bioRxiv ScienceSearch

Biology subjects

Liron Ganel

Publications and source records attributed to Liron Ganel.

2 recordsLinked to original sources

SVScore: An Impact Prediction Tool For Structural Variation

MotivationStructural variation (SV) is an important and diverse source of human genome variation. Over the past several years, much progress has been made in the area of SV detection, but predicting the functional impact of SVs discovered in whole genome sequencing (WGS) studies remains extremely challenging. Accurate SV impact prediction is especially important for WGS-based rare variant association studies and studies of rare disease.\n\nResultsHere we present SVScore, a computational tool for in silico SV impact prediction. SVScore aggregates existing per-base single nucleotide polymorphism pathogenicity scores across relevant genomic intervals for each SV in a manner that considers variant type, gene features, and uncertainty in breakpoint location. We show that in a Finnish cohort, the allele frequency spectrum of SVs with high impact scores is strongly skewed toward lower frequencies, suggesting that these variants are under purifying selection. We further show that SVScore identifies deleterious variants more effectively than naive alternative methods. Finally, our results indicate that high-scoring tandem duplications may be under surprisingly strong selection relative to high-scoring deletions, suggesting that duplications may be more deleterious than previously thought. In conclusion, SVScore provides pathogenicity prediction for SVs that is both informative and meaningful for understanding their functional role in disease.\n\nAvailabilitySVScore is implemented in Perl and available freely at {{http://www.github.com/lganel/SVScore}} for use under the MIT license.\n\nContactihall@wustl.edu\n\nSupplementary informationSupplementary data are available at Bioinformatics online.

Bioinformatics

The impact of structural variation on human gene expression

Structural variants (SVs) are an important source of human genetic diversity but their contribution to traits, disease, and gene regulation remains unclear. The Genotype-Tissue Expression (GTEx) project presents an unprecedented opportunity to address this question due to the availability of deep whole genome sequencing (WGS) and multi-tissue RNA-seq data from 147 individuals. We used comprehensive methods to identify 24,157 high confidence SVs, and mapped cis expression quantitative trait loci (eQTLs) in 13 tissues via joint analysis of SVs, single nucleotide (SNV) and short insertion/deletion (indel) variants. We identified 24,801 eQTLs affecting the expression of 10,101 distinct genes. Based on haplotype structure and heritability partitioning, we estimate that SVs are the causal variant at 3.3-7.0% of eQTLs, which is nearly an order of magnitude higher than prior estimates from low coverage WGS and represents a 26- to 54-fold enrichment relative to their scarcity in the genome. Expression-altering SVs also have significantly larger effect sizes than SNVs and indels. We identified 787 putatively causal SVs predicted to directly alter gene expression, most of which (88.3%) are noncoding variants that show significant enrichment at enhancers and other regulatory elements. By evaluating linkage disequilibrium between SVs, SNVs and indels, we nominate 49 SVs as plausible causal variants at published genome-wide association study (GWAS) loci. Remarkably, 29.9% of the common SV-eQTLs are not well tagged by flanking SNVs, and we observe a notable abundance (relative to SNVs and indels) of rare, high impact SVs associated with aberrant expression of nearby genes. These results suggest that comprehensive WGS-based SV analyses will increase the power of both common and rare variant association studies.

Genomics