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Explore the relationship between phenotype-associated SNPs (GWAS) and function-associated DNA using ENCODE data. Identify functional SNPs associated with diseases through integrative analysis. Utilize multivariate segmentations to integrate various data tracks, including histone modifications, TF-occupancy clusters, and more. Analyze genetic interactions, eQTL data, and allele-specific information to offer mechanistic explanations and improve disease understanding. Workshop conducted on March 07, 2011.
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Variation and Diseasestage 1 AWG workshop March 07, 2011
Using function-associated DNA (ENCODE) to explain phenotype-associated SNPs (GWAS)
Integrative ENCODE analysis of GWAS noncoding SNPs • The multivariate segmentations (Michael and Jason) integrate multiple tracks of data. • The GWAS SNPs are enriched in the segments associated with function. • Pipeline using all the ENCODE data • Summation • GWAS SNPs are enriched in DNase HSs (Stam), enhancers predicted by histone modifications (Brad, Manolis), segments with clusters of TF-occupancy, etc • How many SNPs fall into these individually? (refer to separate papers) Then do union and merge of these to get a composite answer • RNA contigs??
GWAS SNPs are strongly enriched in function-associated segments
Similar patterns of GWAS enrichment in segments from multivariate HMM
Pipeline using all the ENCODE data • Begin with GWAS SNP(s) • Extend from mapped SNP to all SNPs in LD • Do SNPs fall in function-associated segment? • S. Wilder’s “cleaner view” of segmentations? • What features are in segment? • Histone mods, DHS, list of TFs, … • Is SNP in DNase footprint (UW, Duke)? • Is the DNA segments under constraint? Lineage-limited? • Go to Pouya’s motifs: is the SNP in there? • Is the binding allele specific? • Result: candidate functional SNP with testable hypothesis
Published Genome-Wide Associations through 6/2010, 904 published GWA at p<5x10-8 for 165 traits NHGRI GWA Catalog www.genome.gov/GWAStudies 3417 GWAS SNPs, Nov 2010
Use DNase HSs to find functional SNPs “…we find a total of 140 associations in 86 different phenotypes linked to at least one fSNP” Anshul Kundaje, Marc Schaub
Type 1 diabetes locus: Anshul et al Diabetes associated SNP Complete LD fSNP Paint by segments
GWAS uber-associations • Genetic interactions • Unlinked loci associated with same traits • Functional interactions • SOMs on segmentations? • Physical interactions • ChIA-PET, 5C • Connecting any type of interaction with another would be compelling
Heterozygosity Ewan Bob Altschuler …
GWAS SNPs occur in TF occupied segments twice as frequently as regular SNPs All TF ChIP-seq -> Anshul’s consistent peak calls (8M) -> Manoj’s consolidated set (200K) -> Bob Harris’ overlap analysis
eQTLs (Ewan) • To what extent can we find mechanistic explanations for observed eQTL data in lymphoblastoid lines? • Can we provide any additional information to help improve eQTL analysis (eg, proposed trans factors due to knowing chip-seq peaks?)
Integrate features using multivariate segmentations Ernst and Kellis Multivariate HMM (image is old version) M. Hoffman Segway round 5b Dynamic Bayesian network