This work was presented as a poster at the 32nd Annual Meeting of the Society for Maternal-Fetal Medicine; February 2012; Dallas, Texas.
Circulating cell-free fetal DNA for the detection of RHD status and sex using reflex fetal identifiers†
Article first published online: 6 DEC 2012
© 2012 John Wiley & Sons, Ltd.
Volume 33, Issue 1, pages 95–101, January 2013
How to Cite
Moise, K. J., Boring, N. H., O'Shaughnessy, R., Simpson, L. L., Wolfe, H. M., Baxter, J. K., Polzin, W., Eddleman, K. A., Hassan, S. S., Skupski, D., McLennan, G., Paladino, T., Oeth, P. and Bombard, A. (2013), Circulating cell-free fetal DNA for the detection of RHD status and sex using reflex fetal identifiers. Prenat. Diagn., 33: 95–101. doi: 10.1002/pd.4018
Funding sources: Funding for this study was provided by Sequenom, Inc. Sequenom paid fees directly to Baylor College of Medicine for salary support for the PI and a central study coordinator, establishment of a web-based data collection tool, patient enrollment fees at the individual participating centers and consultative fees for an independent statistician to analyze the final data. The study design was undertaken by the PI. All clinical data was entered into a web-based database; Sequenom had no access to this data. The clinical data and corresponding DNA results were initially released to the PI and later to an independent statistician. The manuscript was written by the PI with editorial input from all participating authors. Sequenom, Inc. reviewed the final version of this manuscript and accepted it without alteration.
Conflicts of interest: The PI and all investigators in this study share no financial interests with Sequenom, Inc.
- Issue published online: 7 JAN 2013
- Article first published online: 6 DEC 2012
To determine the sensitivity and specificity of circulating cell-free fetal DNA in determining the fetal RHD status and fetal sex.
Maternal blood was collected in each trimester of pregnancy from RhD negative nonalloimmunized women. Whole blood was centrifuged, separated into plasma and buffy coat, and frozen at –80°C. DNA analysis was conducted via allele-specific primer extensions for exons 4, 5, and 7 of the RHD gene and for a 37-base pair insertion in exon 4 (RHD pseudogene; psi) three Y-chromosome sequences (SRY, DBY, and TTY2), and an extraction control (TGIFL-like X/Y). RhD serotyping on cord blood and gender assessment of the newborns were entered into a Web-based database.
One hundred twenty women were enrolled. The median gestational age at the first venipuncture was 12.4 (range: 10.6–13.9) weeks with 120 samples drawn; 118 samples were drawn at 17.6 (16–20.9) weeks; and 113 samples at 28.7 (27.9–33.9) weeks. Overall accuracy for RHD was 99.1%, 99.1%, and 98.1% for each trimester and was 99.1%, 99.1%, and 100% for fetal sex determination.
Fetal RHD genotyping and sex can be very accurately determined in all three trimesters using circulating cell-free fetal DNA in the maternal circulation. © 2012 John Wiley & Sons, Ltd.