US Patent 10930368 Methods and processes for non-invasive assessment of genetic variations

A method and system for analyzing circulating cell-free nucleic acids from a pregnant female with reduced bias, Counts of sequence reads mapped to portions of a reference genome are obtained. A regression model is generated that models the relationship between the counts and the GC content. The read counts are normalized according to the regression model to remove the GC bias. The normalized counts are used for further analysis, such as the detection of fetal aneuploidy.