Abstract: The invention generally relates to genomic studies and specifically to improved methods for read mapping using identified nucleotides at known locations. The invention provides methods of using identified nucleotides at known places in a genome to guide the analysis of sequence reads from that genome by excluding potential mappings or assemblies that are not congruent with the identified nucleotides. Information about a plurality of SNPs in the subject's genome is used to identify candidate paths through a genomic directed acyclic graph (DAG). Sequence reads are mapped to the candidate paths.

Abstract: The invention includes methods for aligning reads (e.g., nucleic acid reads, amino acid reads) to a reference sequence construct, methods for building the reference sequence construct, and systems that use the alignment methods and constructs to produce sequences. The invention also includes methods and systems for evaluating the quality of the alignment between the reads and the reference sequence construct. The method is scalable, and can be used to align millions of reads to a construct thousands of bases or amino acids long. The invention additionally includes methods for identifying a disease or a genotype based upon alignment of nucleic acid reads to a location in the construct.

Abstract: The invention provides systems and methods for determining patterns of modification to a genome of a subject by representing the genome using a graph, such as a directed acyclic graph (DAG) with divergent paths for regions that are potentially subject to modification, profiling segments of the genome for evidence of epigenetic modification, and aligning the profiled segments to the DAG to determine locations and patterns of the epigenetic modification within the genome.

Abstract: Genomic data is written to disk in a compact format by dividing the data into segments and encoding each segment with the smallest number of bits per character necessary for whatever alphabet of characters appears in that segment. A computer system dynamically chooses the segment boundaries for maximum space savings. A first one of the segments may use a different number of bits per character than a second one of the segments. In one embodiment, dividing the data into segments comprises scanning the data and keeping track of a number of unique characters, noting positions in the sequence where the number increases to a power of two, calculating a compression that would be obtained by dividing the genomic data into one of the plurality of segments at ones of the noted positions, and dividing the genomic data into the plurality of segments at the positions that yield the best compression.

Abstract: The invention provides systems and methods for analyzing viruses by representing viral genetic diversity with a directed acyclic graph (DAG), which allows genetic sequencing technology to detect rare variations and represent otherwise difficult-to-document diversity within a sample. Additionally, a host-specific sequence DAG can be used to effectively segregate viral nucleic acid sequence reads from host sequence reads when a sample from a host is subject to sequencing. Known viral genomes can be represented using a viral reference DAG and the viral sequence reads from the sample can be compared to viral DAG to identify viral species or strains from which the reads were derived. Where the viral sequence reads indicate great genetic diversity in the virus that was infecting the host, those reads can be assembled into a DAG that itself properly represents that diversity.

Abstract: Embodiments of the invention protect information stored in graph-based sequence references by “watermarking” the graph with uniquely identifiable information. The watermark identifies the graph or version thereof in a detectable but nonintrusive manner. In one embodiment, insertions and/or deletions are introduced into regions of the graph.

Abstract: The invention provides methods of analyzing an individual's mtDNA by transforming available reference sequences into a directed graph that compactly represents all the information without duplication and comparing sequence reads from the mtDNA to the graph to identify the individual or describe their mtDNA. A directed graph can represent all of the genetic variation found among the mitochondrial genomes across all of a number of reference organisms while providing a single article to which sequence reads can be aligned or compared. Thus any sequence read or other sequence fragment can be compared, in a single operation, to the article that represents all of the reference mitochondrial sequences.

Abstract: Some embodiments relate to systems for processing one or more computational workflows. In one embodiment, a description of a computational comprises a plurality of applications, in which applications are represented as nodes and edges connect the nodes indicate the flow of data elements between applications. A task execution module is configured to create and execute tasks. An application programming interface (API) is in communication with the task execution module and comprises a plurality of function calls for controlling at least one function of the task execution module. An API script includes instructions to the API to create and execute a plurality of tasks corresponding to the execution of the computational workflow for a plurality of samples. A graphical user interface (GUI) is in communication with the task execution module and configured to receive input from an end user to initiate execution of the API script.

Abstract: In one embodiment, a method of processing a computational workflow comprises receiving a description of a computational workflow. The description comprises a plurality of steps, in which each step has at least one input and at least one output, and further wherein an input from a second step depends on an output from a first step. The description is translated into a static workflow graph stored in a memory, the static workflow graph comprising a plurality of nodes having input ports and output ports, wherein dependencies between inputs and outputs are specified as edges between input ports and output ports. Information about a first set of nodes is then extracted from the static workflow graph and placed into a dynamic graph. A first actionable job is identified from the dynamic graph and executed.

Abstract: The invention provides oncogenomic methods for detecting tumors by identifying circulating tumor DNA. A patient-specific reference directed acyclic graph (DAG) represents known human genomic sequences and non-tumor DNA from the patient as well as known tumor-associated mutations. Sequence reads from cell-free plasma DNA from the patient are mapped to the patient-specific genomic reference graph. Any of the known tumor-associated mutations found in the reads and any de novo mutations found in the reads are reported as the patient's tumor mutation burden.

