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• Introduction
  • Contact information
  • System requirements
  • Installing modules
    • Licensing modules
    • Uninstalling modules
  • Installing server extensions
    • Licensing server extensions
• Methods and tools
  • Methods
    • Trimming
    • Readmapping
    • Deduplication
    • Local realignment
    • Structural variant detection
    • UMI grouping
    • Germline variant detection
    • Somatic variant detection
    • Tumor normal variant detection
    • Limitations
  • Tools
    • LightSpeed Fastq to Germline Variants
      • LightSpeed Fastq to Germline Variants outputs
    • LightSpeed Fastq to Somatic Variants
      • LightSpeed Fastq to Somatic Variants outputs
    • LightSpeed Fastq to Somatic Variants Tumor Normal
      • LightSpeed Fastq to Somatic Variants Tumor Normal outputs
    • Report
• Template Workflows
  • General Template Workflows
    • Fastq to Annotated Germline Variants
      • Outputs from Fastq to Annotated Germline Variants
    • Fastq to Annotated Germline Variants with Coverage Analysis
      • Outputs from Fastq to Annotated Germline Variants with Coverage Analysis
    • Fastq to Annotated Somatic Variants
      • Outputs from Fastq to Annotated Somatic Variants
    • Fastq to Annotated Somatic Variants with Coverage Analysis
      • Outputs from Fastq to Annotated Somatic Variants with Coverage Analysis
    • Fastq to Annotated Somatic Variants (Tumor Normal)
      • Outputs from Fastq to Annotated Somatic Variants (Tumor Normal)
    • Fastq to Annotated Somatic Variants (Tumor Normal) with Coverage Analysis
      • Outputs from Fastq to Annotated Somatic Variants (Tumor Normal) with Coverage Analysis
    • Fastq to Germline CNV Control
      • Outputs from Fastq to Germline CNV Control
    • Fastq to Somatic CNV Control
      • Outputs from Fastq to Somatic CNV Control
  • Template Workflows - QIAseq Targeted DNA
    • QIAseq Fastq to Annotated Germline Variants
      • Outputs from QIAseq Fastq to Annotated Germline Variants
    • QIAseq Fastq to Annotated Somatic Variants
      • Outputs from QIAseq Fastq to Annotated Somatic Variants
    • QIAseq Fastq to Germline CNV Control
      • Outputs from QIAseq Fastq to Germline CNV Control
    • QIAseq Fastq to Somatic CNV Control
      • Outputs from QIAseq Fastq to Somatic CNV Control
  • Template Workflows - QIAseq Targeted DNA Pro
    • QIAseq Pro Fastq to Annotated Germline Variants
      • Outputs from QIAseq Pro Fastq to Annotated Germline Variants
    • QIAseq Pro Fastq to Annotated Somatic Variants
      • Outputs from QIAseq Pro Fastq to Annotated Somatic Variants
    • QIAseq Pro Fastq to Germline CNV Control
      • Outputs from QIAseq Pro Fastq to Germline CNV Control
    • QIAseq Pro Fastq to Somatic CNV Control
      • Outputs from QIAseq Pro Fastq to Somatic CNV Control

Germline variant detection

Based on the read mapping, germline variants are identified at positions where the read alignment supports a significant difference to the reference genome.

This is achieved through a site model, where each position is first assigned a likelihood for each of the genotypes A, C, T, G, N or missing. The algorithm then iterates over the read mapping and adjusts likelihoods per position for each genotype based on observations in the data until the likelihoods no longer change. Note that broken read pairs are not considered.

Each position is then inspected, and positions where the most likely genotype(s) are different from the reference sequence are identified. As the algorithm expects the genome to be diploid and is calling germline variants, only 1 or 2 genotypes per position are considered.

Variant types

LightSpeed Fastq to Germline Variants reports SNPs, MNVs and InDels and replacements provided that the variants are contained within at least one paired end read.

Variant annotations

Variants identified by LightSpeed Fastq to Germline Variants are annotated with the following basic information: Chromosome, Region, Type, Reference, Allele, Reference allele, Length, Zygosity, Count, Coverage, Frequency, QUAL and Genotype. Only single base pair variants, that are not adjacent to any other variants, are assigned a QUAL score.

Read about variant annotations here: http://resources.qiagenbioinformatics.com/manuals/clcgenomicsworkbench/current/index.php?manual=Variant_tracks.html.

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