Mapping and phasing of structural variation in patient genomes using nanopore sequencing

Area of Science:

• Genomics
• Bioinformatics
• Medical Genetics

Background:

• Short-read sequencing has limitations in detecting complex structural variants (SVs), hindering comprehensive genomic analysis.
• Accurate identification and characterization of de novo rearrangements and inherited SVs are crucial for understanding congenital abnormalities.

Purpose of the Study:

• To evaluate the utility of nanopore long-read sequencing and a novel computational pipeline (NanoSV) for detecting and phasing structural variants in patient genomes.
• To compare the performance of long reads versus short reads in identifying complex genomic rearrangements, including de novo chromothripsis.

Main Methods:

• Whole-genome sequencing of two patients with congenital abnormalities using the MinION nanopore sequencer.
• Application of the novel NanoSV computational pipeline for analyzing long-read sequencing data.
• Comparative analysis of SV detection and phasing capabilities between nanopore long reads and traditional short reads.

Main Results:

• Nanopore long reads demonstrated superiority over short reads in detecting de novo chromothripsis rearrangements.
• Long reads enabled efficient phasing of genetic variations, allowing determination of parental origin for chromothripsis breakpoints and resolution of complex rearrangement structures.
• Genome-wide analysis revealed novel SVs, including a significant proportion of retrotransposon insertions, that were missed by short-read sequencing.

Conclusions:

• Nanopore long-read sequencing offers significant advantages for mapping and phasing structural variants, particularly complex rearrangements.
• This approach enhances the detection of de novo and inherited SVs, providing valuable insights for both clinical diagnostics and genetic research.
• The study highlights the potential of long-read sequencing as a powerful tool in patient genome analysis.