Fig. 1

Experimental design and flowchart of data analyses for three trisomic pregnancies study based on cell-free nucleosome footprint low-coverage whole-genome sequencing. The different nucleosome positioning on cfDNA of healthy pregnant women and pregnant women carrying fetuses with trisomy 21, 18 and 13 was analyzed. And finally, the results were integrated analysis and annotated through preprocessing, alignment, quality control, expression index, clustering, and differential analysis of the sequencing data