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1.
Brain ; 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38527854

RESUMEN

Genome-wide association studies have successfully identified many genetic risk loci for dementia, but exact biological mechanisms through which genetic risk factors contribute to dementia remains unclear. Integrating CSF proteomic data with dementia risk loci could reveal intermediate molecular pathways connecting genetic variance to the development of dementia. We tested to what extent effects of known dementia risk loci can be observed in CSF levels of 665 proteins (proximity extension-based (PEA) immunoassays) in a deeply-phenotyped mixed-memory clinic cohort (n=502, mean age (sd) = 64.1 [8.7] years, 181 female [35.4%]), including patients with Alzheimer's disease (AD, n=213), dementia with Lewy bodies (DLB, n=50) and frontotemporal dementia (FTD, n=93), and controls (n=146). Validation was assessed in independent cohorts (n=99 PEA platform, n=198, MRM-targeted mass spectroscopy and multiplex assay). We performed additional analyses stratified according to diagnostic status (AD, DLB, FTD and controls separately), to explore whether associations between CSF proteins and genetic variants were specific to disease or not. We identified four AD risk loci as protein quantitative trait loci (pQTL): CR1-CR2 (rs3818361, P=1.65e-08), ZCWPW1-PILRB (rs1476679, P=2.73e-32), CTSH-CTSH (rs3784539, P=2.88e-24) and HESX1-RETN (rs186108507, P=8.39e-08), of which the first three pQTLs showed direct replication in the independent cohorts. We identified one AD-specific association between a rare genetic variant of TREM2 and CSF IL6 levels (rs75932628, P = 3.90e-7). DLB risk locus GBA showed positive trans effects on seven inter-related CSF levels in DLB patients only. No pQTLs were identified for frontotemporal dementia, either for the total sample as for analyses performed within FTD only. pQTL variants were involved in the immune system, highlighting the importance of this system in the pathophysiology of dementia. We further identified pQTLs in stratified analyses for AD and DLB, hinting at disease-specific pQTLs in dementia. Dissecting the contribution of risk loci to neurobiological processes aids in understanding disease mechanisms underlying dementia.

2.
Acta Neuropathol ; 144(5): 821-842, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36066633

RESUMEN

Amyloid-beta 42 (Aß42) and phosphorylated tau (pTau) levels in cerebrospinal fluid (CSF) reflect core features of the pathogenesis of Alzheimer's disease (AD) more directly than clinical diagnosis. Initiated by the European Alzheimer & Dementia Biobank (EADB), the largest collaborative effort on genetics underlying CSF biomarkers was established, including 31 cohorts with a total of 13,116 individuals (discovery n = 8074; replication n = 5042 individuals). Besides the APOE locus, novel associations with two other well-established AD risk loci were observed; CR1 was shown a locus for Aß42 and BIN1 for pTau. GMNC and C16orf95 were further identified as loci for pTau, of which the latter is novel. Clustering methods exploring the influence of all known AD risk loci on the CSF protein levels, revealed 4 biological categories suggesting multiple Aß42 and pTau related biological pathways involved in the etiology of AD. In functional follow-up analyses, GMNC and C16orf95 both associated with lateral ventricular volume, implying an overlap in genetic etiology for tau levels and brain ventricular volume.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/líquido cefalorraquídeo , Apolipoproteínas E/genética , Biomarcadores/líquido cefalorraquídeo , Proteínas de Ciclo Celular , Humanos , Fragmentos de Péptidos/líquido cefalorraquídeo , Proteínas tau/líquido cefalorraquídeo , Proteínas tau/genética
3.
BMC Neurol ; 22(1): 484, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36522743

