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Blacker, Deborah

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Blacker, Deborah

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    Identifying Medicare beneficiaries with dementia
    (Wiley, 2021-04-26) Moura, Lidia M. V. R.; Festa, Natalia; Price, Mary; Volya, Margarita; Benson, Nicole M.; Zafar, Sahar; Weiss, Max; Blacker, Deborah; Normand, Sharon-Lise; Newhouse, Joseph; Hsu, John
    BACKGROUND/OBJECTIVES: No data exist regarding the validity of International Classification of Disease (ICD)-10 dementia diagnoses within Medicare claims data. We examined the accuracy of claims-based diagnoses with respect to expert clinician adjudication using a novel database with individual-level linkages between electronic health record (EHR) and claims. DESIGN: In this retrospective observational study, two neurologists and two psychiatrists performed a standardized review of patients’ medical records from January-2016 to December-2018, and adjudicated dementia status. We measured the accuracy of three claims-based definitions of dementia against the reference standard. SETTING: Mass-General-Brigham Healthcare (MGB), Massachusetts, USA. PARTICIPANTS: From an eligible population of 40,690 fee-for-service (FFS) Medicare beneficiaries, aged 65-years and older, within the MGB Accountable Care Organization (ACO), we generated a random sample of 1,002 patients, stratified by the pretest likelihood of dementia using administrative surrogates. INTERVENTION: None. MEASUREMENTS: We evaluated the accuracy (area-under-receiver-operating-curve [AUROC]) and calibration (calibration-in-the-large [CITL] and calibration slope) of three ICD-10 claims-based definitions of dementia against clinician-adjudicated standards. We applied inverse probability weighting to reconstruct the eligible population and reported the mean and 95% confidence interval (95% CI) for all performance characteristics, using 10-fold cross-validation (CV). RESULTS: Beneficiaries had an average age of 75.3-years and were predominately female (59%) and non-Hispanic white (93%). The adjudicated prevalence of dementia in the eligible population was 7%. The best performing definition demonstrated excellent accuracy (CV-AUC 0.94; 95% CI 0.92-0.96) and was well-calibrated to the reference standard of clinician-adjudicated dementia (CV-CITL <0.001, CV-slope 0.97). CONCLUSION: This study is the first to validate ICD-10 diagnostic codes against a robust and replicable approach to dementia ascertainment using a real-world clinical reference standard. The best performing definition includes diagnostic codes with strong face validity and outperforms an updated version of a previously validated ICD-9 definition of dementia.
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    Genetic Meta-Analysis of Diagnosed Alzheimer’s Disease Identifies New Risk Loci and Implicates Aβ, Tau, Immunity and Lipid Processing
    (Springer Science and Business Media LLC, 2019-02-28) Grenier-Boley, Benjamin; Sims, Rebecca; Bis, Joshua C.; Damotte, Vincent; Naj, Adam C.; Boland, Anne; Vronskaya, Maria; van der Lee, Sven J.; Amlie-Wolf, Alexandre; Bellenguez, Céline; Frizatti, Aura; Chouraki, Vincent; Martin, Eden R.; Sleegers, Kristel; Badarinarayan, Nandini; Jakobsdottir, Johanna; Hamilton-Nelson, Kara L.; Moreno-Grau, Sonia; Olaso, Robert; Raybould, Rachel; Chen, Yuning; Kuzma, Amanda B.; Hiltunen, Mikko; Morgan, Taniesha; Ahmad, Shahzad; Vardarajan, Badri N.; Epelbaum, Jacques; Hoffmann, Per; Boada, Merce; Beecham, Gary W.; Garnier, Jean-Guillaume; Harold, Denise; Fitzpatrick, Annette L.; Valladares, Otto; Moutet, Marie-Laure; Gerrish, Amy; Smith, Albert V.; Qu, Liming; Bacq, Delphine; Denning, Nicola; Jian, Xueqiu; Zhao, Yi; Del Zompo, Maria; Fox, Nick C.; Choi, Seung-Hoan; Mateo, Ignacio; Hughes, Joseph T.; Adams, Hieab H.; Malamon, John; Sanchez-Garcia, Florentino; Patel, Yogen; Brody, Jennifer A.; Dombroski, Beth A.; Naranjo, Maria Candida Deniz; Daniilidou, Makrina; Eiriksdottir, Gudny; Mukherjee, Shubhabrata; Wallon, David; Uphill, James; Aspelund, Thor; Cantwell, Laura B.; Garzia, Fabienne; Galimberti, Daniela; Hofer, Edith; Butkiewicz, Mariusz; Fin, Bertrand; Scarpini, Elio; Sarnowski, Chloe; Bush, Will