Patents by Inventor Kwan Chee Chan

Kwan Chee Chan 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).

  • Patent number: 10106836
    Abstract: 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.
    Type: Grant
    Filed: March 17, 2014
    Date of Patent: October 23, 2018
    Assignee: The Chinese University of Hong Kong
    Inventors: Yuk Ming Dennis Lo, Wai Kwun Rossa Chiu, Kwan Chee Chan
  • Patent number: 10093976
    Abstract: Systems, methods, and apparatus for determining at least a portion of fetal genome are provided. DNA fragments from a maternal sample (maternal and fetal DNA) can be analyzed to identify alleles at certain loci. The amounts of DNA fragments of the respective alleles at these loci can be analyzed together to determine relative amounts of the haplotypes for these loci and determine which haplotypes have been inherited from the parental genomes. Loci where the parents are a specific combination of homozygous and heterozygous can be analyzed to determine regions of the fetal genome. Reference haplotypes common in the population can be used along with the analysis of the DNA fragments of the maternal sample to determine the maternal and paternal genomes. Determination of mutations, a fractional fetal DNA concentration in a maternal sample, and a proportion of coverage of a sequencing of the maternal sample can also be provided.
    Type: Grant
    Filed: May 15, 2013
    Date of Patent: October 9, 2018
    Assignees: The Chinese University of Hong Kong, Sequenom Inc.
    Inventors: Yuk Ming Dennis Lo, Kwan Chee Chan, Wai Kwon Rossa Chiu, Charles Cantor
  • Publication number: 20180282807
    Abstract: Systems, methods, and apparatus for determining at least a portion of fetal genome are provided. DNA fragments from a maternal sample (maternal and fetal DNA) can be analyzed to identify alleles at certain loci. The amounts of DNA fragments of the respective alleles at these loci can be analyzed together to determine relative amounts of the haplotypes for these loci and determine which haplotypes have been inherited from the parental genomes. Loci where the parents are a specific combination of homozygous and heterozygous can be analyzed to determine regions of the fetal genome. Reference haplotypes common in the population can be used along with the analysis of the DNA fragments of the maternal sample to determine the maternal and paternal genomes. Determination of mutations, a fractional fetal DNA concentration in a maternal sample, and a proportion of coverage of a sequencing of the maternal sample can also be provided.
    Type: Application
    Filed: June 7, 2018
    Publication date: October 4, 2018
    Inventors: Yuk Ming Dennis Lo, Kwan Chee Chan, Wai Kwun Rossa Chiu, Charles Cantor
  • Publication number: 20180237863
    Abstract: Methods are provided to improve the positive predictive value for cancer detection using cell-free nucleic acid samples. Various embodiments are directed to applications (e.g., diagnostic applications) of the analysis of the fragmentation patterns and size of cell-free DNA, e.g., plasma DNA and serum DNA, including nucleic acids from pathogens, including viruses. Embodiments of one application can determine if a subject has a particular condition. For example, a method of present disclosure can determine if a subject has cancer or a tumor, or other pathology. Embodiments of another application can be used to assess the stage of a condition, or the progression of a condition over time. For example, a method of the present disclosure may be used to determine a stage of cancer in a subject, or the progression of cancer in a subject over time (e.g., using samples obtained from a subject at different times).
    Type: Application
    Filed: October 25, 2017
    Publication date: August 23, 2018
    Inventors: Eugeni NAMSARAEV, Yuk-Ming Dennis LO, Rossa Wai Kwun CHIU, Kwan Chee CHAN, Peiyong JIANG, Kun SUN, Wai Kei LAM
  • Publication number: 20180237858
    Abstract: Systems, methods, and apparatuses for performing a prenatal diagnosis of a sequence imbalance are provided. A shift (e.g. to a smaller size distribution) can signify an imbalance in certain circumstances. For example, a size distribution of fragments of nucleic acids from an at-risk chromosome can be used to determine a fetal chromosomal aneuploidy. A size ranking of different chromosomes can be used to determine changes of a rank of an at-risk chromosome from an expected ranking. Also, a difference between a statistical size value for one chromosome can be compared to a statistical size value of another chromosome to identify a significant shift in size. A genotype and haplotype of the fetus may also be determined using a size distribution to determine whether a sequence imbalance occurs in a maternal sample relative to a genotypes or haplotype of the mother, thereby providing a genotype or haplotype of the fetus.
    Type: Application
    Filed: April 20, 2018
    Publication date: August 23, 2018
    Inventors: Yuk Ming Dennis Lo, Kwan Chee Chan, Wai Kwun Rossa Chiu, Wenli Zheng
  • Publication number: 20180216191
    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: September 24, 2014
    Publication date: August 2, 2018
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Miu Fan Lun, Wai Man Chan, Peiyong Jiang
  • Publication number: 20180208999
    Abstract: Various embodiments are directed to applications (e.g., classification of biological samples) of the analysis of the count, the fragmentation patterns, and size of cell-free nucleic acids, e.g., plasma DNA and serum DNA, including nucleic acids from pathogens, such as viruses. Embodiments of one application can determine if a subject has a particular condition. For example, a method of present disclosure can determine if a subject has cancer or a tumor, or other pathology. Embodiments of another application can be used to assess the stage of a condition, or the progression of a condition over time. For example, a method of the present disclosure may be used to determine a stage of cancer in a subject, or the progression of cancer in a subject over time (e.g., using samples obtained from a subject at different times).
