Quality tab

The Quality tab gives you an interactive overview of variant quality across all sequenced individuals in a case. It displays zygosity, quality grades, and metrics tailored to each variant type—helping you evaluate data reliability before interpretation.

Click a family member icon to switch the sample in view.

The Quality tab features:

• Variant quality summary: Displays the overall quality and zygosity for each sample in a pedigree.
• Quality metrics per variant type: Shows the detailed metrics used for each variant type.
• Allele distribution: Visualizes how sequencing reads support reference and alternate alleles.

Tips:

• Use the Quality tab:

  • Before interpretation — to verify if a variant meets minimum quality thresholds
  • For cross-sample comparisons — to check if the variant is consistently high-quality across proband and relatives
  • To filter analysis — by excluding low-quality calls that may be sequencing artefacts
• Always check the variant type first — quality thresholds vary by variant type and caller.
• For CNVs (DRAGEN 4.4+): Pay attention to the allele-specific copy number display [MCN / (CN-MCN)], which provides richer context for mosaic and allele-level events.

Important:

Low quality ≠ irrelevant — in rare cases, important variants may appear low quality due to mapping complexity (e.g., MRJD variants in paralogous regions).

Variants marked low quality may be hidden from your preset filters! Review them in IGV before discarding.