S.; Meslage, Stéphane; Kornhuber, Johannes; White, Charles C.; Song, Yuenjoo; Barber, Robert C.; Engelborghs, Sebastiaan; Sordon, Sabrina; Voijnovic, Dina; Adams, Perrie M.; Vandenberghe, Rik; Mayhaus, Manuel; Cupples, L. Adrienne; Albert, Marilyn S.; De Deyn, Peter P.; Gu, Wei; Himali, Jayanadra J.; Beekly, Duane; Squassina, Alessio; Hartmann, Annette M.; Orellana, Adelina; Blacker, Deborah; Rodriguez-Rodriguez, Eloy; Lovestone, Simon; Garcia, Melissa E.; Doody, Rachelle S.; Munoz-Fernadez, Carmen; Sussams, Rebecca; Lin, Honghuang; Fairchild, Thomas J.; Benito, Yolanda A.; Holmes, Clive; Karamujić-Čomić, Hata; Frosch, Matthew P.; Thonberg, Hakan; Maier, Wolfgang; Roshchupkin, Gennady; Ghetti, Bernardino; Giedraitis, Vilmantas; Kawalia, Amit; Li, Shuo; Huebinger, Ryan M.; Kilander, Lena; Moebus, Susanne; Hernández, Isabel; Kamboh, M. Ilyas; Brundin, RoseMarie; Turton, James; Yang, Qiong; Katz, Mindy J.; Concari, Letizia; Lord, Jenny; Beiser, Alexa S.; Keene, C. Dirk; Helisalmi, Seppo; Kloszewska, Iwona; Kukull, Walter A.; Koivisto, Anne Maria; Lynch, Aoibhinn; Tarraga, Lluís; Larson, Eric B.; Haapasalo, Annakaisa; Lawlor, Brian; Mosley, Thomas H.; Lipton, Richard B.; Solfrizzi, Vincenzo; Gill, Michael; Longstreth, W. T.; Montine, Thomas J.; Frisardi, Vincenza; Diez-Fairen, Monica; Rivadeneira, Fernando; Petersen, Ronald C.; Deramecourt, Vincent; Alvarez, Ignacio; Salani, Francesca; Ciaramella, Antonio; Boerwinkle, Eric; Reiman, Eric M.; Fievet, Nathalie; Rotter, Jerome I.; Reisch, Joan S.; Hanon, Olivier; Cupidi, Chiara; Andre Uitterlinden, A. G.; Royall, Donald R.; Dufouil, Carole; Maletta, Raffaele Giovanni; de Rojas, Itziar; Sano, Mary; Brice, Alexis; Cecchetti, Roberta; George-Hyslop, Peter St; Ritchie, Karen; Tsolaki, Magda; Tsuang, Debby W.; Dubois, Bruno; Craig, David; Wu, Chuang-Kuo; Soininen, Hilkka; Avramidou, Despoina; Albin, Roger L.; Fratiglioni, Laura; Germanou, Antonia; Apostolova, Liana G.; Keller, Lina; Koutroumani, Maria; Arnold, Steven E.; Panza, Francesco; Gkatzima, Olymbia; Asthana, Sanjay; Hannequin, Didier; Whitehead, Patrice; Atwood, Craig S.; Caffarra, Paolo; Hampel, Harald; Quintela, Inés; Carracedo, Ángel; Lannfelt, Lars; Rubinsztein, David C.; Barnes, Lisa L.; Pasquier, Florence; Frölich, Lutz; Barral, Sandra; McGuinness, Bernadette; Beach, Thomas G.; Johnston, Janet A.; Becker, James T.; Passmore, Peter; Bigio, Eileen H.; Schott, Jonathan M.; Bird, Thomas D.; Warren, Jason D.; Boeve, Bradley F.; Lupton, Michelle K.; Bowen, James D.; Proitsi, Petra; Boxer, Adam; Powell, John F.; Burke, James R.; Kauwe, John S. K.; Burns, Jeffrey M.; Mancuso, Michelangelo; Buxbaum, Joseph D.; Bonuccelli, Ubaldo; Cairns, Nigel J.; McQuillin, Andrew; Cao, Chuanhai; Livingston, Gill; Carlson, Chris S.; Bass, Nicholas J.; Carlsson, Cynthia M.; Hardy, John; Carney, Regina M.; Bras, Jose; Carrasquillo, Minerva M.; Guerreiro, Rita; Allen, Mariet; Chui, Helena C.; Fisher, Elizabeth; Masullo, Carlo; Crocco, Elizabeth A.; DeCarli, Charles; Bisceglio, Gina; Dick, Malcolm; Ma, Li; Duara, Ranjan; Graff-Radford, Neill R.; Evans, Denis A.; Hodges, Angela; Faber, Kelley M.; Scherer, Martin; Fallon, Kenneth B.; Riemenschneider, Matthias; Fardo, David W.; Heun, Reinhard; Farlow, Martin R.; Kölsch, Heike; Ferris, Steven; Leber, Markus; Foroud, Tatiana M.; Heuser, Isabella; Galasko, Douglas R.; Giegling, Ina; Gearing, Marla; Hüll, Michael; Geschwind, Daniel H.; Gilbert, John R.; Morris, John; Mayo, Kevin; Feulner, Thomas; Hamilton, Ronald L.; Harrell, Lindy E.; Drichel, Dmitriy; Honig, Lawrence S.; Cushion, Thomas D.; Huentelman, Matthew J.; Hollingworth, Paul; Hulette, Christine M.; Marshall, Rachel; Jarvik, Gail P.; Meggy, Alun; Abner, Erin; Menzies, Georgina E.; Jin, Lee-Way; Leonenko, Ganna; Real, Luis M.; Jun, Gyungah R.; Baldwin, Clinton T.; Grozeva, Detelina; Karydas, Anna; Russo, Giancarlo; Kaye, Jeffrey A.; Kim, Ronald; Jessen, Frank; Kowall, Neil W.; Vellas, Bruno; Kramer, Joel H.; Vardy, Emma; LaFerla, Frank M.; Jöckel, Karl-Heinz; Lah, James J.; Dichgans, Martin; Leverenz, James B.; Mann, David; Levey, Allan I.; Pickering-Brown, Stuart; Lieberman, Andrew P.; Klopp, Norman; Lunetta, Kathryn