Synergy of Total PLAC4 RNA Concentration and Measurement of the RNA Single-Nucleotide Polymorphism Allelic Ratio for the Noninvasive Prenatal Detection of Trisomy 21

Abstract
Background: Maternal plasma mRNA encoded by the PLAC4 gene (placenta-specific 4), which is transcribed from chromosome 21 in placental cells, is a potential marker for the noninvasive assessment of chromosome 21 dosage in the fetus. We evaluated the diagnostic sensitivities and specificities of 2 trisomy 21–screening approaches that use maternal plasma PLAC4 mRNA.
Funding Information
  • University Grants Committee (AoE/M-04/06)