Rare variant phasing and haplotypic expression from RNA-sequencing with phASER

Abstract

Haplotype phasing of genetic variants is important for clinical interpretation of the genome, population genetic analysis, and functional genomic analysis of allelic activity. Here we present phASER, a fast and accurate approach for phasing variants that are overlapped by sequencing reads, including those from RNA-sequencing (RNA-seq), which often span multiple exons due to splicing. This provides 1) dramatically more accurate phasing of rare and de novo variants compared to population-based phasing; 2) phasing of variants in the same gene up to hundreds of kilobases away which cannot be obtained from DNA-sequencing reads; 3) high confidence measures of haplotypic expression, greatly improving power for allelic expression studies.