L.; Wichmann, H-Erich; Lyketsos, Constantine G.; Morgan, Kevin; Marson, Daniel C.; Brown, Kristelle; Martiniuk, Frank; Medway, Christopher; Mash, Deborah C.; Nöthen, Markus M.; Masliah, Eliezer; Hooper, Nigel M.; McCormick, Wayne C.; Daniele, Antonio; McCurry, Susan M.; Bayer, Anthony; McDavid, Andrew N.; Gallacher, John; McKee, Ann C.; van den Bussche, Hendrik; Mesulam, Marsel; Brayne, Carol; Miller, Bruce L.; Riedel-Heller, Steffi; Miller, Carol A.; Miller, Joshua W.; Al-Chalabi, Ammar; Morris, John C.; Shaw, Christopher E.; Myers, Amanda J.; Wiltfang, Jens; O’Bryant, Sid; Olichney, John M.; Alvarez, Victoria; Parisi, Joseph E.; Singleton, Andrew B.; Paulson, Henry L.; Collinge, John; Perry, William R.; Mead, Simon; Peskind, Elaine; Cribbs, David H.; Rossor, Martin; Pierce, Aimee; Ryan, Natalie S.; Poon, Wayne W.; Nacmias, Benedetta; Potter, Huntington; Sorbi, Sandro; Quinn, Joseph F.; Sacchinelli, Eleonora; Raj, Ashok; Spalletta, Gianfranco; Raskind, Murray; Caltagirone, Carlo; Bossù, Paola; Orfei, Maria Donata; Reisberg, Barry; Clarke, Robert; Reitz, Christiane; Smith, A David; Ringman, John M.; Warden, Donald; Roberson, Erik D.; Wilcock, Gordon; Rogaeva, Ekaterina; Bruni, Amalia Cecilia; Rosen, Howard J.; Gallo, Maura; Rosenberg, Roger N.; Ben-Shlomo, Yoav; Sager, Mark A.; Mecocci, Patrizia; Saykin, Andrew J.; Pastor, Pau; Cuccaro, Michael L.; Vance, Jeffery M.; Schneider, Julie A.; Schneider, Lori S.; Slifer, Susan; Seeley, William W.; Smith, Amanda G.; Sonnen, Joshua A.; Spina, Salvatore; Stern, Robert A.; Swerdlow, Russell H.; Tang, Mitchell; Trojanowski, John Q.; Troncoso, Juan C.; Van Deerlin, Vivianna M.; Van Eldik, Linda J.; Vinters, Harry V.; Vonsattel, Jean Paul; Weintraub, Sandra; Welsh-Bohmer, Kathleen A.; Wilhelmsen, Kirk C.; Williamson, Jennifer; Wingo, Thomas S.; Woltjer, Randall L.; Wright, Clinton B.; Yu, Chang-En; Yu, Lei; Saba, Yasaman; Pilotto, Alberto; Bullido, Maria J.; Peters, Oliver; Crane, Paul K.; Bennett, David; Bosco, Paola; Coto, Eliecer; Boccardi, Virginia; De Jager, Phil L.; Lleo, Alberto; Warner, Nick; Lopez, Oscar L.; Ingelsson, Martin; Deloukas, Panagiotis; Cruchaga, Carlos; Graff, Caroline; Gwilliam, Rhian; Fornage, Myriam; Goate, Alison M.; Sanchez-Juan, Pascual; Kehoe, Patrick G.; Amin, Najaf; Ertekin-Taner, Nilifur; Berr, Claudine; Debette, Stéphanie; Love, Seth; Launer, Lenore J.; Younkin, Steven G.; Dartigues, Jean-Francois; Corcoran, Chris; Ikram, M. Arfan; Dickson, Dennis W.; Nicolas, Gael; Campion, Dominique; Tschanz, JoAnn; Schmidt, Helena; Hakonarson, Hakon; Clarimon, Jordi; Munger, Ron; Schmidt, Reinhold; Farrer, Lindsay A.; Van Broeckhoven, Christine; C. O’Donovan, Michael; DeStefano, Anita L.; Jones, Lesley; Haines, Jonathan L.; Deleuze, Jean-Francois; Owen, Michael J.; Gudnason, Vilmundur; Mayeux, Richard; Escott-Price, Valentina; Psaty, Bruce M.; Ramirez, Alfredo; Wang, Li-San; Ruiz, Agustin; van Duijn, Cornelia M.; Holmans, Peter A.; Seshadri, Sudha; Williams, Julie; Amouyel, Phillippe; Schellenberg, Gerard D.; Lambert, Jean-Charles; Pericak-Vance, Margaret A.; Kunkle, Brian; Green, Robert; Growdon, John; Hyman, Bradley; Tanzi, Rudolph
    Risk for late-onset Alzheimer’s disease (LOAD), the most prevalent dementia, is partially driven by genetics. To identify LOAD risk loci, we performed the largest genome-wide association meta-analysis of clinically diagnosed LOAD to date (94,437 individuals). We confirm 20 previous LOAD risk loci and identify five new genome-wide loci (IQCK, ACE, ADAM10, ADAMTS1 and WWOX). Fine-mapping of the human leukocyte antigen (HLA) region confirms the neurological and immune-mediated disease haplotype HLA-DR15 as a risk factor for LOAD. Pathway analysis implicates immunity, lipid metabolism, tau binding proteins and APP metabolism, showing that genetic variants affecting APP and Aβ processing are not only associated with early-onset autosomal dominant Alzheimer’s disease but also with LOAD. Analysis of risk genes and pathways show enrichment for rare variants (P=1.32x10-7) indicating that additional rare variants remain to be identified. We also identify important genetic correlations between LOAD and traits such as family history of dementia and education.
