TESTING METHODOLOGY: DNA isolated from the maternal blood. Which contains fetal DNA.is amplified at 19,488 loci using a targeted PCR assay. and sequenced using a high throughput sequencing data is analyzed using Natera's proprietary MARIA(Next-generation Aneuploidy Testing Using SNPs)algorithm to determine the fetal copy number for chromosomes 13,18,21,X,and Y, thereby identifying whole chromosome abnormalities at these locations,and if ordered,