Patents by Inventor Rossa Wai Kwun Chiu

Rossa Wai Kwun Chiu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20180142300
    Abstract: To detect a fetal mutation inherited from the mother without paternal genetic information, a property of each maternal haplotype can be measured in the cell-free mixture. A separation value between values of the property for the two maternal haplotypes can be compared to thresholds to determine which haplotype is inherited. As measurements of a paternal allele may not be available, embodiments can measure the property at some loci where the fetus is homozygous and some loci where the fetus is heterozygous, but account for such loci where the fetus is heterozygous in the selection of a threshold for determining inheritance of a maternal haplotype. To determine parental haplotypes, direct haplotyping can be performed, and loci within a specified of the mutation can be selected and used in haplotype block for the measurements. Targeted measurements of a region including the mutation using predetermined primer/probes that may be re-used across subjects.
    Type: Application
    Filed: November 20, 2017
    Publication date: May 24, 2018
    Inventors: Wai In Hui, Peiyong Jiang, Kwan Chee Chan, Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu
  • Patent number: 9965585
    Abstract: Systems, apparatus, and methods are provided for determining genetic or molecular aberrations in a biological sample. Biological samples including cell-free DNA fragments are analyzed to identify imbalances in chromosomal regions, e.g., due to deletions and/or amplifications in a tumor. Multiple loci are used for each chromosomal region. Such imbalances can be used to diagnose (screen) a patient for cancer, as well as prognosticate a patient with cancer, or to detect the presence or to monitor the progress of a premalignant condition in a patient. Severity of an imbalance and the number of regions exhibiting an imbalance can be used. A systematic analysis of non-overlapping genomic segments can provide a general screening tool. A patient can be tested over time to track severity of each of one or more chromosomal regions and a number of chromosomal regions to enable screening and prognosticating, as well as monitoring of progress (e.g. after treatment).
    Type: Grant
    Filed: April 17, 2014
    Date of Patent: May 8, 2018
    Assignee: The Chinese University of Hong Kong
    Inventors: Yuk-Ming Dennis Lo, Kwan Chee Chan, Rossa Wai Kwun Chiu, Peiyong Jiang
  • Publication number: 20180105884
    Abstract: Systems, methods, and apparatuses can determine and use methylation profiles of various tissues and samples. Examples are provided. A methylation profile can be deduced for fetal/tumor tissue based on a comparison of plasma methylation (or other sample with cell-free DNA) to a methylation profile of the mother/patient. A methylation profile can be determined for fetal/tumor tissue using tissue-specific alleles to identify DNA from the fetus/tumor when the sample has a mixture of DNA. A methylation profile can be used to determine copy number variations in genome of a fetus/tumor. Methylation markers for a fetus have been identified via various techniques. The methylation profile can be determined by determining a size parameter of a size distribution of DNA fragments, where reference values for the size parameter can be used to determine methylation levels. Additionally, a methylation level can be used to determine a level of cancer.
    Type: Application
    Filed: July 12, 2017
    Publication date: April 19, 2018
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Miu Fan Lun, Wai Man Chan, Peiyong Jiang
  • Publication number: 20180105807
    Abstract: Temporal variations in one or more characteristics measured from a cell-free DNA sample are used to estimate a gestational age of a fetus. Example characteristics include the methylation level measured from the cell-free DNA sample, size of DNA fragments measured from the cell-free DNA sample (e.g., proportion of fetal-derived DNA fragments longer than a specified size), and ending patterns of the DNA fragments align to a reference genome.
    Type: Application
    Filed: October 18, 2017
    Publication date: April 19, 2018
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Peiyong Jiang
  • Publication number: 20170349948
    Abstract: Techniques are provided for detecting hematological disorders using cell-free DNA in a blood sample, e.g., using plasma or serum. For example, an assay can target one or more differentially-methylated regions specific to a particular hematological cell lineage (e.g., erythroblasts). A methylation level can be quantified from the assay to determine an amount of methylated or unmethylated DNA fragments in a cell-free mixture of the blood sample. The methylation level can be compared to one or more cutoff values, e.g., that correspond to a normal range for the particular hematological cell lineage as part of determining a level of a hematological disorder.
