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1.
Genome Res ; 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39406499

RESUMEN

Tandem repeats (TR) play important roles in genomic variation and disease risk in humans. Long-read sequencing allows for the accurate characterization of TRs, however, the underlying bioinformatics perspectives remain challenging. We present otter and TREAT: otter is a fast targeted local assembler, cross-compatible across different sequencing platforms. It is integrated in TREAT, an end-to-end workflow for TR characterization, visualization and analysis across multiple genomes. In a comparison with existing tools based on long-read sequencing data from both Oxford Nanopore Technology (ONT, Simplex and Duplex) and PacBio (Sequel 2 and Revio), otter and TREAT achieved state-of-the-art genotyping and motif characterisation accuracy. Applied to clinically relevant TRs, TREAT/otter significantly identified individuals with pathogenic TR expansions. When applied to a case-control setting, we significantly replicated previously reported associations of TRs with Alzheimer's Disease, including those near or within APOC1 (p=2.63x10-9), SPI1 (p=6.5x10-3) and ABCA7 (p=0.04) genes. We used TREAT/otter to systematically evaluate potential biases when genotyping TRs using diverse ONT and PacBio long-read sequencing datasets. We showed that, in rare cases (0.06%), long-read sequencing suffers from coverage drops in TRs, including the disease-associated TRs in ABCA7 and RFC1 genes. Such coverage drops can lead to TR misgenotyping, hampering the accurate characterization of TR alleles. Taken together, our tools can accurately genotype TR across different sequencing technologies and with minimal requirements, allowing end-to-end analysis and comparisons of TR in human genomes, with broad applications in research and clinical fields.

2.
Proc Natl Acad Sci U S A ; 121(37): e2408262121, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39226352

RESUMEN

Truncating genetic variants of SORL1, encoding the endosome recycling receptor SORLA, have been accepted as causal of Alzheimer's disease (AD). However, most genetic variants observed in SORL1 are missense variants, for which it is complicated to determine the pathogenicity level because carriers come from pedigrees too small to be informative for penetrance estimations. Here, we describe three unrelated families in which the SORL1 coding missense variant rs772677709, that leads to a p.Y1816C substitution, segregates with Alzheimer's disease. Further, we investigate the effect of SORLA p.Y1816C on receptor maturation, cellular localization, and trafficking in cell-based assays. Under physiological circumstances, SORLA dimerizes within the endosome, allowing retromer-dependent trafficking from the endosome to the cell surface, where the luminal part is shed into the extracellular space (sSORLA). Our results showed that the p.Y1816C mutant impairs SORLA homodimerization in the endosome, leading to decreased trafficking to the cell surface and less sSORLA shedding. These trafficking defects of the mutant receptor can be rescued by the expression of the SORLA 3Fn-minireceptor. Finally, we find that iPSC-derived neurons with the engineered p.Y1816C mutation have enlarged endosomes, a defining cytopathology of AD. Our studies provide genetic as well as functional evidence that the SORL1 p.Y1816C variant is causal for AD. The partial penetrance of the mutation suggests this mutation should be considered in clinical genetic screening of multiplex early-onset AD families.


Asunto(s)
Enfermedad de Alzheimer , Endosomas , Proteínas Relacionadas con Receptor de LDL , Proteínas de Transporte de Membrana , Linaje , Humanos , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Endosomas/metabolismo , Proteínas Relacionadas con Receptor de LDL/genética , Proteínas Relacionadas con Receptor de LDL/metabolismo , Femenino , Masculino , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Mutación Missense , Transporte de Proteínas , Multimerización de Proteína , Anciano , Persona de Mediana Edad , Células HEK293
3.
Neurology ; 103(7): e209663, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39270152

