Browsing by Author "Ertekin-Taner, Nilufer"

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    Association of Long Runs of Homozygosity With Alzheimer Disease Among African American Individuals
    (American Medical Association, 2015-11) Ghani, Mahdi; Reitz, Christiane; Cheng, Rong; Vardarajan, Badri Narayan; Jun, Gyungah; Sato, Christine; Naj, Adam; Rajbhandary, Ruchita; 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 A.; 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.; Lee, Joseph H.; Schellenberg, Gerard D.; St. George-Hyslop, Peter; Mayeux, Richard; Rogaeva, Ekaterina; Department of Psychiatry, IU School of Medicine
    IMPORTANCE: Mutations in known causal Alzheimer disease (AD) genes account for only 1% to 3% of patients and almost all are dominantly inherited. Recessive inheritance of complex phenotypes can be linked to long (>1-megabase [Mb]) runs of homozygosity (ROHs) detectable by single-nucleotide polymorphism (SNP) arrays. OBJECTIVE: To evaluate the association between ROHs and AD in an African American population known to have a risk for AD up to 3 times higher than white individuals. DESIGN, SETTING, AND PARTICIPANTS: Case-control study of a large African American data set previously genotyped on different genome-wide SNP arrays conducted from December 2013 to January 2015. Global and locus-based ROH measurements were analyzed using raw or imputed genotype data. We studied the raw genotypes from 2 case-control subsets grouped based on SNP array: Alzheimer's Disease Genetics Consortium data set (871 cases and 1620 control individuals) and Chicago Health and Aging Project-Indianapolis Ibadan Dementia Study data set (279 cases and 1367 control individuals). We then examined the entire data set using imputed genotypes from 1917 cases and 3858 control individuals. MAIN OUTCOMES AND MEASURES: The ROHs larger than 1 Mb, 2 Mb, or 3 Mb were investigated separately for global burden evaluation, consensus regions, and gene-based analyses. RESULTS: The African American cohort had a low degree of inbreeding (F ~ 0.006). In the Alzheimer's Disease Genetics Consortium data set, we detected a significantly higher proportion of cases with ROHs greater than 2 Mb (P = .004) or greater than 3 Mb (P = .02), as well as a significant 114-kilobase consensus region on chr4q31.3 (empirical P value 2 = .04; ROHs >2 Mb). In the Chicago Health and Aging Project-Indianapolis Ibadan Dementia Study data set, we identified a significant 202-kilobase consensus region on Chr15q24.1 (empirical P value 2 = .02; ROHs >1 Mb) and a cluster of 13 significant genes on Chr3p21.31 (empirical P value 2 = .03; ROHs >3 Mb). A total of 43 of 49 nominally significant genes common for both data sets also mapped to Chr3p21.31. Analyses of imputed SNP data from the entire data set confirmed the association of AD with global ROH measurements (12.38 ROHs >1 Mb in cases vs 12.11 in controls; 2.986 Mb average size of ROHs >2 Mb in cases vs 2.889 Mb in controls; and 22% of cases with ROHs >3 Mb vs 19% of controls) and a gene-cluster on Chr3p21.31 (empirical P value 2 = .006-.04; ROHs >3 Mb). Also, we detected a significant association between AD and CLDN17 (empirical P value 2 = .01; ROHs >1 Mb), encoding a protein from the Claudin family, members of which were previously suggested as AD biomarkers. CONCLUSIONS AND RELEVANCE: To our knowledge, we discovered the first evidence of increased burden of ROHs among patients with AD from an outbred African American population, which could reflect either the cumulative effect of multiple ROHs to AD or the contribution of specific loci harboring recessive mutations and risk haplotypes in a subset of patients. Sequencing is required to uncover AD variants in these individuals.
