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Item A high-resolution HLA reference panel capturing global population diversity enables multi-ancestry fine-mapping in HIV host response(Springer Nature, 2021) Luo, Yang; Kanai, Masahiro; Choi, Wanson; Li, Xinyi; Sakaue, Saori; Yamamoto, Kenichi; Ogawa, Kotaro; Gutierrez-Arcelus, Maria; Gregersen, Peter K.; Stuart, Philip E.; Elder, James T.; Forer, Lukas; Schönherr, Sebastian; Fuchsberger, Christian; Smith, Albert V.; Fellay, Jacques; Carrington, Mary; Haas, David W.; Guo, Xiuqing; Palmer, Nicholette D.; Chen, Yii-Der Ida; Rotter, Jerome I.; Taylor, Kent D.; Rich, Stephen S.; Correa, Adolfo; Wilson, James G.; Kathiresan, Sekar; Cho, Michael H.; Metspalu, Andres; Esko, Tonu; Okada, Yukinori; Han, Buhm; NHLBI Trans-Omics for Precision Medicine (TOPMed) Consortium; McLaren, Paul J.; Raychaudhuri, Soumya; Obstetrics and Gynecology, School of MedicineFine-mapping to plausible causal variation may be more effective in multi-ancestry cohorts, particularly in the MHC, which has population-specific structure. To enable such studies, we constructed a large (n = 21,546) HLA reference panel spanning five global populations based on whole-genome sequences. Despite population-specific long-range haplotypes, we demonstrated accurate imputation at G-group resolution (94.2%, 93.7%, 97.8% and 93.7% in admixed African (AA), East Asian (EAS), European (EUR) and Latino (LAT) populations). Applying HLA imputation to genome-wide association study data for HIV-1 viral load in three populations (EUR, AA and LAT), we obviated effects of previously reported associations from population-specific HIV studies and discovered a novel association at position 156 in HLA-B. We pinpointed the MHC association to three amino acid positions (97, 67 and 156) marking three consecutive pockets (C, B and D) within the HLA-B peptide-binding groove, explaining 12.9% of trait variance.Item CYP2C8, CYP2C9, and CYP2C19 Characterization Using Next-Generation Sequencing and Haplotype Analysis: A GeT-RM Collaborative Project(Elsevier, 2022) Gaedigk, Andrea; Boone, Erin C.; Scherer, Steven E.; Lee, Seung-Been; Numanagić, Ibrahim; Sahinalp, Cenk; Smith, Joshua D.; McGee, Sean; Radhakrishnan, Aparna; Qin, Xiang; Wang, Wendy Y.; Farrow, Emily G.; Gonzaludo, Nina; Halpern, Aaron L.; Nickerson, Deborah A.; Miller, Neil A.; Pratt, Victoria M.; Kalman, Lisa V.; Medical and Molecular Genetics, School of MedicinePharmacogenetic tests typically target selected sequence variants to identify haplotypes that are often defined by star (∗) allele nomenclature. Due to their design, these targeted genotyping assays are unable to detect novel variants that may change the function of the gene product and thereby affect phenotype prediction and patient care. In the current study, 137 DNA samples that were previously characterized by the Genetic Testing Reference Material (GeT-RM) program using a variety of targeted genotyping methods were recharacterized using targeted and whole genome sequencing analysis. Sequence data were analyzed using three genotype calling tools to identify star allele diplotypes for CYP2C8, CYP2C9, and CYP2C19. The genotype calls from next-generation sequencing (NGS) correlated well to those previously reported, except when novel alleles were present in a sample. Six novel alleles and 38 novel suballeles were identified in the three genes due to identification of variants not covered by targeted genotyping assays. In addition, several ambiguous genotype calls from a previous study were resolved using the NGS and/or long-read NGS data. Diplotype calls were mostly consistent between the calling algorithms, although several discrepancies were noted. This study highlights the utility of NGS for pharmacogenetic testing and demonstrates that there are many novel alleles that are yet to be discovered, even in highly characterized genes such as CYP2C9 and CYP2C19.Item The fourth apolipoprotein E haplotype found in the Yoruba of Ibadan(Wiley, 2006-06) Murrell, Jill R.; Price, Brandon M.; Baiyewu, Olusegun; Gureje, Oye; Deeg, Mark; Hendrie, Hugh; Ogunniyi, Adesola; Hall, Kathleen; Department of Medicine, IU School of MedicineItem Genome-Wide Discovery of Drug-Dependent Human Liver Regulatory Elements(PLOS (Public Library of