Methods for using mosaicism in nucleic acids sampled distal to their origin
Disclosed herein are methods for improving detection and monitoring of human diseases. The methods can be used to provide spatial and/or developmental localization of the source of each differential mutation within the body. The methods can also be used to generate a mutation map of a subject. And the mutation map can be used to monitoring state(s) of health of one or more tissues of a subject.
1. A method for identifying a non-fetal source of cell-free or surface-bound nucleic acid molecules in a blood sample from a body of a subject, comprising:
(a) separating said blood sample into at least a first component that includes said cell-free or surface-bound nucleic acid molecules and a second component that includes leukocytes, wherein said non-fetal source of said cell-free or surface-bound nucleic acid molecules is unknown;
(b) extracting nucleic acid molecules from said first component and said leukocytes from said second component;
(c) independently sequencing extracted nucleic acid molecules from said first component and second component to generate a first set of sequence reads and a second set of sequence reads from said first and second components, respectively; and
(d) subsequent to (c), identifying said non-fetal source of said cell-free or surface-bound nucleic acid molecules in said body of said subject.
2. The method of claim 1 , further comprising providing a report and/or a therapeutic intervention based on an identification of said non-fetal source.
3. The method of claim 1 , wherein said non-fetal source is identified as a tissue or group of tissues of said subject.
4. The method of claim 1 , wherein said nucleic acid molecules of said second component are extracted by disrupting said leukocytes.
5. The method of claim 1 , wherein said nucleic acid molecules extracted from said first component and said second component are sequenced in a combined pool.
6. The method of claim 1 , wherein said subject is a human subject.
7. The method of claim 1 , wherein said source of said cell-free or surface-bound nucleic acid molecules is not previously known.
8. The method of claim 1 , wherein said non-fetal source is a tissue in said body of said subject.
9. The method of claim 1 , wherein separating said blood sample into said first component and said second component comprises centrifugation.
10. The method of claim 1 , wherein separating said blood sample into at least said first component comprises isolating surface-bound nucleic acid molecules from blood cells, circulating fetal cells, circulating endothelial cells, circulating tumor cells, or a combination thereof.
11. The method of claim 10 , wherein said blood cells are erythrocytes.
12. The method of claim 1 , further comprising enriching said extracted nucleic acid molecules.
13. The method of claim 12 , wherein said extracted nucleic acid molecules are enriched based on mean size, mean GC content, genomic regions, genomic region feature, or a combination thereof.
14. The method of claim 1 , wherein said separating of said blood sample into at least said first component and said second component comprises enriching one or more cell types using flow cytometry.
15. The method of claim 1 , further comprising detecting said differential mutations of said subject using said first set of sequence reads and said second set of sequence reads.