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    Patterns of Anticonvulsant Use and Adverse Drug Events in Older Adults
    (Wiley, 2020-10-02) Moura, Lidia Maria; Smith, Jason R.; Yan, Zhiyu; Blacker, Deborah; Schwamm, Lee; Newhouse, Joseph; Hernandez-Diaz, Sonia; Hsu, John
    Purpose: To examine indications for, duration of use, and rate of adverse drug events (ADE) attributable to anticonvulsant initiation, as adjudicated by expert review of electronic health records (EHR) of older adults. Methods: We identified a cohort of community-dwelling Medicare beneficiaries with linked EHR (aged 65+, continuously enrolled with a large health system/until death between 2012-2014, n=20,945) and drew a stratified EHR review sample (n=1,534). An expert reviewed all records to adjudicate anticonvulsant use, years of use, indication for use, and evidence of ADEs attributable to anticonvulsant initiation. After excluding patients with insufficient EHR data (n=37; 2%), we reconstructed the cohort using inverse probability weights to resemble the original cohort of eligible beneficiaries (n=20,380). Among incident users of a single anticonvulsant, we estimated the rate of ADEs and described the type and severity of ADEs. Results: Overall, 12% (n=2,469) of eligible beneficiaries used at least one anticonvulsant in the 2012-2014 period (4% [n=757] incident users, 8% [n=1,712] prevalent users). Incident users were most frequently prescribed gabapentin (n=461/757, 61%), benzodiazepines (n=122/757, 16%), and levetiracetam (n=74/757, 10%); the most common indication was pain relief (n=214; 28%) followed by epilepsy (n=53; 7%). Among incident users, the overall ADE rate was 10/100 person-years (95% CI 4-20/100 person-years), of which 29% (n=28/97) were life-threatening (e.g., somnolence). Most ADEs among incident monotherapy users were nervous-system related (68%, n=66/97). Conclusions: Many older adult community-dwelling Traditional Medicare beneficiaries had clinically significant ADEs likely attributable to the initiation of anticonvulsant therapy, which was begun for a range of indications.
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    Impaired memory is more closely associated with brain beta-amyloid than leukoaraiosis in hypertensive patients with cognitive symptoms
    (Public Library of Science, 2018) Smith, Eric E.; Muzikansky, Alona; McCreary, Cheryl R.; Batool, Saima; Viswanathan, Anand; Dickerson, Bradford; Johnson, Keith; Greenberg, Steven; Blacker, Deborah
    Background: Hypertension is the strongest modifiable risk factor for subcortical ischemic changes and is also a risk factor for Alzheimer’s dementia. We used neuroimaging to investigate the pathological basis of early cognitive symptoms in patients with hypertension. Methods: In this cross-sectional cohort study 67 patients age >60 years with hypertension and Clinical Dementia Rating scale score of 0.5 without dementia, and without history of symptomatic stroke, underwent MRI for measurement of subcortical vascular changes and positron emission tomography (PET) scan with Pittsburgh Compound B (PiB-PET) to detect beta-amyloid deposition. These imaging measures were related to neuropsychological tests of memory, executive function and processing speed. Results: Mean age was 75.0 (standard deviation, SD, 7.3). Mean neuropsychological Z scores were: episodic memory -0.63 (SD 1.23), executive function -0.40 (SD 1.10), processing speed -0.24 (SD 0.88); 22 of the 67 subjects met criteria for mild cognitive impairment (MCI) and the remaining 45 subjects had subjective cognitive concerns only. In multivariable models adjusting for age and years of education, each 0.1 unit increase in mean cortical PiB-PET binding was associated with 0.14 lower mean Z score for episodic memory (95% CI -0.28 to -0.01). This means that for every 0.1 unit increase in mean cortical PiB-PET, episodic memory was 0.14 standard deviations lower. White matter hyperintensity volume, silent brain infarcts and microbleeds were not associated with neuropsychological test scores. Conclusions: Episodic memory was prominently affected in hypertensive participants with MCI or subjective cognitive concerns, and was associated with PiB-PET binding. This suggests a prominent role for Alzheimer pathology in cognitive impairment even in hypertensive participants at elevated risk for vascular cognitive impairment.
