8 results about "Fetal aneuploidy" patented technology

The present invention provides processes for determining accurate risk probabilities for fetal aneuploidies. Specifically, the invention provides non-invasive evaluation of genomic variations through chromosome-selective sequencing and non-host fraction data analysis of maternal samples.

The invention provides compositions and methods for determining the fraction of fetal nucleic acids in a maternal sample comprising a mixture of fetal and maternal nucleic acids. The fraction of fetal nucleic acids can be used in determining the presence or absence of fetal aneuploidy.

This invention relates to a method for non-invasive prenatal screening using cell-free DNA extraction. Specifically, the invention provides a method and system for extracting cell-free DNA from liquid biological samples. The method can be used for determining fetal DNA fractions and for non-invasive prenatal screening of fetal aneuploidy and analysis of other types of cell-free DNA.

A method for determining copy number variations (CNV) of a sequence of interest in a test sample that comprises a mixture of nucleic acids that are known or are suspected to differ in the amount of one or more sequence of interest. The method comprises a statistical approach that accounts for accrued variability stemming from process-related, interchromosomal and inter-sequencing variability. The method is applicable to determining CNV of any fetal aneuploidy, and CNVs known or suspected to be associated with a variety of medical conditions.

Provided herein are methods and systems for cell-free DNA extraction from liquid biological samples. The methods can be employed for determination of fetal DNA fraction and non- invasive prenatal screening of fetal aneuploidies and analyses of other types of cell-free DNA.

Disclosed is a method to achieve digital quantification of DNA (i.e., counting differences between identical sequences) using direct shotgun sequencing followed by mapping to the chromosome of origin and enumeration of fragments per chromosome. The preferred method uses massively parallel sequencing, which can produce tens of millions of short sequence tags in a single run and enabling a sampling that can be statistically evaluated. By counting the number of sequence tags mapped to a predefined window in each chromosome, the over- or under-representation of any chromosome in maternal plasma DNA contributed by an aneuploid fetus can be detected. This method does not require the differentiation of fetal versus maternal DNA. The median count of autosomal values is used as a normalization constant to account for differences in total number of sequence tags is used for comparison between samples and between chromosomes.

The present disclosure provides methods for non-invasive prenatal screening (NIPS) of fetal aneuploidies. The present methods are based on analyzing cell-free fetal DNA (cff DNA) found in a pregnant woman's circulation through the next generation sequencing (NGS) technology. Particularly, the present methods analyze the relative abundance of different fetal genomic fragments present in the maternal sample, where the fragments can be aligned to particular chromosomal locations of the fetal genome. The relative abundance information is indicative as to whether a particular chromosome is overrepresented or underrepresented in a fetal genome as compared to normal individuals, and thus can be used to detect fetal aneuploidy. Additionally, methods for increasing the positive predictive values (PPV) of NIPS by excluding false-positive detections are also provided.

The application relates to a method and device for detecting fetal aneuploidy and copy number variation in maternal plasma free DNA and application. The method comprises the following steps: obtaining sequencing data based on a conventional non-targeted whole genome sequencing mode, so as to group sequencing templates and generate analyzable sub-libraries; extracting sequencing depth information of different genomic intervals in the sequencing data; grouping according to the feature vector / matrix extracted from the sequencing data, and counting and extracting the depth information of the genomic intervals from different groups; and constructing a classifier through machine learning to further accurately distinguish the variations carried by the fetus and the variations carried by the mother. The method and device can accurately distinguish the variations carried by the fetus and the variations carried by the mother, and the method and device have strong compatibility, wide applicability and low cost, and can realize accurate distinction and detection of fetal free DNA genome aneuploidy and copy number variation only by using ultra-low sequencing depth.