Abstract: Various embodiments of the disclosure relate to systems and methods for aligning a sequence read to a graph reference. In one embodiment, the method comprises selecting a first node from a graph reference, the graph reference comprising a plurality of nodes connected by a plurality of directed edges, at least one node of the plurality of nodes having a nucleotide sequence. The method further comprises traversing the graph reference according to a depth-first search, and comparing a sequence read to nucleotide sequences generated from the traversal of the graph reference. The traversal of the graph is then modified in response to a determination that each and every node associated with a given nucleotide sequence was previously evaluated.

Abstract: Embodiments of the invention utilize a graph-based approach for simulating genomic datasets from large scale populations. Genomic data may be represented as a directed acyclic graph (DAG) that incorporates individual sample data including variant type, position, and zygosity. A simulator may operate on the DAG to generate variant datasets based on probabilistic traversal of the DAG. This probabilistic traversal reflects genomic variant types associated with the subpopulation used to build the DAG, and as a result, the generated variant datasets maintain statistical fidelity to the original sample data.

Abstract: The invention provides methods of analyzing an individual's mtDNA by transforming available reference sequences into a directed graph that compactly represents all the information without duplication and comparing sequence reads from the mtDNA to the graph to identify the individual or describe their mtDNA. A directed graph can represent all of the genetic variation found among the mitochondrial genomes across all of a number of reference organisms while providing a single article to which sequence reads can be aligned or compared. Thus any sequence read or other sequence fragment can be compared, in a single operation, to the article that represents all of the reference mitochondrial sequences.

Abstract: Systems and methods for analyzing genomic information can include obtaining a sequence read including genetic information; identifying, within a graph representing a reference genome, a plurality of candidate mapping positions that relate to the genetic information, the graph comprising nodes representing genetic sequences and edges connecting pairs of nodes; determining, by means of a computer system, whether an alignment with the graph surrounding each of the plurality of candidate mapping positions is advanced or basic; and performing for each candidate mapping position, by means of the computer system, a local alignment based on whether the local alignment is advanced or basic. The advanced local alignment can include a first-local-alignment algorithm, and the basic local alignment includes a second-local-alignment algorithm. Based on the local alignments, the mapped position of the sequence read can be identified within the genome.

Abstract: A method for generating a query of a genomic data store includes receiving, by a query generator executing on a computing device, from a graphical user interface, an identification of a first entity of a first entity class for inclusion in a resource description framework (RDF) query. The method includes receiving from the graphical user interface, an identification of a second entity of the first entity class, the second entity having a bi-directional relationship with the first entity. The method includes automatically generating an RDF query based upon the received identification of the first entity and the received identification of the second entity. The method includes executing the RDF query to select, from a plurality of genomic data sets, at least one genomic data set for at least one patient cohort. The method includes providing a listing of genomic data sets resulting from executing the RDF query.

Abstract: Systems and methods for data storage and retrieval for a computer memory include processing a computational workflow having multiple data-processing steps, generating and storing a first hash value associated with a first step of the data-processing steps based on an input to the first step, generating and storing a second hash value associated with a second step of the data-processing steps based on the generated first hash value, and reconstructing a computational state of the workflow based on the second hash value, and thereby avoid re-execution of a portion of the workflow corresponding to the second hash value.

Abstract: In one embodiment, a method of encoding variation data for a population comprises receiving, by a variant encoding engine executing on a processor, information describing genetic variation of a population of individuals. The information comprises a plurality of variable sites within the reference genome of the population and the genotypes of a plurality of individuals in the population with respect to those variable sites. The method further comprises selecting an encoding strategy for the information based on the characteristics of the genetic variation across the population, and encoding the information according to the selected encoding strategy. In certain embodiments, selecting an encoding strategy may comprise determining the variability of a variable site within the population, and encoding information associated with the variable site based on the variability.

Abstract: The invention provides methods and system for making specific base calls at specific loci using a reference sequence construct, e.g., a directed acyclic graph (DAG) that represents known variants at each locus of the genome. Because the sequence reads are aligned to the DAG during alignment, the subsequent step of comparing a mutation, vis-a-vis the reference genome, to a table of known mutations can be eliminated. The disclosed methods and systems are notably efficient in dealing with structural variations within a genome or mutations that are within a structural variation.

Abstract: In one embodiment, a method for identifying candidate sequences for genotyping a genomic sample comprises obtaining a plurality of sequence reads mapping to a genomic region of interest. The plurality of sequence reads are assembled into a directed acyclic graph (DAG) comprising a plurality of branch sites representing variation present in the set of sequence reads, each branch site comprising two or more branches. A path through the DAG comprises a set of successive branches over two or more branch sites and represents a possible candidate sequence of the genomic sample. One or more paths through the DAG are ranked by calculating scores for one or more branch sites, wherein the calculated score comprises a number of sequence reads that span multiple branch sites in a given path. At least one path is selected as a candidate sequence based at least in part on its rank.

Abstract: The invention provides oncogenomic methods for detecting tumors by identifying circulating tumor DNA. A patient-specific reference directed acyclic graph (DAG) represents known human genomic sequences and non-tumor DNA from the patient as well as known tumor-associated mutations. Sequence reads from cell-free plasma DNA from the patient are mapped to the patient-specific genomic reference graph. Any of the known tumor-associated mutations found in the reads and any de novo mutations found in the reads are reported as the patient's tumor mutation burden.