Diagnostic method
AssigneeBTG International Limited
InventorMaj Anita Hulten
Life of this patent
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Abstract
A method for the identification of foetal DNA in a maternal DNA-containing sample such as a blood or vaginal sample, said method comprising (a) isolating DNA from said sample, (b) subjecting said DNA to exonucleolytic digestion by an enzyme so as to remove end regions of each DNA molecule, and (c) detecting the presence of a DNA sequence remaining in foetal DNA but absent form maternal DNA as a result of said digestion process. Once identified, the foetal DNA can be subject to diagnosis for example to detect chromosomal/DNA abnormalities, including in particular aneuploides such as foetal trisomy 21.
Claims42
A method for the identification of foetal DNA in a maternal DNA-containing sample, said method comprising (a) isolating DNA from said sample, (b) subjecting said DNA to exonucleolytic digestion by an enzyme so as to remove end regions of said DNA, and (c) detecting the presence of a DNA sequence remaining in foetal DNA but absent from maternal DNA as a result of said digestion process.
A method according to any one of the preceding claims wherein DNA from step (a) is cut using a restriction enzyme into fragments prior to step (b).
A method according to any one of the preceding claims wherein foetal DNA is isolated from maternal DNA.
A method according to any one of the preceding claims wherein the said DNA sequence remaining in foetal DNA is a telomere sequence or a chromosome marker located proximal the telomere region.
A method according to any one of the preceding claims wherein the said DNA sequence is detected using a first labelled probe which is specific for said sequence.
A method according to any one of the preceding claims wherein the exonucleolytic enzyme is Bal31.
A method according to any one of the preceding claims wherein the amount of DNA of foetal origin in the sample is determined.
A method according to any one of the preceding claims wherein foetal DNA in the sample is amplified.
A method according to any one of the preceding claims wherein foetal DNA identified is subjected to pre-natal diagnosis.
A method according to any one of the preceding claims wherein before step (c), DNA is separated according to size.
A kit for identifying foetal DNA in a maternal blood or vaginal sample, said kit comprising means for extracting DNA from a blood or vaginal sample, an exonucleolytic enzyme capable of digesting DNA, and a labelled primer suitable for detecting a specific DNA sequence found in a terminal region of DNA.
A method for the identification of foetal DNA in a maternal DNA-containing sample, substantially as hereinbefore described.
A kit for the identification of foetal DNA in a maternal DNA-containing sample substantially as hereinbefore described.
Dependencies are inferred from the claim text.