    Type: Application
    Filed: May 30, 2017
    Publication date: December 7, 2017
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Kun Sun
  • Publication number: 20170233829
    Abstract: Methods, systems, and apparatus determine whether a first chromosomal region exhibits a deletion or an amplification associated with cancer in a sample from a subject (e.g., where the sample includes a mixture of cell-free DNA from tumor cells and non-malignant cells. Nucleic acid molecules of the biological sample are sequenced. Respective amounts of a clinically-relevant chromosomal region and of background chromosomal region(s) 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 first chromosomal region exhibits a deletion or an amplification associated with cancer.
    Type: Application
    Filed: May 5, 2017
    Publication date: August 17, 2017
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan
  • Patent number: 9732390
    Abstract: Systems, methods, and apparatuses can determine and use methylation profiles of various tissues and samples. Examples are provided. A methylation profile can be deduced for fetal/tumor tissue based on a comparison of plasma methylation (or other sample with cell-free DNA) to a methylation profile of the mother/patient. A methylation profile can be determined for fetal/tumor tissue using tissue-specific alleles to identify DNA from the fetus/tumor when the sample has a mixture of DNA. A methylation profile can be used to determine copy number variations in genome of a fetus/tumor. Methylation markers for a fetus have been identified via various techniques. The methylation profile can be determined by determining a size parameter of a size distribution of DNA fragments, where reference values for the size parameter can be used to determine methylation levels. Additionally, a methylation level can be used to determine a level of cancer.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: August 15, 2017
    Assignee: The Chinese University of Hong Kong
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Miu Fan Lun, Wai Man Chan, Peiyong Jiang
  • Publication number: 20170220736
    Abstract: Systems, apparatus, and methods are provided for determining aberrations in a biological sample from an organism. Biological samples including cell-free DNA fragments are analyzed to identify imbalances in chromosomal regions, e.g., due to deletions and/or amplifications in a tumor. Multiple loci are used for each chromosomal region. Imbalances can be used to diagnose a patient for cancer, prognosticate a patient with cancer, or to detect the presence or monitor progress of a premalignant condition. The severity of an imbalance as well as the number of regions exhibiting an imbalance can be used. A systematic analysis of non-overlapping segments of a genome can provide a general screening tool for a sample. Additionally, a patient can be tested over time to track severity of each of one or more chromosomal regions and a number of chromosomal regions to enable screening and prognosticating, as well as monitoring of progress (e.g. after treatment).
    Type: Application
    Filed: April 19, 2017
    Publication date: August 3, 2017
    Inventors: Yuk-Ming Dennis Lo, Kwan Chee Chan, Rossa Wai Kwun Chiu, Peiyong Jiang
  • Publication number: 20170218450
    Abstract: Methods, systems, and apparatus determine whether a first chromosomal region exhibits a deletion or an amplification associated with cancer in a sample from a subject (e.g., where the sample includes a mixture of cell-free DNA from tumor cells and non-malignant cells. Nucleic acid molecules of the biological sample are sequenced. Respective amounts of a clinically-relevant chromosomal region and of background chromosomal region(s) 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 first chromosomal region exhibits a deletion or an amplification associated with cancer.
    Type: Application
    Filed: March 30, 2017
    Publication date: August 3, 2017
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan
  • Publication number: 20170175195
    Abstract: The present invention provides a new method for detecting or monitoring a liver disease in a subject that has no indication of any liver pathologies, by measuring the amount of concentration of albumin mRNA in an acellular blood sample from the subject, and then comparing the amount or concentration of albumin mRNA with a standard control.
