System for increasing the accuracy of non invasive prenatal diagnostics and liquid biopsy by observed loci bias correction at single base resolution

Abstract

Techniques for measuring abundances of sequences includes obtaining first data that indicates a target sequence at a plurality of loci, wherein the target sequence comprises a plurality of bins of loci for which a relative abundance is indicative of a condition of interest. Second data is determined that indicates alignment with the target sequence of reads of DNA fragments in a sample from the subject. Third data is determined that indicates locus dependent observed variations in abundance. A raw count Hj of reads is determined that start at each locus j; and, a copy number of a first bin is determined based on a sum over all loci in the first bin of expected counts for each partition weighted by the locus dependent observed variations. Output data that indicates condition of the subject based at least in part on the copy number of the first bin is presented.