Rare cell analysis using sample splitting and DNA tags
View Patent ↗The present invention provides systems, apparatuses, and methods to detect the presence of fetal cells when mixed with a population of maternal cells in a sample and to test fetal abnormalities, e.g. aneuploidy. The present invention involves labeling regions of genomic DNA in each cell in said mixed sample with different labels wherein each label is specific to each cell and quantifying the labeled regions of genomic DNA from each cell in the mixed sample. More particularly the invention involves quantifying labeled DNA polymorphisms from each cell in the mixed sample.
1. A method for fetal diagnosis comprising:
labeling one or more genomic DNA regions in fetal and non-fetal cells, enriched from a maternal blood sample, wherein said labels distinguish between individual cells;
splitting said fetal and non-fetal cells such that individual cells are in addressable locations; and
determining the presence or absence of a fetal abnormality by analyzing said labeled genomic DNA regions.
2. The method of claim 1 , further comprising amplifying said one or more genomic DNA regions from each cell to generate a plurality of amplicons.
3. The method of claim 2 , further comprising pooling said amplicons.
4. The method of claim 2 , wherein said regions of genomic DNA comprise one or more polymorphisms.
5. The method of claim 4 , wherein said polymorphisms are STRs or SNPs.
6. The method of claim 2 , wherein said amplification is performed by multiplex PCR.
7. The method of claim 6 , wherein said amplification also comprises nested PCR.
8. The method of claim 1 , wherein said labels each comprise a unique tag sequence specific for each addressable location.
9. The method of claim 1 , wherein said genomic DNA regions are located on two or more chromosomes of interest.
10. A method for fetal diagnosis comprising:
labeling one or more cDNA sequences generated from fetal and non-fetal cells, wherein said fetal and non-fetal cells are enriched from a maternal blood sample, wherein said labels distinguish between individual cells
splitting said fetal and non-fetal cells such that individual cells are in addressable locations; and
determining the presence or absence of a fetal abnormality by analyzing said labeled cDNA regions.
11. A method of fetal diagnosis comprising:
labeling at least two genomic DNA regions on one or more chromosomes of interest in fetal and non-fetal cells, enriched from a maternal blood sample, wherein said labels distinguish between individual cells; and
determining the presence or absence of a fetal abnormality by analyzing said two or more labeled genomic DNA regions.
12. A method of fetal diagnosis comprising:
labeling one or more genomic DNA regions in fetal and non-fetal cells, enriched from a maternal blood sample, wherein said labels distinguish between individual cells; and
determining the presence or absence of a fetal abnormality by analyzing said labeled genomic DNA regions;
wherein said analyzing comprises performing ultra-deep sequencing or quantitative genotyping.