Browsing by Author "Sweet, Robert A."

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    Genetic associations with psychosis and affective disturbance in Alzheimer's disease
    (Wiley, 2024-05-23) Antonsdottir, Inga Margret; Creese, Byron; Klei, Lambertus; DeMichele-Sweet, Mary Ann A.; Weamer, Elise A.; Garcia-Gonzalez, Pablo; Marquie, Marta; Boada, Mercè; Alarcón-Martín, Emilio; Valero, Sergi; NIA-LOAD Family Based Study Consortium; Alzheimer's Disease Genetics Consortium (ADGC); AddNeuroMed Consortium; Liu, Yushi; Hooli, Basavaraj; Aarsland, Dag; Selbaek, Geir; Bergh, Sverre; Rongve, Arvid; Saltvedt, Ingvild; Skjellegrind, Håvard K.; Engdahl, Bo; Andreassen, Ole A.; Borroni, Barbara; Mecocci, Patrizia; Wedatilake, Yehani; Mayeux, Richard; Foroud, Tatiana; Ruiz, Agustín; Lopez, Oscar L.; Kamboh, M. Ilyas; Ballard, Clive; Devlin, Bernie; Lyketsos, Constantine; Sweet, Robert A.; Medical and Molecular Genetics, School of Medicine
    Introduction: Individuals with Alzheimer's disease (AD) commonly experience neuropsychiatric symptoms of psychosis (AD+P) and/or affective disturbance (depression, anxiety, and/or irritability, AD+A). This study's goal was to identify the genetic architecture of AD+P and AD+A, as well as their genetically correlated phenotypes. Methods: Genome-wide association meta-analysis of 9988 AD participants from six source studies with participants characterized for AD+P AD+A, and a joint phenotype (AD+A+P). Results: AD+P and AD+A were genetically correlated. However, AD+P and AD+A diverged in their genetic correlations with psychiatric phenotypes in individuals without AD. AD+P was negatively genetically correlated with bipolar disorder and positively with depressive symptoms. AD+A was positively correlated with anxiety disorder and more strongly correlated than AD+P with depressive symptoms. AD+P and AD+A+P had significant estimated heritability, whereas AD+A did not. Examination of the loci most strongly associated with the three phenotypes revealed overlapping and unique associations. Discussion: AD+P, AD+A, and AD+A+P have both shared and divergent genetic associations pointing to the importance of incorporating genetic insights into future treatment development. Highlights: It has long been known that psychotic and affective symptoms are often comorbid in individuals diagnosed with Alzheimer's disease. Here we examined for the first time the genetic architecture underlying this clinical observation, determining that psychotic and affective phenotypes in Alzheimer's disease are genetically correlated. Nevertheless, psychotic and affective phenotypes in Alzheimer's disease diverged in their genetic correlations with psychiatric phenotypes assessed in individuals without Alzheimer's disease. Psychosis in Alzheimer's disease was negatively genetically correlated with bipolar disorder and positively with depressive symptoms, whereas the affective phenotypes in Alzheimer's disease were positively correlated with anxiety disorder and more strongly correlated than psychosis with depressive symptoms. Psychosis in Alzheimer's disease, and the joint psychotic and affective phenotype, had significant estimated heritability, whereas the affective in AD did not. Examination of the loci most strongly associated with the psychotic, affective, or joint phenotypes revealed overlapping and unique associations.
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    Genetic Risk for Schizophrenia and Psychosis in Alzheimer Disease
    (Nature Publishing group, 2018-04) DeMichele-Sweet, Mary Ann A.; Weamer, Elise A.; Klei, Lambertus; Vrana, Dylan T.; Hollingshead, Deborah J.; Seltman, Howard J.; Sims, Rebecca; Foroud, Tatiana; Hernandez, Isabel; Moreno-Grau, Sonia; Tárraga, Lluís; Boada, Mercè; Ruiz, Agustin; Williams, Julie; Mayeux, Richard; Lopez, Oscar L.; Sibille, Etienne L.; Kamboh, M. Ilyas; Devlin, Bernie; Sweet, Robert A.; Medical and Molecular Genetics, School of Medicine
    Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer Disease, affecting ~ 40% to 60% of individuals with AD (AD with psychosis, AD+P). In comparison to AD subjects without psychosis, AD+P subjects have more rapid cognitive decline and poor outcomes. Prior studies have estimated the heritability of psychosis in AD at 61%, but the underlying genetic sources of this risk are not known. We evaluated a Discovery Cohort of 2876 AD subjects with (N=1761) or without psychosis (N=1115). All subjects were genotyped using a custom genotyping array designed to evaluate SNPs with evidence of genetic association with AD+P and include SNPs affecting or putatively affecting risk for schizophrenia and Alzheimer disease. Results were replicated in an independent cohort of 2194 AD subjects with (N=734) or without psychosis (N=1460). We found that AD+P is associated with polygenic risk for a set of novel loci and inversely associated with polygenic risk for schizophrenia. Among the biologic pathways identified by the associations of schizophrenia SNPs with AD+P are endosomal trafficking, autophagy, and calcium channel signaling. These findings provide the first clear demonstration that AD+P is associated with common genetic variation. In addition, they provide an unbiased link between polygenic risk for schizophrenia and a lower risk of psychosis in AD. This provides an opportunity to leverage progress made in identifying the biologic effects of schizophrenia alleles to identify novel mechanisms protecting against more rapid cognitive decline and psychosis risk in AD.