RESUMEN

BACKGROUND AND OBJECTIVES: More than 200 genetic variants have been associated with multiple sclerosis (MS) susceptibility. However, it is unclear to what extent genetic factors influence lifetime risk of MS. Using a population-based birth-year cohort, we investigate the effect of genetics on lifetime risk of MS. METHODS: In the Project Y study, we tracked down almost all persons with MS (pwMS) from birth year 1966 in the Netherlands. As control participants, we included non-MS participants from the Project Y cohort (born 1965-1967 in the Netherlands) and non-MS participants from the Amsterdam Dementia Cohort born between 1963 and 1969. Genetic variants associated with MS were determined in pwMS and control participants using genotyping or imputation methods. Polygenic risk scores (PRSs) based on variants and weights from the largest genetic study in MS were calculated for each participant and assigned into deciles based on the PRS distribution in the control participants. We examined the lifetime risk for each decile and the association between PRS and MS disease variables, including age at onset and time to secondary progression. RESULTS: MS-PRS was calculated for 285 pwMS (mean age 53.0 ± 0.9 years, 72.3% female) and 267 control participants (mean age 51.8 ± 3.2 years, 58.1% female). Based on the lifetime risk estimation, we observed that 1:2,739 of the women with the lowest 30% genetic risk developed MS, whereas 1:92 of the women with the top 10% highest risk developed MS. For men, only 1:7,900 developed MS in the lowest 30% genetic risk group, compared with 1:293 men with the top 10% genetic risk. The PRS was not significantly associated with age at onset and time to secondary progression in both sexes. DISCUSSION: Our results show that the lifetime risk of MS is strongly influenced by genetic factors. Our findings have the potential to support diagnostic certainty in individuals with suspected MS: a high PRS could strengthen a diagnosis, but especially a PRS from the lowest tail of the PRS distribution should be considered a red flag and could prevent misdiagnosing conditions that mimic MS.


Asunto(s)
Predisposición Genética a la Enfermedad , Herencia Multifactorial , Esclerosis Múltiple , Humanos , Esclerosis Múltiple/genética , Esclerosis Múltiple/epidemiología , Masculino , Femenino , Persona de Mediana Edad , Herencia Multifactorial/genética , Predisposición Genética a la Enfermedad/genética , Países Bajos/epidemiología , Cohorte de Nacimiento , Edad de Inicio , Estudios de Cohortes , Factores de Riesgo , Progresión de la Enfermedad , Puntuación de Riesgo Genético
4.
Alzheimers Dement ; 20(6): 3864-3875, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38634500

RESUMEN

BACKGROUND: Alzheimer's disease (AD) prevalence increases with age, yet a small fraction of the population reaches ages > 100 years without cognitive decline. We studied the genetic factors associated with such resilience against AD. METHODS: Genome-wide association studies identified 86 single nucleotide polymorphisms (SNPs) associated with AD risk. We estimated SNP frequency in 2281 AD cases, 3165 age-matched controls, and 346 cognitively healthy centenarians. We calculated a polygenic risk score (PRS) for each individual and investigated the functional properties of SNPs enriched/depleted in centenarians. RESULTS: Cognitively healthy centenarians were enriched with the protective alleles of the SNPs associated with AD risk. The protective effect concentrated on the alleles in/near ANKH, GRN, TMEM106B, SORT1, PLCG2, RIN3, and APOE genes. This translated to >5-fold lower PRS in centenarians compared to AD cases (P = 7.69 × 10-71), and 2-fold lower compared to age-matched controls (P = 5.83 × 10-17). DISCUSSION: Maintaining cognitive health until extreme ages requires complex genetic protection against AD, which concentrates on the genes associated with the endolysosomal and immune systems. HIGHLIGHTS: Cognitively healthy cent enarians are enriched with the protective alleles of genetic variants associated with Alzheimer's disease (AD). The protective effect is concentrated on variants involved in the immune and endolysosomal systems. Combining variants into a polygenic risk score (PRS) translated to > 5-fold lower PRS in centenarians compared to AD cases, and ≈ 2-fold lower compared to middle-aged healthy controls.


Asunto(s)
Enfermedad de Alzheimer , Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido Simple , Humanos , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/prevención & control , Femenino , Masculino , Anciano de 80 o más Años , Predisposición Genética a la Enfermedad , Herencia Multifactorial/genética , Alelos , Estudios de Casos y Controles
5.
Brain ; 147(10): 3522-3533, 2024 Oct 03.
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 (standard deviation, 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, mass reaction monitoring-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 = 1.65 × 10-8), ZCWPW1-PILRB (rs1476679, P = 2.73 × 10-32), CTSH-CTSH (rs3784539, P = 2.88 × 10-24) and HESX1-RETN (rs186108507, P = 8.39 × 10-8), 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 = 3.90 × 10-7). DLB risk locus GBA showed positive trans effects on seven inter-related CSF levels in DLB patients only. No pQTLs were identified for FTD loci, either for the total sample as for analyses performed within FTD only. Protein QTL 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.