    Type: Application
    Filed: January 25, 2018
    Publication date: July 26, 2018
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Peiyong Jiang, Wai Kei Lam
  • Publication number: 20180202003
    Abstract: A frequency of somatic mutations in a biological sample (e.g., plasma or serum) of a subject undergoing screening or monitoring for cancer, can be compared with that in the constitutional DNA of the same subject. A parameter can derived from these frequencies and used to determine a classification of a level of cancer. False positives can be filtered out by requiring any variant locus to have at least a specified number of variant sequence reads (tags), thereby providing a more accurate parameter. The relative frequencies for different variant loci can be analyzed to determine a level of heterogeneity of tumors in a patient.
    Type: Application
    Filed: December 22, 2017
    Publication date: July 19, 2018
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Peiyong Jiang
  • Publication number: 20180157793
    Abstract: A fractional concentration of clinically-relevant DNA in a mixture of DNA from a biological sample is determined based on amounts of DNA fragments at multiple sizes. For example, the fractional concentration of fetal DNA in maternal plasma or tumor DNA in a patient's plasma can be determined. The size of DNA fragments in a sample is shown to be correlated with a proportion of fetal DNA and a proportion of tumor DNA, respectively. Calibration data points (e.g., as a calibration function) indicate a correspondence between values of a size parameter and the fractional concentration of the clinically-relevant DNA. For a given sample, a first value of a size parameter can be determined from the sizes of DNA fragments in a sample. A comparison of the first value to the calibration data points can provide the estimate of the fractional concentration of the clinically-relevant DNA.
    Type: Application
    Filed: January 30, 2018
    Publication date: June 7, 2018
    Inventors: Yuk Ming Dennis Lo, Wai Kwun Rossa Chiu, Kwan Chee Chan, Wenli Zheng, Peiyong Jiang, Jiawei Liao
  • Publication number: 20180149636
    Abstract: Diseases (e.g., cancer) of a particular organ can be detected by analyzing cell-free DNA. Some embodiments may use an organ-associated sample that is from a particular organ or passes through the particular organ, as may occur, for example, in urine, saliva, blood, and stool samples. In some embodiments, methylation levels of cell-free DNA can be measured in a sample. Tissue-specific methylation patterns can be used to determine fractional contributions from different tissue types. In other embodiments, sizes of organ-associated cell-free DNA can be measured. A statistical measure of the size profile may indicate that cell-free DNA fragments are collectively longer than expected for subjects with healthy tissue compared to non-healthy tissue. In other embodiments, two different samples can be analyzed to determine whether a particular organ has cancer. Cell-free DNA in a blood sample and organ-associated sample can both be analyzed to identify chromosomal regions exhibiting a copy number aberration.
    Type: Application
    Filed: November 30, 2017
    Publication date: May 31, 2018
    Inventors: Yuk-Ming Dennis Lo, Rossa Wai Kwun Chiu, Kwan Chee Chan, Peiyong Jiang, Hua Tse Timothy Cheng
  • Patent number: 9982300
    Abstract: Systems, methods, and apparatuses for performing a prenatal diagnosis of a sequence imbalance are provided. A shift (e.g. to a smaller size distribution) can signify an imbalance in certain circumstances. For example, a size distribution of fragments of nucleic acids from an at-risk chromosome can be used to determine a fetal chromosomal aneuploidy. A size ranking of different chromosomes can be used to determine changes of a rank of an at-risk chromosome from an expected ranking. Also, a difference between a statistical size value for one chromosome can be compared to a statistical size value of another chromosome to identify a significant shift in size. A genotype and haplotype of the fetus may also be determined using a size distribution to determine whether a sequence imbalance occurs in a maternal sample relative to a genotypes or haplotype of the mother, thereby providing a genotype or haplotype of the fetus.
    Type: Grant
    Filed: November 25, 2013
    Date of Patent: May 29, 2018
    Assignee: The Chinese University of Hong Kong
    Inventors: Yuk Ming Dennis Lo, Kwan Chee Chan, Wai Kwun Rossa Chiu, Wenli Zheng
  • 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: 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: 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
  • Patent number: 9892230
    Abstract: A fractional concentration of clinically-relevant DNA in a mixture of DNA from a biological sample is determined based on amounts of DNA fragments at multiple sizes. For example, the fractional concentration of fetal DNA in maternal plasma or tumor DNA in a patient's plasma can be determined. The size of DNA fragments in a sample is shown to be correlated with a proportion of fetal DNA and a proportion of tumor DNA, respectively. Calibration data points (e.g., as a calibration function) indicate a correspondence between values of a size parameter and the fractional concentration of the clinically-relevant DNA. For a given sample, a first value of a size parameter can be determined from the sizes of DNA fragments in a sample. A comparison of the first value to the calibration data points can provide the estimate of the fractional concentration of the clinically-relevant DNA.
    Type: Grant
    Filed: March 7, 2013
    Date of Patent: February 13, 2018
    Assignee: The Chinese University of Hong Kong
    Inventors: Yuk Ming Dennis Lo, Wai Kwun Rossa Chiu, Kwan Chee Chan, Wenli Zheng, Peiyong Jiang, Jiawei Liao
  • 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: 20170235877
    Abstract: A classification of a level of cancer in an organism is determined by analyzing a biological sample of the organism. The biological sample comprises clinically-relevant DNA and other DNA. At least some of the DNA is cell-free in the biological sample. An amount of a first set of DNA fragments from the biological sample corresponding to each of a plurality of sizes is measured. A first value of a first parameter is calculated based on the amounts of DNA fragments at the plurality of sizes. The first value is compared to a reference value. A classification of a level of cancer in the organism is determined based on the comparison.
    Type: Application
    Filed: May 5, 2017
    Publication date: August 17, 2017
    Inventors: Yuk Ming Dennis LO, Wai Kwun Rossa Chiu, Kwan Chee Chan, Wenli Zheng, Peiyong Jiang, Jiawei Liao
  • 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