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    Genome-wide association identifies the first risk loci for psychosis in Alzheimer disease
    (Springer Nature, 2021) DeMichele-Sweet, Mary Ann A.; Klei, Lambertus; Creese, Byron; Harwood, Janet C.; Weamer, Elise A.; McClain, Lora; Sims, Rebecca; Hernandez, Isabel; Moreno-Grau, Sonia; Tárraga, Lluís; Boada, Mercè; Alarcón-Martín, Emilio; Valero, Sergi; NIA-LOAD Family Based Study Consortium; Alzheimer’s Disease Genetics Consortium (ADGC); Liu, Yushi; Hooli, Basavaraj; Aarsland, Dag; Selbaek, Geir; Bergh, Sverre; Rongve, Arvid; Saltvedt, Ingvild; Skjellegrind, Håvard K.; Engdahl, Bo; Stordal, Eystein; Andreassen, Ole A.; Djurovic, Srdjan; Athanasiu, Lavinia; Seripa, Davide; Borroni, Barbara; Albani, Diego; Forloni, Gianluigi; Mecocci, Patrizia; Serretti, Alessandro; De Ronchi, Diana; Politis, Antonis; Williams, Julie; Mayeux, Richard; Foroud, Tatiana; Ruiz, Agustín; Ballard, Clive; Holmans, Peter; Lopez, Oscar L.; Kamboh, M. Ilyas; Devlin, Bernie; Sweet, Robert A.; Medical and Molecular Genetics, School of Medicine
    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.
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    Polygenic risk score penetrance & recurrence risk in familial Alzheimer disease
    (Wiley, 2023) Qiao, Min; Lee, Annie J.; Reyes-Dumeyer, Dolly; Tosto, Giuseppe; Faber, Kelley; Goate, Alison; Renton, Alan; Chao, Michael; Boeve, Brad; Cruchaga, Carlos; Pericak-Vance, Margaret; Haines, Jonathan L.; Rosenberg, Roger; Tsuang, Debby; Sweet, Robert A.; Bennett, David A.; Wilson, Robert S.; Foroud, Tatiana; Mayeux, Richard; Vardarajan, Badri N.; Medical and Molecular Genetics, School of Medicine
    Objective: To compute penetrance and recurrence risk using a genome-wide PRS (including and excluding the APOE region) in families with Alzheimer's disease. Methods: Genotypes from the National Institute on Aging Late-Onset Alzheimer's Disease Family-Based Study and a study of familial Alzheimer's disease in Caribbean Hispanics were used to compute PRS with and without variants in the 2 MB region flanking APOE. PRS was calculated in using clumping/thresholding and Bayesian methods and was assessed for association with Alzheimer's disease and age at onset. Penetrance and recurrence risk for carriers in highest and lowest PRS quintiles were compared separately within APOE-ε4 carriers and non-carriers. Results: PRS excluding the APOE region was strongly associated with clinical and neuropathological diagnosis of AD. PRS association with AD was similar in participants who did not carry an APOE-ε4 allele (OR = 1.74 [1.53-1.91]) compared with APOE-ε4 carriers (1.53 [1.4-1.68]). Compared to the lowest quintile, the highest PRS quintile had a 10% higher penetrance at age 70 (p = 0.0006) and a 20% higher penetrance at age 80 (p < 10e-05). Stratifying by APOE-ε4 allele, PRS in the highest quintile was significantly more penetrant than the lowest quintile, both, within APOE-ε4 carriers (14.5% higher at age 80, p = 0.002) and non-carriers (26% higher at 80, p < 10e-05). Recurrence risk for siblings conferred by a co-sibling in the highest PRS quintile increased from 4% between the ages of 65-74 years to 39% at age 85 and older. Interpretation: PRS can be used to estimate penetrance and recurrence risk in familial Alzheimer's disease among carriers and non-carries of APOE-ε4.
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    The National Institute on Aging Late-Onset Alzheimer’s Disease Family Based Study: A resource for genetic discovery
    (Wiley, 2022) Reyes-Dumeyer, Dolly; Faber, Kelley; Vardarajan, Badri; Goate, Alison; Renton, Alan; Chao, Michael; Boeve, Brad; Cruchaga, Carlos; Pericak-Vance, Margaret; Haines, Jonathan L.; Rosenberg, Roger; Tsuang, Debby; Sweet, Robert A.; Bennett, David A.; Wilson, Robert S.; Foroud, Tatiana; Mayeux, Richard; Medical and Molecular Genetics, School of Medicine
    Introduction: The National Institute on Aging Late-Onset Alzheimer's Disease Family Based Study (NIA-LOAD FBS) was established to study the genetic etiology of Alzheimer's disease (AD). Methods: Recruitment focused on families with two living affected siblings and a third first-degree relative similar in age with or without dementia. Uniform assessments were completed, DNA was obtained, as was neuropathology, when possible. Apolipoprotein E (APOE) genotypes, genome-wide single nucleotide polymorphism (SNP) arrays, and sequencing was completed in most families. Results: APOE genotype modified the age-at-onset in many large families. Novel variants and known variants associated with early- and late-onset AD and frontotemporal dementia were identified supporting an international effort to solve AD genetics. Discussion: The NIA-LOAD FBS is the largest collection of familial AD worldwide, and data or samples have been included in 123 publications addressing the genetic etiology of AD. Genetic heterogeneity and variability in the age-at-onset provides opportunities to investigate the complexity of familial AD.