Browsing by Subject "Linkage disequilibrium"

Now showing 1 - 7 of 7
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    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 Medicine
    Fine-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.
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    Dosage Transmission Disequilibrium Test (dTDT) for Linkage and Association Detection
    (Public Library of Science, 2013-05-14) Zhang, Zhehao; Wang, Jen-Chyong; Howells, William; Lin, Peng; Agrawal, Arpana; Edenberg, Howard J.; Tischfield, Jay A.; Schuckit, Marc A.; Bierut, Laura J.; Goate, Alison; Rice, John P.; Biochemistry and Molecular Biology, School of Medicine
    Both linkage and association studies have been successfully applied to identify disease susceptibility genes with genetic markers such as microsatellites and Single Nucleotide Polymorphisms (SNPs). As one of the traditional family-based studies, the Transmission/Disequilibrium Test (TDT) measures the over-transmission of an allele in a trio from its heterozygous parents to the affected offspring and can be potentially useful to identify genetic determinants for complex disorders. However, there is reduced information when complete trio information is unavailable. In this study, we developed a novel approach to "infer" the transmission of SNPs by combining both the linkage and association data, which uses microsatellite markers from families informative for linkage together with SNP markers from the offspring who are genotyped for both linkage and a Genome-Wide Association Study (GWAS). We generalized the traditional TDT to process these inferred dosage probabilities, which we name as the dosage-TDT (dTDT). For evaluation purpose, we developed a simulation procedure to assess its operating characteristics. We applied the dTDT to the simulated data and documented the power of the dTDT under a number of different realistic scenarios. Finally, we applied our methods to a family study of alcohol dependence (COGA) and performed individual genotyping on complete families for the top signals. One SNP (rs4903712 on chromosome 14) remained significant after correcting for multiple testing Methods developed in this study can be adapted to other platforms and will have widespread applicability in genomic research when case-control GWAS data are collected in families with existing linkage data.
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    Efficient region-based test strategy uncovers genetic risk factors for functional outcome in bipolar disorder
    (Elsevier, 2019-01-01) Budde, Monika; Friedrichs, Stefanie; Alliey-Rodriguez, Ney; Ament, Seth; Badner, Judith A.; Berrettini, Wade H.; Bloss, Cinnamon S.; Byerley, William; Cichon, Sven; Comes, Ashley L.; Coryell, William; Craig, David W.; Degenhardt, Franziska; Edenberg, Howard J.; Foroud, Tatiana; Forstner, Andreas J.; Frank, Josef; Gershon, Elliot S.; Goes, Fernando S.; Greenwood, Tiffany A.; Guo, Yiran; Hipolito, Maria; Hood, Leroy; Keating, Brendan J.; Koller, Daniel L.; Lawson, William B.; Liu, Chunyu; Mahon, Pamela B.; McInnis, Melvin G.; McMahon, Francis J.; Meier, Sandra M.; Mühleisen, Thomas W.; Murray, Sarah S.; Nievergelt, Caroline M.; Nurnberger, John I.; Nwulia, Evaristus A.; Potash, James B.; Quarless, Danjuma; Rice, John; Roach, Jared C.; Scheftner, William A.; Schork, Nicholas J.; Shekhtman, Tatyana; Shilling, Paul D.; Smith, Erin N.; Streit, Fabian; Strohmaier, Jana; Szelinger, Szabolcs; Treutlein, Jens; Witt, Stephanie H.; Zandi, Peter P.; Zhang, Peng; Zöllner, Sebastian; Bickeböller, Heike; Falkai, Peter G.; Kelsoe, John R.; Nöthen, Markus M.; Rietschel, Marcella; Schulze, Thomas G.; Malzahn, Dörthe; Biochemistry and Molecular Biology, School of Medicine
    Genome-wide association studies of case-control status have advanced the understanding of the genetic basis of psychiatric disorders. Further progress may be gained by increasing sample size but also by new analysis strategies that advance the exploitation of existing data, especially for clinically important quantitative phenotypes. The functionally-informed efficient region-based test strategy (FIERS) introduced herein uses prior knowledge on biological function and dependence of genotypes within a powerful statistical framework with improved sensitivity and specificity for detecting consistent genetic effects across studies. As proof of concept, FIERS was used for the first genome-wide single nucleotide polymorphism (SNP)-based investigation on bipolar disorder (BD) that focuses on an important aspect of disease course, the functional outcome. FIERS identified a significantly associated locus on chromosome 15 (hg38: chr15:48965004 – 49464789 bp) with consistent effect strength between two independent studies (GAIN/TGen: European Americans, BOMA: Germans; n = 1592 BD patients in total). Protective and risk haplotypes were found on the most strongly associated SNPs. They contain a CTCF binding site (rs586758); CTCF sites are known to regulate sets of genes within a chromatin domain. The rs586758 – rs2086256 – rs1904317 haplotype is located in the promoter flanking region of the COPS2 gene, close to microRNA4716, and the EID1, SHC4, DTWD1 genes as plausible biological candidates. While implication with BD is novel, COPS2, EID1, and SHC4 are known to be relevant for neuronal differentiation and function and DTWD1 for psychopharmacological side effects. The test strategy FIERS that enabled this discovery is equally applicable for tag SNPs and sequence data.
