Natera, Inc.
SYSTEMS AND METHODS FOR DETERMINING ANEUPLOIDY RISK USING SAMPLE FETAL FRACTION

Abstract:

Disclosed herein are system, method, and computer program product embodiments for determining aneuploidy risk in a target sample of maternal blood or plasma based on the amount of fetal DNA. An embodiment operates by receiving known genetic data from known prenatal testing samples and genetic data for the target sample. A fetal fraction distribution is determined for the known genetic data based on gestational age and the maternal weight associated with the target sample. A model is then generated based on a fixed ratio reduction of the determined fetal fraction distribution. A fetal fraction based data likelihood for the target sample is then determined for each of the plurality of ploidy states using the generated model. An aneuploidy risk score is then outputted based on applying a Bayesian probability determination that combines each fetal fraction based data likelihood with a previously determined risk score as a conditional value.