Methods for non-invasive prenatal ploidy calling

US11332785B2 · kind B2 · utility

Assignee

• Natera, Inc. · US

Inventors

• Matthew Rabinowitz · San Francisco, US
• George Gemelos · Walnut, US
• Milena Banjevic · Los Altos Hills, US
• Allison Ryan · Redwood City, US
• Zachary Demko · San Francisco, US
• Matthew Hill · Belmont, US
• Bernhard Zimmermann · Manteca, US
• Johan Baner · San Francisco, US
• Styrmir Sigurjonsson · San Jose, US

Key dates

• Filing date: May 14, 2019
• Grant date: May 17, 2022
• Expiry date: May 14, 2039

Classification

• Technology area (CPC G): Physics
• CPC primary: G16B40/00
• WIPO field: Biotechnology
• WIPO sector: Chemistry

Abstract

The present disclosure provides methods for determining the ploidy status of a chromosome in a gestating fetus from genotypic data measured from a mixed sample of DNA comprising DNA from both the mother of the fetus and from the fetus, and optionally from genotypic data from the mother and father. The ploidy state is determined by using a joint distribution model to create a plurality of expected allele distributions for different possible fetal ploidy states given the parental genotypic data, and comparing the expected allelic distributions to the pattern of measured allelic distributions measured in the mixed sample, and choosing the ploidy state whose expected allelic distribution pattern most closely matches the observed allelic distribution pattern. The mixed sample of DNA may be preferentially enriched at a plurality of polymorphic loci in a way that minimizes the allelic bias, for example using massively multiplexed targeted PCR.