    Type: Application
    Filed: December 20, 2016
    Publication date: June 22, 2017
    Inventors: YUK MING DENNIS LO, Rossa Wai Kwun CHIU, Rebecca Wing Yan CHAN
  • Publication number: 20170081720
    Abstract: Embodiments of the present invention provide methods, systems, and apparatus for deducing the fetal DNA fraction in maternal plasma without using paternal or fetal genotypes. Maternal genotype information may be obtained from a maternal-only DNA sample or may be assumed from shallow-depth sequencing of a biological sample having both maternal and fetal DNA molecules. Because sequencing may be at shallow depths, a locus may have only few reads and may fail to exhibit a non-maternal allele even if a non-maternal allele is present. However, normalized parameters that characterize non-maternal alleles sequenced can be used to provide an accurate estimate of the fetal DNA fraction, even if the amount of non-maternal alleles is in error. Methods described herein may not need high-depth sequencing or enrichment of specific regions. As a result, these methods can be integrated into widely used non-invasive prenatal testing and other diagnostics.
    Type: Application
    Filed: September 22, 2016
    Publication date: March 23, 2017
    Inventors: Yuk-Ming Dennis Lo, Peiyong Jiang, Kwan Chee Chan, Rossa Wai Kwun Chiu
  • Publication number: 20170073774
    Abstract: Embodiments are related to the accurate detection of somatic mutations in the plasma (or other samples containing cell-free DNA) of cancer patients and for subjects being screened for cancer. The detection of these molecular markers would be useful for the screening, detection, monitoring, management, and prognostication of cancer patients. For example, a mutational load can be determined from the identified somatic mutations, and the mutational load can be used to screen for any or various types of cancers, where no prior knowledge about a tumor or possible cancer of the subject may be required. Embodiments can be useful for guiding the use of therapies (e.g. targeted therapy, immunotherapy, genome editing, surgery, chemotherapy, embolization therapy, anti-angiogenesis therapy) for cancers. Embodiments are also directed to identifying de novo mutations in a fetus by analyzing a maternal sample having cell-free DNA from the fetus.
    Type: Application
    Filed: November 28, 2016
    Publication date: March 16, 2017
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Peiyong Jiang
  • Publication number: 20170044606
    Abstract: Embodiments may include a method of determining a nucleic acid sequence. The method may include receiving a plurality of DNA fragments. The method may also include concatemerizing a first set of the DNA fragments to obtain a concatemer. The method may include performing single-molecule sequencing of the concatemer to obtain a first sequence of the concatemer. In some embodiments, single-molecule sequencing may be performed using a nanopore, and the method may include passing the concatemer through a nanopore. A first electrical signal may then be detected as the concatemer passes through the nanopore. The first electrical signal may correspond to a first sequence of the concatemer. In addition, the method may include analyzing the first electrical signal to determine the first sequence. Subsequences of the first sequence may be aligned to identify sequences corresponding to each of the first set of the DNA fragments.
    Type: Application
    Filed: August 12, 2016
    Publication date: February 16, 2017
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Suk Hang Cheng
  • Publication number: 20170029900
    Abstract: Systems, apparatuses, and method are provided for determining the contributions of different tissues to a biological sample that includes a mixture of cell-free DNA molecules from various tissues types, e.g., as occurs in plasma or serum and other body fluids. Embodiments can analyze the methylation patterns of the DNA mixture (e.g., methylation levels at particular loci) for a particular haplotype and determine fractional contributions of various tissue types to the DNA mixture, e.g., of fetal tissue types or tissue types of specific organs that might have a tumor. Such fractional contributions determined for a haplotype can be used in a variety of ways.
    Type: Application
    Filed: July 20, 2016
    Publication date: February 2, 2017
    Inventors: Yuk-Ming Dennis Lo, Kwan Chee Chan, Rossa Wai Kwun Chiu, Peiyong Jiang, Kun Sun
  • Patent number: 9556490
    Abstract: The present invention provides a new method for detecting or monitoring a liver disease in a subject that has no indication of any liver pathologies, by measuring the amount of concentration of albumin mRNA in an acellular blood sample from the subject, and then comparing the amount or concentration of albumin mRNA with a standard control.
