DNA Sequencing versus Standard Prenatal Aneuploidy Screening

To the Editor: Bianchi et al. (Feb. 27 issue) 1 described noninvasive diagnosis of fetal aneuploidy from cell-free DNA (cfDNA) in maternal plasma with the use of an Illumina HiSeq massively parallel sequencing platform and compared this method with standard prenatal aneuploidy screening. They concluded that prenatal screening by assay of cfDNA had significantly lower false positive rates and higher positive predictive values for detection of trisomies 21 and 18 than did standard screening. We screened for fetal aneuploidy using cfDNA from 2275 pregnant women (each of whom carried a single fetus) by means of a benchtop semiconductor sequencing platform (Ion . . .