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    Gene-Wide Analysis Detects Two New Susceptibility Genes for Alzheimer's Disease
    (Public Library of Science, 2014) Escott-Price, Valentina; Bellenguez, Céline; Wang, Li-San; Choi, Seung-Hoan; Harold, Denise; Jones, Lesley; Holmans, Peter; Gerrish, Amy; Vedernikov, Alexey; Richards, Alexander; DeStefano, Anita L.; Lambert, Jean-Charles; Ibrahim-Verbaas, Carla A.; Naj, Adam C.; Sims, Rebecca; Jun, Gyungah; Bis, Joshua C.; Beecham, Gary W.; Grenier-Boley, Benjamin; Russo, Giancarlo; Thornton-Wells, Tricia A.; Denning, Nicola; Smith, Albert V.; Chouraki, Vincent; Thomas, Charlene; Ikram, M. Arfan; Zelenika, Diana; Vardarajan, Badri N.; Kamatani, Yoichiro; Lin, Chiao-Feng; Schmidt, Helena; Kunkle, Brian; Dunstan, Melanie L.; Vronskaya, Maria; Johnson, Andrew D.; Ruiz, Agustin; Bihoreau, Marie-Thérèse; Reitz, Christiane; Pasquier, Florence; Hollingworth, Paul; Hanon, Olivier; Fitzpatrick, Annette L.; Buxbaum, Joseph D.; Campion, Dominique; Crane, Paul K.; Baldwin, Clinton; Becker, Tim; Gudnason, Vilmundur; Cruchaga, Carlos; Craig, David; Amin, Najaf; Berr, Claudine; Lopez, Oscar L.; De Jager, Philip; Deramecourt, Vincent; Johnston, Janet A.; Evans, Denis; Lovestone, Simon; Letenneur, Luc; Hernández, Isabel; Rubinsztein, David C.; Eiriksdottir, Gudny; Sleegers, Kristel; Goate, Alison M.; Fiévet, Nathalie; Huentelman, Matthew J.; Gill, Michael; Brown, Kristelle; Kamboh, M. Ilyas; Keller, Lina; Barberger-Gateau, Pascale; McGuinness, Bernadette; Larson, Eric B.; Myers, Amanda J.; Dufouil, Carole; Todd, Stephen; Wallon, David; Love, Seth; Rogaeva, Ekaterina; Gallacher, John; George-Hyslop, Peter St; Clarimon, Jordi; Lleo, Alberto; Bayer, Anthony; Tsuang, Debby W.; Yu, Lei; Tsolaki, Magda; Bossù, Paola; Spalletta, Gianfranco; Proitsi, Petra; Collinge, John; Sorbi, Sandro; Garcia, Florentino Sanchez; Fox, Nick C.; Hardy, John; Naranjo, Maria Candida Deniz; Bosco, Paolo; Clarke, Robert; Brayne, Carol; Galimberti, Daniela; Scarpini, Elio; Bonuccelli, Ubaldo; Mancuso, Michelangelo; Siciliano, Gabriele; Moebus, Susanne; Mecocci, Patrizia; Zompo, Maria Del; Maier, Wolfgang; Hampel, Harald; Pilotto, Alberto; Frank-García, Ana; Panza, Francesco; Solfrizzi, Vincenzo; Caffarra, Paolo; Nacmias, Benedetta; Perry, William; Mayhaus, Manuel; Lannfelt, Lars; Hakonarson, Hakon; Pichler, Sabrina; Carrasquillo, Minerva M.; Ingelsson, Martin; Beekly, Duane; Alvarez, Victoria; Zou, Fanggeng; Valladares, Otto; Younkin, Steven G.; Coto, Eliecer; Hamilton-Nelson, Kara L.; Gu, Wei; Razquin, Cristina; Pastor, Pau; Mateo, Ignacio; Owen, Michael J.; Faber, Kelley M.; Jonsson, Palmi V.; Combarros, Onofre; O'Donovan, Michael C.; Cantwell, Laura B.; Soininen, Hilkka; Blacker, Deborah; Mead, Simon; Mosley, Thomas H.; Bennett, David A.; Harris, Tamara B.; Fratiglioni, Laura; Holmes, Clive; de Bruijn, Renee F. A. G.; Passmore, Peter; Montine, Thomas J.; Bettens, Karolien; Rotter, Jerome I.; Brice, Alexis; Morgan, Kevin; Foroud, Tatiana M.; Kukull, Walter A.; Hannequin, Didier; Powell, John F.; Nalls, Michael A.; Ritchie, Karen; Lunetta, Kathryn L.; Kauwe, John S. K.; Boerwinkle, Eric; Riemenschneider, Matthias; Boada, Mercè; Hiltunen, Mikko; Martin, Eden R.; Schmidt, Reinhold; Rujescu, Dan; Dartigues, Jean-François; Mayeux, Richard; Tzourio, Christophe; Hofman, Albert; Nöthen, Markus M.; Graff, Caroline; Psaty, Bruce M.; Haines, Jonathan L.; Lathrop, Mark; Pericak-Vance, Margaret A.; Launer, Lenore J.; Van Broeckhoven, Christine; Farrer, Lindsay A.; van Duijn, Cornelia M.; Ramirez, Alfredo; Seshadri, Sudha; Schellenberg, Gerard D.; Amouyel, Philippe; Williams, Julie
    Background: Alzheimer's disease is a common debilitating dementia with known heritability, for which 20 late onset susceptibility loci have been identified, but more remain to be discovered. This study sought to identify new susceptibility genes, using an alternative gene-wide analytical approach which tests for patterns of association within genes, in the powerful genome-wide association dataset of the International Genomics of Alzheimer's Project Consortium, comprising over 7 m genotypes from 25,580 Alzheimer's cases and 48,466 controls. Principal Findings In addition to earlier reported genes, we detected genome-wide significant loci on chromosomes 8 (TP53INP1, p = 1.4×10−6) and 14 (IGHV1-67 p = 7.9×10−8) which indexed novel susceptibility loci. Significance The additional genes identified in this study, have an array of functions previously implicated in Alzheimer's disease, including aspects of energy metabolism, protein degradation and the immune system and add further weight to these pathways as potential therapeutic targets in Alzheimer's disease.
