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Evaluation of memory endophenotypes for association with CLU, CR1, and PICALM variants in black and white subjects.
Alzheimers Dement
PUBLISHED: 11-18-2014
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Genetic variants at the CLU, CR1, and PICALM loci associate with risk for late-onset Alzheimer's disease (LOAD) in genomewide association studies. In this study, our aim was to determine whether the LOAD risk variants at these three loci influence memory endophenotypes in black and white subjects.
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Effects of multiple genetic Loci on age at onset in late-onset Alzheimer disease: a genome-wide association study.
Adam C Naj, Gyungah Jun, Christiane Reitz, Brian W Kunkle, William Perry, Yo Son Park, Gary W Beecham, Ruchita A Rajbhandary, Kara L Hamilton-Nelson, Li-San Wang, John S K Kauwe, Matthew J Huentelman, Amanda J Myers, Thomas D Bird, Bradley F Boeve, Clinton T Baldwin, Gail P Jarvik, Paul K Crane, Ekaterina Rogaeva, M Michael Barmada, F Yesim Demirci, Carlos Cruchaga, Patricia L Kramer, Nilüfer Ertekin-Taner, John Hardy, Neill R Graff-Radford, Robert C Green, Eric B Larson, Peter H St George-Hyslop, Joseph D Buxbaum, Denis A Evans, Julie A Schneider, Kathryn L Lunetta, M Ilyas Kamboh, Andrew J Saykin, Eric M Reiman, Philip L De Jager, David A Bennett, John C Morris, Thomas J Montine, Alison M Goate, Deborah Blacker, Debby W Tsuang, Hakon Hakonarson, Walter A Kukull, Tatiana M Foroud, Eden R Martin, Jonathan L Haines, Richard P Mayeux, Lindsay A Farrer, Gerard D Schellenberg, Margaret A Pericak-Vance, , Marilyn S Albert, Roger L Albin, Liana G Apostolova, Steven E Arnold, Robert Barber, Lisa L Barnes, Thomas G Beach, James T Becker, Duane Beekly, Eileen H Bigio, James D Bowen, Adam Boxer, James R Burke, Nigel J Cairns, Laura B Cantwell, Chuanhai Cao, Chris S Carlson, Regina M Carney, Minerva M Carrasquillo, Steven L Carroll, Helena C Chui, David G Clark, Jason Corneveaux, David H Cribbs, Elizabeth A Crocco, Charles DeCarli, Steven T DeKosky, Malcolm Dick, Dennis W Dickson, Ranjan Duara, Kelley M Faber, Kenneth B Fallon, Martin R Farlow, Steven Ferris, Matthew P Frosch, Douglas R Galasko, Mary Ganguli, Marla Gearing, Daniel H Geschwind, Bernardino Ghetti, John R Gilbert, Jonathan D Glass, John H Growdon, Ronald L Hamilton, Lindy E Harrell, Elizabeth Head, Lawrence S Honig, Christine M Hulette, Bradley T Hyman, Gregory A Jicha, Lee-Way Jin, Anna Karydas, Jeffrey A Kaye, Ronald Kim, Edward H Koo, Neil W Kowall, Joel H Kramer, Frank M Laferla, James J Lah, James B Leverenz, Allan I Levey, Ge Li, Andrew P Lieberman, Chiao-Feng Lin, Oscar L Lopez, Constantine G Lyketsos, Wendy J Mack, Frank Martiniuk, Deborah C Mash, Eliezer Masliah, Wayne C McCormick, Susan M McCurry, Andrew N McDavid, Ann C McKee, Marsel Mesulam, Bruce L Miller, Carol A Miller, Joshua W Miller, Jill R Murrell, John M Olichney, Vernon S Pankratz, Joseph E Parisi, Henry L Paulson, Elaine Peskind, Ronald C Petersen, Aimee Pierce, Wayne W Poon, Huntington Potter, Joseph F Quinn, Ashok Raj, Murray Raskind, Barry Reisberg, John M Ringman, Erik D Roberson, Howard J Rosen, Roger N Rosenberg, Mary Sano, Lon S Schneider, William W Seeley, Amanda G Smith, Joshua A Sonnen, Salvatore Spina, Robert A Stern, Rudolph E Tanzi, Tricia A Thornton-Wells, John Q Trojanowski, Juan C Troncoso, Otto Valladares, Vivianna M Van Deerlin, Linda J Van Eldik, Badri N Vardarajan, Harry V Vinters, Jean Paul Vonsattel, Sandra Weintraub, Kathleen A Welsh-Bohmer, Jennifer Williamson, Sarah Wishnek, Randall L Woltjer, Clinton B Wright, Steven G Younkin, Chang-En Yu, Lei Yu.
JAMA Neurol
PUBLISHED: 09-10-2014
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Because APOE locus variants contribute to risk of late-onset Alzheimer disease (LOAD) and to differences in age at onset (AAO), it is important to know whether other established LOAD risk loci also affect AAO in affected participants.
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Late-onset Alzheimer's risk variants in memory decline, incident mild cognitive impairment, and Alzheimer's disease.
Neurobiol. Aging
PUBLISHED: 08-04-2014
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We tested association of nine late-onset Alzheimer's disease (LOAD) risk variants from genome-wide association studies (GWAS) with memory and progression to mild cognitive impairment (MCI) or LOAD (MCI/LOAD) in older Caucasians, cognitively normal at baseline and longitudinally evaluated at Mayo Clinic Rochester and Jacksonville (n>2000). Each variant was tested both individually and collectively using a weighted risk score. APOE-e4 associated with worse baseline memory and increased decline with highly significant overall effect on memory. CLU-rs11136000-G associated with worse baseline memory and incident MCI/LOAD. MS4A6A-rs610932-C associated with increased incident MCI/LOAD and suggestively with lower baseline memory. ABCA7-rs3764650-C and EPHA1-rs11767557-A associated with increased rates of memory decline in subjects with a final diagnosis of MCI/LOAD. PICALM-rs3851179-G had an unexpected protective effect on incident MCI/LOAD. Only APOE-inclusive risk scores associated with worse memory and incident MCI/LOAD. The collective influence of the nine top LOAD GWAS variants on memory decline and progression to MCI/LOAD appears limited. Discovery of biologically functional variants at these loci may uncover stronger effects on memory and incident disease.