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    Genome-wide association study identifies 48 common genetic variants associated with handedness
    (Springer Nature, 2021) Cuellar-Partida, Gabriel; Tung, Joyce Y.; Eriksson, Nicholas; Albrecht, Eva; Aliev, Fazil; Andreassen, Ole A.; Barroso, Inês; Beckmann, Jacques S.; Boks, Marco P.; Boomsma, Dorret I.; Boyd, Heather A.; Breteler, Monique M. B.; Campbell, Harry; Chasman, Daniel I.; Cherkas, Lynn F.; Davies, Gail; de Geus, Eco J. C.; Deary, Ian J.; Deloukas, Panos; Dick, Danielle M.; Duffy, David L.; Eriksson, Johan G.; Esko, Tõnu; Feenstra, Bjarke; Geller, Frank; Gieger, Christian; Giegling, Ina; Gordon, Scott D.; Han, Jiali; Hansen, Thomas F.; Hartmann, Annette M.; Hayward, Caroline; Heikkilä, Kauko; Hicks, Andrew A.; Hirschhorn, Joel N.; Hottenga, Jouke-Jan; Huffman, Jennifer E.; Hwang, Liang-Dar; Ikram, M. Arfan; Kaprio, Jaakko; Kemp, John P.; Khaw, Kay-Tee; Klopp, Norman; Konte, Bettina; Kutalik, Zoltan; Lahti, Jari; Li, Xin; Loos, Ruth J. F.; Luciano, Michelle; Magnusson, Sigurdur H.; Mangino, Massimo; Marques-Vidal, Pedro; Martin, Nicholas G.; McArdle, Wendy L.; McCarthy, Mark I.; Medina-Gomez, Carolina; Melbye, Mads; Melville, Scott A.; Metspalu, Andres; Milani, Lili; Mooser, Vincent; Nelis, Mari; Nyholt, Dale R.; O'Connell, Kevin S.; Ophoff, Roel A.; Palmer, Cameron; Palotie, Aarno; Palviainen, Teemu; Pare, Guillaume; Paternoster, Lavinia; Peltonen, Leena; Penninx, Brenda W. J. H.; Polasek, Ozren; Pramstaller, Peter P.; Prokopenko, Inga; Raikkonen, Katri; Ripatti, Samuli; Rivadeneira, Fernando; Rudan, Igor; Rujescu, Dan; Smit, Johannes H.; Smith, George Davey; Smoller, Jordan W.; Soranzo, Nicole; Spector, Tim D.; St. Pourcain, Beate; Starr, John M.; Stefánsson, Hreinn; Steinberg, Stacy; Teder-Laving, Maris; Thorleifsson, Gudmar; Stefánsson, Kári; Timpson, Nicholas J.; Uitterlinden, André G.; van Duijn, Cornelia M.; van Rooij, Frank J. A.; Vink, Jaqueline M.; Vollenweider, Peter; Vuoksimaa, Eero; Waeber, Gérard; Wareham, Nicholas J.; Warrington, Nicole; Waterworth, Dawn; Werge, Thomas; Wichmann, H-Erich; Widen, Elisabeth; Willemsen, Gonneke; Wright, Alan F.; Wright, Margaret J.; Xu, Mousheng; Zhao, Jing Hua; Kraft, Peter; Hinds, David A.; Lindgren, Cecilia M.; Mägi, Reedik; Neale, Benjamin M.; Evans, David M.; Medland, Sarah E.; Epidemiology, School of Public Health
    Handedness has been extensively studied because of its relationship with language and the over-representation of left-handers in some neurodevelopmental disorders. Using data from the UK Biobank, 23andMe and the International Handedness Consortium, we conducted a genome-wide association meta-analysis of handedness (N = 1,766,671). We found 41 loci associated (P < 5 × 10-8) with left-handedness and 7 associated with ambidexterity. Tissue-enrichment analysis implicated the CNS in the aetiology of handedness. Pathways including regulation of microtubules and brain morphology were also highlighted. We found suggestive positive genetic correlations between left-handedness and neuropsychiatric traits, including schizophrenia and bipolar disorder. Furthermore, the genetic correlation between left-handedness and ambidexterity is low (rG = 0.26), which implies that these traits are largely influenced by different genetic mechanisms. Our findings suggest that handedness is highly polygenic and that the genetic variants that predispose to left-handedness may underlie part of the association with some psychiatric disorders.
