Special Instructions
A Clinical Questionnaire for Reveal SNP Microarray - POC must be completed. If prior NIPT or maternal serum screening studies have been performed, include copy of report.
Expected Turnaround Time
12 - 18 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.
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.
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.
Storage Instructions
Maintain specimen at room temperature.
Causes for Rejection
Quantity not sufficient for analysis; necrotic tissue submitted
Test Details
Use
Detects chromosomal imbalance that may be associated with fetal loss and is ideal for detection of complete or partial moles
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.
Methodology
Whole genome SNP-based copy-number microarray analysis targeting 2.695 million copy-number and allele-specific genome sites
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.PubMed 19795450