Guardant Health, Inc.
DETERMINING TUMOR FRACTION FOR A SAMPLE BASED ON METHYL BINDING DOMAIN CALIBRATION DATA

Abstract:

The application is directed to systems and processes to determine an estimate for tumor fraction of a sample. In various examples, amounts of methylation of nucleic acids can be determined based on a strength of binding by the nucleic acids to methyl binding domain (MBD). The nucleic acids can be partitioned according to the strength of binding to MBD. Additionally, a number of cytosine-guanine regions for the nucleic acids can be determined. Amounts of methylation of classification regions of the nucleic acids can be determined based on the partition information associated with the nucleic acids and the number of cytosine-guanine regions of the nucleic acids. The classification regions can have differing amounts of methylation in tumor cells and non-tumor cells. The estimate for tumor fraction of the sample can be determined according to the amounts of methylation of the classification regions.