Assay systems for genetic analysis
The present invention provides assays systems and methods for detection of chromosomal abnormalities and status of single loci associated with monogenic or polygenic traits in a sample containing nucleic acids from a maternal and a fetal source.
1. A method for simultaneous detection of a presence or absence of a fetal copy number variation (CNV) of a genomic region and a presence or absence of one or more fetal polymorphisms in a maternal sample comprising fetal and maternal cell-free DNA, comprising the steps of:
(a) hybridizing at least 24 first sets of two fixed sequence oligonucleotides to the cell-free DNA in the maternal sample, wherein each first set is complementary to a locus in a first genomic region from a first chromosome or a first portion of a chromosome, wherein at least one of the two fixed sequence oligonucleotides in each first set comprises a universal primer region, wherein the two fixed sequence oligonucleotides of each first set hybridize immediately adjacent to each other, and wherein the melting temperatures (T m s) of first fixed sequence oligonucleotides of each first set vary in a range of two degrees centigrade;
(b) hybridizing at least 24 second sets of two fixed sequence oligonucleotides to the cell-free DNA in the maternal sample, wherein each second set is complementary to a locus in a second genomic region from a second chromosome or a second portion of a chromosome, wherein at least one of the two fixed sequence oligonucleotides in each second set comprises a universal primer region, wherein the two fixed sequence oligonucleotides of each second set hybridize immediately adjacent to each other, and wherein the T m s of first fixed sequence oligonucleotides of each second set vary in a range of two degrees centigrade;
(c) hybridizing a third set of two fixed sequence oligonucleotides to the cell-free DNA in the maternal sample, wherein the third set is complementary to a polymorphic locus, wherein at least one of the two fixed sequence oligonucleotides of the third set comprises a universal primer region, and wherein the two fixed sequence oligonucleotides of the third set hybridize immediately adjacent to each other;
(d) ligating the hybridized oligonucleotides of each first, second, and third set to create contiguous ligation products complementary to the loci in the first genomic region, the second genomic region, and the polymorphic locus;
(e) amplifying the contiguous ligation products using primers complementary to the universal primer regions of each first, second, and third set of two fixed sequence oligonucleotides to create amplification products;
(f) isolating the amplification products; and
(g) detecting
(i) the presence or absence of a fetal polymorphism in the polymorphic locus; and
(ii) the presence or absence of a fetal CNV by observing a statistical variation in the quantity of isolated amplification products of the first genomic region and the quantity of isolated amplification products of the second genomic region.
2. The method of claim 1 , wherein the first and second genomic regions are located on the same chromosome.
3. The method of claim 1 , wherein the first and second genomic regions are located on different chromosomes.
4. The method of claim 1 , wherein the first genomic region, the second genomic region, and the polymorphic locus are located on different chromosomes.
5. The method of claim 1 , wherein the isolated amplification products of the first genomic region, the second genomic region, and the polymorphic locus are detected by sequencing or hybridization.
6. The method of claim 5 , wherein the isolated amplification products are isolated as individual molecules prior to sequencing or hybridization.
7. The method of claim 5 , wherein the isolated amplification products are further amplified to create identical copies of all or a portion of the amplification products prior to sequencing or hybridization.
8. The method of claim 5 , wherein the isolated amplification products are further amplified to create identical copies of molecules complementary to all or a portion of the amplification products prior to sequencing or hybridization.
9. The method of claim 5 , wherein the universal primer regions are used in sequence determination of the amplification products.
10. The method of claim 1 , wherein the first genomic region is located on a chromosome selected from the group consisting of chromosomes 13, 18, 21, 22, X, and Y.
11. The method of claim 1 , wherein the second genomic region is located on a chromosome selected from the group consisting of chromosomes 13, 18, 21, 22, X, and Y.
12. The method of claim 1 , wherein the polymorphic locus is located on a chromosome selected from the group consisting of chromosomes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 19, 20, 23, and Y.
13. The method of claim 1 , wherein one or more of each set of fixed sequence oligonucleotides comprises precircle probes.
14. The method of claim 1 , wherein at least one locus in the first genomic region and at least one locus in the second genomic region do not comprise a polymorphism.
