Patent ID: 8756020
Filing Date: 2014-06-17
Classification: G16B

Abstract:
1. A computer-implemented process for calculating risk probabilities for fetal aneuploidies in a maternal sample, wherein at least one processor coupled to a memory executes a software component that performs the process comprising: determining a frequency of a first set of at least twelve or more non-polymorphic loci from a first chromosome in the maternal sample; determining a frequency of a second set of at least twelve or more non-polymorphic loci from a second chromosome in the maternal sample; determining the frequency of a third set of at least twelve or more polymorphic loci from one or more chromosomes other than the first and second chromosome in the maternal sample; determining an overall frequency of the non-polymorphic and polymorphic loci; computing a chromosome proportion metric for the first and second chromosome in the maternal sample using the overall frequency of the non-polymorphic loci; comparing the frequency of the polymorphic loci to determine a percent fetal nucleic acid in the maternal sample; for each first and second chromosome, measuring a deviation from an expected chromosome proportion metric when a chromosome is euploid; for each first and second chromosome, measuring a deviation from an expected chromosome proportion metric when a chromosome is aneuploid using the computed percent fetal nucleic acid in the maternal sample; and calculating an initial risk probability score for the maternal sample based on the deviations from the expected chromosome proportion metrics for the first and second chromosomes.