PT - JOURNAL ARTICLE AU - Páll Melsted AU - Shannon Hateley AU - Isaac Charles Joseph AU - Harold Pimentel AU - Nicolas Bray AU - Lior Pachter TI - Fusion detection and quantification by pseudoalignment AID - 10.1101/166322 DP - 2017 Jan 01 TA - bioRxiv PG - 166322 4099 - http://biorxiv.org/content/early/2017/07/20/166322.short 4100 - http://biorxiv.org/content/early/2017/07/20/166322.full AB - RNA sequencing in cancer cells is a powerful technique to detect chromosomal rearrangements, allowing for de novo discovery of actively expressed fusion genes. Here we focus on the problem of detecting gene fusions from raw sequencing data, assembling the reads to define fusion transcripts and their associated breakpoints, and quantifying their abundances. Building on the pseudoalignment idea that simplifies and accelerates transcript quantification, we introduce a novel approach to fusion detection based on inspecting paired reads that cannot be pseudoaligned due to conflicting matches. The method and software, called pizzly, filters false positives, assembles new transcripts from the fusion reads, and reports candidate fusions. With pizzly, fusion detection from raw RNA-Seq reads can be performed in a matter of minutes, making the program suitable for the analysis of large cancer gene expression databases and for clinical use. pizzly is available at https://github.com/pmelsted/pizzly