Repeat expansion and methylation state analysis with nanopore sequencing

Expansions of short tandem repeats are genetic variants that have been implicated in neuropsychiatric and other disorders but their assessment remains challenging with current molecular methods. Here, we developed a Cas12a-based enrichment strategy for nanopore sequencing that, combined with a new algorithm for raw signal analysis, enables us to efficiently target, sequence and precisely quantify repeat numbers as well as their DNA methylation status. Taking advantage of these single molecule nanopore signals provides therefore unprecedented opportunities to study pathological repeat expansions.