@article {6283, title = {Whole-genome sequence-based analysis of high-density lipoprotein cholesterol.}, journal = {Nat Genet}, volume = {45}, year = {2013}, month = {2013 Aug}, pages = {899-901}, abstract = {

We describe initial steps for interrogating whole-genome sequence data to characterize the genetic architecture of a complex trait, levels of high-density lipoprotein cholesterol (HDL-C). We report whole-genome sequencing and analysis of 962 individuals from the Cohorts for Heart and Aging Research in Genetic Epidemiology (CHARGE) studies. From this analysis, we estimate that common variation contributes more to heritability of HDL-C levels than rare variation, and screening for mendelian variants for dyslipidemia identified individuals with extreme HDL-C levels. Whole-genome sequencing analyses highlight the value of regulatory and non-protein-coding regions of the genome in addition to protein-coding regions.

}, keywords = {Cholesterol, HDL, Computational Biology, Databases, Genetic, Genetic Variation, Genome, Human, Genome-Wide Association Study, Genomics, Heterozygote, Humans, Open Reading Frames}, issn = {1546-1718}, doi = {10.1038/ng.2671}, author = {Morrison, Alanna C and Voorman, Arend and Johnson, Andrew D and Liu, Xiaoming and Yu, Jin and Li, Alexander and Muzny, Donna and Yu, Fuli and Rice, Kenneth and Zhu, Chengsong and Bis, Joshua and Heiss, Gerardo and O{\textquoteright}Donnell, Christopher J and Psaty, Bruce M and Cupples, L Adrienne and Gibbs, Richard and Boerwinkle, Eric} } @article {6547, title = {Sequencing of 2 subclinical atherosclerosis candidate regions in 3669 individuals: Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium Targeted Sequencing Study.}, journal = {Circ Cardiovasc Genet}, volume = {7}, year = {2014}, month = {2014 Jun}, pages = {359-64}, abstract = {

BACKGROUND: Atherosclerosis, the precursor to coronary heart disease and stroke, is characterized by an accumulation of fatty cells in the arterial intimal-medial layers. Common carotid intima media thickness (cIMT) and plaque are subclinical atherosclerosis measures that predict cardiovascular disease events. Previously, genome-wide association studies demonstrated evidence for association with cIMT (SLC17A4) and plaque (PIK3CG).

METHODS AND RESULTS: We sequenced 120 kb around SLC17A4 (6p22.2) and 251 kb around PIK3CG (7q22.3) among 3669 European ancestry participants from the Atherosclerosis Risk in Communities (ARIC) study, Cardiovascular Health Study (CHS), and Framingham Heart Study (FHS) in Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. Primary analyses focused on 438 common variants (minor allele frequency >=1\%), which were independently meta-analyzed. A 3{\textquoteright} untranslated region CCDC71L variant (rs2286149), upstream from PIK3CG, was the most significant finding in cIMT (P=0.00033) and plaque (P=0.0004) analyses. A SLC17A4 intronic variant was also associated with cIMT (P=0.008). Both were in low linkage disequilibrium with the genome-wide association study single nucleotide polymorphisms. Gene-based tests including T1 count and sequence kernel association test for rare variants (minor allele frequency <1\%) did not yield statistically significant associations. However, we observed nominal associations for rare variants in CCDC71L and SLC17A3 with cIMT and of the entire 7q22 region with plaque (P=0.05).

CONCLUSIONS: Common and rare variants in PIK3CG and SLC17A4 regions demonstrated modest association with subclinical atherosclerosis traits. Although not conclusive, these findings may help to understand the genetic architecture of regions previously implicated by genome-wide association studies and identify variants within these regions for further investigation in larger samples.

}, keywords = {Aged, Aged, 80 and over, Aging, Atherosclerosis, Class Ib Phosphatidylinositol 3-Kinase, Cohort Studies, European Continental Ancestry Group, Female, Genetic Variation, Genome-Wide Association Study, Genomics, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Sequence Analysis, DNA, Sodium-Phosphate Cotransporter Proteins, Type I}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.113.000116}, author = {Bis, Joshua C and White, Charles C and Franceschini, Nora and Brody, Jennifer and Zhang, Xiaoling and Muzny, Donna and Santibanez, Jireh and Gibbs, Richard and Liu, Xiaoming and Lin, Honghuang and Boerwinkle, Eric and Psaty, Bruce M and North, Kari E and Cupples, L Adrienne and O{\textquoteright}Donnell, Christopher J} } @article {6597, title = {Association of exome sequences with plasma C-reactive protein levels in >9000 participants.}, journal = {Hum Mol Genet}, volume = {24}, year = {2015}, month = {2015 Jan 15}, pages = {559-71}, abstract = {

