Introduction

Structural variants (SVs), including deletions, duplications, inversions, insertions, and translocations, are a major cause of genetic disease and are recognized as clinically actionable findings in rare and inherited disease and oncology. While next-generation sequencing (NGS) technologies have significantly improved the detection of these complex genomic alterations, translating large-scale structural data into clinically meaningful insight remains a challenge.

In clinical diagnostics, accurate interpretation requires not only sensitive variant detection but also clear visualization of genomic architecture. Conventional linear genome browsers can be limited when representing complex rearrangements, multi-breakpoint events, or inter-chromosomal translocations. Circular genome visualization provides an intuitive and comprehensive way to display genome-wide structural variation within a single integrated view.

By arranging chromosomes in a circular layout and representing structural variants as arcs connecting breakpoint loci, Circos-based visualizations allow scientists to rapidly assess genomic instability, identify recurrent rearrangements, and contextualize findings relative to known disease-associated regions. This approach is valuable in rare disease workflows involving balanced rearrangements or cryptic chromosomal events and oncology diagnostics, where tumour genomes frequently exhibit complex structural patterns.

Geneyx Implementation of Circos Plot

To support the enhanced interrogation of structural variation, Geneyx Analysis now incorporates this feature as a new standard. It is seamlessly integrated into every analysis where SV/CNV VCF is available, whether short read or long read, in a sequencing platform agnostic manner.

This allows:

1. Improved Interpretation of Complex Rearrangements

Clinical genomes often contain complex, multi-breakpoint rearrangements that are difficult to interpret using traditional linear genome browsers. Circular visualization enables simultaneous, genome-wide representation of intra- and interchromosomal events, making patterns such as clustered translocations, chromosomal shattering, or large inversions immediately apparent. This holistic view supports more accurate classification of complex SVs.

2. Enhanced Detection of Clinically Relevant Patterns

Certain structural signatures, including recurrent translocation partners or localized breakpoint hotspots, may have diagnostic, prognostic, or therapeutic relevance. By visualizing all chromosomes in a unified layout, Circos plots facilitate rapid identification of these patterns, improving the ability to correlate genomic architecture with disease mechanisms.

3. Strengthened Quality Control and Validation

Visualization also serves as an additional quality assurance layer. Unexpected clustering of breakpoints, anomalous interchromosomal connections, or inconsistent copy number patterns can be rapidly identified, prompting further technical review.

The Circos Plot

The circos diagram within Geneyx provides a visual summary of chromosomal structure and detected variants, with the ability to filter on variant type and by local allele frequency, to allow analysis of data in context.