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Genome-wide association interaction analysis for Alzheimer's disease.
Neurobiol. Aging
PUBLISHED: 05-19-2014
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We propose a minimal protocol for exhaustive genome-wide association interaction analysis that involves screening for epistasis over large-scale genomic data combining strengths of different methods and statistical tools. The different steps of this protocol are illustrated on a real-life data application for Alzheimer's disease (AD) (2259 patients and 6017 controls from France). Particularly, in the exhaustive genome-wide epistasis screening we identified AD-associated interacting SNPs-pair from chromosome 6q11.1 (rs6455128, the KHDRBS2 gene) and 13q12.11 (rs7989332, the CRYL1 gene) (p = 0.006, corrected for multiple testing). A replication analysis in the independent AD cohort from Germany (555 patients and 824 controls) confirmed the discovered epistasis signal (p = 0.036). This signal was also supported by a meta-analysis approach in 5 independent AD cohorts that was applied in the context of epistasis for the first time. Transcriptome analysis revealed negative correlation between expression levels of KHDRBS2 and CRYL1 in both the temporal cortex (? = -0.19, p = 0.0006) and cerebellum (? = -0.23, p < 0.0001) brain regions. This is the first time a replicable epistasis associated with AD was identified using a hypothesis free screening approach.
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Differential clinicopathologic and genetic features of late-onset amnestic dementias.
Acta Neuropathol.
PUBLISHED: 05-12-2014
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Hippocampal sclerosis of the elderly (HpScl) and Alzheimer's disease (AD), especially the limbic-predominant subtype (LP-AD), are amnestic syndromes that can be difficult to distinguish. To complicate matters, a subset has concomitant HpScl and AD (HpScl-AD). We examined a large cohort of autopsy-confirmed cases of HpScl, HpScl-AD, LP-AD, and typical AD to identify distinct clinical, genetic, and pathologic characteristics. HpScl cases were significantly older at death and had a substantially slower rate of cognitive decline than the AD subtypes. Genetic analysis revealed that the AD groups (AD, LP-AD, and HpScl-AD) were more likely to be APOE ?4 carriers. In contrast, the HpScl groups (HpScl and HpScl-AD) were more likely to exhibit genetic variants in GRN and TMEM106B that are associated with frontotemporal lobar degeneration. The HpScl groups had a high frequency of TDP-43 pathology that was most often Type A morphology and distribution, while typical AD and LP-AD had a significantly lower frequency of TDP-43 pathology that was most often Type B. These results suggest that HpScl and AD are pathologically and genetically distinct and non-synergistic neurodegenerative processes that present with amnestic dementia. Pure HpScl and HpScl with concomitant AD occur most often in elderly individuals.
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Late-onset Alzheimer disease genetic variants in posterior cortical atrophy and posterior AD.
Neurology
PUBLISHED: 03-26-2014
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To investigate association of genetic risk factors for late-onset Alzheimer disease (LOAD) with risk of posterior cortical atrophy (PCA), a syndrome of visual impairment with predominant Alzheimer disease (AD) pathology in posterior cortical regions, and with risk of "posterior AD" neuropathology.
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ApoE variant p.V236E is associated with markedly reduced risk of Alzheimer's disease.
Mol Neurodegener
PUBLISHED: 02-21-2014
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Recent genome-wide association studies (GWAS) of late-onset Alzheimer's disease (LOAD) have identified single nucleotide polymorphisms (SNPs) which show significant association at the well-known APOE locus and at nineteen additional loci. Among the functional, disease-associated variants at these loci, missense variants are particularly important because they can be readily investigated in model systems to search for novel therapeutic targets. It is now possible to perform a low-cost search for these "actionable" variants by genotyping the missense variants at known LOAD loci already cataloged on the Exome Variant Server (EVS). In this proof-of-principle study designed to explore the efficacy of this approach, we analyzed three rare EVS variants in APOE, p.L28P, p.R145C and p.V236E, in our case control series of 9114 subjects. p.R145C proved to be too rare to analyze effectively. The minor allele of p.L28P, which was in complete linkage disequilibrium (D' = 1) with the far more common APOE ?4 allele, showed no association with LOAD (P = 0.75) independent of the APOE ?4 allele. p.V236E was significantly associated with a marked reduction in risk of LOAD (P = 7.5 × 10???; OR = 0.10, 0.03 to 0.45). The minor allele of p.V236E, which was in complete linkage disequilibrium (D' = 1) with the common APOE ?3 allele, identifies a novel LOAD-associated haplotype (APOE ?3b) which is associated with decreased risk of LOAD independent of the more abundant APOE ?2, ?3 and ?4 haplotypes. Follow-up studies will be important to confirm the significance of this association and to better define its odds ratio. The ApoE p.V236E substitution is the first disease-associated change located in the lipid-binding, C-terminal domain of the protein. Thus our study (i) identifies a novel APOE missense variant which may profitably be studied to better understand how ApoE function may be modified to reduce risk of LOAD and (ii) indicates that analysis of protein-altering variants cataloged on the EVS can be a cost-effective way to identify actionable functional variants at recently discovered LOAD loci.
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Association of MAPT haplotypes with Alzheimer's disease risk and MAPT brain gene expression levels.
Alzheimers Res Ther
PUBLISHED: 01-01-2014
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MAPT encodes for tau, the predominant component of neurofibrillary tangles that are neuropathological hallmarks of Alzheimer's disease (AD). Genetic association of MAPT variants with late-onset AD (LOAD) risk has been inconsistent, although insufficient power and incomplete assessment of MAPT haplotypes may account for this.
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Gene-wide analysis detects two new susceptibility genes for Alzheimer's disease.
