Patent ID: 8700338
Filing Date: 2014-04-15
Classification: C12Q,G16B

Abstract:
1. A process implemented by a program executed on a computer for calculating an odds ratio for a fetal aneuploidy in a maternal sample, the process steps comprising: measuring fetal proportion and chromosome dosage for two or more chromosomes in a simultaneous assay, wherein the fetal proportion is measured by interrogating polymorphic loci in the maternal sample and comparing loci that are different in maternal DNA and fetal DNA; calculating a first value of likelihood that a first fetal chromosome is disomic using the expected chromosome dosage of a first chromosome if the first fetal chromosome were disomic; calculating a second value of likelihood that a first fetal chromosome were aneuploid using the expected chromosome dosage of the first chromosome if the first fetal chromosome were aneuploid adjusted for the measured fetal proportion in the maternal sample to account for the expected representation of the first chromosome if it were aneuploid; providing data on prior risk of aneuploidy for at least a first fetal chromosome based on extrinsic characteristics; computing the odds that the first fetal chromosome is aneuploid by comparing the measured chromosome dosage for the two or more chromosomes in the maternal sample to the first value of likelihood that a first fetal chromosome is disomic and to the second value of likelihood that a first fetal chromosome is aneuploid; and adjusting the odds that the first fetal chromosome is aneuploid based on prior risk of aneuploidy.