The authors' implementation of the SNP-based classification method incorrectly assumes that each SNP's fetal genotype is inherited independently from adjacent loci, ignoring the information available using linkage. In contrast, Natera's SNP-based method incorporates the effect of chromosome recombinations...
Sample preparation and analysis of cell-free DNA (cfDNA) were performed as previously described (Natera Inc, Austin, TX).14 Noninvasive prenatal testing (NIPT) results indicating a risk of ≥1/100 for a trisomy were categorized as high risk and those at <1/100 as low risk. In the cases...