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    LD‐informed deep learning for Alzheimer's gene loci detection using WGS data
    (Wiley, 2025-01-16) Jo, Taeho; Bice, Paula; Nho, Kwangsik; Saykin, Andrew J.; Alzheimer’s Disease Sequencing Project; Radiology and Imaging Sciences, School of Medicine
    Introduction: The exponential growth of genomic datasets necessitates advanced analytical tools to effectively identify genetic loci from large-scale high throughput sequencing data. This study presents Deep-Block, a multi-stage deep learning framework that incorporates biological knowledge into its AI architecture to identify genetic regions as significantly associated with Alzheimer's disease (AD). The framework employs a three-stage approach: (1) genome segmentation based on linkage disequilibrium (LD) patterns, (2) selection of relevant LD blocks using sparse attention mechanisms, and (3) application of TabNet and Random Forest algorithms to quantify single nucleotide polymorphism (SNP) feature importance, thereby identifying genetic factors contributing to AD risk. Methods: The Deep-Block was applied to a large-scale whole genome sequencing (WGS) dataset from the Alzheimer's Disease Sequencing Project (ADSP), comprising 7416 non-Hispanic white (NHW) participants (3150 cognitively normal older adults (CN), 4266 AD). Results: 30,218 LD blocks were identified and then ranked based on their relevance with Alzheimer's disease. Subsequently, the Deep-Block identified novel SNPs within the top 1500 LD blocks and confirmed previously known variants, including APOE rs429358 and rs769449. Expression Quantitative Trait Loci (eQTL) analysis across 13 brain regions provided functional evidence for the identified variants. The results were cross-validated against established AD-associated loci from the European Alzheimer's and Dementia Biobank (EADB) and the GWAS catalog. Discussion: The Deep-Block framework effectively processes large-scale high throughput sequencing data while preserving SNP interactions during dimensionality reduction, minimizing bias and information loss. The framework's findings are supported by tissue-specific eQTL evidence across brain regions, indicating the functional relevance of the identified variants. Additionally, the Deep-Block approach has identified both known and novel genetic variants, enhancing our understanding of the genetic architecture and demonstrating its potential for application in large-scale sequencing studies. Highlights: Growing genomic datasets require advanced tools to identify genetic loci in sequencing. Deep-Block, a novel AI framework, was used to process large-scale ADSP WGS data. Deep-Block identified both known and novel AD-associated genetic loci.rs429358 (APOE) was key; rs11556505 (TOMM40), rs34342646 (NECTIN2) were significant. The AI framework uses biological knowledge to enhance detection of Alzheimer's loci.