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    Genome-wide analyses as part of the international FTLD-TDP whole-genome sequencing consortium reveals novel disease risk factors and increases support for immune dysfunction in FTLD
    (Springer, 2019-02-09) Pottier, Cyril; Ren, Yingxue; Perkerson, Ralph B.; Baker, Matt; Jenkins, Gregory D.; van Blitterswijk, Marka; DeJesus-Hernandez, Mariely; van Rooij, Jeroen G. J.; Murray, Melissa E.; Christopher, Elizabeth; McDonnell, Shannon K.; Fogarty, Zachary; Batzler, Anthony; Tian, Shulan; Vicente, Cristina T.; Matchett, Billie; Karydas, Anna M.; Hsiung, Ging-Yuek Robin; Seelaar, Harro; Mol, Merel O.; Finger, Elizabeth C.; Graff, Caroline; Öijerstedt, Linn; Neumann, Manuela; Heutink, Peter; Synofzik, Matthis; Matthis, Carlo; Prudlo, Johannes; Rizzu, Patrizia; Simon-Sanchez, Javier; Edbauer, Dieter; Roeber, Sigrun; Diehl-Schmid, Janine; Evers, Bret M.; King, Andrew; Mesulam, M. Marsel; Weintraub, Sandra; Geula, Changiz; Bieniek, Kevin F.; Petrucelli, Leonard; Ahern, Geoffrey L.; Reiman, Eric M.; Woodruff, Bryan K.; Caselli, Richard J.; Huey, Edward D.; Farlow, Martin R.; Grafman, Jordan; Mead, Simon; Grinberg, Lea T.; Spina, Salvatore; Grossman, Murray; Irwin, David J.; Lee, Edward B.; Suh, EunRan; Snowden, Julie; Mann, David; Ertekin-Taner, Nilufer; Uitti, Ryan J.; Wszolek, Zbigniew K.; Josephs, Keith A.; Parisi, Joseph E.; Knopman, David S.; Petersen, Ronald C.; Hodges, John R.; Piguet, Olivier; Geier, Ethan G.; Yokoyama, Jennifer S.; Rissman, Robert A.; Rogaeva, Ekaterina; Keith, Julia; Zinman, Lorne; Tartaglia, Maria Carmela; Cairns, Nigel J.; Cruchaga, Carlos; Ghetti, Bernardino; Kofler, Julia; Lopez, Oscar L.; Beach, Thomas G.; Arzberger, Thomas; Herms, Jochen; Honig, Lawrence S.; Vonsattel, Jean Paul; Halliday, Glenda M.; Kwok, John B.; White, Charles L.; Gearing, Marla; Glass, Jonathan; Rollinson, Sara; Pickering-Brown, Stuart; Rohrer, Jonathan D.; Trojanowski, John Q.; Van Deerlin, Vivianna; Bigio, Eileen H.; Troakes, Claire; Al-Sarraj, Safa; Asmann, Yan; Miller, Bruce L.; Graff-Radford, Neill R.; Boeve, Bradley F.; Seeley, William W.; Mackenzie, Ian R. A.; van Swieten, John C.; Dickson, Dennis W.; Biernacka, Joanna M.; Rademakers, Rosa; Neurology, School of Medicine
    Frontotemporal lobar degeneration with neuronal inclusions of the TAR DNA-binding protein 43 (FTLD-TDP) represents the most common pathological subtype of FTLD. We established the international FTLD-TDP whole genome sequencing consortium to thoroughly characterize the known genetic causes of FTLD-TDP and identify novel genetic risk factors. Through the study of 1,131 unrelated Caucasian patients, we estimated that C9orf72 repeat expansions and GRN loss-of-function mutations account for 25.5% and 13.9% of FTLD-TDP patients, respectively. Mutations in TBK1 (1.5%) and other known FTLD genes (1.4%) were rare, and the disease in 57.7% of FTLD-TDP patients was unexplained by the known FTLD genes. To unravel the contribution of common genetic factors to the FTLD-TDP etiology in these patients, we conducted a two-stage association study comprising the analysis of whole-genome sequencing data from 517 FTLD-TDP patients and 838 controls, followed by targeted genotyping of the most associated genomic loci in 119 additional FTLD-TDP patients and 1653 controls. We identified three genome-wide significant FTLD-TDP risk loci: one new locus at chromosome 7q36 within the DPP6 gene led by rs118113626 (pvalue=4.82e-08, OR=2.12), and two known loci: UNC13A, led by rs1297319 (pvalue=1.27e-08, OR=1.50) and HLA-DQA2 led by rs17219281 (pvalue=3.22e-08, OR=1.98). While HLA represents a locus previously implicated in clinical FTLD and related neurodegenerative disorders, the association signal in our study is independent from previously reported associations. Through inspection of our whole genome sequence data for genes with an excess of rare loss-of-function variants in FTLD-TDP patients (n≥3) as compared to controls (n=0), we further discovered a possible role for genes functioning within the TBK1-related immune pathway (e.g. DHX58, TRIM21, IRF7) in the genetic etiology of FTLD-TDP. Together, our study based on the largest cohort of unrelated FTLD-TDP patients assembled to date provides a comprehensive view of the genetic landscape of FTLD-TDP, nominates novel FTLD-TDP risk loci, and strongly implicates the immune pathway in FTLD-TDP pathogenesis.