RESUMEN

BACKGROUND: What combination of risk factors for Alzheimer's disease (AD) are most predictive of cognitive decline in cognitively unimpaired individuals remains largely unclear. We studied associations between APOE genotype, AD-Polygenic Risk Scores (AD-PRS), amyloid-ß pathology and decline in cognitive functioning over time in a large sample of cognitively unimpaired older individuals. METHODS: We included 276 cognitively unimpaired older individuals (75 ± 10 years, 63% female) from the EMIF-AD PreclinAD cohort. An AD-PRS was calculated including 83 genome-wide significant variants. The APOE gene was not included in the PRS and was analyzed separately. Baseline amyloid-ß status was assessed by visual read of [18F]flutemetamol-PET standardized uptake value images. At baseline and follow-up (2.0 ± 0.4 years), the cognitive domains of memory, attention, executive function, and language were measured. We used generalized estimating equations corrected for age, sex and center to examine associations between APOE genotype and AD-PRS with amyloid-ß status. Linear mixed models corrected for age, sex, center and education were used to examine associations between APOE genotype, AD-PRS and amyloid-ß status, and their interaction on changes in cognitive functioning over time. RESULTS: Fifty-two participants (19%) had abnormal amyloid-ß, and 84 participants (31%) carried at least one APOE ε4 allele. APOE genotype and AD-PRS were both associated with abnormal amyloid-ß status. Increasingly more risk-full APOE genotype, a high AD-PRS and an abnormal amyloid-ß status were associated with steeper decline in memory functioning in separate models (all p ≤ 0.02). A model including 4-way interaction term (APOE×AD-PRS×amyloid-ß×time) was not significant. When modelled together, both APOE genotype and AD-PRS predicted steeper decline in memory functioning (APOE ß(SE)=-0.05(0.02); AD-PRS ß(SE)=-0.04(0.01)). Additionally, when modelled together, both amyloid-ß status and AD-PRS predicted a steeper decline in memory functioning (amyloid-ß ß(SE)=-0.07(0.04); AD-PRS ß(SE)=-0.04(0.01)). Modelling both APOE genotype and amyloid-ß status, we observed an interaction, in which APOE genotype was related to steeper decline in memory and language functioning in amyloid-ß abnormal individuals only (ß(SE)=-0.13(0.06); ß(SE)=-0.22(0.07), respectively). CONCLUSION: Our results suggest that APOE genotype is related to steeper decline in memory and language functioning in individuals with abnormal amyloid-ß only. Furthermore, independent of amyloid-ß status other genetic risk variants contribute to memory decline in initially cognitively unimpaired older individuals.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Femenino , Humanos , Masculino , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides , Disfunción Cognitiva/complicaciones , Genotipo , Apolipoproteínas E/genética , Trastornos de la Memoria , Factores de Riesgo , Tomografía de Emisión de Positrones , Apolipoproteína E4/genética
4.
Nature ; 533(7604): 539-42, 2016 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-27225129

RESUMEN

Educational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals. Here we report the results of a genome-wide association study (GWAS) for educational attainment that extends our earlier discovery sample of 101,069 individuals to 293,723 individuals, and a replication study in an independent sample of 111,349 individuals from the UK Biobank. We identify 74 genome-wide significant loci associated with the number of years of schooling completed. Single-nucleotide polymorphisms associated with educational attainment are disproportionately found in genomic regions regulating gene expression in the fetal brain. Candidate genes are preferentially expressed in neural tissue, especially during the prenatal period, and enriched for biological pathways involved in neural development. Our findings demonstrate that, even for a behavioural phenotype that is mostly environmentally determined, a well-powered GWAS identifies replicable associated genetic variants that suggest biologically relevant pathways. Because educational attainment is measured in large numbers of individuals, it will continue to be useful as a proxy phenotype in efforts to characterize the genetic influences of related phenotypes, including cognition and neuropsychiatric diseases.


