Genome-wide association identifies the first risk loci for psychosis in Alzheimer disease
DeMichele-Sweet, Mary Ann A.; Klei, Lambertus; Creese, Byron; Harwood, Janet C.; Weamer, Elise A.; McClain, Lora; Sims, Rebekka; Hernández, Isabel; Moreno-Grau, Sonia; Tárraga, Lluís; Boada, Mercè; Alarcón-Martín, Emilio; Valero, Sergi; Liu, Yushi; Hooli, Basavaraj; Aarsland, Dag; Selbæk, Geir; Bergh, Sverre; Rongve, Arvid; Saltvedt, Ingvild; Skjellegrind, Håvard; Engdahl, Bo Lars; Stordal, Eystein; Andreassen, Ole Andreas; Djurovic, Srdjan; Athanasiu, Lavinia; Seripa, Davide; Borroni, Barbara; Albani, Diego; Forloni, Gianluigi; Mecocci, Patrizia; Seretti, Alessandro; De Ronchi, Diana; Politis, Antonis; Williams, Julie; Mayeux, Richard; Foroud, Tatiana; Ruiz, Agustin; Ballard, Clive; Holmans, Peter; Lopez, Oscar L.; Kamboh, M. Ilyas; Devlin, Bernie; Sweet, Robert A.
Peer reviewed, Journal article
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Date
2021Metadata
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Original version
10.1038/s41380-021-01152-8Abstract
Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD with psychosis, AD + P). AD + P affects ~50% of individuals with AD, identifies a subgroup with poor outcomes, and is associated with a greater degree of cognitive impairment and depressive symptoms, compared to subjects without psychosis (AD − P). Although the estimated heritability of AD + P is 61%, genetic sources of risk are unknown. We report a genome-wide meta-analysis of 12,317 AD subjects, 5445 AD + P. Results showed common genetic variation accounted for a significant portion of heritability. Two loci, one in ENPP6 (rs9994623, O.R. (95%CI) 1.16 (1.10, 1.22), p = 1.26 × 10−8) and one spanning the 3′-UTR of an alternatively spliced transcript of SUMF1 (rs201109606, O.R. 0.65 (0.56–0.76), p = 3.24 × 10−8), had genome-wide significant associations with AD + P. Gene-based analysis identified a significant association with APOE, due to the APOE risk haplotype ε4. AD + P demonstrated negative genetic correlations with cognitive and educational attainment and positive genetic correlation with depressive symptoms. We previously observed a negative genetic correlation with schizophrenia; instead, we now found a stronger negative correlation with the related phenotype of bipolar disorder. Analysis of polygenic risk scores supported this genetic correlation and documented a positive genetic correlation with risk variation for AD, beyond the effect of ε4. We also document a small set of SNPs likely to affect risk for AD + P and AD or schizophrenia. These findings provide the first unbiased identification of the association of psychosis in AD with common genetic variation and provide insights into its genetic architecture.