摘要:
Embodiments of this invention provide methods, systems, and apparatus for determining whether a fetal chromosomal aneuploidy exists from a biological sample obtained from a pregnant female. Nucleic acid molecules of the biological sample are sequenced, such that a fraction of the genome is sequenced. Respective amounts of a clinically-relevant chromosome and of background chromosomes are determined from results of the sequencing. The determination of the relative amounts may count sequences of only certain length. A parameter derived from these amounts (e.g. a ratio) is compared to one or more cutoff values, thereby determining a classification of whether a fetal chromosomal aneuploidy exists. Prior to sequencing, the biological sample may be enriched for DNA fragments of a particular sizes.
摘要:
Embodiments of this invention provide methods, systems, and apparatus for determining whether a fetal chromosomal aneuploidy exists from a biological sample obtained from a pregnant female. Nucleic acid molecules of the biological sample are sequenced, such that a fraction of the genome is sequenced. Respective amounts of a clinically-relevant chromosome and of background chromosomes are determined from results of the sequencing. A parameter derived from these amounts (e.g. a ratio) is compared to one or more cutoff values, thereby determining a classification of whether a fetal chromosomal aneuploidy exists.
摘要:
This application describes the discovery that, in a pregnant woman, certain genes (such as RASSF1A, APC, CASP8, RARB, SCGB3A1, DAB2IP, PTPN6, THY1, TMEFF2, and PYCARD) originated from a fetus are highly methylated, whereas the same genes of maternal origin are unmethylated. This discovery allows the easy detection of one or more of these methylated fetal genes in a biological sample from a pregnant woman, serving as a universal indicator of the presence of fetal DNA in the sample. These fetal methylation markers are particularly useful as positive controls for a non-invasive analytical process during which the quality and quantity of fetal DNA are monitored. These newly identified fetal markers can also be measured directly for diagnosis of certain pregnancy-related conditions.
摘要:
Embodiments of this invention provide methods, systems, and apparatus for determining whether a fetal chromosomal aneuploidy exists from a biological sample obtained from a pregnant female. Nucleic acid molecules of the biological sample are sequenced, such that a fraction of the genome is sequenced. Respective amounts of a clinically-relevant chromosome and of background chromosomes are determined from results of the sequencing. A parameter derived from these amounts (e.g. a ratio) is compared to one or more cutoff values, thereby determining a classification of whether a fetal chromosomal aneuploidy exists.
摘要:
Methods, systems, and apparatus are provided for determining whether a nucleic acid sequence imbalance exists within a biological sample. One or more cutoff values for determining an imbalance of, for example, the ratio of the two sequences (or sets of sequences) are chosen. The cutoff value may be determined based at least in part on the percentage of fetal DNA in a sample, such as maternal plasma, containing a background of maternal nucleic acid sequences. The cutoff value may also be determined based on an average concentration of a sequence per reaction. In one aspect, the cutoff value is determined from a proportion of informative wells that are estimated to contain a particular nucleic acid sequence, where the proportion is determined based on the above-mentioned percentage and/or average concentration. The cutoff value may be determined using many different types of methods, such as sequential probability ratio testing (SPRT).
摘要:
This application describes the discovery that, in a pregnant woman, certain genes (such as RASSF1A, APC, CASP8, RARB, SCGB3A1, DAB2IP, PTPN6, THY1, TMEFF2, and PYCARD) originated from a fetus are highly methylated, whereas the same genes of maternal origin are unmethylated. This discovery allows the easy detection of one or more of these methylated fetal genes in a biological sample from a pregnant woman, serving as a universal indicator of the presence of fetal DNA in the sample. These fetal methylation markers are particularly useful as positive controls for a non-invasive analytical process during which the quality and quantity of fetal DNA are monitored. These newly identified fetal markers can also be measured directly for diagnosis of certain pregnancy-related conditions.
摘要:
Embodiments of this invention provide methods, systems, and apparatus for determining whether a fetal chromosomal aneuploidy exists from a biological sample obtained from a pregnant female. Nucleic acid molecules of the biological sample are sequenced, such that a fraction of the genome is sequenced. Respective amounts of a clinically-relevant chromosome and of background chromosomes are determined from results of the sequencing. The determination of the relative amounts may count sequences of only certain length. A parameter derived from these amounts (e.g. a ratio) is compared to one or more cutoff values, thereby determining a classification of whether a fetal chromosomal aneuploidy exists. Prior to sequencing, the biological sample may be enriched for DNA fragments of a particular sizes.
摘要:
Embodiments of this invention provide methods, systems, and apparatus for determining whether a fetal chromosomal aneuploidy exists from a biological sample obtained from a pregnant female. Nucleic acid molecules of the biological sample are sequenced, such that a fraction of the genome is sequenced. Respective amounts of a clinically-relevant chromosome and of background chromosomes are determined from results of the sequencing. The determination of the relative amounts may count sequences of only certain length. A parameter derived from these amounts (e.g. a ratio) is compared to one or more cutoff values, thereby determining a classification of whether a fetal chromosomal aneuploidy exists. Prior to sequencing, the biological sample may be enriched for DNA fragments of a particular sizes.
摘要:
This application describes the discovery that, in a pregnant woman, certain genes (such as RASSF1A, APC, CASP8, RARB, SCGB3A1, DAB2IP, PTPN6, THY1, TMEFF2, and PYCARD) originated from a fetus are highly methylated, whereas the same genes of maternal origin are unmethylated. This discovery allows the easy detection of one or more of these methylated fetal genes in a biological sample from a pregnant woman, serving as a universal indicator of the presence of fetal DNA in the sample. These fetal methylation markers are particularly useful as positive controls for a non-invasive analytical process during which the quality and quantity of fetal DNA are monitored. These newly identified fetal markers can also be measured directly for diagnosis of certain pregnancy-related conditions.
摘要:
This application describes the discovery that, in a pregnant woman, certain genes (such as RASSF1A, APC, CASP8, RARB, SCGB3A1, DAB2IP, PTPN6, THY1, TMEFF2, and PYCARD) originated from a fetus are highly methylated, whereas the same genes of maternal origin are unmethylated. This discovery allows the easy detection of one or more of these methylated fetal genes in a biological sample from a pregnant woman, serving as a universal indicator of the presence of fetal DNA in the sample. These fetal methylation markers are particularly useful as positive controls for a non-invasive analytical process during which the quality and quantity of fetal DNA are monitored. These newly identified fetal markers can also be measured directly for diagnosis of certain pregnancy-related conditions.