Asunto(s)
Encéfalo/metabolismo , Escolaridad , Feto/metabolismo , Regulación de la Expresión Génica/genética , Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido Simple/genética , Enfermedad de Alzheimer/genética , Trastorno Bipolar/genética , Cognición , Biología Computacional , Interacción Gen-Ambiente , Humanos , Anotación de Secuencia Molecular , Esquizofrenia/genética , Reino Unido
5.
Alzheimers Dement ; 17(10): 1663-1674, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34002480

RESUMEN

INTRODUCTION: There is increasing interest in plasma amyloid beta (Aß) as an endophenotype of Alzheimer's disease (AD). Identifying the genetic determinants of plasma Aß levels may elucidate important biological processes that determine plasma Aß measures. METHODS: We included 12,369 non-demented participants from eight population-based studies. Imputed genetic data and measured plasma Aß1-40, Aß1-42 levels and Aß1-42/Aß1-40 ratio were used to perform genome-wide association studies, and gene-based and pathway analyses. Significant variants and genes were followed up for their association with brain positron emission tomography Aß deposition and AD risk. RESULTS: Single-variant analysis identified associations with apolipoprotein E (APOE) for Aß1-42 and Aß1-42/Aß1-40 ratio, and BACE1 for Aß1-40. Gene-based analysis of Aß1-40 additionally identified associations for APP, PSEN2, CCK, and ZNF397. There was suggestive evidence for interaction between a BACE1 variant and APOE ε4 on brain Aß deposition. DISCUSSION: Identification of variants near/in known major Aß-processing genes strengthens the relevance of plasma-Aß levels as an endophenotype of AD.


Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/genética , Precursor de Proteína beta-Amiloide/genética , Amiloide , Apolipoproteínas E/genética , Ácido Aspártico Endopeptidasas/genética , Estudio de Asociación del Genoma Completo , Voluntarios Sanos , Presenilina-2/genética , Enfermedad de Alzheimer/genética , Amiloide/sangre , Amiloide/metabolismo , Encéfalo/metabolismo , Humanos , Tomografía de Emisión de Positrones
6.
Acta Neuropathol ; 140(6): 811-830, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32926214

RESUMEN

Alzheimer's disease (AD) is characterized by amyloid-beta (Aß) deposits, which come in myriad morphologies with varying clinical relevance. Previously, we observed an atypical Aß deposit, referred to as the coarse-grained plaque. In this study, we evaluate the plaque's association with clinical disease and perform in-depth immunohistochemical and morphological characterization. The coarse-grained plaque, a relatively large (Ø ≈ 80 µm) deposit, characterized as having multiple cores and Aß-devoid pores, was prominent in the neocortex. The plaque was semi-quantitatively scored in the middle frontal gyrus of Aß-positive cases (n = 74), including non-demented cases (n = 15), early-onset (EO)AD (n = 38), and late-onset (LO)AD cases (n = 21). The coarse-grained plaque was only observed in cases with clinical dementia and more frequently present in EOAD compared to LOAD. This plaque was associated with a homozygous APOE ε4 status and cerebral amyloid angiopathy (CAA). In-depth characterization was done by studying the coarse-grained plaque's neuritic component (pTau, APP, PrPC), Aß isoform composition (Aß40, Aß42, AßN3pE, pSer8Aß), its neuroinflammatory component (C4b, CD68, MHC-II, GFAP), and its vascular attribution (laminin, collagen IV, norrin). The plaque was compared to the classic cored plaque, cotton wool plaque, and CAA. Similar to CAA but different from classic cored plaques, the coarse-grained plaque was predominantly composed of Aß40. Furthermore, the coarse-grained plaque was distinctly associated with both intense neuroinflammation and vascular (capillary) pathology. Confocal laser scanning microscopy (CLSM) and 3D analysis revealed for most coarse-grained plaques a particular Aß40 shell structure and a direct relation with vessels. Based on its morphological and biochemical characteristics, we conclude that the coarse-grained plaque is a divergent Aß plaque-type associated with EOAD. Differences in Aß processing and aggregation, neuroinflammatory response, and vascular clearance may presumably underlie the difference between coarse-grained plaques and other Aß deposits. Disentangling specific Aß deposits between AD subgroups may be important in the search for disease-mechanistic-based therapies.