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    Properties of permutation-based gene tests and controlling type 1 error using a summary statistic based gene test
    (BioMed Central, 2013) Swanson, David M; Blacker, Deborah; AlChawa, Taofik; Ludwig, Kerstin U; Mangold, Elisabeth; Lange, Christoph
    Background: The advent of genome-wide association studies has led to many novel disease-SNP associations, opening the door to focused study on their biological underpinnings. Because of the importance of analyzing these associations, numerous statistical methods have been devoted to them. However, fewer methods have attempted to associate entire genes or genomic regions with outcomes, which is potentially more useful knowledge from a biological perspective and those methods currently implemented are often permutation-based. Results: One property of some permutation-based tests is that their power varies as a function of whether significant markers are in regions of linkage disequilibrium (LD) or not, which we show from a theoretical perspective. We therefore develop two methods for quantifying the degree of association between a genomic region and outcome, both of whose power does not vary as a function of LD structure. One method uses dimension reduction to “filter” redundant information when significant LD exists in the region, while the other, called the summary-statistic test, controls for LD by scaling marker Z-statistics using knowledge of the correlation matrix of markers. An advantage of this latter test is that it does not require the original data, but only their Z-statistics from univariate regressions and an estimate of the correlation structure of markers, and we show how to modify the test to protect the type 1 error rate when the correlation structure of markers is misspecified. We apply these methods to sequence data of oral cleft and compare our results to previously proposed gene tests, in particular permutation-based ones. We evaluate the versatility of the modification of the summary-statistic test since the specification of correlation structure between markers can be inaccurate. Conclusion: We find a significant association in the sequence data between the 8q24 region and oral cleft using our dimension reduction approach and a borderline significant association using the summary-statistic based approach. We also implement the summary-statistic test using Z-statistics from an already-published GWAS of Chronic Obstructive Pulmonary Disorder (COPD) and correlation structure obtained from HapMap. We experiment with the modification of this test because the correlation structure is assumed imperfectly known.
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    Common genetic variants in the CLDN2 and PRSS1-PRSS2 loci alter risk for alcohol-related and sporadic pancreatitis
    (2012) Whitcomb, David C.; LaRusch, Jessica; Krasinskas, Alyssa M.; Klei, Lambertus; Smith, Jill P.; Brand, Randall E.; Neoptolemos, John P.; Lerch, Markus M.; Tector, Matt; Sandhu, Bimaljit S.; Guda, Nalini M.; Orlichenko, Lidiya; Alkaade, Samer; Amann, Stephen T.; Anderson, Michelle A.; Baillie, John; Banks, Peter A.; Conwell, Darwin; Coté, Gregory A.; Cotton, Peter B.; DiSario, James; Farrer, Lindsay A.; Forsmark, Chris E.; Johnstone, Marianne; Gardner, Timothy B.; Gelrud, Andres; Greenhalf, William; Haines, Jonathan L.; Hartman, Douglas J.; Hawes, Robert A.; Lawrence, Christopher; Lewis, Michele; Mayerle, Julia; Mayeux, Richard; Melhem, Nadine M.; Money, Mary E.; Muniraj, Thiruvengadam; Papachristou, Georgios I.; Pericak-Vance, Margaret A.; Romagnuolo, Joseph; Schellenberg, Gerard D.; Sherman, Stuart; Simon, Peter; Singh, Vijay K.; Slivka, Adam; Stolz, Donna; Sutton, Robert; Weiss, Frank Ulrich; Wilcox, C. Mel; Zarnescu, Narcis Octavian; Wisniewski, Stephen R.; O'Connell, Michael R.; Kienholz, Michelle L.; Roeder, Kathryn; Barmada, M. Michael; Yadav, Dhiraj; Devlin, Bernie; Albert, Marilyn S.; Albin, Roger L.; Apostolova, Liana G.; Arnold, Steven E.; Baldwin, Clinton T.; Barber, Robert; Barnes, Lisa L.; Beach, Thomas G.; Beecham, Gary W.; Beekly, Duane; Bennett, David A.; Bigio, Eileen H.; Bird, Thomas D.; Blacker, Deborah; Boxer, Adam; Burke, James R.; Buxbaum, Joseph D.; Cairns, Nigel J.; Cantwell, Laura B.; Cao, Chuanhai; Carney, Regina M.; Carroll, Steven L.; Chui, Helena C.; Clark, David G.; Cribbs, David H.; Crocco, Elizabeth A.; Cruchaga, Carlos; DeCarli, Charles; Demirci, F. Yesim; Dick, Malcolm; Dickson, Dennis W.; Duara, Ranjan; Ertekin-Taner, Nilufer; Faber, Kelley M.; Fallon, Kenneth B.; Farlow, Martin R.; Ferris, Steven; Foroud, Tatiana M.; Frosch, Matthew; Galasko, Douglas R.; Ganguli, Mary; Gearing, Marla; Geschwind, Daniel H.; Ghetti, Bernardino; Gilbert, John R.; Gilman, Sid; Glass, Jonathan D.; Goate, Alison M.; Graff-Radford, Neill R.; Green, Robert; Growdon, John; Hakonarson, Hakon; Hamilton-Nelson, Kara L.; Hamilton, Ronald L.; Harrell, Lindy E.; Head, Elizabeth; Honig, Lawrence S.; Hulette, Christine