C-reactive protein (CRP) concentration is a heritable systemic marker of inflammation that is associated with cardiovascular disease risk. Genome-wide association studies have identified CRP-associated common variants associated in \~{}25 genes. Our aims were to apply exome sequencing to (1) assess whether the candidate loci contain rare coding variants associated with CRP levels and (2) perform an exome-wide search for rare variants in novel genes associated with CRP levels. We exome-sequenced 6050 European-Americans (EAs) and 3109 African-Americans (AAs) from the NHLBI-ESP and the CHARGE consortia, and performed association tests of sequence data with measured CRP levels. In single-variant tests across candidate loci, a novel rare (minor allele frequency = 0.16\%) CRP-coding variant (rs77832441-A; p.Thr59Met) was associated with 53\% lower mean CRP levels (P = 2.9 {\texttimes} 10(-6)). We replicated the association of rs77832441 in an exome array analysis of 11 414 EAs (P = 3.0 {\texttimes} 10(-15)). Despite a strong effect on CRP levels, rs77832441 was not associated with inflammation-related phenotypes including coronary heart disease. We also found evidence for an AA-specific association of APOE-ε2 rs7214 with higher CRP levels. At the exome-wide significance level (P < 5.0 {\texttimes} 10(-8)), we confirmed associations for reported common variants of HNF1A, CRP, IL6R and TOMM40-APOE. In gene-based tests, a burden of rare/lower frequency variation in CRP in EAs (P <= 6.8 {\texttimes} 10(-4)) and in retinoic acid receptor-related orphan receptor α (RORA) in AAs (P = 1.7 {\texttimes} 10(-3)) were associated with CRP levels at the candidate gene level (P < 2.0 {\texttimes} 10(-3)). This inquiry did not elucidate novel genes, but instead demonstrated that variants distributed across the allele frequency spectrum within candidate genes contribute to CRP levels.

}, keywords = {Adult, African Americans, C-Reactive Protein, Cardiovascular Diseases, Cohort Studies, European Continental Ancestry Group, Exome, Female, Gene Frequency, Genetic Predisposition to Disease, Genome-Wide Association Study, Hepatocyte Nuclear Factor 1-alpha, Humans, Male, Plasma, Polymorphism, Single Nucleotide, Receptors, Interleukin-6, Risk Factors}, issn = {1460-2083}, doi = {10.1093/hmg/ddu450}, author = {Schick, Ursula M and Auer, Paul L and Bis, Joshua C and Lin, Honghuang and Wei, Peng and Pankratz, Nathan and Lange, Leslie A and Brody, Jennifer and Stitziel, Nathan O and Kim, Daniel S and Carlson, Christopher S and Fornage, Myriam and Haessler, Jeffery and Hsu, Li and Jackson, Rebecca D and Kooperberg, Charles and Leal, Suzanne M and Psaty, Bruce M and Boerwinkle, Eric and Tracy, Russell and Ardissino, Diego and Shah, Svati and Willer, Cristen and Loos, Ruth and Melander, Olle and McPherson, Ruth and Hovingh, Kees and Reilly, Muredach and Watkins, Hugh and Girelli, Domenico and Fontanillas, Pierre and Chasman, Daniel I and Gabriel, Stacey B and Gibbs, Richard and Nickerson, Deborah A and Kathiresan, Sekar and Peters, Ulrike and Dupuis, Jos{\'e}e and Wilson, James G and Rich, Stephen S and Morrison, Alanna C and Benjamin, Emelia J and Gross, Myron D and Reiner, Alex P} } @article {6689, title = {Association of Rare Loss-Of-Function Alleles in HAL, Serum Histidine: Levels and Incident Coronary Heart Disease.}, journal = {Circ Cardiovasc Genet}, volume = {8}, year = {2015}, month = {2015 Apr}, pages = {351-5}, abstract = {

BACKGROUND: Histidine is a semiessential amino acid with antioxidant and anti-inflammatory properties. Few data are available on the associations between genetic variants, histidine levels, and incident coronary heart disease (CHD) in a population-based sample.

