Patent Document ID: 20140336060
Application ID: 14446232
Patent Flag: 0

Claim One:
1. A method for determining the number of copies of a chromosome or chromosome segment of interest in the genome of at least one gestating fetus, the method comprising: sequencing DNA from a first fraction of each mixed sample in a plurality of mixed samples from a plurality of pregnant mothers to obtain a first set of measured genetic data at a plurality of loci on a chromosome or chromosome segment of interest; wherein each mixed sample comprises DNA from a fetus and DNA from the mother of the fetus; creating a plurality of hypotheses specifying the number of copies of the chromosome or chromosome segment of interest in the genome of at least one of the fetuses; determining, on a computer, a first probability for each of the hypotheses using the first set of measured genetic data; sequencing DNA from a second fraction of a least one of the mixed samples for which the first probability of an aneuploid number of copies of the chromosome or chromosome segment of interest is above a threshold value to obtain a second set of measured genetic data at the plurality of loci on the chromosome or chromosome segment of interest; determining, on a computer, a second probability for each of the hypotheses using the second set of measured genetic data and optionally the first set of measured genetic data; and selecting the hypothesis with the greatest probability for the second probability determination, thereby determining the number of copies of the chromosome or chromosome segment of interest in the genome of at least one of the fetuses.