Science), 2014-10-02) Smith, Robin P.; Eckalbar, Walter L.; Morrissey, Kari M.; Luizon, Marcelo R.; Hoffmann, Thomas J.; Sun, Xuefeng; Jones, Stacy L.; Aldred, Shelley Force; Ramamoorthy, Anuradha; Desta, Zeruesenay; Liu, Yunlong; Skaar, Todd C.; Trinklein, Nathan D.; Giacomini, Kathleen M.; Ahituv, Nadav; Department of Medicine, School of MedicineInter-individual variation in gene regulatory elements is hypothesized to play a causative role in adverse drug reactions and reduced drug activity. However, relatively little is known about the location and function of drug-dependent elements. To uncover drug-associated elements in a genome-wide manner, we performed RNA-seq and ChIP-seq using antibodies against the pregnane X receptor (PXR) and three active regulatory marks (p300, H3K4me1, H3K27ac) on primary human hepatocytes treated with rifampin or vehicle control. Rifampin and PXR were chosen since they are part of the CYP3A4 pathway, which is known to account for the metabolism of more than 50% of all prescribed drugs. We selected 227 proximal promoters for genes with rifampin-dependent expression or nearby PXR/p300 occupancy sites and assayed their ability to induce luciferase in rifampin-treated HepG2 cells, finding only 10 (4.4%) that exhibited drug-dependent activity. As this result suggested a role for distal enhancer modules, we searched more broadly to identify 1,297 genomic regions bearing a conditional PXR occupancy as well as all three active regulatory marks. These regions are enriched near genes that function in the metabolism of xenobiotics, specifically members of the cytochrome P450 family. We performed enhancer assays in rifampin-treated HepG2 cells for 42 of these sequences as well as 7 sequences that overlap linkage-disequilibrium blocks defined by lead SNPs from pharmacogenomic GWAS studies, revealing 15/42 and 4/7 to be functional enhancers, respectively. A common African haplotype in one of these enhancers in the GSTA locus was found to exhibit potential rifampin hypersensitivity. Combined, our results further suggest that enhancers are the predominant targets of rifampin-induced PXR activation, provide a genome-wide catalog of PXR targets and serve as a model for the identification of drug-responsive regulatory elements.Item High Resolution Genomic Scans Reveal Genetic Architecture Controlling Alcohol Preference in Bidirectionally Selected Rat Model(Plos, 2016-08) Lo, Chiao-Ling; Lossie, Amy C.; Liang, Tiebing; Liu, Yunlong; Xuei, Xiaoling; Lumeng, Lawrence; Zhou, Feng C.; Muir, William M.; Department of Anatomy & Cell Biology, IU School of MedicineInvestigations on the influence of nature vs. nurture on Alcoholism (Alcohol Use Disorder) in human have yet to provide a clear view on potential genomic etiologies. To address this issue, we sequenced a replicated animal model system bidirectionally-selected for alcohol preference (AP). This model is uniquely suited to map genetic effects with high reproducibility, and resolution. The origin of the rat lines (an 8-way cross) resulted in small haplotype blocks (HB) with a corresponding high level of resolution. We sequenced DNAs from 40 samples (10 per line of each replicate) to determine allele frequencies and HB. We achieved ~46X coverage per line and replicate. Excessive differentiation in the genomic architecture between lines, across replicates, termed signatures of selection (SS), were classified according to gene and region. We identified SS in 930 genes associated with AP. The majority (50%) of the SS were confined to single gene regions, the greatest numbers of which were in promoters (284) and intronic regions (169) with the least in exon's (4), suggesting that differences in AP were primarily due to alterations in regulatory regions. We confirmed previously identified genes and found many new genes associated with AP. Of those newly identified genes, several demonstrated neuronal function involved in synaptic memory and reward behavior, e.g. ion channels (Kcnf1, Kcnn3, Scn5a), excitatory receptors (Grin2a, Gria3, Grip1), neurotransmitters (Pomc), and synapses (Snap29). This study not only reveals the polygenic architecture of AP, but also emphasizes the importance of regulatory elements, consistent with other complex traits.Item Major chromosome 5H