Association of Rare APOE Missense Variants V236E and R251G with Risk of Alzheimer Disease

Yann le Guen, Michael E. Belloy, Benjamin Grenier-Boley, Itziar de Rojas, Atahualpa Castillo-Morales, Iris Jansen, Aude Nicolas, C. line Bellenguez, Carolina Dalmasso, Fahri Küçükali, Sarah J. Eger, Katrine Laura Rasmussen, Jesper Qvist Thomassen, Jean-François Deleuze, Zihuai He, Valerio Napolioni, Philippe Amouyel, Frank Jessen, Patrick G. Kehoe, Cornelia van DuijnMagda Tsolaki, Pascual Sánchez-Juan, Kristel Sleegers, Martin Ingelsson, Giacomina Rossi, Mikko Hiltunen, Rebecca Sims, Wiesje M. van der Flier, Alfredo Ramirez, Ole A. Andreassen, Ruth Frikke-Schmidt, Julie Williams, Agustín Ruiz, Jean-Charles Lambert, Michael D. Greicius, Beatrice Arosio, Luisa Benussi, Anne Boland, Barbara Borroni, Paolo Caffarra, Delphine Daian, Antonio Daniele, Stéphanie Debette, Carole Dufouil, Emrah Düzel, Daniela Galimberti, Vilmantas Giedraitis, Timo Grimmer, Caroline Graff, Edna Grünblatt, Olivier Hanon, Lucrezia Hausner, Stefanie Heilmann-Heimbach, Henne Holstege, Jakub Hort, Deckert Jürgen, Teemu Kuulasmaa, Aad van der Lugt, Carlo Masullo, Patrizia Mecocci, Shima Mehrabian, Alexandre de Mendonça, Susanne Moebus, Benedetta Nacmias, Gael Nicolas, Robert Olaso, Goran Papenberg, Lucilla Parnetti, Florence Pasquier, Oliver Peters, Yolande A. L. Pijnenburg, Julius Popp, Innocenzo Rainero, Inez Ramakers, Steffi Riedel-Heller, Nikolaos Scarmeas, Philip Scheltens, Norbert Scherbaum, Anja Schneider, Davide Seripa, Hilkka Soininen, Vincenzo Solfrizzi, Gianfranco Spalletta, Alessio Squassina, John van Swieten, Thomas J. Tegos, Lucio Tremolizzo, Frans Verhey, Martin Vyhnalek, Jens Wiltfang, Mercè Boada, Pablo García-González, Raquel Puerta, Luis M. Real, Victoria Álvarez, María J. Bullido, Jordi Clarimon, José María García-Alberca, Pablo Mir, Fermin Moreno, Pau Pastor, Gerard Piñol-Ripoll, Laura Molina-Porcel, Jordi Pérez-Tur, Eloy Rodríguez-Rodríguez, Jose Luís Royo, Raquel Sánchez-Valle, Martin Dichgans, Dan Rujescu

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2 Citations (Scopus)

Abstract

Importance: The APOE ϵ2 and APOE ϵ4 alleles are the strongest protective and risk-increasing, respectively, genetic variants for late-onset Alzheimer disease (AD). However, the mechanisms linking APOE to AD - particularly the apoE protein's role in AD pathogenesis and how this is affected by APOE variants - remain poorly understood. Identifying missense variants in addition to APOE ϵ2 and APOE ϵ4 could provide critical new insights, but given the low frequency of additional missense variants, AD genetic cohorts have previously been too small to interrogate this question robustly. Objective: To determine whether rare missense variants on APOE are associated with AD risk. Design, Setting, and Participants: Association with case-control status was tested in a sequenced discovery sample (stage 1) and followed up in several microarray imputed cohorts as well as the UK Biobank whole-exome sequencing resource using a proxy-AD phenotype (stages 2 and 3). This study combined case-control, family-based, population-based, and longitudinal AD-related cohorts that recruited referred and volunteer participants. Stage 1 included 37409 nonunique participants of European or admixed European ancestry, with 11868 individuals with AD and 11934 controls passing analysis inclusion criteria. In stages 2 and 3, 475473 participants were considered across 8 cohorts, of which 84513 individuals with AD and proxy-AD and 328372 controls passed inclusion criteria. Selection criteria were cohort specific, and this study was performed a posteriori on individuals who were genotyped. Among the available genotypes, 76195 were excluded. All data were retrieved between September 2015 and November 2021 and analyzed between April and November 2021. Main Outcomes and Measures: In primary analyses, the AD risk associated with each missense variant was estimated, as appropriate, with either linear mixed-model regression or logistic regression. In secondary analyses, associations were estimated with age at onset using linear mixed-model regression and risk of conversion to AD using competing-risk regression. Results: A total of 544384 participants were analyzed in the primary case-control analysis; 312476 (57.4%) were female, and the mean (SD; range) age was 64.9 (15.2; 40-110) years. Two missense variants were associated with a 2-fold to 3-fold decreased AD risk: APOE ϵ4 (R251G) (odds ratio, 0.44; 95% CI, 0.33-0.59; P = 4.7 × 10-8) and APOE ϵ3 (V236E) (odds ratio, 0.37; 95% CI, 0.25-0.56; P = 1.9 × 10-6). Additionally, the cumulative incidence of AD in carriers of these variants was found to grow more slowly with age compared with noncarriers. Conclusions and Relevance: In this genetic association study, a novel variant associated with AD was identified: R251G always coinherited with ϵ4 on the APOE gene, which mitigates the ϵ4-associated AD risk. The protective effect of the V236E variant, which is always coinherited with ϵ3 on the APOE gene, was also confirmed. The location of these variants confirms that the carboxyl-terminal portion of apoE plays an important role in AD pathogenesis. The large risk reductions reported here suggest that protein chemistry and functional assays of these variants should be pursued, as they have the potential to guide drug development targeting APOE..
Original languageEnglish
Pages (from-to)652-663
Number of pages12
JournalJAMA Neurology
Volume79
Issue number7
DOIs
Publication statusPublished - 1 Jul 2022

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