Valentina Escott-Price, Celine Bellenguez, Li-San Wang, Seung-Hoan Choi, Denise Harold, Lesley Jones, Peter Holmans, Amy Gerrish, Alexey Vedernikov, Alexander Richards, Anita L Destefano, Jean-Charles Lambert, Carla A Ibrahim-Verbaas, Adam C Naj, Rebecca Sims, Gyungah Jun, Joshua C Bis, Gary W Beecham, Benjamin Grenier-Boley, Giancarlo Russo, Tricia A Thornton-Wells, Nicola Denning, Albert V Smith, Vincent Chouraki, Charlene Thomas, M Arfan Ikram, Diana Zelenika, Badri N Vardarajan, Yoichiro Kamatani, Chiao-Feng Lin, Helena Schmidt, Brian Kunkle, Melanie L Dunstan, Maria Vronskaya, , Andrew D Johnson, Agustin Ruíz, Marie-Therese Bihoreau, Christiane Reitz, Florence Pasquier, Paul Hollingworth, Olivier Hanon, Annette L Fitzpatrick, Joseph D Buxbaum, Dominique Campion, Paul K Crane, Clinton Baldwin, Tim Becker, Vilmundur Gudnason, Carlos Cruchaga, David Craig, Najaf Amin, Claudine Berr, Oscar L Lopez, Philip L De Jager, Vincent Deramecourt, Janet A Johnston, Denis Evans, Simon Lovestone, Luc Letenneur, Isabel Hernández, David C Rubinsztein, Gudny Eiriksdottir, Kristel Sleegers, Alison M Goate, Nathalie Fiévet, Matthew J Huentelman, Michael Gill, Kristelle Brown, M Ilyas Kamboh, Lina Keller, Pascale Barberger-Gateau, Bernadette McGuinness, Eric B Larson, Amanda J Myers, Carole Dufouil, Stephen Todd, David Wallon, Seth Love, Ekaterina Rogaeva, John Gallacher, Peter St George-Hyslop, Jordi Clarimón, Alberto Lleó, Anthony Bayer, Debby W Tsuang, Lei Yu, Magda Tsolaki, Paola Bossù, Gianfranco Spalletta, Petra Proitsi, John Collinge, Sandro Sorbi, Florentino Sanchez Garcia, Nick C Fox, John Hardy, Maria Candida Deniz Naranjo, Paolo Bosco, Robert Clarke, Carol Brayne, Daniela Galimberti, Elio Scarpini, Ubaldo Bonuccelli, Michelangelo Mancuso, Gabriele Siciliano, Susanne Moebus, Patrizia Mecocci, Maria Del Zompo, Wolfgang Maier, Harald Hampel, Alberto Pilotto, Ana Frank-García, Francesco Panza, Vincenzo Solfrizzi, Paolo Caffarra, Benedetta Nacmias, William Perry, Manuel Mayhaus, Lars Lannfelt, Hakon Hakonarson, Sabrina Pichler, Minerva M Carrasquillo, Martin Ingelsson, Duane Beekly, Victoria Alvarez, Fanggeng Zou, Otto Valladares, Steven G Younkin, Eliecer Coto, Kara L Hamilton-Nelson, Wei Gu, Cristina Razquin, Pau Pastor, Ignacio Mateo, Michael J Owen, Kelley M Faber, Palmi V Jonsson, Onofre Combarros, Michael C O'Donovan, Laura B Cantwell, Hilkka Soininen, Deborah Blacker, Simon Mead, Thomas H Mosley, David A Bennett, Tamara B Harris, Laura Fratiglioni, Clive Holmes, Renée F A G de Bruijn, Peter Passmore, Thomas J Montine, Karolien Bettens, Jerome I Rotter, Alexis Brice, Kevin Morgan, Tatiana M Foroud, Walter A Kukull, Didier Hannequin, John F Powell, Michael A Nalls, Karen Ritchie, Kathryn L Lunetta, John S K Kauwe, Eric Boerwinkle, Matthias Riemenschneider, Mercè Boada, Mikko Hiltunen, Eden R Martin, Reinhold Schmidt, Dan Rujescu, Jean-Francois Dartigues, Richard Mayeux, Christophe Tzourio, Albert Hofman, Markus M Nöthen, Caroline Graff, Bruce M Psaty, Jonathan L Haines, Mark Lathrop, Margaret A Pericak-Vance, Lenore J Launer, Christine Van Broeckhoven, Lindsay A Farrer, Cornelia M van Duijn, Alfredo Ramírez, Sudha Seshadri, Gerard D Schellenberg, Philippe Amouyel, Julie Williams.
PLoS ONE
PUBLISHED: 01-01-2014
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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.
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LRRTM3 interacts with APP and BACE1 and has variants associating with late-onset Alzheimers disease (LOAD).
PLoS ONE
PUBLISHED: 01-01-2013
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Leucine rich repeat transmembrane protein 3 (LRRTM3) is member of a synaptic protein family. LRRTM3 is a nested gene within ?-T catenin (CTNNA3) and resides at the linkage peak for late-onset Alzheimers disease (LOAD) risk and plasma amyloid ? (A?) levels. In-vitro knock-down of LRRTM3 was previously shown to decrease secreted A?, although the mechanism of this is unclear. In SH-SY5Y cells overexpressing APP and transiently transfected with LRRTM3 alone or with BACE1, we showed that LRRTM3 co-localizes with both APP and BACE1 in early endosomes, where BACE1 processing of APP occurs. Additionally, LRRTM3 co-localizes with APP in primary neuronal cultures from Tg2576 mice transduced with LRRTM3-expressing adeno-associated virus. Moreover, LRRTM3 co-immunoprecipitates with both endogenous APP and overexpressed BACE1, in HEK293T cells transfected with LRRTM3. SH-SY5Y cells with knock-down of LRRTM3 had lower BACE1 and higher CTNNA3 mRNA levels, but no change in APP. Brain mRNA levels of LRRTM3 showed significant correlations with BACE1, CTNNA3 and APP in ?400 humans, but not in LRRTM3 knock-out mice. Finally, we assessed 69 single nucleotide polymorphisms (SNPs) within and flanking LRRTM3 in 1,567 LOADs and 2,082 controls and identified 8 SNPs within a linkage disequilibrium block encompassing 5UTR-Intron 1 of LRRTM3 that formed multilocus genotypes (MLG) with suggestive global association with LOAD risk (p?=?0.06), and significant individual MLGs. These 8 SNPs were genotyped in an independent series (1,258 LOADs and 718 controls) and had significant global and individual MLG associations in the combined dataset (p?=?0.02-0.05). Collectively, these results suggest that protein interactions between LRRTM3, APP and BACE1, as well as complex associations between mRNA levels of LRRTM3, CTNNA3, APP and BACE1 in humans might influence APP metabolism and ultimately risk of AD.
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Linking protective GAB2 variants, increased cortical GAB2 expression and decreased Alzheimers disease pathology.