Asunto(s)
Enfermedad de Alzheimer/patología , Encéfalo/patología , Angiopatía Amiloide Cerebral/patología , Placa Amiloide/patología , Edad de Inicio , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/metabolismo , Capilares/patología , Angiopatía Amiloide Cerebral/genética , Femenino , Humanos , Masculino , Neuritas/patología
7.
Acta Neuropathol ; 139(6): 1025-1044, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32166339

RESUMEN

A rare coding variant (rs72824905, p.P522R) conferring protection against Alzheimer's disease (AD) was identified in the gene encoding the enzyme phospholipase-C-γ2 (PLCG2) that is highly expressed in microglia. To explore the protective nature of this variant, we employed latent process linear mixed models to examine the association of p.P522R with longitudinal cognitive decline in 3595 MCI patients, and in 10,097 individuals from population-based studies. Furthermore, association with CSF levels of pTau181, total tau, and Aß1-42 was assessed in 1261 MCI patients. We found that MCI patients who carried the p.P522R variant showed a slower rate of cognitive decline compared to non-carriers and that this effect was mediated by lower pTau181 levels in CSF. The effect size of the association of p.P522R with the cognitive decline and pTau181 was similar to that of APOE-ε4, the strongest genetic risk factor for AD. Interestingly, the protective effect of p.P522R was more pronounced in MCI patients with low Aß1-42 levels suggesting a role of PLCG2 in the response to amyloid pathology. In line with this hypothesis, we observed no protective effect of the PLCG2 variant on the cognitive decline in population-based studies probably due to the lower prevalence of amyloid positivity in these samples compared to MCI patients. Concerning the potential biological underpinnings, we identified a network of co-expressed proteins connecting PLCG2 to APOE and TREM2 using unsupervised co-regulatory network analysis. The network was highly enriched for the complement cascade and genes differentially expressed in disease-associated microglia. Our data show that p.P522R in PLCG2 reduces AD disease progression by mitigating tau pathology in the presence of amyloid pathology and, as a consequence, maintains cognitive function. Targeting the enzyme PLCG2 might provide a new therapeutic approach for treating AD.


Asunto(s)
Enfermedad de Alzheimer/patología , Disfunción Cognitiva/genética , Disfunción Cognitiva/patología , Fosfolipasa C gamma/metabolismo , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/genética , Biomarcadores/análisis , Cognición/fisiología , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas tau/líquido cefalorraquídeo , Proteínas tau/metabolismo
9.
Genomics ; 111(4): 808-818, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-29857119

RESUMEN

The Alzheimer's Disease Sequencing Project (ADSP) performed whole genome sequencing (WGS) of 584 subjects from 111 multiplex families at three sequencing centers. Genotype calling of single nucleotide variants (SNVs) and insertion-deletion variants (indels) was performed centrally using GATK-HaplotypeCaller and Atlas V2. The ADSP Quality Control (QC) Working Group applied QC protocols to project-level variant call format files (VCFs) from each pipeline, and developed and implemented a novel protocol, termed "consensus calling," to combine genotype calls from both pipelines into a single high-quality set. QC was applied to autosomal bi-allelic SNVs and indels, and included pipeline-recommended QC filters, variant-level QC, and sample-level QC. Low-quality variants or genotypes were excluded, and sample outliers were noted. Quality was assessed by examining Mendelian inconsistencies (MIs) among 67 parent-offspring pairs, and MIs were used to establish additional genotype-specific filters for GATK calls. After QC, 578 subjects remained. Pipeline-specific QC excluded ~12.0% of GATK and 14.5% of Atlas SNVs. Between pipelines, ~91% of SNV genotypes across all QCed variants were concordant; 4.23% and 4.56% of genotypes were exclusive to Atlas or GATK, respectively; the remaining ~0.01% of discordant genotypes were excluded. For indels, variant-level QC excluded ~36.8% of GATK and 35.3% of Atlas indels. Between pipelines, ~55.6% of indel genotypes were concordant; while 10.3% and 28.3% were exclusive to Atlas or GATK, respectively; and ~0.29% of discordant genotypes were. The final WGS consensus dataset contains 27,896,774 SNVs and 3,133,926 indels and is publicly available.


