Reveal® SNP Microarray is a high-density array that detects chromosomal imbalances related to fetal loss. ACOG recommends reflexing to microarray when routine chromosome analysis fails. Reveal SNP Microarray can also be performed directly on POC tissue without having to grow cells, optimizing success rate and turnaround time. Partial moles (associated with triploidy) and complete invasive molar pregnancies (of androgenic origin) can be readily diagnosed. The abnormalities in complete molar pregnancies cannot be detected by chromosome analysis, and neither complete nor partial moles can be analyzed by oligo or BAC CGH array technologies. Clinical indications: Fetal loss/stillbirth when conventional chromosome analysis cannot be obtained; identification of genomic imbalance or androgenic chromosome origin in partial or complete molar pregnancies; phenotypic abnormalities with apparently balanced chromosome rearrangements or unidentified marker chromosomes.
Test Details
Use
Detects chromosomal imbalance that may be associated with fetal loss and is ideal for detection of complete or partial moles
Methodology
Whole genome SNP-based copy-number microarray analysis targeting 2.695 million copy-number and allele-specific genome sites
Specimen Requirements
Specimen
Preferred nonfixed tissue or products of conception (POC)/placental villus biopsy; formalin-fixed paraffin-embedded tissue; (Samples received in fixative are subject to additional charge for histopathology processing and reporting); unstained tissue slides
Volume
>2-4 mm3 tissue
Container
Sterile container containing transport media provided by our laboratory, Ringer's lactate, or Hanks' balanced salt solution
Collection
Aseptically obtain a small piece of fetal tissue that does not appear necrotic. If specimen is a POC, placental villi or membranes may be the only fetal-derived tissue available, and an effort should be made to submit these tissues rather than maternal decidua.
Special Instructions
A Clinical Questionnaire for Reveal SNP Microarray - POC must be completed.
Causes for Rejection
Quantity not sufficient for analysis; necrotic tissue submitted
Storage Instructions
Maintain specimen at room temperature.
Additional Information
Limitations
Unable to determine genotypes on some formalin-fixed tissue (blocks/slides), allowing only genomic dosage to be determined. This assay does not detect balanced rearrangements, low-level mosaicism (<10%), or tetraploidy.