METHODS AND RESULTS: By conducting whole exome sequencing on 1152 African Americans in the Atherosclerosis Risk in Communities (ARIC) study and focusing on loss-of-function (LoF) variants, we identified 3 novel rare LoF variants in HAL, a gene that encodes histidine ammonia-lyase in the first step of histidine catabolism. These LoF variants had large effects on blood histidine levels (β=0.26; P=1.2{\texttimes}10(-13)). The positive association with histidine levels was replicated by genotyping an independent sample of 718 ARIC African Americans (minor allele frequency=1\%; P=1.2{\texttimes}10(-4)). In addition, high blood histidine levels were associated with reduced risk of developing incident CHD with an average of 21.5 years of follow-up among African Americans (hazard ratio=0.18; P=1.9{\texttimes}10(-4)). This finding was validated in an independent sample of European Americans from the Framingham Heart Study (FHS) Offspring Cohort. However, LoF variants in HAL were not directly significantly associated with incident CHD after meta-analyzing results from the CHARGE Consortium.

CONCLUSIONS: Three LoF mutations in HAL were associated with increased histidine levels, which in turn were shown to be inversely related to the risk of CHD among both African Americans and European Americans. Future investigations on the association between HAL gene variation and CHD are warranted.

}, keywords = {Adult, African Americans, Alleles, Coronary Disease, European Continental Ancestry Group, Female, Histidine, Histidine Ammonia-Lyase, Humans, Male, Mutation}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.114.000697}, author = {Yu, Bing and Li, Alexander H and Muzny, Donna and Veeraraghavan, Narayanan and de Vries, Paul S and Bis, Joshua C and Musani, Solomon K and Alexander, Danny and Morrison, Alanna C and Franco, Oscar H and Uitterlinden, Andre and Hofman, Albert and Dehghan, Abbas and Wilson, James G and Psaty, Bruce M and Gibbs, Richard and Wei, Peng and Boerwinkle, Eric} } @article {8564, title = {A hybrid computational strategy to address WGS variant analysis in >5000 samples.}, journal = {BMC Bioinformatics}, volume = {17}, year = {2016}, month = {2016 Sep 10}, pages = {361}, abstract = {

BACKGROUND: The decreasing costs of sequencing are driving the need for cost effective and real time variant calling of whole genome sequencing data. The scale of these projects are far beyond the capacity of typical computing resources available with most research labs. Other infrastructures like the cloud AWS environment and supercomputers also have limitations due to which large scale joint variant calling becomes infeasible, and infrastructure specific variant calling strategies either fail to scale up to large datasets or abandon joint calling strategies.

RESULTS: We present a high throughput framework including multiple variant callers for single nucleotide variant (SNV) calling, which leverages hybrid computing infrastructure consisting of cloud AWS, supercomputers and local high performance computing infrastructures. We present a novel binning approach for large scale joint variant calling and imputation which can scale up to over 10,000 samples while producing SNV callsets with high sensitivity and specificity. As a proof of principle, we present results of analysis on Cohorts for Heart And Aging Research in Genomic Epidemiology (CHARGE) WGS freeze 3 dataset in which joint calling, imputation and phasing of over 5300 whole genome samples was produced in under 6 weeks using four state-of-the-art callers. The callers used were SNPTools, GATK-HaplotypeCaller, GATK-UnifiedGenotyper and GotCloud. We used Amazon AWS, a 4000-core in-house cluster at Baylor College of Medicine, IBM power PC Blue BioU at Rice and Rhea at Oak Ridge National Laboratory (ORNL) for the computation. AWS was used for joint calling of 180~TB of BAM files, and ORNL and Rice supercomputers were used for the imputation and phasing step. All other steps were carried out on the local compute cluster. The entire operation used 5.2 million core hours and only transferred a total of 6~TB of data across the platforms.

CONCLUSIONS: Even with increasing sizes of whole genome datasets, ensemble joint calling of SNVs for low coverage data can be accomplished in a scalable, cost effective and fast manner by using heterogeneous computing platforms without compromising on the quality of variants.

}, keywords = {Databases, Genetic, Genome, Human, Genomics, High-Throughput Nucleotide Sequencing, Humans}, issn = {1471-2105}, doi = {10.1186/s12859-016-1211-6}, author = {Huang, Zhuoyi and Rustagi, Navin and Veeraraghavan, Narayanan and Carroll, Andrew and Gibbs, Richard and Boerwinkle, Eric and Venkata, Manjunath Gorentla and Yu, Fuli} }