# Circular genome view

**TL;DR:** The circular genome view lays out an entire assembly as a ring and
draws long-range structural variants as chords across the interior, one arc per
event connecting its two breakpoints. An arc with its two ends in different
chromosome segments is an inter-chromosomal event, which no single linear window
can hold.

<Figure caption="A circular genome view of a structural-variant VCF. Each chord connects the two breakpoints of one variant; arcs spanning between different chromosomes are inter-chromosomal events (translocations/breakends)." src="/img/jbrowse-img/circular_chords.png" />

## Opening a circular genome view

- Launch **Circular view** from the **Add** menu in the main menu bar
- Select an assembly in the import form and click **Open**. The ring appears
  with one segment per chromosome
- Add a variant track from the view's track selector; SV chords render
  automatically as a **Chord variant display**

The view reads standard VCF/VCF.gz variant tracks. Chords are drawn from
long-range records (`SVTYPE=BND` breakends and translocations). Single-locus
deletions and duplications load but don't produce an informative chord.

## Interacting with chords

- **Hover** a chord to highlight it and see the variant it represents
- **Click** a chord to open that variant's feature details
- From the feature-detail panel's **Breakends** section, use **Open in
  breakpoint split view** to open a
  [breakpoint split view](https://jbrowse.org/jb2-staging/docs/user_guides/sv_visualization#breakpoint-split-view)
  centered on the event's two breakpoints

To triage many variants at once, use the
[SV inspector](https://jbrowse.org/jb2-staging/docs/user_guides/sv_inspector_view), which pairs this same
circular overview with a filterable variant table and cross-filters the two
together.

## See also

- [](https://jbrowse.org/jb2-staging/docs/user_guides/sv_inspector_view)
- [Structural variant visualization](https://jbrowse.org/jb2-staging/docs/user_guides/sv_visualization)
- [Cancer SVs (C-GIAB) tutorial](https://jbrowse.org/jb2-staging/docs/tutorials/sv_visualization_cgiab)
- [ChordVariantDisplay config schema](https://jbrowse.org/jb2-staging/docs/config/chordvariantdisplay)
- [Gallery: structural variant examples](https://jbrowse.org/jb2-staging/gallery/#sv)