnancies should be appropriately labeled and placed in separate transport containers with a separate request form for each twin. Rubber stopper and/or frozen specimen cannot be processed.

Storage Instructions

Maintain specimen at room temperature. Do not refrigerate or freeze.

Patient Preparation

The patient preferably should have had ultrasound studies (to verify fetal life, detect multiple gestation, confirm gestational age, localize placenta).

Causes for Rejection

Upon receipt, suitability of specimen will be determined by the Cytogenetics laboratory.

Footnotes

1. Nicolaides K, Brizot Mde L, Patel F, Snijders R. Comparison of chorionic villus sampling and amniocentesis for fetal karyotyping at 10-13 weeks' gestation. Lancet. 1994 Aug 13; 334(8920):435-439. Erratum: 1994 Sep 17; 344(8925):830.7914564
2. Ledbetter DH, Zachary JM, Simpson JL, et al. Cytogenetic results from the US Collaborative Study on CVS. Prenat Diagn. 1992 May; 12(5):317-345. 1523201
3. Desnick RJ, Schuette JL, Golbus MS, et al. First-trimester biochemical and molecular diagnoses using chorionic villi: High accuracy in the US Collaborative Study. Prenat Diagn. 1992 May; 12(5):357-372. 1523203
4. DiLiberti JH, Greenstein MA, Rosengren SS. Prenatal diagnosis. Pediatr Rev. 1992 Sep; 13(9):334-342. 1409163
5. Chueh J, Golbus MS. Prenatal diagnosis using fetal cells in the maternal circulation. Semin Perinatol. 1990 Dec; 14(6):471-482. 2077667

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
052104 Chromosome Amnio RFX CMA 62389-2 052138 Cells Counted 64095-3
052104 Chromosome Amnio RFX CMA 62389-2 052139 Colonies 64096-1
052104 Chromosome Amnio RFX CMA 62389-2 052140 Cells Analyzed 64092-0
052104 Chromosome Amnio RFX CMA 62389-2 052141 Cells Karyotyped 64091-2
052104 Chromosome Amnio RFX CMA 62389-2 052143 GTG Band Resolution Achieved 64093-8
052104 Chromosome Amnio RFX CMA 62389-2 052144 Cytogenetic Diagnosis 62356-1
052104 Chromosome Amnio RFX CMA 62389-2 052016 Cytogenetic Interpretation 64094-6
052104 Chromosome Amnio RFX CMA 62389-2 052146 Specimen Type 48002-0
052104 Chromosome Amnio RFX CMA 62389-2 052017 Director Review: 48672-0
052104 Chromosome Amnio RFX CMA 62389-2 052320 Reflex N/A
052104 Chromosome Amnio RFX CMA 62389-2 512123 PDF 11502-2
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052138
Result Code NameCells Counted
UofM
Result LOINC64095-3
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052139
Result Code NameColonies
UofM
Result LOINC64096-1
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052140
Result Code NameCells Analyzed
UofM
Result LOINC64092-0
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052141
Result Code NameCells Karyotyped
UofM
Result LOINC64091-2
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052143
Result Code NameGTG Band Resolution Achieved
UofM
Result LOINC64093-8
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052144
Result Code NameCytogenetic Diagnosis
UofM
Result LOINC62356-1
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052016
Result Code NameCytogenetic Interpretation
UofM
Result LOINC64094-6
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052146
Result Code NameSpecimen Type
UofM
Result LOINC48002-0
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052017
Result Code NameDirector Review:
UofM
Result LOINC48672-0
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code052320
Result Code NameReflex
UofM
Result LOINCN/A
Order Code052104
Order Code NameChromosome Amnio RFX CMA
Order Loinc62389-2
Result Code512123
Result Code NamePDF
UofM
Result LOINC11502-2
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 1
Order Code510098
Order NameChromosome Microarray
Result Code510216
Result NameChromosome Microarray
UofM
Result LOINCN/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 1
Order Code510098
Order NameChromosome Microarray
Result Code510043
Result NameSpecimen Type
UofM
Result LOINC31208-2
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 1
Order Code510098
Order NameChromosome Microarray
Result Code510044
Result Name# of Genotyping Targets
UofM
Result LOINCN/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 1
Order Code510098
Order NameChromosome Microarray
Result Code510045
Result NameArray Type
UofM
Result LOINCN/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 1
Order Code510098
Order NameChromosome Microarray
Result Code510048
Result NameDiagnosis
UofM
Result LOINC48000-4
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 1
Order Code510098
Order NameChromosome Microarray
Result Code510049
Result NameInterpretation
UofM
Result LOINC50398-7
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 1
Order Code510098
Order NameChromosome Microarray
Result Code510061
Result NameDirector Review
UofM
Result LOINC48672-0
Reflex Table for Reflex
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 510098 Chromosome Microarray 512123 PDF 11502-2
Reflex 1
Order Code510098
Order NameChromosome Microarray
Result Code512123
Result NamePDF
UofM
Result LOINC11502-2