M.; Hyman, Bradley; Jicha, Gregory A.; Jin, Lee-Way; Jun, Gyungah; Kamboh, M. Ilyas; Karydas, Anna; Kaye, Jeffrey A.; Kim, Ronald; Koo, Edward H.; Kowall, Neil W.; Kramer, Joel H.; Kramer, Patricia; Kukull, Walter A.; LaFerla, Frank M.; Lah, James J.; Leverenz, James B.; Levey, Allan I.; Li, Ge; Lin, Chiao-Feng; Lieberman, Andrew P.; Lopez, Oscar L.; Lunetta, Kathryn L.; Lyketsos, Constantine G.; Mack, Wendy J.; Marson, Daniel C.; Martin, Eden R.; Martiniuk, Frank; Mash, Deborah C.; Masliah, Eliezer; McKee, Ann C.; Mesulam, Marsel; Miller, Bruce L.; Miller, Carol A.; Miller, Joshua W.; Montine, Thomas J.; Morris, John C.; Murrell, Jill R.; Naj, Adam C.; Olichney, John M.; Parisi, Joseph E.; Peskind, Elaine; Petersen, Ronald C.; Pierce, Aimee; Poon, Wayne W.; Potter, Huntington; Quinn, Joseph F.; Raj, Ashok; Raskind, Murray; Reiman, Eric M.; Reisberg, Barry; Reitz, Christiane; Ringman, John M.; Roberson, Erik D.; Rosen, Howard J.; Rosenberg, Roger N.; Sano, Mary; Saykin, Andrew J.; Schneider, Julie A.; Schneider, Lon S.; Seeley, William W.; Smith, Amanda G.; Sonnen, Joshua A.; Spina, Salvatore; Stern, Robert A.; Tanzi, Rudolph; Trojanowski, John Q.; Troncoso, Juan C.; Tsuang, Debby W.; Valladares, Otto; Van Deerlin, Vivianna M.; Van Eldik, Linda J.; Vardarajan, Badri N.; Vinters, Harry V.; Vonsattel, Jean Paul; Wang, Li-San; Weintraub, Sandra; Welsh-Bohmer, Kathleen A.; Williamson, Jennifer; Woltjer, Randall L.; Wright, Clinton B.; Younkin, Steven G.; Yu, Chang-En; Yu, Lei
    Pancreatitis is a complex, progressively destructive inflammatory disorder. Alcohol was long thought to be the primary causative agent, but genetic contributions have been of interest since the discovery that rare PRSS1, CFTR, and SPINK1 variants were associated with pancreatitis risk. We now report two significant genome-wide associations identified and replicated at PRSS1-PRSS2 (1×10-12) and x-linked CLDN2 (p < 1×10-21) through a two-stage genome-wide study (Stage 1, 676 cases and 4507 controls; Stage 2, 910 cases and 4170 controls). The PRSS1 variant affects susceptibility by altering expression of the primary trypsinogen gene. The CLDN2 risk allele is associated with atypical localization of claudin-2 in pancreatic acinar cells. The homozygous (or hemizygous male) CLDN2 genotype confers the greatest risk, and its alleles interact with alcohol consumption to amplify risk. These results could partially explain the high frequency of alcohol-related pancreatitis in men – male hemizygous frequency is 0.26, female homozygote is 0.07.
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    Quantifying the Role of Adverse Events in the Mortality Difference between First and Second-Generation Antipsychotics in Older Adults: Systematic Review and Meta-Synthesis
    (Public Library of Science, 2014) Jackson, John; Schneeweiss, Sebastian; VanderWeele, Tyler; Blacker, Deborah
    Background: Observational studies have reported higher mortality among older adults treated with first-generation antipsychotics (FGAs) versus second-generation antipsychotics (SGAs). A few studies examined risk for medical events, including stroke, ventricular arrhythmia, venous thromboembolism, myocardial infarction, pneumonia, and hip fracture. Objectives: 1) Review robust epidemiologic evidence comparing mortality and medical event risk between FGAs and SGAs in older adults; 2) Quantify how much these medical events explain the observed mortality difference between FGAs and SGAs. Data sources Pubmed and Science Citation Index. Study eligibility criteria, participants, and interventions Studies of antipsychotic users that: 1) evaluated mortality or medical events specified above; 2) restricted to populations with a mean age of 65 years or older 3) compared FGAs to SGAs, or both to a non-user group; (4) employed a “new user” design; (5) adjusted for confounders assessed prior to antipsychotic initiation; (6) and did not require survival after antipsychotic initiation. A separate search was performed for mortality estimates associated with the specified medical events. Study appraisal and synthesis methods For each medical event, we used a non-parametric model to estimate lower and upper bounds for the proportion of the mortality difference—comparing FGAs to SGAs—mediated by their difference in risk for the medical event. Results: We provide a brief, updated summary of the included studies and the biological plausibility of these mechanisms. Of the 1122 unique citations retrieved, we reviewed 20 observational cohort studies that reported 28 associations. We identified hip fracture, stroke, myocardial infarction, and ventricular arrhythmias as potential intermediaries on the causal pathway from antipsychotic type to death. However, these events did not appear to explain the entire mortality difference. Conclusions: The current literature suggests that hip fracture, stroke, myocardial infarction, and ventricular arrhythmias partially explain the mortality difference between SGAs and FGAs.
