Fig. 1.

Workflow and functions of NIPTeR. a A BAM file is transformed into an NIPTSample object; b a series of NIPTSample objects can then be transformed into an NIPTControlGroup object; c optional LOESS or weighted bin GC correction; d optional chi-squared-based variation reduction; e optional comparison of NIPTSample and NIPTControlGroup and possible selection of a subset that best-matches the control group samples; f three different prediction methods: Z-score, normalized chromosome value or regression-based Z-score; g optional check of control group statistics