PLoS ONE
PUBLISHED: 01-01-2013
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GRB-associated binding protein 2 (GAB2) represents a compelling genome-wide association signal for late-onset Alzheimers disease (LOAD) with reported odds ratios (ORs) ranging from 0.75-0.85. We tested eight GAB2 variants in four North American Caucasian case-control series (2,316 LOAD, 2,538 controls) for association with LOAD. Meta-analyses revealed ORs ranging from (0.61-1.20) with no significant association (all p>0.32). Four variants were hetergeneous across the populations (all p<0.02) due to a potentially inflated effect size (OR?=?0.61-0.66) only observed in the smallest series (702 LOAD, 209 controls). Despite the lack of association in our series, the previously reported protective association for GAB2 remained after meta-analyses of our data with all available previously published series (11,952-22,253 samples; OR?=?0.82-0.88; all p<0.04). Using a freely available database of lymphoblastoid cell lines we found that protective GAB2 variants were associated with increased GAB2 expression (p?=?9.5×10(-7)-9.3×10(-6)). We next measured GAB2 mRNA levels in 249 brains and found that decreased neurofibrillary tangle (r?=?-0.34, p?=?0.0006) and senile plaque counts (r?=?-0.32, p?=?0.001) were both good predictors of increased GAB2 mRNA levels albeit that sex (r?=?-0.28, p?=?0.005) may have been a contributing factor. In summary, we hypothesise that GAB2 variants that are protective against LOAD in some populations may act functionally to increase GAB2 mRNA levels (in lymphoblastoid cells) and that increased GAB2 mRNA levels are associated with significantly decreased LOAD pathology. These findings support the hypothesis that Gab2 may protect neurons against LOAD but due to significant population heterogeneity, it is still unclear whether this protection is detectable at the genetic level.
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Replication of EPHA1 and CD33 associations with late-onset Alzheimers disease: a multi-centre case-control study.
Mol Neurodegener
PUBLISHED: 05-26-2011
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A recently published genome-wide association study (GWAS) of late-onset Alzheimers disease (LOAD) revealed genome-wide significant association of variants in or near MS4A4A, CD2AP, EPHA1 and CD33. Meta-analyses of this and a previously published GWAS revealed significant association at ABCA7 and MS4A, independent evidence for association of CD2AP, CD33 and EPHA1 and an opposing yet significant association of a variant near ARID5B. In this study, we genotyped five variants (in or near CD2AP, EPHA1, ARID5B, and CD33) in a large (2,634 LOAD, 4,201 controls), independent dataset comprising six case-control series from the USA and Europe. We performed meta-analyses of the association of these variants with LOAD and tested for association using logistic regression adjusted by age-at-diagnosis, gender, and APOE ?4 dosage.
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Ataxin-2 repeat-length variation and neurodegeneration.
Hum. Mol. Genet.
PUBLISHED: 05-24-2011
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Expanded glutamine repeats of the ataxin-2 (ATXN2) protein cause spinocerebellar ataxia type 2 (SCA2), a rare neurodegenerative disorder. More recent studies have suggested that expanded ATXN2 repeats are a genetic risk factor for amyotrophic lateral sclerosis (ALS) via an RNA-dependent interaction with TDP-43. Given the phenotypic diversity observed in SCA2 patients, we set out to determine the polymorphic nature of the ATXN2 repeat length across a spectrum of neurodegenerative disorders. In this study, we genotyped the ATXN2 repeat in 3919 neurodegenerative disease patients and 4877 healthy controls and performed logistic regression analysis to determine the association of repeat length with the risk of disease. We confirmed the presence of a significantly higher number of expanded ATXN2 repeat carriers in ALS patients compared with healthy controls (OR = 5.57; P= 0.001; repeat length >30 units). Furthermore, we observed significant association of expanded ATXN2 repeats with the development of progressive supranuclear palsy (OR = 5.83; P= 0.004; repeat length >30 units). Although expanded repeat carriers were also identified in frontotemporal lobar degeneration, Alzheimers and Parkinsons disease patients, these were not significantly more frequent than in controls. Of note, our study identified a number of healthy control individuals who harbor expanded repeat alleles (31-33 units), which suggests caution should be taken when attributing specific disease phenotypes to these repeat lengths. In conclusion, our findings confirm the role of ATXN2 as an important risk factor for ALS and support the hypothesis that expanded ATXN2 repeats may predispose to other neurodegenerative diseases, including progressive supranuclear palsy.
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Common variants at MS4A4/MS4A6E, CD2AP, CD33 and EPHA1 are associated with late-onset Alzheimers disease.