15. The method of claim 1 , wherein the first and second genomic regions are each single genes.
16. A method for determining a likelihood of a fetal copy number variation (CNV) of a genomic region and a presence or absence of one or more fetal polymorphisms in a maternal sample comprising fetal and maternal cell-free DNA, comprising the steps of:
(a) hybridizing at least 24 first sets of two fixed sequence oligonucleotides to the cell-free DNA in the maternal sample, wherein each first set is complementary to a locus in a first genomic region from a first chromosome or a first portion of a chromosome, wherein at least one of the two fixed sequence oligonucleotides in each first set comprises a universal primer region, wherein the two fixed sequence oligonucleotides of each first set hybridize immediately adjacent to each other, and wherein the melting temperatures (T m s) of first fixed sequence oligonucleotides of each first set vary in a range of two degrees centigrade;
(b) hybridizing at least 24 second sets of two fixed sequence oligonucleotides to the cell-free DNA in the maternal sample, wherein each second set is complementary to a locus in a second genomic region from a second chromosome or a second portion of a chromosome, wherein at least one of the two fixed sequence oligonucleotides in each second set comprises a universal primer region, wherein the two fixed sequence oligonucleotides of each second set hybridize immediately adjacent to each other, and wherein the T m s of first fixed sequence oligonucleotides of each second set vary in a range of two degrees centigrade;
(c) hybridizing a third set of two fixed sequence oligonucleotides to the cell-free DNA in the maternal sample, wherein the third set of two fixed sequence oligonucleotides is complementary to a polymorphic locus, wherein at least one of the two fixed sequence oligonucleotides of the third set comprises a universal primer region, and wherein the two fixed sequence oligonucleotides of the third set hybridize immediately adjacent to each other;
(d) ligating the hybridized oligonucleotides of each first, second, and third set to create contiguous ligation products complementary to the loci in the first genomic region, the second genomic region, and the polymorphic locus;
(e) amplifying the contiguous ligation products using primers complementary to the universal primer regions of each first, second, and third set of two fixed sequence oligonucleotides to create amplification products;
(f) isolating the amplification products;
(g) detecting the isolated amplification products; and
(h) determining
(i) a likelihood of a fetal CNV using the quantified total isolated amplification products corresponding to the first genomic region and the quantified total amplification products corresponding to the second genomic region; wherein a likelihood of a fetal CNV is indicated if the quantified total of amplification products from the loci of first and second genomic regions vary statistically; and
(ii) the presence or absence of a fetal polymorphism from the isolated amplification products corresponding to the polymorphic locus.
17. The method of claim 16 , wherein the first and second genomic regions are located on the same chromosome.
18. The method of claim 16 , wherein the first and second genomic regions are located on different chromosomes.
19. The method of claim 16 , wherein the first genomic region, the second genomic region, and the polymorphic locus are located on different chromosomes.
20. The method of claim 16 , wherein the isolated amplification products of the first genomic region, the second genomic region, and the polymorphic locus are detected by sequencing or hybridization.
21. The method of claim 20 , wherein the isolated amplification products are isolated as individual molecules prior to sequencing or hybridization.
22. The method of claim 20 , wherein the individual isolated amplification products are further amplified to create identical copies of all or a portion of the individual amplification products prior to sequencing or hybridization.
23. The method of claim 20 , wherein the individual isolated amplification products are further amplified to create identical copies of molecules complementary to all or a portion of the individual amplification products prior to sequencing or hybridization.
24. The method of claim 20 , wherein the universal primer regions are used in sequence determination of the isolated amplification products.
25. The method of claim 16 , wherein the first genomic region is located on a chromosome selected from the group consisting of chromosomes 13, 18, 21, 22, X, and Y.
26. The method of claim 16 , wherein the second genomic region is located on a chromosome selected from the group consisting of chromosomes 13, 18, 21, 22, X, and Y.
27. The method of claim 16 , wherein the polymorphic locus is located on a chromosome selected from the group consisting of chromosomes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 19, 20, 23, and Y.
28. The method of claim 16 , wherein one or more of each set of fixed sequence oligonucleotides comprises a precircle probe.
29. The method of claim 16 , wherein at least one locus in the first genomic region and at least one locus in the second genomic region do not comprise a polymorphism.
30. The method of claim 16 , wherein the first and second genomic regions are each single genes.