摘要:
Techniques are provided for determining inheritance of maternal and paternal haplotypes in preganncies with multiple fetuses. Maternal inheritance can be determined at loci where the mother is heterozygous and the paternally inherited alleles are known (e.g., the father is homozygous). Two types of loci may be used, where one type has the paternal allele appear on a first maternal haplotype, and another type has the paternal allele appear on a second maternal haplotype. Paternal inheritance can be determined from loci where the father is heterozygous and the maother is homozygous. Amounts of different alleles at each locus can be measured. A comparison of the amounts (e.g., using a fractional concentration of each allele and cutoffs) can be used to determine the haplotype inheritance. A haplotype can be linked to a condition of interest.
摘要:
Methods are provided for diagnosing pregnancy-associated disorders, determining allelic ratios, determining maternal or fetal contributions to circulating transcripts, and/or identifying maternal or fetal markers using a sample from a pregnant female subject. Also provided is use of a gene for diagnosing a pregnancy-associated disorder in a pregnant female subject.
摘要:
A method of analyzing a biological sample of an organism, the biological sample including DNA originating from normal cells and potentially from cells associated with cancer, wherein at least some of the DNA is cell-free in the biological sample, the method comprising: for each size of a plurality of sizes: measuring an amount of a first set of DNA fragments from the biological sample corresponding to the size; calculating a first value of a first parameter based on the amounts of DNA fragments at multiple sizes, the first parameter providing a statistical measure of a size profile of DNA fragments in the biological sample; comparing the first value to a reference value; and determining a classification of a level of cancer in the organism based on the comparison.
摘要:
This invention provides several ways of managing GC bias that occurs during seequencing and analysis of genomic DNA. Maternal plasma can be used as a source of fetal DNA for analysis. DNA segments or tags obtained from the plasma can be aligned with a chromosomal region of interest and with an artificial reference chromosome assembled from regions of the genome having matching GC content. This technology can be used, for example, to detect and evaluate aneuploidy and other chromosomal abnormalities.
摘要:
Progress of chromosomal aberrations in an organism is determined using biological samples including nucleic acid molecules originating from normal cells and potentially from cells associated with a disease, at least some of the nucleic acid molecules being cell-free. Non-overlapping chromosomal regions of a reference genome of the organism are determined. At a plurality of times: for each of plural nucleic acid molecules, a location thereof in the reference genome is determined; and for each chromosomal region: a respective group of nucleic acid molecules is identified as being therefrom based on the identified locations; a respective value defining a property of the nucleic acid molecules is calculated and compared to a reference value to determine a classification of whether the chromosomal region exhibits a deletion or an amplification. The classifications at the plurality of times are used to determine the progress of the chromosomal aberrations in the organism.
摘要:
The contributions of different tissues to a DNA mixture are determined using methylation levels at particular genomic sites. Tissue-specific methylation levels of M tissue types can be used to deconvolve mixture methylation levels measured in the DNA mixture, to determine fraction contributions of each of the M tissue types. Various types of genomic sites can be chosen to have particular properties across tissue types and across individuals, so as to provide increased accuracy in determining contributions of the various tissue types. The fractional contributions can be used to detect abnormal contributions of a particular tissue, indicating a disease state for the tissue. A differential in fractional contributions for different sizes of DNA fragments can also be used to identify a diseased state of a particular tissue. A sequence imbalance for a particular chromosomal region can be detected in a particular tissue, e.g., identifying a location of a tumor.
摘要:
Methods, apparatuses, and system are provided for analyzing a maternal sample to determine whether a male fetus of a pregnant female has inherited an X-linked mutation from the mother. A percentage of fetal DNA in the sample is obtained, and cutoff values for the two possibilities (fetus inherits mutant or normal allele) are determined. A proportion of mutant alleles relative to a normal allele on the X-chromosome can then be compared to the cutoff values to make a classification of which allele is inherited. Alternatively, a number of alleles from a target region on the X-chromosome can be compared to a number of alleles from a reference region on the X-chromosome to identify a deletion or amplification. The fetal DNA percentage can be computed by counting reactions with a fetal-specific allele, and correcting the number to account for a statistical distribution among the reactions.