Asunto(s)
Enfermedad de Alzheimer/genética , Estudio de Asociación del Genoma Completo/normas , Técnicas de Genotipaje/normas , Control de Calidad , Secuenciación Completa del Genoma/normas , Algoritmos , Femenino , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Técnicas de Genotipaje/métodos , Humanos , Masculino , Polimorfismo Genético , Secuenciación Completa del Genoma/métodos
10.
Hum Mol Genet ; 26(2): 438-453, 2017 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-28073927

RESUMEN

Primary open-angle glaucoma (POAG), the most common optic neuropathy, is a heritable disease. Siblings of POAG cases have a ten-fold increased risk of developing the disease. Intraocular pressure (IOP) and optic nerve head characteristics are used clinically to predict POAG risk. We conducted a genome-wide association meta-analysis of IOP and optic disc parameters and validated our findings in multiple sets of POAG cases and controls. Using imputation to the 1000 genomes (1000G) reference set, we identified 9 new genomic regions associated with vertical cup-disc ratio (VCDR) and 1 new region associated with IOP. Additionally, we found 5 novel loci for optic nerve cup area and 6 for disc area. Previously it was assumed that genetic variation influenced POAG either through IOP or via changes to the optic nerve head; here we present evidence that some genomic regions affect both IOP and the disc parameters. We characterized the effect of the novel loci through pathway analysis and found that pathways involved are not entirely distinct as assumed so far. Further, we identified a novel association between CDKN1A and POAG. Using a zebrafish model we show that six6b (associated with POAG and optic nerve head variation) alters the expression of cdkn1a. In summary, we have identified several novel genes influencing the major clinical risk predictors of POAG and showed that genetic variation in CDKN1A is important in POAG risk.


Asunto(s)
Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Glaucoma de Ángulo Abierto/genética , Proteínas de Homeodominio/genética , Enfermedades del Nervio Óptico/genética , Proteínas de Pez Cebra/genética , Femenino , Genoma Humano , Estudio de Asociación del Genoma Completo , Glaucoma de Ángulo Abierto/patología , Humanos , Presión Intraocular/genética , Masculino , Persona de Mediana Edad , Disco Óptico/patología , Enfermedades del Nervio Óptico/patología , Tonometría Ocular
11.
Acta Neuropathol ; 138(2): 237-250, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31131421

RESUMEN

The genetic variant rs72824905-G (minor allele) in the PLCG2 gene was previously associated with a reduced Alzheimer's disease risk (AD). The role of PLCG2 in immune system signaling suggests it may also protect against other neurodegenerative diseases and possibly associates with longevity. We studied the effect of the rs72824905-G on seven neurodegenerative diseases and longevity, using 53,627 patients, 3,516 long-lived individuals and 149,290 study-matched controls. We replicated the association of rs72824905-G with reduced AD risk and we found an association with reduced risk of dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD). We did not find evidence for an effect on Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) risks, despite adequate sample sizes. Conversely, the rs72824905-G allele was associated with increased likelihood of longevity. By-proxy analyses in the UK Biobank supported the associations with both dementia and longevity. Concluding, rs72824905-G has a protective effect against multiple neurodegenerative diseases indicating shared aspects of disease etiology. Our findings merit studying the PLCγ2 pathway as drug-target.


