SNP Microarray−Products of Conception (POC)/Tissue (Reveal®)

CPT 81229
Synonyms
  • Reveal® SNP Microarray−Products of Conception (POC)/Tissue

Test Details

Use

This test will detect chromosomal imbalance 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. It will also allow the detection of complete or partial molar pregnancies.

Special Instructions

Pertinent medical findings must accompany test request form. For formalin fixed paraffin embedded blocks or slides, test number will be updated to Microarray-Products of Conception (POC) Reveal® FFPE [511997]. If <8 mg nonfixed tissue is received, sample will be assessed to run on the Oncoscan Microarray platform, and test number adjusted as necessary and client notified.

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

Limitations

Unable to determine genotypes on some formalin-fixed tissue (blocks/slides), allowing only genomic dosage to be determined. This SNP assay 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.

Methodology

SNP microarray analysis is performed using the Cytoscan® HD Accel platform, which uses 743,130 SNP probes and 2,029,441 NPCN probes with a median spacing of 0.818 kb.

References

Coppinger J, Alliman S, Lamb A, et al. 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

Additional Information

The microarray will detect DNA copy-number changes at a threshold >1 Mb for deletions, >2 Mb for duplications.

Specimen Requirements

Information on collection, storage, and volume

Specimen

Nonfixed tissue, products of conception (POC) or placental villus biopsy

Volume

>8 mg tissue

Container

Submit biopsies in a sterile tube with sterile Ringer's lactate, Hanks' balanced salt solution or Labcorp transport medium. The transport tube (a sterile specimen container with transport medium) is available from Labcorp. Please call customer service at 800-345-4363. Specialized kits are now available for POC microarray testing. To order, please contact your local Labcorp representative (PeopleSoft No. 89063, Catalogue item ID No. 39025G). If no transport media is available, sterile isotonic saline can be used for transport. Do not use urine containers for shipping.

Storage Instructions

Specimens should be sent to the laboratory immediately. Maintain specimen at room temperature. Specimen may be refrigerated if there is a delay in shipment. Do not freeze.

Causes for Rejection

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

Collection

Aseptically obtain a small piece of tissue with subepidermal layers. Best results are obtained from placental villi, which remain viable much longer than fetal tissue. This is especially true in stillborn cases in which both cord blood and tissue samples are often not viable. If specimen is a product of conception, submit biopsies in a sterile tube with sterile Ringer's lactate, Hanks' balanced salt solution or Labcorp transport media. Gross contamination and necrotic tissue cannot be processed.