Adam C Naj, Gyungah Jun, Gary W Beecham, Li-San Wang, Badri Narayan Vardarajan, Jacqueline Buros, Paul J Gallins, Joseph D Buxbaum, Gail P Jarvik, Paul K Crane, Eric B Larson, Thomas D Bird, Bradley F Boeve, Neill R Graff-Radford, Philip L De Jager, Denis Evans, Julie A Schneider, Minerva M Carrasquillo, Nilüfer Ertekin-Taner, Steven G Younkin, Carlos Cruchaga, John S K Kauwe, Petra Nowotny, Patricia Kramer, John Hardy, Matthew J Huentelman, Amanda J Myers, Michael M Barmada, F Yesim Demirci, Clinton T Baldwin, Robert C Green, Ekaterina Rogaeva, Peter St George-Hyslop, Steven E Arnold, Robert Barber, Thomas Beach, Eileen H Bigio, James D Bowen, Adam Boxer, James R Burke, Nigel J Cairns, Chris S Carlson, Regina M Carney, Steven L Carroll, Helena C Chui, David G Clark, Jason Corneveaux, Carl W Cotman, Jeffrey L Cummings, Charles DeCarli, Steven T DeKosky, Ramon Diaz-Arrastia, Malcolm Dick, Dennis W Dickson, William G Ellis, Kelley M Faber, Kenneth B Fallon, Martin R Farlow, Steven Ferris, Matthew P Frosch, Douglas R Galasko, Mary Ganguli, Marla Gearing, Daniel H Geschwind, Bernardino Ghetti, John R Gilbert, Sid Gilman, Bruno Giordani, Jonathan D Glass, John H Growdon, Ronald L Hamilton, Lindy E Harrell, Elizabeth Head, Lawrence S Honig, Christine M Hulette, Bradley T Hyman, Gregory A Jicha, Lee-Way Jin, Nancy Johnson, Jason Karlawish, Anna Karydas, Jeffrey A Kaye, Ronald Kim, Edward H Koo, Neil W Kowall, James J Lah, Allan I Levey, Andrew P Lieberman, Oscar L Lopez, Wendy J Mack, Daniel C Marson, Frank Martiniuk, Deborah C Mash, Eliezer Masliah, Wayne C McCormick, Susan M McCurry, Andrew N McDavid, Ann C McKee, Marsel Mesulam, Bruce L Miller, Carol A Miller, Joshua W Miller, Joseph E Parisi, Daniel P Perl, Elaine Peskind, Ronald C Petersen, Wayne W Poon, Joseph F Quinn, Ruchita A Rajbhandary, Murray Raskind, Barry Reisberg, John M Ringman, Erik D Roberson, Roger N Rosenberg, Mary Sano, Lon S Schneider, William Seeley, Michael L Shelanski, Michael A Slifer, Charles D Smith, Joshua A Sonnen, Salvatore Spina, Robert A Stern, Rudolph E Tanzi, John Q Trojanowski, Juan C Troncoso, Vivianna M Van Deerlin, Harry V Vinters, Jean Paul Vonsattel, Sandra Weintraub, Kathleen A Welsh-Bohmer, Jennifer Williamson, Randall L Woltjer, Laura B Cantwell, Beth A Dombroski, Duane Beekly, Kathryn L Lunetta, Eden R Martin, M Ilyas Kamboh, Andrew J Saykin, Eric M Reiman, David A Bennett, John C Morris, Thomas J Montine, Alison M Goate, Deborah Blacker, Debby W Tsuang, Hakon Hakonarson, Walter A Kukull, Tatiana M Foroud, Jonathan L Haines, Richard Mayeux, Margaret A Pericak-Vance, Lindsay A Farrer, Gerard D Schellenberg.
Nat. Genet.
PUBLISHED: 03-10-2011
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The Alzheimer Disease Genetics Consortium (ADGC) performed a genome-wide association study of late-onset Alzheimer disease using a three-stage design consisting of a discovery stage (stage 1) and two replication stages (stages 2 and 3). Both joint analysis and meta-analysis approaches were used. We obtained genome-wide significant results at MS4A4A (rs4938933; stages 1 and 2, meta-analysis P (P(M)) = 1.7 × 10(-9), joint analysis P (P(J)) = 1.7 × 10(-9); stages 1, 2 and 3, P(M) = 8.2 × 10(-12)), CD2AP (rs9349407; stages 1, 2 and 3, P(M) = 8.6 × 10(-9)), EPHA1 (rs11767557; stages 1, 2 and 3, P(M) = 6.0 × 10(-10)) and CD33 (rs3865444; stages 1, 2 and 3, P(M) = 1.6 × 10(-9)). We also replicated previous associations at CR1 (rs6701713; P(M) = 4.6 × 10(-10), P(J) = 5.2 × 10(-11)), CLU (rs1532278; P(M) = 8.3 × 10(-8), P(J) = 1.9 × 10(-8)), BIN1 (rs7561528; P(M) = 4.0 × 10(-14), P(J) = 5.2 × 10(-14)) and PICALM (rs561655; P(M) = 7.0 × 10(-11), P(J) = 1.0 × 10(-10)), but not at EXOC3L2, to late-onset Alzheimers disease susceptibility.
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Common variants at ABCA7, MS4A6A/MS4A4E, EPHA1, CD33 and CD2AP are associated with Alzheimers disease.
Paul Hollingworth, Denise Harold, Rebecca Sims, Amy Gerrish, Jean-Charles Lambert, Minerva M Carrasquillo, Richard Abraham, Marian L Hamshere, Jaspreet Singh Pahwa, Valentina Moskvina, Kimberley Dowzell, Nicola Jones, Alexandra Stretton, Charlene Thomas, Alex Richards, Dobril Ivanov, Caroline Widdowson, Jade Chapman, Simon Lovestone, John Powell, Petroula Proitsi, Michelle K Lupton, Carol Brayne, David C Rubinsztein, Michael Gill, Brian Lawlor, Aoibhinn Lynch, Kristelle S Brown, Peter A Passmore, David Craig, Bernadette McGuinness, Stephen Todd, Clive Holmes, David Mann, A David Smith, Helen Beaumont, Donald Warden, Gordon Wilcock, Seth Love, Patrick G Kehoe, Nigel M Hooper, Emma R L C Vardy, John Hardy, Simon Mead, Nick C Fox, Martin Rossor, John Collinge, Wolfgang Maier, Frank Jessen, Eckart Rüther, Britta Schürmann, Reiner Heun, Heike Kölsch, Hendrik van den Bussche, Isabella Heuser, Johannes Kornhuber, Jens Wiltfang, Martin Dichgans, Lutz Frölich, Harald Hampel, John Gallacher, Michael Hüll, Dan Rujescu, Ina Giegling, Alison M Goate, John S K Kauwe, Carlos Cruchaga, Petra Nowotny, John C Morris, Kevin Mayo, Kristel Sleegers, Karolien Bettens, Sebastiaan Engelborghs, Peter P De Deyn, Christine Van Broeckhoven, Gill Livingston, Nicholas J Bass, Hugh Gurling, Andrew McQuillin, Rhian Gwilliam, Panagiotis Deloukas, Ammar Al-Chalabi, Christopher E Shaw, Magda Tsolaki, Andrew B Singleton, Rita Guerreiro, Thomas W Mühleisen, Markus M Nöthen, Susanne Moebus, Karl-Heinz Jöckel, Norman Klopp, H-Erich Wichmann, V Shane Pankratz, Sigrid B Sando, Jan O Aasly, Maria Barcikowska, Zbigniew K Wszolek, Dennis W Dickson, Neill R Graff-Radford, Ronald C Petersen, , Cornelia M van Duijn, Monique M B Breteler, M Arfan Ikram, Anita L Destefano, Annette L Fitzpatrick, Oscar Lopez, Lenore J Launer, Sudha Seshadri, Claudine Berr, Dominique Campion, Jacques Epelbaum, Jean-Francois Dartigues, Christophe Tzourio, Annick Alpérovitch, Mark Lathrop, Thomas M Feulner, Patricia Friedrich, Caterina Riehle, Michael Krawczak, Stefan Schreiber, Manuel Mayhaus, S Nicolhaus, Stefan Wagenpfeil, Stacy Steinberg, Hreinn Stefansson, Kari Stefansson, Jón Snaedal, Sigurbjorn Bjornsson, Palmi V Jonsson, Vincent Chouraki, Benjamin Genier-Boley, Mikko Hiltunen, Hilkka Soininen, Onofre Combarros, Diana Zelenika, Marc Delepine, María J Bullido, Florence Pasquier, Ignacio Mateo, Ana Frank-García, Elisa Porcellini, Olivier Hanon, Eliecer Coto, Victoria Alvarez, Paolo Bosco, Gabriele Siciliano, Michelangelo Mancuso, Francesco Panza, Vincenzo Solfrizzi, Benedetta Nacmias, Sandro Sorbi, Paola Bossù, Paola Piccardi, Beatrice Arosio, Giorgio Annoni, Davide Seripa, Alberto Pilotto, Elio Scarpini, Daniela Galimberti, Alexis Brice, Didier Hannequin, Federico Licastro, Lesley Jones, Peter A Holmans, Thorlakur Jonsson, Matthias Riemenschneider, Kevin Morgan, Steven G Younkin, Michael J Owen, Michael O'Donovan, Philippe Amouyel, Julie Williams.