haplotype switch structures the European two-rowed spring barley germplasm of the past 190 years(Springer, 2023-07-21) Wonneberger, Ronja; Schreiber, Miriam; Haaning, Allison; Muehlbauer, Gary J.; Waugh, Robbie; Stein, Nils; Pediatrics, School of MedicineSelection over 70 years has led to almost complete fixation of a haplotype spanning ~ 250 Mbp of chomosome 5H in European two-rowed spring barleys, possibly originating from North Africa. Plant breeding and selection have shaped the genetic composition of modern crops over the past decades and centuries and have led to great improvements in agronomic and quality traits. Knowledge of the genetic composition of breeding germplasm is essential to make informed decisions in breeding programs. In this study, we characterized the structure and composition of 209 barley cultivars representative of the European two-rowed spring barley germplasm of the past 190 years. Utilizing high-density SNP marker data, we identified a distinct centromeric haplotype spanning a ~ 250 Mbp large region on chromosome 5H which likely was first introduced into the European breeding germplasm in the early to mid-twentieth century and has been non-recombining and under strong positive selection over the past 70 years. Almost all cultivars in our panel that were released after 2000 carry this new haplotype, suggesting that this region carries one or several genes conferring highly beneficial traits. Using the global barley collection of the German Federal ex situ gene bank at IPK Gatersleben, we found the new haplotype at high frequencies in six-rowed spring-type landraces from Northern Africa, from which it may have been introduced into modern European barley germplasm via southern European landraces. The presence of a 250 Mbp genomic region characterized by lack of recombination and high levels of fixation in modern barley germplasm has substantial implications for the genetic diversity of the modern barley germplasm and for barley breeding.Item Multi-trait genome-wide association study of opioid addiction: OPRM1 and beyond(Springer Nature, 2022-10-07) Gaddis, Nathan; Mathur, Ravi; Marks, Jesse; Zhou, Linran; Quach, Bryan; Waldrop, Alex; Levran, Orna; Agrawal, Arpana; Randesi, Matthew; Adelson, Miriam; Jeffries, Paul W.; Martin, Nicholas G.; Degenhardt, Louisa; Montgomery, Grant W.; Wetherill, Leah; Lai, Dongbing; Bucholz, Kathleen; Foroud, Tatiana; Porjesz, Bernice; Runarsdottir, Valgerdur; Tyrfingsson, Thorarinn; Einarsson, Gudmundur; Gudbjartsson, Daniel F.; Webb, Bradley Todd; Crist, Richard C.; Kranzler, Henry R.; Sherva, Richard; Zhou, Hang; Hulse, Gary; Wildenauer, Dieter; Kelty, Erin; Attia, John; Holliday, Elizabeth G.; McEvoy, Mark; Scott, Rodney J.; Schwab, Sibylle G.; Maher, Brion S.; Gruza, Richard; Kreek, Mary Jeanne; Nelson, Elliot C.; Thorgeirsson, Thorgeir; Stefansson, Kari; Berrettini, Wade H.; Gelernter, Joel; Edenberg, Howard J.; Bierut, Laura; Hancock, Dana B.; Johnson, Eric Otto; Medical and Molecular Genetics, School of MedicineOpioid addiction (OA) is moderately heritable, yet only rs1799971, the A118G variant in OPRM1, has been identified as a genome-wide significant association with OA and independently replicated. We applied genomic structural equation modeling to conduct a GWAS of the new Genetics of Opioid Addiction Consortium (GENOA) data together with published studies (Psychiatric Genomics Consortium, Million Veteran Program, and Partners Health), comprising 23,367 cases and effective sample size of 88,114 individuals of European ancestry. Genetic correlations among the various OA phenotypes were uniformly high (rg > 0.9). We observed the strongest evidence to date for OPRM1: lead SNP rs9478500 (p = 2.56 × 10-9). Gene-based analyses identified novel genome-wide significant associations with PPP6C and FURIN. Variants within these loci appear to be pleiotropic for addiction and related traits.Item A New Statistic to Evaluate Imputation Reliability(Public Library of Science, 2010-03-15) Lin, Peng; Hartz, Sarah M.; Zhang, Zhehao; Saccone, Scott F.; Wang, Jia; Tischfield, Jay A.; Edenberg, Howard J.; Kramer, John R.; Goate, Alison M.; Bierut, Laura J.; Rice, John P.; COGA Collaborators COGEND Collaborators, GENEVA; Biochemistry and Molecular Biology, School of MedicineBackground As