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Lessons learnt from the 1000 Genomes Project about sequencing in populations. Gil McVean Wellcome Trust Centre for Human Genetics and Department of Statistics, University of Oxford. Some questions. What has the 1000 Genomes Project told us about how to sequence (in) populations
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Lessons learnt from the 1000 Genomes Project about sequencing in populations Gil McVean Wellcome Trust Centre for Human Genetics and Department of Statistics, University of Oxford
Some questions • What has the 1000 Genomes Project told us about how to sequence (in) populations • What has the 1000 Genomes Project told us about populations
CEU FIN GBR CHB TSI JPT IBS CDX CHS YRI GWB KHV LWK GHN MAB Samples for the 1000 Genomes Project ASW AJM ACB MXL PUR CLM PEL Samples from S. Asia Major population groups comprised of subpopulations of c. 100 each
The role of the 1000G Project in medical genetics • A catalogue of variants • 95% of variants at 1% frequency in populations of interest • A representation of ‘normal’ variation • A set of haplotypes for imputation into GWAS • A training ground for sequencing/statistical/computational technologies
Samples for the 1000 Genomes Project: Pilot CEU CHB TSI* JPT CHS* YRI LWK* *Exon pilot only
Population-scale genome sequencing Haplotypes 2x 10x
>15 million SNPs, >50% of them novel dbSNP entries increased by 70%
A robust and modular pipeline for analysis of population-scale sequence data
An efficient format for storing aligned reads and a set of tools to manipulate and view the files • SAM/BAM format for storing (aligned) reads Bioinformatics (2009) http://samtools.sourceforge.net
An information-rich format for storing generic haplotype/genotype data and tools for manipulating the files http://vcftools.sourceforge.net
An understanding of the ‘rare functional variant load’ carried by individuals c. 250 LOF / person c. 75 HGMD DM
USH2A • Mutations cause with Usher syndrome • 66 missense variants in dbSNP • 2/3 detected in 1000 Genomes Pilot • One HGMD ‘disease-causing’ variant homozygous in 3 YRI • Other reports indicate this is not a real disease-causing variant
Samples for the 1000 Genomes Project: Phase1 CEU FIN GBR CHB ASW TSI JPT CHS YRI MXL PUR LWK CLM
Lesson 1. The low-coverage model works for variant discovery
Lesson 3.The genome has a large grey area where variant calling is hard
Lesson 4. Joint calling of different variant types substantially improves the quality of calls
Closely related populations can have substantially different rare variants
Spatial heterogeneity in non-genetic risk can differentially confound association studies for rare and common variants Iain Mathieson
Thanks to the many... • Steering committee • Co-chairs: Richard Durbin and David Altshuler • Samples and ELSI Committee • Co-chairs: AravindaChakravarti and LeenaPeltonen • Data Production Group • Co-chairs: Elaine Mardis and Stacey Gabriel • Analysis Group • Co-Chairs: Gil McVean and Goncalo Abecasis • Subgroups in gene-targeted sequencing (Richard Gibbs) and population genetics (Molly Przeworski) • Structural Variation Group • Co-chairs: Matt Hurles, Charles Lee and Evan Eichler • DCC • Co-Chairs: Paul Flicek and Steve Sherry