Nat. Genet.
PUBLISHED: 03-10-2011
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We sought to identify new susceptibility loci for Alzheimers disease through a staged association study (GERAD+) and by testing suggestive loci reported by the Alzheimers Disease Genetic Consortium (ADGC) in a companion paper. We undertook a combined analysis of four genome-wide association datasets (stage 1) and identified ten newly associated variants with P ? 1 × 10(-5). We tested these variants for association in an independent sample (stage 2). Three SNPs at two loci replicated and showed evidence for association in a further sample (stage 3). Meta-analyses of all data provided compelling evidence that ABCA7 (rs3764650, meta P = 4.5 × 10(-17); including ADGC data, meta P = 5.0 × 10(-21)) and the MS4A gene cluster (rs610932, meta P = 1.8 × 10(-14); including ADGC data, meta P = 1.2 × 10(-16)) are new Alzheimers disease susceptibility loci. We also found independent evidence for association for three loci reported by the ADGC, which, when combined, showed genome-wide significance: CD2AP (GERAD+, P = 8.0 × 10(-4); including ADGC data, meta P = 8.6 × 10(-9)), CD33 (GERAD+, P = 2.2 × 10(-4); including ADGC data, meta P = 1.6 × 10(-9)) and EPHA1 (GERAD+, P = 3.4 × 10(-4); including ADGC data, meta P = 6.0 × 10(-10)).
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Multiple insulin degrading enzyme variants alter in vitro reporter gene expression.
PLoS ONE
PUBLISHED: 02-10-2011
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The insulin degrading enzyme (IDE) variant, v311 (rs6583817), is associated with increased post-mortem cerebellar IDE mRNA, decreased plasma ?-amyloid (A?), decreased risk for Alzheimers disease (AD) and increased reporter gene expression, suggesting that it is a functional variant driving increased IDE expression. To identify other functional IDE variants, we have tested v685, rs11187061 (associated with decreased cerebellar IDE mRNA) and variants on H6, the haplotype tagged by v311 (v10; rs4646958, v315; rs7895832, v687; rs17107734 and v154; rs4646957), for altered in vitro reporter gene expression. The reporter gene expression levels associated with the second most common haplotype (H2) successfully replicated the post-mortem findings in hepatocytoma (0.89 fold-change, p?=?0.04) but not neuroblastoma cells. Successful in vitro replication was achieved for H6 in neuroblastoma cells when the sequence was cloned 5 to the promoter (1.18 fold-change, p?=?0.006) and 3 to the reporter gene (1.29 fold change, p?=?0.003), an effect contributed to by four variants (v10, v315, v154 and v311). Since IDE mediates A? degradation, variants that regulate IDE expression could represent good therapeutic targets for AD.
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Genome-wide screen identifies rs646776 near sortilin as a regulator of progranulin levels in human plasma.
Am. J. Hum. Genet.
PUBLISHED: 10-07-2010
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Recent studies suggest progranulin (GRN) is a neurotrophic factor. Loss-of-function mutations in the progranulin gene (GRN) cause frontotemporal lobar degeneration (FTLD), a progressive neurodegenerative disease affecting ?10% of early-onset dementia patients. Using an enzyme-linked immunosorbent assay, we previously showed that GRN is detectable in human plasma and can be used to predict GRN mutation status. This study also showed a wide range in plasma GRN levels in non-GRN mutation carriers, including controls. We have now performed a genome-wide association study of 313,504 single-nucleotide polymorphisms (SNPs) in 533 control samples and identified on chromosome 1p13.3 two SNPs with genome-wide significant association with plasma GRN levels (top SNP rs646776; p = 1.7 × 10?³?). The association of rs646776 with plasma GRN levels was replicated in two independent series of 508 controls (p = 1.9 × 10?¹?) and 197 FTLD patients (p = 6.4 × 10?¹²). Overall, each copy of the minor C allele decreased GRN levels by ?15%. SNP rs646776 is located near sortilin (SORT1), and the minor C allele of rs646776 was previously associated with increased SORT1 mRNA levels. Supporting these findings, overexpression of SORT1 in cultured HeLa cells dramatically reduced GRN levels in the conditioned media, whereas knockdown of SORT1 increased extracellular GRN levels. In summary, we identified significant association of a locus on chromosome 1p13.3 with plasma GRN levels through an unbiased genome-wide screening approach and implicated SORT1 as an important regulator of GRN levels. This finding opens avenues for future research into GRN biology and the pathophysiology of neurodegenerative diseases.
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Investigation of 15 of the top candidate genes for late-onset Alzheimers disease.
Hum. Genet.