Asunto(s)
Demencia/genética , Longevidad/genética , Mutación , Fosfolipasa C gamma/genética , Alelos , Enfermedad de Alzheimer/genética , Esclerosis Amiotrófica Lateral/genética , Encéfalo/inmunología , Encéfalo/metabolismo , Encéfalo/patología , Demencia Frontotemporal/genética , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Enfermedad por Cuerpos de Lewy/genética , Microglía/metabolismo , Esclerosis Múltiple/genética , Neuroimagen , Enfermedad de Parkinson/genética , Riesgo
12.
PLoS Genet ; 12(10): e1006327, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27764101

RESUMEN

We performed an exome-wide association analysis in 1393 late-onset Alzheimer's disease (LOAD) cases and 8141 controls from the CHARGE consortium. We found that a rare variant (P155L) in TM2D3 was enriched in Icelanders (~0.5% versus <0.05% in other European populations). In 433 LOAD cases and 3903 controls from the Icelandic AGES sub-study, P155L was associated with increased risk and earlier onset of LOAD [odds ratio (95% CI) = 7.5 (3.5-15.9), p = 6.6x10-9]. Mutation in the Drosophila TM2D3 homolog, almondex, causes a phenotype similar to loss of Notch/Presenilin signaling. Human TM2D3 is capable of rescuing these phenotypes, but this activity is abolished by P155L, establishing it as a functionally damaging allele. Our results establish a rare TM2D3 variant in association with LOAD susceptibility, and together with prior work suggests possible links to the ß-amyloid cascade.


Asunto(s)
Enfermedad de Alzheimer/genética , Proteínas de Drosophila/genética , Proteínas de la Membrana/genética , Receptores Notch/genética , Tropomiosina/genética , Edad de Inicio , Anciano , Alelos , Enfermedad de Alzheimer/patología , Precursor de Proteína beta-Amiloide/genética , Animales , Apolipoproteínas E/genética , Drosophila melanogaster/genética , Exoma/genética , Femenino , Estudio de Asociación del Genoma Completo , Genómica , Humanos , Islandia , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Mutación , Fenotipo , Población Blanca
15.
Alzheimers Dement ; 14(7): 848-857, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29494809

RESUMEN

INTRODUCTION: Exploring the role of Alzheimer's disease (AD) implicated pathways in the predementia phase may provide new insight for preventive and clinical trials targeting disease specific pathways. METHODS: We constructed weighted Genetic risk scores, first based on 20 genome-wide significant AD risk variants and second clustering these variants within pathways. Risk scores were investigated for their association with AD, mild cognitive impairment, and brain magnetic resonance imaging phenotypes including white matter lesions, hippocampal volume, and brain volume. RESULTS: The risk score capturing endocytosis pathway was significantly associated with mild cognitive impairment (P = 1.44 × 10-4). Immune response (P = .016) and clathrin/AP2 adaptor complex pathway (P = 3.55 × 10-3) excluding apolipoprotein E also showed modest association with white matter lesions but did not sustain Bonferroni correction (P = 9.09 × 10-4). DISCUSSION: Our study suggests that the clinical spectrum of early AD pathology is explained by different biological pathways, in particular, the endocytosis, clathrin/AP2 adaptor complex, and immune response pathways, that are independent of apolipoprotein E (APOE).


Asunto(s)
Enfermedad de Alzheimer/genética , Disfunción Cognitiva/genética , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/patología , Encéfalo/patología , Disfunción Cognitiva/patología , Endocitosis/genética , Femenino , Hipocampo/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Países Bajos , Estudios Prospectivos , Factores de Riesgo , Sustancia Blanca/patología
16.
Alzheimers Dement ; 14(6): 723-733, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29519576