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    Novel Alzheimer Disease Risk Loci and Pathways in African American Individuals Using the African Genome Resources Panel
    (American Medical Association, 2021-01-01) Kunkle, Brian W.; Schmidt, Michael; Klein, Hans-Ulrich; Naj, Adam C.; Hamilton-Nelson, Kara L.; Larson, Eric B.; Evans, Denis A.; De Jager, Phil L.; Crane, Paul K.; Buxbaum, Joe D.; Ertekin-Taner, Nilufer; Go, Rodney C.P.; Obisesan, Thomas O.; Kamboh, Ilyas; Bennett, David A.; Hall, Kathleen S.; Goate, Alison M.; Foroud, Tatiana M.; Martin, Eden R.; Wang, Li-Sao; Byrd, Goldie S.; Farrer, Lindsay A.; Haines, Jonathan L.; Schellenberg, Gerard D.; Mayeux, Richard; Pericak-Vance, Margaret A.; Reitz, Christiane; Graff-Radford, Neill R.; Martinez, Izri; Ayodele, Temitope; Logue, Mark W.; Cantwell, Laura B.; Jean-Francois, Melissa; Kuzma, Amanda B.; Adams, L.D.; Vance, Jeffery M.; Cuccaro, Michael L.; Chung, Jaeyoon; Mez, Jesse; Lunetta, Kathryn L.; Jun, Gyungah R.; Lopez, Oscar L.; Hendrie, Hugh C.; Reiman, Eric M.; Kowall, Neil W.; Leverenz, James B.; Small, Scott A.; Levey, Allan I.; Golde, Todd E.; Saykin, Andrew J.; Starks, Takiyah D.; Albert, Marilyn S.; Hyman, Bradley T.; Petersen, Ronald C.; Sano, Mary; Wisniewski, Thomas; Vassar, Robert; Kaye, Jeffrey A.; Henderson, Victor W.; DeCarli, Charles; LaFerla, Frank M.; Brewer, James B.; Miller, Bruce L.; Swerdlow, Russell H.; Van Eldik, Linda J.; Paulson, Henry L.; Trojanowski, John Q.; Chui, Helena C.; Rosenberg, Roger N.; Craft, Suzanne; Grabowski, Thomas J.; Asthana, Sanjay; Morris, John C.; Strittmatter, Stephen M.; Kukull, Walter A.; Psychiatry, School of Medicine
    Importance: Compared with non-Hispanic White individuals, African American individuals from the same community are approximately twice as likely to develop Alzheimer disease. Despite this disparity, the largest Alzheimer disease genome-wide association studies to date have been conducted in non-Hispanic White individuals. In the largest association analyses of Alzheimer disease in African American individuals, ABCA7, TREM2, and an intergenic locus at 5q35 were previously implicated. Objective: To identify additional risk loci in African American individuals by increasing the sample size and using the African Genome Resource panel. Design, setting, and participants: This genome-wide association meta-analysis used case-control and family-based data sets from the Alzheimer Disease Genetics Consortium. There were multiple recruitment sites throughout the United States that included individuals with Alzheimer disease and controls of African American ancestry. Analysis began October 2018 and ended September 2019. Main outcomes and measures: Diagnosis of Alzheimer disease. Results: A total of 2784 individuals with Alzheimer disease (1944 female [69.8%]) and 5222 controls (3743 female [71.7%]) were analyzed (mean [SD] age at last evaluation, 74.2 [13.6] years). Associations with 4 novel common loci centered near the intracellular glycoprotein trafficking gene EDEM1 (3p26; P = 8.9 × 10-7), near the immune response gene ALCAM (3q13; P = 9.3 × 10-7), within GPC6 (13q31; P = 4.1 × 10-7), a gene critical for recruitment of glutamatergic receptors to the neuronal membrane, and within VRK3 (19q13.33; P = 3.5 × 10-7), a gene involved in glutamate neurotoxicity, were identified. In addition, several loci associated with rare variants, including a genome-wide significant intergenic locus near IGF1R at 15q26 (P = 1.7 × 10-9) and 6 additional loci with suggestive significance (P ≤ 5 × 10-7) such as API5 at 11p12 (P = 8.8 × 10-8) and RBFOX1 at 16p13 (P = 5.4 × 10-7) were identified. Gene expression data from brain tissue demonstrate association of ALCAM, ARAP1, GPC6, and RBFOX1 with brain β-amyloid load. Of 25 known loci associated with Alzheimer disease in non-Hispanic White individuals, only APOE, ABCA7, TREM2, BIN1, CD2AP, FERMT2, and WWOX were implicated at a nominal significance level or stronger in African American individuals. Pathway analyses strongly support the notion that immunity, lipid processing, and intracellular trafficking pathways underlying Alzheimer disease in African American individuals overlap with those observed in non-Hispanic White individuals. A new pathway emerging from these analyses is the kidney system, suggesting a novel mechanism for Alzheimer disease that needs further exploration. Conclusions and relevance: While the major pathways involved in Alzheimer disease etiology in African American individuals are similar to those in non-Hispanic White individuals, the disease-associated loci within these pathways differ.