PUBLISHED: 08-24-2010
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The 12 genome-wide association studies (GWAS) published to-date for late-onset Alzheimers disease (LOAD) have identified over 40 candidate LOAD risk modifiers, in addition to apolipoprotein (APOE) ?4. A few of these novel LOAD candidate genes, namely BIN1, CLU, CR1, EXOC3L2 and PICALM, have shown consistent replication, and are thus credible LOAD susceptibility genes. To evaluate other promising LOAD candidate genes, we have added data from our large, case-control series (n=5,043) to meta-analyses of all published follow-up case-control association studies for six LOAD candidate genes that have shown significant association across multiple studies (TNK1, GAB2, LOC651924, GWA_14q32.13, PGBD1 and GALP) and for an additional nine previously suggested candidate genes. Meta-analyses remained significant at three loci after addition of our data: GAB2 (OR=0.78, p=0.007), LOC651924 (OR=0.91, p=0.01) and TNK1 (OR=0.92, p=0.02). Breslow-Day tests revealed significant heterogeneity between studies for GAB2 (p<0.0001) and GWA_14q32.13 (p=0.006). We have also provided suggestive evidence that PGBD1 (p=0.04) and EBF3 (p=0.03) are associated with age-at-onset of LOAD. Finally, we tested for interactions between these 15 genes, APOE ?4 and the five novel LOAD genes BIN1, CLU, CR1, EXOC3L2 and PICALM but none were significant after correction for multiple testing. Overall, this large, independent follow-up study for 15 of the top LOAD candidate genes provides support for GAB2 and LOC651924 (6q24.1) as risk modifiers of LOAD and novel associations between PGBD1 and EBF3 with age-at-onset.
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Genetic evidence implicates the immune system and cholesterol metabolism in the aetiology of Alzheimers disease.
PLoS ONE
PUBLISHED: 06-23-2010
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Late Onset Alzheimers disease (LOAD) is the leading cause of dementia. Recent large genome-wide association studies (GWAS) identified the first strongly supported LOAD susceptibility genes since the discovery of the involvement of APOE in the early 1990s. We have now exploited these GWAS datasets to uncover key LOAD pathophysiological processes.
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Replication of CLU, CR1, and PICALM associations with alzheimer disease.
Arch. Neurol.
PUBLISHED: 06-14-2010
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To test for replication of the association between variants in the CLU, CR1, and PICALM genes with Alzheimer disease.
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Association and heterogeneity at the GAPDH locus in Alzheimers disease.
Neurobiol. Aging
PUBLISHED: 04-19-2010
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Glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH) and its paralogs were implicated in late-onset Alzheimers disease (LOAD), although the strength and direction of association have not been consistent. We genotyped 3 previously reported single nucleotide polymorphisms (SNPs; rs3741916-GAPDH 5 UTR, rs2029721-pGAPD, and rs4806173-GAPDHS) in 3 case-control series (2112 cases and 3808 controls). Rs3741916 showed the strongest LOAD association (p = 0.003). The minor allele of rs3741916 showed a protective effect in our combined series (odds ratio [OR] = 0.87%, 95% confidence interval [CI] = 0.79-0.96). This is consistent with results from the 2 published follow-up studies and in opposite direction of the original report. Meta-analysis of the published series with ours suggests presence of heterogeneity (Breslow-Day p < 0.0001). Meta-analysis of only the follow-up series including ours revealed a significant protective effect for the minor allele of rs3741916 (OR = 0.85%, 95% CI = 0.76-0.96, p = 0.009). Our results support the presence of LOAD variants and heterogeneity at the GAPDH locus. The most promising rs3741916 variant is unlikely to be functional given opposing effects in different series. Identification of functional variant(s) in this region likely awaits deep sequencing.
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Genome-wide association study identifies variants at CLU and PICALM associated with Alzheimers disease.
Nat. Genet.
PUBLISHED: 04-28-2009
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We undertook a two-stage genome-wide association study (GWAS) of Alzheimers disease (AD) involving over 16,000 individuals, the most powerful AD GWAS to date. In stage 1 (3,941 cases and 7,848 controls), we replicated the established association with the apolipoprotein E (APOE) locus (most significant SNP, rs2075650, P = 1.8 x 10(-157)) and observed genome-wide significant association with SNPs at two loci not previously associated with the disease: at the CLU (also known as APOJ) gene (rs11136000, P = 1.4 x 10(-9)) and 5 to the PICALM gene (rs3851179, P = 1.9 x 10(-8)). These associations were replicated in stage 2 (2,023 cases and 2,340 controls), producing compelling evidence for association with Alzheimers disease in the combined dataset (rs11136000, P = 8.5 x 10(-10), odds ratio = 0.86; rs3851179, P = 1.3 x 10(-9), odds ratio = 0.86).
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Genetic variation in PCDH11X is associated with susceptibility to late-onset Alzheimers disease.
Nat. Genet.
PUBLISHED: 01-11-2009
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By analyzing late-onset Alzheimers disease (LOAD) in a genome-wide association study (313,504 SNPs, three series, 844 cases and 1,255 controls) and evaluating the 25 SNPs with the most significant allelic association in four additional series (1,547 cases and 1,209 controls), we identified a SNP (rs5984894) on Xq21.3 in PCDH11X that is strongly associated with LOAD in individuals of European descent from the United States. Analysis of rs5984894 by multivariable logistic regression adjusted for sex gave global P values of 5.7 x 10(-5) in stage 1, 4.8 x 10(-6) in stage 2 and 3.9 x 10(-12) in the combined data. Odds ratios were 1.75 (95% CI = 1.42-2.16) for female homozygotes (P = 2.0 x 10(-7)) and 1.26 (95% CI = 1.05-1.51) for female heterozygotes (P = 0.01) compared to female noncarriers. For male hemizygotes (P = 0.07) compared to male noncarriers, the odds ratio was 1.18 (95% CI = 0.99-1.41).
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TREM2 variants in Alzheimers disease.
N. Engl. J. Med.
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Homozygous loss-of-function mutations in TREM2, encoding the triggering receptor expressed on myeloid cells 2 protein, have previously been associated with an autosomal recessive form of early-onset dementia.
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Evaluation of the role of SNCA variants in survival without neurological disease.
PLoS ONE
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A variety of definitions of successful aging have been proposed, many of which relate to longevity, freedom from disease and disability, or preservation of high physical and cognitive function. Many behavioral, biomedical, and psychological factors have been linked with these various measures of successful aging, however genetic predictors are less understood. Parkinsons disease (PD) is an age-related neurodegenerative disorder, and variants in the ?-synuclein gene (SNCA) affect susceptibility to PD. This exploratory study examined whether SNCA variants may also promote successful aging as defined by survival without neurological disease.