RESUMEN

INTRODUCTION: Metabolite, lipid, and lipoprotein lipid profiling can provide novel insights into mechanisms underlying incident dementia and Alzheimer's disease. METHODS: We studied eight prospective cohorts with 22,623 participants profiled by nuclear magnetic resonance or mass spectrometry metabolomics. Four cohorts were used for discovery with replication undertaken in the other four to avoid false positives. For metabolites that survived replication, combined association results are presented. RESULTS: Over 246,698 person-years, 995 and 745 cases of incident dementia and Alzheimer's disease were detected, respectively. Three branched-chain amino acids (isoleucine, leucine, and valine), creatinine and two very low density lipoprotein (VLDL)-specific lipoprotein lipid subclasses were associated with lower dementia risk. One high density lipoprotein (HDL; the concentration of cholesterol esters relative to total lipids in large HDL) and one VLDL (total cholesterol to total lipids ratio in very large VLDL) lipoprotein lipid subclass was associated with increased dementia risk. Branched-chain amino acids were also associated with decreased Alzheimer's disease risk and the concentration of cholesterol esters relative to total lipids in large HDL with increased Alzheimer's disease risk. DISCUSSION: Further studies can clarify whether these molecules play a causal role in dementia pathogenesis or are merely markers of early pathology.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Aminoácidos de Cadena Ramificada/metabolismo , Demencia , Metabolómica/métodos , Adulto , Anciano , Enfermedad de Alzheimer/patología , Biomarcadores/metabolismo , Demencia/metabolismo , Demencia/patología , Humanos , Lipoproteínas/metabolismo , Imagen por Resonancia Magnética , Espectrometría de Masas , Persona de Mediana Edad , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo
17.
Alzheimers Dement ; 14(6): 707-722, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29316447

RESUMEN

INTRODUCTION: Identifying circulating metabolites that are associated with cognition and dementia may improve our understanding of the pathogenesis of dementia and provide crucial readouts for preventive and therapeutic interventions. METHODS: We studied 299 metabolites in relation to cognition (general cognitive ability) in two discovery cohorts (N total = 5658). Metabolites significantly associated with cognition after adjusting for multiple testing were replicated in four independent cohorts (N total = 6652), and the associations with dementia and Alzheimer's disease (N = 25,872) and lifestyle factors (N = 5168) were examined. RESULTS: We discovered and replicated 15 metabolites associated with cognition including subfractions of high-density lipoprotein, docosahexaenoic acid, ornithine, glutamine, and glycoprotein acetyls. These associations were independent of classical risk factors including high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, and apolipoprotein E (APOE) genotypes. Six of the cognition-associated metabolites were related to the risk of dementia and lifestyle factors. DISCUSSION: Circulating metabolites were consistently associated with cognition, dementia, and lifestyle factors, opening new avenues for prevention of cognitive decline and dementia.


Asunto(s)
Biomarcadores/metabolismo , Disfunción Cognitiva/metabolismo , Demencia/metabolismo , Adulto , Anciano , Enfermedad de Alzheimer/metabolismo , Estudios de Cohortes , Femenino , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Factores de Riesgo
18.
Hum Mutat ; 38(8): 1025-1032, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28493391

RESUMEN

Recently, the Haplotype Reference Consortium (HRC) released a large imputation panel that allows more accurate imputation of genetic variants. In this study, we compared a set of directly assayed common and rare variants from an exome array to imputed genotypes, that is, 1000 genomes project (1000GP) and HRC. We showed that imputation using the HRC panel improved the concordance between assayed and imputed genotypes at common, and especially, low-frequency variants. Furthermore, we performed a genome-wide association meta-analysis of vertical cup-disc ratio, a highly heritable endophenotype of glaucoma, in four cohorts using 1000GP and HRC imputations. We compared the results of the meta-analysis using 1000GP to the meta-analysis results using HRC. Overall, we found that using HRC imputation significantly improved P values (P = 3.07 × 10-61 ), particularly for suggestive variants. Both meta-analyses were performed in the same sample size, yet we found eight genome-wide significant loci in the HRC-based meta-analysis versus seven genome-wide significant loci in the 1000GP-based meta-analysis. This study provides supporting evidence of the new avenues for gene discovery and fine mapping that the HRC imputation panel offers.


