Method of detecting mutations associated with thrombosis
The present invention provides a method for the simultaneous identification of two or more single base changes in a plurality of target nucleotide sequences that are markers associated with cardiovascular diseases such as deep vein thrombosis and the like. Multiplex detection is accomplished using multiplexed tagged allele specific primer extension (ASPE) and hybridization of such extended primers to a probe, preferably an addressable anti-tagged support.
1. A method for detecting in a nucleic acid sample the presence or absence of at least two variant nucleotides associated with thrombosis, the method comprising the steps of:
a) amplifying from the sample regions of DNA that include at least two selected nucleotide positions for which variants are known to be associated with thrombosis, to form amplified DNA products;
b) hybridizing at least two tagged allele specific extension primers to a complementary target sequence in the amplified DNA products, wherein each tagged allele specific extension primer has a 3′-end hybridizing portion capable of hybridizing to the corresponding amplified DNA and a 5′-end tag portion complementary to a corresponding anti-tag sequence, the terminal nucleotide of the 3′ end hybridizing portion being either complementary to a suspected variant nucleotide or to the corresponding wild type nucleotide, the nucleotide sequences of the at least two tagged allele specific extension primers consisting of sequences selected from the group consisting of SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 10, and SEQ ID NO: 12;
c) extending the at least two tagged allele specific extension primers, using labelled nucleotides, if the terminal nucleotide of each 3′ end hybridizing portion is a perfect match to the corresponding amplified DNA product; and
d) hybridizing the at least two tagged allele specific extension primers to their corresponding anti-tag sequences and detecting the presence of labelled extension products.
2. The method of claim 1 , wherein the 5′-end tag portions of the at least two tagged allele specific primers each comprise a sequence selected from the group consisting of bases 1 to 24 of SEQ ID NO: 1 to SEQ ID NO: 12 and wherein the sequence of each 5′-end tag portion is different from each other 5′-end tag portion.
3. The method of claim 1 wherein the anti-tag sequence is coupled to a solid support.
4. The method of claim 3 wherein the solid support is selected from the group consisting of beads, spectrally coded beads, and a chip based microarray.
5. The method of claim 1 wherein the step of amplifying is conducted by PCR using a set of PCR amplification primers, said set comprising at least two pairs of PCR primers selected from the group of pairs consisting of:
SEQ ID NO: 13 and SEQ ID NO: 14, SEQ ID NO: 15 and SEQ ID NO: 16, SEQ ID NO: 17 and SEQ ID NO: 18, SEQ ID NO: 19 and SEQ ID NO: 20, SEQ ID NO: 21 and SEQ ID NO: 22, and SEQ ID NO: 23 and SEQ ID NO: 24, wherein the at least two pairs of PCR primers are selected for their ability to amplify regions of DNA that include sequences to which the selected at least two tagged allele-specific extension primers will hybridize.
6. A method for detecting in a nucleic acid sample the presence or absence of at least two variant nucleotides associated with thrombosis, the method comprising the steps of;
a) amplifying from the sample regions of DNA that include at least two selected nucleotide positions for which variants are known to be associated with thrombosis to form amplified DNA products;
b) hybridizing at least two tagged allele specific extension primers to a complementary target sequence in the amplified DNA products, the nucleotide sequences of the at least two tagged allele specific extension primers consisting of sequences selected from the group consisting of SEQ ID NO: 1 to SEQ ID NO: 12;
c) extending the at least two tagged allele specific extension primers, using labelled nucleotides, if the terminal nucleotide of each 3′ end hybridizing portion is a perfect match to the corresponding amplified DNA product; and
d) hybridizing the at least two tagged allele specific extension primers to their corresponding anti-tag sequences and detecting the presence of labelled extension products.
7. The method of claim 6 wherein the anti-tag sequence is coupled to a solid support.
8. The method of claim 7 wherein the solid support is selected from the group consisting of beads, spectrally coded beads, and a chip based microarray.
9. The method of claim 6 wherein the step of amplifying is conducted by PCR using a set of PCR amplification primers, said set comprising at least two pairs of PCR primers selected from the group of pairs consisting of:
SEQ ID NO: 13 and SEQ ID NO: 14, SEQ ID NO: 15 and SEQ ID NO: 16, SEQ ID NO: 17 and SEQ ID NO: 18, SEQ ID NO: 19 and SEQ ID NO: 20, SEQ ID NO: 21 and SEQ ID NO: 22, and SEQ ID NO: 23 and SEQ ID NO: 24, wherein the at least two pairs of PCR primers are selected for their ability to amplify regions of DNA that include sequences to which the selected at least two tagged allele-specific extension primers will hybridize.
10. An improved method of simultaneously detecting in a sample the presence or absence of variant nucleotides associated with thrombosis, wherein the improvement comprises simultaneously identifying the presence or absence of variant nucleotides associated with thrombosis via allele specific primer extension using a set of primers, the nucleotide sequences of the primers consisting of sequences selected from the group consisting of SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 10, and SEQ ID NO: 12.
11. An improved method of simultaneously detecting in a sample the presence or absence of variant nucleotides associated with thrombosis, wherein the improvement comprises simultaneously identifying the presence or absence of variant nucleotides associated with thrombosis via allele specific primer extension using a set of primers, the nucleotide sequences of the primers consisting of sequences selected from the group consisting of SEQ ID NO: 1 to SEQ ID NO: 12.