    Type: Grant
    Filed: May 4, 2015
    Date of Patent: January 31, 2017
    Assignee: The Chinese University of Hong Kong
    Inventors: Yuk Ming Dennis Lo, Rossa Wai Kwun Chiu, Rebecca Wing Yan Chan
  • Publication number: 20170024513
    Abstract: Factors affecting the fragmentation pattern of cell-free DNA (e.g., plasma DNA) and the applications, including those in molecular diagnostics, of the analysis of cell-free DNA fragmentation patterns are described. Various applications can use a property of a fragmentation pattern to determine a proportional contribution of a particular tissue type, to determine a genotype of a particular tissue type (e.g., fetal tissue in a maternal sample or tumor tissue in a sample from a cancer patient), and/or to identify preferred ending positions for a particular tissue type, which may then be used to determine a proportional contribution of a particular tissue type.
    Type: Application
    Filed: July 25, 2016
    Publication date: January 26, 2017
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Peiyong Jiang
  • Publication number: 20160217251
    Abstract: An aberration in a fetal genome can be identified by analyzing a sample of fetal and maternal DNA. Classifications of whether an aberration (amplification or deletion) exists in a subchromosomal region are determined using count-based and size-based methods. The count classification and the size classification can be used in combination to determine whether only the fetus or only the mother, or both, have the aberration in the subchromosomal region, thereby avoiding false positives when the mother has the aberration and the fetus does not.
    Type: Application
    Filed: January 12, 2016
    Publication date: July 28, 2016
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Peiyong Jiang, Cheuk Yin Jandy Yu
  • Publication number: 20160203260
    Abstract: An amount of mitochondrial DNA molecules relative to an amount of nuclear DNA molecules is determined in a biological sample, and the relative amount is used for various purposes, e.g., screening, detection, prognostication or monitoring of various physiological and pathological conditions. As examples, an amount of mitochondrial DNA can be used to estimate a concentration of DNA of a tissue type, such as a fetal DNA concentration, tumor DNA concentration, or a concentration of DNA in the biological sample derived from a non-hematopoietic tissue source. Sequencing techniques can be used to determine a mitochondrial DNA concentration in a sample for an accurate detection of a level of cancer. A level of an auto-immune disease is also determined using a relative amount of mitochondrial DNA molecules compared nuclear DNA molecules.
    Type: Application
    Filed: January 12, 2016
    Publication date: July 14, 2016
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Peiyong Jiang
  • Publication number: 20160201142
    Abstract: Analysis of tumor-derived circulating cell-free DNA opens up new possibilities for performing liquid biopsies for solid tumor assessment or cancer screening. However, many aspects of the biological characteristics of tumor-derived cell-free DNA remain unclear. Regarding the size profile of plasma DNA molecules, some studies reported increased integrity of tumor-derived plasma DNA while others reported shorter tumor-derived plasma DNA molecules. We performed an analysis of the size profiles of plasma DNA in patients with cancer using massively parallel sequencing at single base resolution and in a genomewide manner. Tumor-derived plasma DNA molecules were further identified using chromosome arm-level z-score analysis (CAZA). We showed that populations of aberrantly short and long DNA molecules co-existed in the plasma of patients with cancer. The short ones preferentially carried the tumor-associated copy number aberrations. These results show the ability to use plasma DNA as a molecular diagnostic tool.
    Type: Application
    Filed: January 12, 2016
    Publication date: July 14, 2016
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Peiyong Jiang
  • Publication number: 20160017419
    Abstract: 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.
    Type: Application
    Filed: July 20, 2015
    Publication date: January 21, 2016
    Inventors: Rossa Wai Kwun Chiu, Kwan Chee Chan, Yuk-Ming Dennis Lo, Peiyong Jiang, Kun Sun