Systems and methods to detect rare mutations and copy number variation
The present disclosure provides a system and method for the detection of rare mutations and copy number variations in cell free polynucleotides. Generally, the systems and methods comprise sample preparation, or the extraction and isolation of cell free polynucleotide sequences from a bodily fluid; subsequent sequencing of cell free polynucleotides by techniques known in the art; and application of bioinformatics tools to detect rare mutations and copy number variations as compared to a reference. The systems and methods also may contain a database or collection of different rare mutations or copy number variation profiles of different diseases, to be used as additional references in aiding detection of rare mutations, copy number variation profiling or general genetic profiling of a disease.
1 . A method for monitoring residual disease in a subject, the method comprising:
(a) providing a first sample from the subject comprising genomic polynucleotides and sequencing the genomic polynucleotides or amplicons thereof to generate a first set of sequence data, wherein the first sample is obtained from a tumor biopsy from the subject;
(b) determining a frequency of cancer mutations which are single base substitutions from the first set of sequence data from the first sample;
(c) providing a second sample from the subject comprising cell-free deoxyribonucleic acid (cfDNA) molecules, enriching cfDNA molecules, or amplicons thereof, which comprise target regions of interest comprising the cancer mutations to provide enriched molecules and sequencing the enriched molecules or amplicons thereof to produce a second set of sequence data, wherein the second sample is obtained from the subject after the subject has undergone a course of treatment for cancer;
(d) determining a frequency of the cancer mutations discovered in the first sample from the second set of sequence data from the second sample; and
(e) determining a presence or absence of cancer in the subject based on an analysis of the frequency of the cancer mutations from the second set of sequence data from the second sample, thereby monitoring for the residual disease in the subject.
2 . The method of claim 1 , wherein the second sample is a blood sample.
3 . The method of claim 2 , wherein the second sample comprises between 1 nanogram (ng) to 100 ng of cfDNA molecules.
4 . The method of claim 3 , wherein adapters are ligated to a plurality of the cfDNA molecules prior to sequencing to generate tagged polynucleotides.
5 . The method of claim 4 , wherein the adapters comprise binding sites for universal amplification primers.
6 . The method of claim 5 , wherein the tagged polynucleotides are amplified to generate amplified progeny polynucleotides.
7 . The method of claim 6 , wherein the enrichment is of the amplified progeny polynucleotides.
8 . The method of claim 7 , wherein the enrichment comprises an amplification-based enrichment.
9 . The method of claim 7 , wherein the enrichment comprises oligonucleotide probes that selectively hybridize to the target regions of interest.
10 . The method of claim 7 , wherein the target regions of interest comprise exon regions, non-coding regions, or both.
11 . The method of claim 1 , wherein the cancer is colorectal cancer, lung cancer, or breast cancer.
12 . The method of claim 7 , wherein the first set of sequence data and the second set of sequence data comprise sequencing reads.
13 . The method of claim 12 , wherein the sequencing reads from the second set of sequencing data from the second sample are mapped to a reference sequence.
14 . The method of claim 13 , wherein a plurality of sequencing reads that map to the reference sequence are grouped into families having a same start and stop base position.
15 . The method of claim 13 , wherein the adapters further comprise molecular barcodes, and wherein a plurality of sequencing reads that map to the reference sequence are grouped into families having a same start and stop base position and the same molecular barcode sequence.
16 . The method of claim 13 , wherein cancer mutations in the second set of sequence data from the second sample are determined by comparing the sequencing reads to the reference sequence.
17 . The method of claim 14 , wherein cancer mutations in the second set of sequence data from the second sample are determined by collapsing sequencing reads within each family to yield a base call at a genetic locus and determining a frequency of one or more bases called at the locus from among the families.
18 . The method of claim 15 , wherein cancer mutations in the second set of sequence data from the second sample are determined by collapsing sequencing reads within each family to yield a base call at a genetic locus and determining a frequency of one or more bases called at the locus from among the families.
19 . The method of claim 1 , wherein the first set of sequence data comprises sequencing reads from the genomic polynucleotides, wherein the frequency of cancer mutations from the first set of sequence data from the first sample is determined by comparing sequencing reads to a reference sequence.
20 . The method of claim 1 , wherein the course of treatment is selected based on the frequency of cancer mutations determined from the first sample.
21 . The method of claim 15 , wherein the plurality of cfDNA molecules is ligated to adapters comprising n number of molecular barcodes, wherein n is at least 2 and no more than 10,000*z, wherein z is a mean of an expected number of duplicate molecules of cfDNA molecules in the second sample having identical start and stop positions.
22 . A method for monitoring residual disease in a subject, the method comprising:
(a) providing a first sample from the subject comprising genomic polynucleotides and sequencing the genomic polynucleotides or amplicons thereof to generate a first set of sequence data, wherein the first sample is obtained from a tumor biopsy from the subject;
(b) determining a frequency of cancer mutations which are at most 5 nucleotides in length from the first set of sequence data from the first sample;
(c) providing a second sample from the subject comprising cell-free deoxyribonucleic acid (cfDNA) molecules, enriching cfDNA molecules, or amplicons thereof, which comprise target regions of interest comprising the cancer mutations to provide enriched molecules and sequencing the enriched molecules or amplicons thereof to produce a second set of sequence data, wherein the second sample is obtained from the subject after the subject has undergone a course of treatment for cancer;
(d) determining a frequency of the cancer mutations discovered in the first sample from the second set of sequence data from the second sample; and
(e) determining a presence or absence of cancer in the subject based on an analysis of the frequency of the cancer mutations from the second set of sequence data from the second sample, thereby monitoring for the residual disease in the subject.
23 . The method of claim 22 , wherein the cancer mutations are single base substitutions or insertions or deletions (indels).
24 . The method of claim 22 , wherein the second sample is a blood sample that comprises between 1 nanogram (ng) to 100 ng of cfDNA molecules.
25 . The method of claim 23 , wherein:
(i) adapters are ligated to a plurality of the cfDNA molecules to generate tagged polynucleotides,
(ii) the tagged polynucleotides are amplified to generate amplified progeny polynucleotides.
26 . The method of claim 25 , wherein the enrichment is of the amplified progeny polynucleotides, wherein the enrichment comprises an amplification-based enrichment or the use of probes that selectively hybridize to the target regions of interest.
27 . The method of claim 26 , wherein the first set of sequence data and the second set of sequence data comprise sequencing reads, wherein the sequencing reads from either the first set of sequence data and/or the second set of sequencing data from the second sample are:
(i) mapped to a reference sequence,
(ii) grouped into families having at least a same start and stop base position, and
(iii) cancer mutations in the first set of sequence data and/or second set of sequence data are determined by collapsing sequencing reads within each family to yield a base call at a genetic locus and determining a frequency of one or more bases called at the locus from among the families.
28 . The method of claim 26 , wherein the first set of sequence data comprises sequencing reads from the genomic polynucleotides, wherein the frequency of cancer mutations from the first set of sequence data from the first sample is determined by comparing sequencing reads to a reference sequence.
29 . The method of claim 27 , wherein the plurality of cfDNA molecules is ligated to adapters comprising n number of molecular barcodes, wherein n is at least 2 and no more than 10,000*z, wherein z is a mean of an expected number of duplicate molecules of cfDNA molecules in the second sample having identical start and stop positions, and wherein the grouping of sequencing reads into families comprises using information from the start and stop base position and the molecular barcodes.