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    Progress in Polygenic Composite Scores in Alzheimer’s and other Complex Diseases
    (Elsevier, 2019-05) Chasioti, Danai; Yan, Jingwen; Nho, Kwangsik; Saykin, Andrew J.; BioHealth Informatics, School of Informatics and Computing
    Advances in high-throughput genotyping and next-generation sequencing (NGS) coupled with larger sample sizes brings the realization of precision medicine closer than ever. Polygenic approaches incorporating the aggregate influence of multiple genetic variants can contribute to a better understanding of the genetic architecture of many complex diseases and facilitate patient stratification. This review addresses polygenic concepts, methodological developments, hypotheses, and key issues in study design. Polygenic risk scores (PRSs) have been applied to many complex diseases and here we focus on Alzheimer's disease (AD) as a primary exemplar. This review was designed to serve as a starting point for investigators wishing to use PRSs in their research and those interested in enhancing clinical study designs through enrichment strategies.
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    Variants in the ATP-Binding Cassette Transporter (ABCA7), Apolipoprotein E ε4, and the Risk of Late-Onset Alzheimer Disease in African Americans
    (American Medical Association, 2013) Reitz, Christiane; Jun, Gyungah; Naj, Adam; Rajbhandary, Ruchita; Vardarajan, Badri Narayan; Wang, Li-San; Valladares, Otto; Lin, Chiao-Feng; Larson, Eric B.; Graff-Radford, Neill R.; Evans, Denis; De Jager, Philip L.; Crane, Paul K.; Buxbaum, Joseph D.; Murrell, Jill R.; Raj, Towfique; Ertekin-Taner, Nilufer; Logue, Mark; Baldwin, Clinton T.; Green, Robert C.; Barnes, Lisa L.; Cantwell, Laura B.; Fallin, M. Daniele; Go, Rodney C. P.; Griffith, Patrick; Obisesan, Thomas O.; Manly, Jennifer J.; Lunetta, Kathryn L.; Kamboh, M. Ilyas; Lopez, Oscar L.; Bennett, David A.; Hendrie, Hugh; Hall, Kathleen S.; Goate, Alison M.; Byrd, Goldie S.; Kukull, Walter A.; Foroud, Tatiana M.; Haines, Jonathan L.; Farrer, Lindsay A.; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Mayeux, Richard; Alzheimer Disease Genetics Consortium; Psychiatry, School of Medicine
    Importance: Genetic variants associated with susceptibility to late-onset Alzheimer disease are known for individuals of European ancestry, but whether the same or different variants account for the genetic risk of Alzheimer disease in African American individuals is unknown. Identification of disease-associated variants helps identify targets for genetic testing, prevention, and treatment. Objective: To identify genetic loci associated with late-onset Alzheimer disease in African Americans. Design, setting, and participants: The Alzheimer Disease Genetics Consortium (ADGC) assembled multiple data sets representing a total of 5896 African Americans (1968 case participants, 3928 control participants) 60 years or older that were collected between 1989 and 2011 at multiple sites. The association of Alzheimer disease with genotyped and imputed single-nucleotide polymorphisms (SNPs) was assessed in case-control and in family-based data sets. Results from individual data sets were combined to perform an inverse variance-weighted meta-analysis, first with genome-wide analyses and subsequently with gene-based tests for previously reported loci. Main outcomes and measures: Presence of Alzheimer disease according to standardized criteria. Results: Genome-wide significance in fully adjusted models (sex, age, APOE genotype, population stratification) was observed for a SNP in ABCA7 (rs115550680, allele = G; frequency, 0.09 cases and 0.06 controls; odds ratio [OR], 1.79 [95% CI, 1.47-2.12]; P = 2.2 × 10(-9)), which is in linkage disequilibrium with SNPs previously associated with Alzheimer disease in Europeans (0.8 < D' < 0.9). The effect size for the SNP in ABCA7 was comparable with that of the APOE ϵ4-determining SNP rs429358 (allele = C; frequency, 0.30 cases and 0.18 controls; OR, 2.31 [95% CI, 2.19-2.42]; P = 5.5 × 10(-47)). Several loci previously associated with Alzheimer disease but not reaching significance in genome-wide analyses were replicated in gene-based analyses accounting for linkage disequilibrium between markers and correcting for number of tests performed per gene (CR1, BIN1, EPHA1, CD33; 0.0005 < empirical P < .001). Conclusions and relevance: In this meta-analysis of data from African American participants, Alzheimer disease was significantly associated with variants in ABCA7 and with other genes that have been associated with Alzheimer disease in individuals of European ancestry. Replication and functional validation of this finding is needed before this information is used in clinical settings.