the amount of data from genome wide association studies grows dramatically, many interesting scientific questions require imputation to combine or expand datasets. However, there are two situations for which imputation has been problematic: (1) polymorphisms with low minor allele frequency (MAF), and (2) datasets where subjects are genotyped on different platforms. Traditional measures of imputation cannot effectively address these problems. Methodology/Principal Findings We introduce a new statistic, the imputation quality score (IQS). In order to differentiate between well-imputed and poorly-imputed single nucleotide polymorphisms (SNPs), IQS adjusts the concordance between imputed and genotyped SNPs for chance. We first evaluated IQS in relation to minor allele frequency. Using a sample of subjects genotyped on the Illumina 1 M array, we extracted those SNPs that were also on the Illumina 550 K array and imputed them to the full set of the 1 M SNPs. As expected, the average IQS value drops dramatically with a decrease in minor allele frequency, indicating that IQS appropriately adjusts for minor allele frequency. We then evaluated whether IQS can filter poorly-imputed SNPs in situations where cases and controls are genotyped on different platforms. Randomly dividing the data into “cases” and “controls”, we extracted the Illumina 550 K SNPs from the cases and imputed the remaining Illumina 1 M SNPs. The initial Q-Q plot for the test of association between cases and controls was grossly distorted (λ = 1.15) and had 4016 false positives, reflecting imputation error. After filtering out SNPs with IQS<0.9, the Q-Q plot was acceptable and there were no longer false positives. We then evaluated the robustness of IQS computed independently on the two halves of the data. In both European Americans and African Americans the correlation was >0.99 demonstrating that a database of IQS values from common imputations could be used as an effective filter to combine data genotyped on different platforms. Conclusions/Significance IQS effectively differentiates well-imputed and poorly-imputed SNPs. It is particularly useful for SNPs with low minor allele frequency and when datasets are genotyped on different platforms.Item PharmVar GeneFocus: CYP2B6(Wiley, 2021) Desta, Zeruesenay; El-Boraie, Ahmed; Gong, Li; Somogyi, Andrew A.; Lauschke, Volker M.; Dandara, Collet; Klein, Kathrin; Miller, Neil; Klein, Teri E.; Tyndale, Rachel F.; Whirl-Carrillo, Michelle; Gaedigk, Andrea; Medicine, School of MedicineThe Pharmacogene Variation Consortium (PharmVar) catalogs star (*) allele nomenclature for the polymorphic human CYP2B6 gene. Genetic variation within the CYP2B6 gene locus impacts the metabolism or bioactivation of clinically important drugs. Of particular importance are efficacy and safety concerns regarding: efavirenz, which is used for the treatment of HIV type-1 infection; methadone, a mainstay in the treatment of opioid use disorder and as an analgesic; ketamine, used as an antidepressant and analgesic; and bupropion, which is prescribed to treat depression and for smoking cessation. This GeneFocus provides a comprehensive overview and summary of CYP2B6 and describes how haplotype information catalogued by PharmVar is utilized by the Pharmacogenomics Knowledgebase (PharmGKB) and the Clinical Pharmacogenetics Implementation Consortium (CPIC).Item PharmVar GeneFocus: CYP2C19(Wiley, 2021) Botton, Mariana R.; Whirl-Carrillo, Michelle; Del Tredici, Andria L.; Sangkuhl, Katrin; Cavallari, Larisa H.; Agúndez, José A.; Duconge, Jorge; Lee, Ming Ta Michael; Woodahl, Erica L.; Claudio-Campos, Karla; Daly, Ann K.; Klein, Teri E.; Pratt, Victoria M.; Scott, Stuart A.; Gaedigk, Andrea; Medicine, School of MedicineThe Pharmacogene Variation Consortium (PharmVar) catalogues star (*) allele nomenclature for the polymorphic human CYP2C19 gene. CYP2C19 genetic variation impacts the metabolism of many drugs and has been associated with both efficacy and safety issues for several commonly prescribed medications. This GeneFocus provides a comprehensive overview and summary of CYP2C19 and describes how haplotype information catalogued by PharmVar is utilized by the Pharmacogenomics Knowledgebase and the Clinical Pharmacogenetics Implementation Consortium (CPIC).