- Prenatal diagnosis
The potential presence of maternal cells in Chorionic villa (CVS) or Amniotic Fluid (AF) samples poses a significant risk of prenatal misdiagnosis. This is particularly of concern because the sensitivity of the polymerase chain reaction (PCR)-based molecular assays may lead to a positive result based on the presence of a very small amount of mutation-positive maternal cells. This test consists in genotyping of 16 loci on both a maternal and fetal sample (15 polymorphic STRs and the sex-specific Amelogenin marker): Penta E, D18S51, D21S11, TH01, D3S1358, FGA, TPOX, D8S1179, vWA, Amelogenin, Penta D, CSF1PO, D16S539, D7S820, D13S317 and D5S818.
This test is performed on the fetal and maternal DNA samples using the PowerPlex 16 System (Promega). Markers are genotyped by multiplex PCR amplification and capillary electrophoresis.
Analysis is dependent on correct reporting of family relationships. DNA variants located in primer binding sites and rare genotyping errors can result in inaccurate diagnosis. Mosaicism levels lower than 5% may not be detected by this assay. The analysis of samples contaminated at ratios lower than this may be inconclusive. The quantity of the X and Y chromosomes cannot be determined by this method.
Turnaround time: 3-5 working days
Specimens accepted:
- 1 x 4 mL blood in EDTA tube (purple top tube)
- Buccal swab
- For any other sample type, contact the laboratory for testing availability
A fetal sample must also be provided unless one is already available at our laboratory.
Submit your test request using our molecular genetics requisition.