Asunto(s)
Exoma/genética , Haplotipos/genética , Frecuencia de los Genes/genética , Variación Genética/genética , Genoma Humano/genética , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Polimorfismo de Nucleótido Simple/genética
19.
Hum Mol Genet ; 24(9): 2689-99, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25637523

RESUMEN

Primary open-angle glaucoma (POAG) is a blinding disease. Two important risk factors for this disease are a positive family history and elevated intraocular pressure (IOP), which is also highly heritable. Genes found to date associated with IOP and POAG are ABCA1, CAV1/CAV2, GAS7 and TMCO1. However, these genes explain only a small part of the heritability of IOP and POAG. We performed a genome-wide association study of IOP in the population-based Rotterdam Study I and Rotterdam Study II using single nucleotide polymorphisms (SNPs) imputed to 1000 Genomes. In this discovery cohort (n = 8105), we identified a new locus associated with IOP. The most significantly associated SNP was rs58073046 (ß = 0.44, P-value = 1.87 × 10(-8), minor allele frequency = 0.12), within the gene ARHGEF12. Independent replication in five population-based studies (n = 7471) resulted in an effect size in the same direction that was significantly associated (ß = 0.16, P-value = 0.04). The SNP was also significantly associated with POAG in two independent case-control studies [n = 1225 cases and n = 4117 controls; odds ratio (OR) = 1.53, P-value = 1.99 × 10(-8)], especially with high-tension glaucoma (OR = 1.66, P-value = 2.81 × 10(-9); for normal-tension glaucoma OR = 1.29, P-value = 4.23 × 10(-2)). ARHGEF12 plays an important role in the RhoA/RhoA kinase pathway, which has been implicated in IOP regulation. Furthermore, it binds to ABCA1 and links the ABCA1, CAV1/CAV2 and GAS7 pathway to Mendelian POAG genes (MYOC, OPTN, WDR36). In conclusion, this study identified a novel association between IOP and ARHGEF12.


Asunto(s)
Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Glaucoma/genética , Glaucoma/fisiopatología , Presión Intraocular/genética , Factores de Intercambio de Guanina Nucleótido Rho/genética , Anciano , Femenino , Expresión Génica , Estudio de Asociación del Genoma Completo , Glaucoma/epidemiología , Glaucoma de Ángulo Abierto/genética , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Masculino , Metaanálisis como Asunto , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Mapeo de Interacción de Proteínas , Mapas de Interacción de Proteínas , Factores de Intercambio de Guanina Nucleótido Rho/metabolismo
20.
Hum Brain Mapp ; 38(5): 2408-2423, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28145022

RESUMEN

BACKGROUND: The combination of genetics and imaging has improved their understanding of the brain through studies of aggregate measures obtained from high-resolution structural imaging. Voxel-wise analyses have the potential to provide more detailed information of genetic influences on the brain. Here they report a large-scale study of the heritability of gray matter at voxel resolution (1 × 1 × 1 mm). METHODS: Validated voxel-based morphometry (VBM) protocols were applied to process magnetic resonance imaging data of 3,239 unrelated subjects from a population-based study and 491 subjects from two family-based studies. Genome-wide genetic data was used to estimate voxel-wise gray matter heritability of the unrelated subjects and pedigree-structure was used to estimate heritability in families. They subsequently associated two genetic variants, known to be linked with subcortical brain volume, with most heritable voxels to determine if this would enhance their association signals. RESULTS: Voxels significantly heritable in both estimates mapped to subcortical structures, but also voxels in the language areas of the left hemisphere were found significantly heritable. When comparing regional patterns of heritability, family-based estimates were higher than population-based estimates. However, regional consistency of the heritability measures across study designs was high (Pearson's correlation coefficient = 0.73, P = 2.6 × 10-13 ). They further show enhancement of the association signal of two previously discovered genetic loci with subcortical volume by using only the most heritable voxels. CONCLUSION: Gray matter voxel-wise heritability can be reliably estimated with different methods. Combining heritability estimates from multiple studies is feasible to construct reliable heritability maps of gray matter voxels. Hum Brain Mapp 38:2408-2423, 2017. © 2017 Wiley Periodicals, Inc.


Asunto(s)
Salud de la Familia , Ligamiento Genético , Sustancia Gris/diagnóstico por imagen , Imagen por Resonancia Magnética , Anciano , Anciano de 80 o más Años , Austria , Mapeo Encefálico , Estudios de Cohortes , Planificación en Salud Comunitaria , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Países Bajos
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