Fetal RHD genotype detection from circulating cell‐free fetal DNA in maternal plasma in non‐sensitized RhD negative women

Abstract

Objective To examine the performance of the SensiGene Fetal RHD Genotyping Laboratory Developed Test (RHD Genotyping LDT) using circulating cell-free fetal DNA (ccff DNA) extracted from maternal plasma.Methods ccff DNA was extracted from maternal blood from non-sensitized women with singleton pregnancies in two cohorts, one with a serotype reference (11-13 weeks' gestation) and one with the reference source (6-30 weeks' gestation). The presence of three RHD exon sequences (exons 4, 5, 7), the psi-pseudogene, three Y-chromosome sequences (SRY, DBY and TTTY2), and the X/Y-chromosome TGIF gene control were determined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry-the RHD Genotyping LDT. ResultsThe cohort with a serotype RhD reference showed correct classification in 201 of 207 patients, a test accuracy of 97.1%, with a sensitivity and specificity for prediction of RhD serotype of 97.2 and 96.8%, respectively. The cohort with a genotype RHD reference showed correct classification in 198 of 199 patients, indicating a test accuracy of 99.5% with a sensitivity and specificity for prediction of RHD genotype of 100.0 and 98.3%, respectively. ConclusionFetal RHD genotyping can accurately be determined using ccff DNA in the first and second trimesters of pregnancy.

Detection of fetal RHD pseudogene (RHDΨ) and hybrid RHD-CE-Ds from RHD-negative pregnant women with a free DNA fetal kit

“…Most of the studies examined samples from all three trimesters of pregnancy, but the majority were from the second and third trimesters (Bombard et al, 2011). The results of our study were from all trimesters.…”

“…Several studies have examined the prenatal detection of fetal RHD genotyping from analysis of cell-free fetal DNA in maternal plasma (Bombard et al, 2011). Almost all labora-tories carrying out fetal D typing on fetal DNA in maternal plasma employ quantitative realtime PCR technology with TaqMan chemistry (Daniels et al, 2007).…”

Avances en terapia fetal

“…[29][30][31] • Espectrofotometría del líquido amniótico (Delta O-450 en el gráfico de Liley) • Velocidad del pico sistólico de la arteria cerebral media (PS-ACM) • Cordocentesis: es el estándar de oro para evaluar el grado de anemia fetal.…”

The Maternal-Fetal Medicine: An Update

“…Prophylaxis is not available to prevent these cases. The fetal RhD antigen status can be determined by cordocentesis, DNA-based Rh typing using amniotic fluid, or chorionic villus sampling or by using fetal cell free DNA in maternal plasma [26].…”