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    APOE-related risk of mild cognitive impairment and dementia for prevention trials: An analysis of four cohorts
    (Public Library of Science, 2017) Qian, Jing; Wolters, Frank J.; Beiser, Alexa; Haan, Mary; Ikram, M. Arfan; Karlawish, Jason; Langbaum, Jessica B.; Neuhaus, John M.; Reiman, Eric M.; Roberts, J. Scott; Seshadri, Sudha; Tariot, Pierre N.; Woods, Beth McCarty; Betensky, Rebecca; Blacker, Deborah
    Background: With the onset of prevention trials for individuals at high risk for Alzheimer disease, there is increasing need for accurate risk prediction to inform study design and enrollment, but available risk estimates are limited. We developed risk estimates for the incidence of mild cognitive impairment (MCI) or dementia among cognitively unimpaired individuals by APOE-e4 dose for the genetic disclosure process of the Alzheimer’s Prevention Initiative Generation Study, a prevention trial in cognitively unimpaired APOE-e4/e4 homozygote individuals. Methods and findings We included cognitively unimpaired individuals aged 60–75 y, consistent with Generation Study eligibility criteria, from the National Alzheimer’s Coordinating Center (NACC) (n = 5,073, 158 APOE-e4/e4), the Rotterdam Study (n = 6,399, 156 APOE-e4/e4), the Framingham Heart Study (n = 4,078, 67 APOE-e4/e4), and the Sacramento Area Latino Study on Aging (SALSA) (n = 1,294, 11 APOE-e4/e4). We computed stratified cumulative incidence curves by age (60–64, 65–69, 70–75 y) and APOE-e4 dose, adjusting for the competing risk of mortality, and determined risk of MCI and/or dementia by genotype and baseline age. We also used subdistribution hazard regression to model relative hazard based on age, APOE genotype, sex, education, family history of dementia, vascular risk, subjective memory concerns, and baseline cognitive performance. The four cohorts varied considerably in age, education, ethnicity/race, and APOE-e4 allele frequency. Overall, cumulative incidence was uniformly higher in NACC than in the population-based cohorts. Among APOE-e4/e4 individuals, 5-y cumulative incidence was as follows: in the 60–64-y age stratum, it ranged from 0% to 5.88% in the three population-based cohorts versus 23.06% in NACC; in the 65–69-y age stratum, from 9.42% to 10.39% versus 34.62%; and in the 70–75-y age stratum, from 18.64% to 33.33% versus 38.34%. Five-year incidence of dementia was negligible except for APOE-e4/e4 individuals and those over 70 y. Lifetime incidence (to age 80–85 y) of MCI or dementia for the APOE-e4/e4 individuals in the long-term Framingham and Rotterdam cohorts was 34.69%–38.45% at age 60–64 y, 30.76%–40.26% at 65–69 y, and 33.3%–35.17% at 70–75 y. Confidence limits for these estimates are often wide, particularly for APOE-e4/e4 individuals and for the dementia outcome at 5 y. In regression models, APOE-e4 dose and age both consistently increased risk, as did lower education, subjective memory concerns, poorer baseline cognitive performance, and family history of dementia. We discuss several limitations of the study, including the small numbers of APOE-e4/e4 individuals, missing data and differential dropout, limited ethnic and racial diversity, and differences in definitions of exposure and outcome variables. Conclusions: Estimates of the absolute risk of MCI or dementia, particularly over short time intervals, are sensitive to sampling and a variety of methodological factors. Nonetheless, such estimates were fairly consistent across the population-based cohorts, and lower than those from a convenience cohort and those estimated in prior studies—with implications for informed consent and design for clinical trials targeting high-risk individuals.
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    A QTL Genome Scan of the Metabolic Syndrome and its Component Traits
    (BioMed Central, 2003) McQueen, Matthew B; Bertram, Lars; Rimm, Eric; Blacker, Deborah; Santangelo, Susan L.
    Background: Because high blood pressure, altered lipid levels, obesity, and diabetes so frequently occur together, they are sometimes collectively referred to as the metabolic syndrome. While there have been many studies of each metabolic syndrome trait separately, few studies have attempted to analyze them combined, i.e., as one composite variable, in quantitative trait linkage or association analysis. We used genotype and phenotype data from the Framingham Heart Study to perform a full-genome scan for quantitative trait loci underlying the metabolic syndrome. Results: Heritability estimates for all of the covariate-adjusted and age- and gender-standardized individual traits, and the composite metabolic syndrome trait, were all fairly high (0.39–0.62), and the composite trait was among the highest at 0.61. The composite trait yielded no regions with suggestive linkage by Lander and Kruglyak's criteria, although there were several noteworthy regions for individual traits, some of which were also observed for the composite variable. Conclusion: Despite its high heritability, the composite metabolic syndrome trait variable did not increase the power to detect or localize linkage peaks in this sample. However, this strategy and related methods of combining correlated individual traits deserve further investigation, particularly in settings with complex causal pathways.