Analysis based on the size of fetal DNA in maternal plasma

摘要

A method of analyzing a biological sample of an organism, the biological sample including DNA originating from normal cells and potentially from cells associated with cancer, wherein at least some of the DNA is cell-free in the biological sample, the method comprising: for each size of a plurality of sizes: measuring an amount of a first set of DNA fragments from the biological sample corresponding to the size; calculating a first value of a first parameter based on the amounts of DNA fragments at multiple sizes, the first parameter providing a statistical measure of a size profile of DNA fragments in the biological sample; comparing the first value to a reference value; and determining a classification of a level of cancer in the organism based on the comparison.