The aim of the study was to demonstrate the influence of target gene and amplification product length on the performance of fetal gender determination systems using maternal plasma. A total of 40 pairs of plasma DNA samples from pregnant women and genomic DNA samples from maternal blood, amniotic fluid and paternal blood were isolated for gender determination by amplification of the amelogenin gene and 17 Y-chromosome STR loci, using three different commercial kits. The gender of the fetuses was confirmed by cytogenetic analysis or phenotype at birth. Both the AmpF？STR-Identifiler amplification kit and the Mini-STR Amplification kit for amelogenin gene detection were reliable in determining fetal gender (92.0% and 96.0%, respectively), but false negatives were present in both systems. AmpF？STR-Yfiler was found to be fully reliable as it amplified Y-STR in all cases of pregnancies with male fetuses and thus was 100% correct in determining fetal gender. The results demonstrated that multiple fluorescent PCR for 17 Y-STR loci was more reliable than AMELY gene testing in fetal sex determination with maternal plasma. We also found that the shorter amplification products could improve the performance of fetal gender determination systems.
References
[1]
Lo, Y.M.D.; Corbetta, N.; Chamberlain, P.F.; Rai, V.; Sargent, I.L.; Redman, C.W.G.; Wainscoat, J.S. Presence of fetal DNA in maternal plasma and serum. Lancet 1997, 350, 485–487.
[2]
Devaney, S.A.; Palomaki, G.E.; Scott, J.A.; Bianchi, D.W. Noninvasive fetal sex determination using cell-free fetal DNA: A systematic review and meta-analysis. J. Am. Med. Assoc 2011, 306, 627–636.
[3]
Mannucci, A.; Sullivan, K.M.; Ivanov, P.L.; Gill, P. Forensic application of a rapid and quantitative DNA sex test by amplification of the X–Y homologous gene amelogenin. Int. J. Legal Med 1994, 106, 190–193.
[4]
Johnson, C.L.; Warren, J.H.; Giles, R.C.; Staub, R.W. Validation and uses of a Y-chromosome STR 10-plex for forensic and paternity laboratories. J. Forensic Sci 2003, 48, 1260–1268.
[5]
Sullivan, K.M.; Mannucci, A.; Kimpton, C.P.; Gill, P. A rapid and quantitative DNA sex test: Fluorescence-based PCR analysis of X–Y homologous gene amelogenin. BioTechniques 1993, 15, 636–638.
[6]
Fan, H.C.; Blumenfeld, Y.J.; Chitkara, U.; Hudgins, L.; Quake, S.R. Analysis of the size distributions of fetal and maternal cell-free DNA by paired-end sequencing. Clin. Chem 2010, 56, 1279–1286.
[7]
Birch, L.; English, C.A.; O’Donoghue, K.; Barigye, O.; Fisk, N.M.; Keer, J.T. Accurate and robust quantification of circulating fetal and total DNA in maternal plasma from 5 to 41 weeks of gestation. Clin. Chem 2005, 51, 312–320.
[8]
Lun, F.M.F.; Chiu, R.W.K.; Allen Chan, K.C.; Yeung Leung, T.; Kin Lau, T.; Lo, Y.M.D. Microfluidics digital PCR reveals a Higher than expected fraction of fetal DNA in maternal plasma. Clin. Chem 2008, 54, 1664–1672.
[9]
Steinlechner, M.; Berger, B.; Niederstatter, H.; Parson, W. Rare failures in the amelogenin sex test. Int. J. Legal Med 2002, 116, 117–120.
[10]
Walsh, P.S.; Metzger, D.A.; Higuchi, R. Chelex 100 as a medium for simple extraction of DNA for PCR-based typing from forensic material. BioTechniques 1991, 10, 506–513.
