In this PacBio Virtual Global Summit 2020 presentation, Pi-Chuan Chang of Google shares how DeepVariant identifies SNPs and Indels in PacBio HiFi data, starting from the v0.8 release (April 2019). In her talk, Chang details recent accuracy improvements that won the PrecisionFDA Truth Challenge v2, which are now available in the latest release (v1.0 in September 2020). Learn more about PacBio at https://pacb.com/ Legal & Trademarks: Visit https://www.pacb.com/legal-and-trademarks/
Yunfei Guo, from the University of Southern California, presents his ASHG 2015 poster on a de novo assembly of a diploid Asian genome. The uniform coverage of long-read sequencing helped access regions previously unresolvable due to high GC bias or long repeats. The assembly allowed scientists to fill some 400 gaps in the latest human reference genome, including some as long as 50 kb.
Tetsuo Ashizawa, Director of the Neuroscience Research Program at Houston Methodist Research Institute, presents a novel amplification-free targeted enrichment method using CRISPR-Cas9 for the disease-causing repeat expansion in SCA10. Using long-read sequencing, he has been able to span multi-kilobase repetitive regions and identify interruption sequence motifs that correlate with alternative clinical phenotypes in individuals from varying ethnic backgrounds. Webinar registration required.
Meredith Ashby, from PacBio, presents how large-insert targeted sequencing (LITS) provides a more comprehensive picture of structural variation relevant to human disease and genomic disorders, providing insights into possible rearrangement mechanisms in Potocki-Lupski syndrome and revealing subtleties in cancer biology. Webinar registration required.
Melissa Laird Smith from Icahn Institute at Mt. Sinai reviews her work studying the genetic background of immune response by characterizing population diversity at the immunoglobulin heavy chain locus. Webinar registration required.
PacBio bioinformatician Aaron Wenger presents this ASHG 2016 poster demonstrating human structural variation detection at varying coverage levels with SMRT Sequencing on the Sequel System. Results were compared to truth sets for well-characterized genomes. Results indicate that even low coverage of SMRT Sequencing makes it possible to detect hundreds of SVs that are missed in high-coverage short-read sequencing data.
PacBio’s Jenny Ekholm presents this ASHG 2016 poster on a new method being developed that enriches for unamplified DNA and uses SMRT Sequencing to characterize repeat expansion disorders. Incorporating the CRISPR/Cas9 system to target specific genes allows for amplification-free enrichment to preserve epigenetic information and avoid PCR bias. Internal studies have shown that the approach can successfully be used to target and sequence the CAG repeat responsible for Huntington’s disease, the repeat associated with ALS, and more. The approach allows for pooling many samples and sequencing with a single SMRT Cell.
Michael Lutz, from the Duke University Medical Center, discussed a recently published software tool that can now be used in a pipeline with SMRT Sequencing data to find structural variant biomarkers for neurodegenerative diseases with a focus on Alzheimer’s disease, ALS, and Lewy body dementia. His team is particularly interested in short sequence repeats and short tandem repeats, which have already been implicated in neurodegenerative disease.
Jonas Korlach spoke about recent SMRT Sequencing updates, such as latest Sequel System chemistry release (1.2.1) and updates to the Integrative Genomics Viewer that’s now update optimized for PacBio data. He presented the recent data release of structural variation detected in the NA12878 genome, including many more insertions and deletions than short-read-based technologies were able to find.
Euan Ashley from Stanford University started with the premise that while current efforts in the field of genomics medicine address 30% of patient cases, there’s a need for new approaches to make sense of the remaining 70%. Toward that end, he said that accurately calling structural variants is a major need. In one translational research example, Ashley said that SMRT Sequencing with the Sequel System allowed his team to identify six potentially causative genes in an individual with complex and varied symptoms; one gene was associated with Carney syndrome, which was a match for the person’s physiology and was later…
Melissa Laird Smith discussed how the Icahn School of Medicine at Mount Sinai uses long-read sequencing for translational research. She gave several examples of targeted sequencing projects run on the Sequel System including CYP2D6, phased mutations of GLA in Fabry’s disease, structural variation breakpoint validation in glioblastoma, and full-length immune profiling of TCR sequences.
In this ASHG 2017 presentation, Charles Lee of The Jackson Laboratory for Genomic Medicine presented work from the Human Genome Structural Variation Consortium. He shared data from efforts to utilize multiple platforms for the comprehensive discovery of structural variations—including insertions, deletions, inversions and mobile element insertions—in individual genomes. By combining various technologies, this research identified 7 times more structural variation per person than was previously known to exist.
In this ASHG 2017 presentation, Jonas Korlach, the CSO of PacBio shared updates on three applications featuring SMRT Sequencing on the Sequel System, highlighting structural variant detection, targeted sequencing and the Iso-Seq method of RNA sequencing. He provided details on structural variant calling using pbsv to call insertions and deletions and compared PacBio variant calling with other technologies. Korlach described how targeted sequencing can be used to interrogate repeat expansions, detect and phase minor variants and can access medically relevant but previously inaccessible gene targets. He presented research featuring the Iso-Seq method that identified isoforms, corrected previous isoform annotations and…
In this ASHG 2017 presentation, Han Brunner of Radboud University Medical Center presented research using SMRT Sequencing to detect structural variants to uncover the genetic causes of intellectual disability. He shared that long-read sequencing enabled detection of 25,000 structural variants per genome. Brunner presented data from patient trios to identify de novo structural variant candidates and ongoing validation work to determine the causative mutations of intellectual disability.
In this ASHG workshop presentation, Janet Song of Stanford School of Medicine shared research on resolving a tandem repeat array implicated in bipolar disorder and schizophrenia. These psychiatric diseases share a number of genomic risk variants, she noted, but scientists continue to search for a specific causal variant in the CACNA1C gene suggested by previous genome-wide association studies. SMRT Sequencing of this region in 16 individuals identified a series of 30-mer repeats, containing a total of about 50 variants. Analysis showed that 10 variants were linked to protective or risk haplotypes. Song aims to study the function of these variants…