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Novel late-onset Alzheimer disease loci variants associate with brain gene expression.
Neurology
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Recent genome-wide association studies (GWAS) of late-onset Alzheimer disease (LOAD) identified 9 novel risk loci. Discovery of functional variants within genes at these loci is required to confirm their role in Alzheimer disease (AD). Single nucleotide polymorphisms that influence gene expression (eSNPs) constitute an important class of functional variants. We therefore investigated the influence of the novel LOAD risk loci on human brain gene expression.
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Brain expression genome-wide association study (eGWAS) identifies human disease-associated variants.
PLoS Genet.
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Genetic variants that modify brain gene expression may also influence risk for human diseases. We measured expression levels of 24,526 transcripts in brain samples from the cerebellum and temporal cortex of autopsied subjects with Alzheimers disease (AD, cerebellar n=197, temporal cortex n=202) and with other brain pathologies (non-AD, cerebellar n=177, temporal cortex n=197). We conducted an expression genome-wide association study (eGWAS) using 213,528 cisSNPs within ± 100 kb of the tested transcripts. We identified 2,980 cerebellar cisSNP/transcript level associations (2,596 unique cisSNPs) significant in both ADs and non-ADs (q<0.05, p=7.70 × 10(-5)-1.67 × 10(-82)). Of these, 2,089 were also significant in the temporal cortex (p=1.85 × 10(-5)-1.70 × 10(-141)). The top cerebellar cisSNPs had 2.4-fold enrichment for human disease-associated variants (p<10(-6)). We identified novel cisSNP/transcript associations for human disease-associated variants, including progressive supranuclear palsy SLCO1A2/rs11568563, Parkinsons disease (PD) MMRN1/rs6532197, Pagets disease OPTN/rs1561570; and we confirmed others, including PD MAPT/rs242557, systemic lupus erythematosus and ulcerative colitis IRF5/rs4728142, and type 1 diabetes mellitus RPS26/rs1701704. In our eGWAS, there was 2.9-3.3 fold enrichment (p<10(-6)) of significant cisSNPs with suggestive AD-risk association (p<10(-3)) in the Alzheimers Disease Genetics Consortium GWAS. These results demonstrate the significant contributions of genetic factors to human brain gene expression, which are reliably detected across different brain regions and pathologies. The significant enrichment of brain cisSNPs among disease-associated variants advocates gene expression changes as a mechanism for many central nervous system (CNS) and non-CNS diseases. Combined assessment of expression and disease GWAS may provide complementary information in discovery of human disease variants with functional implications. Our findings have implications for the design and interpretation of eGWAS in general and the use of brain expression quantitative trait loci in the study of human disease genetics.
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Glutathione S-transferase omega genes in Alzheimer and Parkinson disease risk, age-at-diagnosis and brain gene expression: an association study with mechanistic implications.
Mol Neurodegener
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Glutathione S-transferase omega-1 and 2 genes (GSTO1, GSTO2), residing within an Alzheimer and Parkinson disease (AD and PD) linkage region, have diverse functions including mitigation of oxidative stress and may underlie the pathophysiology of both diseases. GSTO polymorphisms were previously reported to associate with risk and age-at-onset of these diseases, although inconsistent follow-up study designs make interpretation of results difficult. We assessed two previously reported SNPs, GSTO1 rs4925 and GSTO2 rs156697, in AD (3,493 ADs vs. 4,617 controls) and PD (678 PDs vs. 712 controls) for association with disease risk (case-controls), age-at-diagnosis (cases) and brain gene expression levels (autopsied subjects).
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Genetic variants influencing human aging from late-onset Alzheimers disease (LOAD) genome-wide association studies (GWAS).
Neurobiol. Aging
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Genetics plays a crucial role in human aging with up to 30% of those living to the mid-80s being determined by genetic variation. Survival to older ages likely entails an even greater genetic contribution. There is increasing evidence that genes implicated in age-related diseases, such as cancer and neuronal disease, play a role in affecting human life span. We have selected the 10 most promising late-onset Alzheimers disease (LOAD) susceptibility genes identified through several recent large genome-wide association studies (GWAS). These 10 LOAD genes (APOE, CLU, PICALM, CR1, BIN1, ABCA7, MS4A6A, CD33, CD2AP, and EPHA1) have been tested for association with human aging in our dataset (1385 samples with documented age at death [AAD], age range: 58-108 years; mean age at death: 80.2) using the most significant single nucleotide polymorphisms (SNPs) found in the previous studies. Apart from the APOE locus (rs2075650) which showed compelling evidence of association with risk on human life span (p = 5.27 × 10(-4)), none of the other LOAD gene loci demonstrated significant evidence of association. In addition to examining the known LOAD genes, we carried out analyses using age at death as a quantitative trait. No genome-wide significant SNPs were discovered. Increasing sample size and statistical power will be imperative to detect genuine aging-associated variants in the future. In this report, we also discuss issues relating to the analysis of genome-wide association studies data from different centers and the bioinformatic approach required to distinguish spurious genome-wide significant signals from real SNP associations.
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Functional and genetic analysis of haplotypic sequence variation at the nicastrin genomic locus.
Neurobiol. Aging
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Nicastrin (NCSTN) is a component of the ?-secretase complex and therefore potentially a candidate risk gene for Alzheimers disease. Here, we have developed a novel functional genomics methodology to express common locus haplotypes to assess functional differences. DNA recombination was used to engineer 5 bacterial artificial chromosomes (BACs) to each express a different haplotype of the NCSTN locus. Each NCSTN-BAC was delivered to knockout nicastrin (Ncstn(-/-)) cells and clonal NCSTN-BAC(+)/Ncstn(-/-) cell lines were created for functional analyses. We showed that all NCSTN-BAC haplotypes expressed nicastrin protein and rescued ?-secretase activity and amyloid beta (A?) production in NCSTN-BAC(+)/Ncstn(-/-) lines. We then showed that genetic variation at the NCSTN locus affected alternative splicing in human postmortem brain tissue. However, there was no robust functional difference between clonal cell lines rescued by each of the 5 different haplotypes. Finally, there was no statistically significant association of NCSTN with disease risk in the 4 cohorts. We therefore conclude that it is unlikely that common variation at the NCSTN locus is a risk factor for Alzheimers disease.
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