🏥 Three Real-World Clinical Applications of Long-Read Sequencing
Session 4 Clinical TranslationResolving the Complex CYP2D6 Locus
Disentangling CYP2D6 from the 94% identical CYP2D7 pseudogene; phasing whole-gene deletions (*5), tandem duplications (*1xN/*2xN), and hybrid conversions (*36-*10) for precise metabolizer status.
Pathogenic Tandem Repeat Expansions
Single-molecule sizing and native 5mC methylation profiling of expanded repeat loci: C9orf72 (ALS/FTD hexanucleotide), HTT (Huntington CAG), and FMR1 (Fragile X CGG).
Real-Time Pathogen & AMR Surveillance
Rapid on-site MinION pathogen identification, full assembly of circular antimicrobial resistance (AMR) plasmids, and bacterial 6mA/4mC epigenetic restriction-modification characterization.
12 Modular Curriculum Chapters
Comprehensive practical manuals with Dorado neural basecalling recipes, minimap2 presets, cuteSV/Sniffles2 structural variant pipelines, and clinical case analyses.
Module 1: Long-Read Sequencing Chemistries: Oxford Nanopore (ONT) vs. PacBio SMRT
Comparative biophysics of third-generation sequencing: protein nanopore resistive ionic current sensors (ONT R10.4.2) vs. Zero-Mode Waveguide (ZMW) single-molecule real-time synthesis (PacBio HiFi).
Module 2: Key Long-Read Data Formats: FAST5, POD5, FASTQ & SAM/BAM Specifications
Technical evolution of raw ionic current containers: from hierarchical HDF5 (FAST5) to high-speed columnar Apache Arrow (POD5), plus long-read BAM tags (MM/ML for methylation).
Module 3: Navigating Public Long-Read Repositories: NCBI SRA & GIAB Consortium
Accessing benchmark datasets from the Genome in a Bottle (GIAB) consortium and Human Pangenome Reference Consortium (HPRC); programmatic retrieval via AWS Open Data and SRA toolkit.
Module 4: Neural Basecalling Architecture: From Raw Signal to FASTQ with Dorado
Translating analog ionic current squiggles into digital sequence: Connectionist Temporal Classification (CTC), Transformer/CRF architectures, Super-Accurate (SUP) models, and 5mC methylation.
Module 5: Long-Read Quality Control: NanoPlot, Read Length Distributions & N50 Metrics
Evaluating third-generation sequencing metrics: logarithmic read length histograms, read length N50 calculation, Phred quality score distributions, and flowcell pore health analytics.
Module 6: Long-Read Filtering & Preprocessing: Chopper, Filtlong & Downsampling
Optimizing reads for downstream assembly and alignment: length thresholds, quality filtering with chopper, adapter trimming, and depth normalization via rasusa.
Module 7: Long-Read Alignment Mechanics: Minimap2 Algorithmic Presets & Galaxy Workflows
Minimizer sketching, seed-and-extend chaining, and splice-aware alignment with minimap2; constructing reproducible end-to-end Galaxy pipelines from FASTQ to indexed BAM.
Module 8: Alignment Quality Assessment: Samtools Stats, Depth & Mosdepth Profiling
Post-alignment metrics: mapping quality distributions (MAPQ 60 vs 0), chimeric read detection, GC bias profiling, and high-speed coverage auditing with mosdepth.
Module 9: IGV Curation for Long Reads: Split Reads, Haplotype Blocks & Technical Artifacts
Interactive manual review: configuring IGV consensus mode, inspecting supplementary split reads (SA tag), visualizing phased haplotype blocks, and identifying homopolymer artifacts.
Module 10: Structural Variant Calling: cuteSV, Sniffles2 & PBSV Algorithmic Tuning
Discovery and genotyping of structural variants ($> 50\text{ bp}$): signatures, clustering algorithms, parameter optimization for Oxford Nanopore and PacBio HiFi, and GIAB benchmarking.
Module 11: Structural VCF 4.2 Interpretation: INFO Fields, Filtering & Functional Annotation
Deciphering structural VCF specifications: SVTYPE, SVLEN, END, CIPOS, genotype likelihoods (DR/DV), high-confidence filtering, and AnnotSV gene dosage impact scoring.
Module 12: Real-World Clinical Case Studies: Pharmacogenomics (CYP2D6), Rare Diseases & Pathogens
Translational applications: solving the polymorphic CYP2D6 star-allele puzzle, detecting pathogenic tandem repeat expansions in rare diseases, and real-time AMR pathogen surveillance.