Resolving the chromatin impact of mosaic variants with targeted Fiber-seq

Abstract

Accurately quantifying the functional consequences of noncoding mosaic variants requires the pairing of DNA sequences with both accessible and closed chromatin architectures along individual DNA molecules-a pairing that cannot be achieved using traditional fragmentation-based chromatin assays. We demonstrate that targeted single-molecule chromatin fiber sequencing (Fiber-seq) achieves this, permitting single-molecule, long-read genomic, and epigenomic profiling across targeted >100 kb loci with ∼10-fold enrichment over untargeted sequencing. Targeted Fiber-seq reveals that pathogenic expansions of the