Asunto(s)
Enfermedad de Alzheimer , Demencia , Demencia Frontotemporal , Estudio de Asociación del Genoma Completo , Proteoma , Humanos , Femenino , Masculino , Anciano , Persona de Mediana Edad , Demencia Frontotemporal/genética , Demencia Frontotemporal/líquido cefalorraquídeo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/líquido cefalorraquídeo , Proteoma/genética , Demencia/líquido cefalorraquídeo , Demencia/genética , Enfermedad por Cuerpos de Lewy/genética , Enfermedad por Cuerpos de Lewy/líquido cefalorraquídeo , Predisposición Genética a la Enfermedad , Estudios de Cohortes , Factores de Riesgo , Biomarcadores/líquido cefalorraquídeo
6.
Alzheimers Dement ; 19(11): 5036-5047, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37092333

RESUMEN

INTRODUCTION: Neuropathological substrates associated with neurodegeneration occur in brains of the oldest old. How does this affect cognitive performance? METHODS: The 100-plus Study is an ongoing longitudinal cohort study of centenarians who self-report to be cognitively healthy; post mortem brain donation is optional. In 85 centenarian brains, we explored the correlations between the levels of 11 neuropathological substrates with ante mortem performance on 12 neuropsychological tests. RESULTS: Levels of neuropathological substrates varied: we observed levels up to Thal-amyloid beta phase 5, Braak-neurofibrillary tangle (NFT) stage V, Consortium to Establish a Registry for Alzheimer's Disease (CERAD)-neuritic plaque score 3, Thal-cerebral amyloid angiopathy stage 3, Tar-DNA binding protein 43 (TDP-43) stage 3, hippocampal sclerosis stage 1, Braak-Lewy bodies stage 6, atherosclerosis stage 3, cerebral infarcts stage 1, and cerebral atrophy stage 2. Granulovacuolar degeneration occurred in all centenarians. Some high performers had the highest neuropathology scores. DISCUSSION: Only Braak-NFT stage and limbic-predominant age-related TDP-43 encephalopathy (LATE) pathology associated significantly with performance across multiple cognitive domains. Of all cognitive tests, the clock-drawing test was particularly sensitive to levels of multiple neuropathologies.


Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Anciano de 80 o más Años , Humanos , Péptidos beta-Amiloides/metabolismo , Centenarios , Estudios Longitudinales , Enfermedad de Alzheimer/patología , Encéfalo/patología , Ovillos Neurofibrilares/patología , Neuropatología , Cognición
8.
Alzheimers Dement ; 19(7): 2831-2841, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36583547

RESUMEN

INTRODUCTION: With increasing age, neuropathological substrates associated with Alzheimer's disease (AD) accumulate in brains of cognitively healthy individuals-are they resilient, or resistant to AD-associated neuropathologies? METHODS: In 85 centenarian brains, we correlated NIA (amyloid) stages, Braak (neurofibrillary tangle) stages, and CERAD (neuritic plaque) scores with cognitive performance close to death as determined by Mini-Mental State Examination (MMSE) scores. We assessed centenarian brains against 2131 brains from AD patients, non-AD demented, and non-demented individuals in an age continuum ranging from 16 to 100+ years. RESULTS: With age, brains from non-demented individuals reached the NIA and Braak stages observed in AD patients, while CERAD scores remained lower. In centenarians, NIA stages varied (22.4% were the highest stage 3), Braak stages rarely exceeded stage IV (5.9% were V), and CERAD scores rarely exceeded 2 (4.7% were 3); within these distributions, we observed no correlation with the MMSE (NIA: P = 0.60; Braak: P = 0.08; CERAD: P = 0.16). DISCUSSION: Cognitive health can be maintained despite the accumulation of high levels of AD-related neuropathological substrates. HIGHLIGHTS: Cognitively healthy elderly have AD neuropathology levels similar to AD patients. AD neuropathology loads do not correlate with cognitive performance in centenarians. Some centenarians are resilient to the highest levels of AD neuropathology.


Asunto(s)
Enfermedad de Alzheimer , Ovillos Neurofibrilares , Anciano de 80 o más Años , Humanos , Anciano , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Ovillos Neurofibrilares/patología , Placa Amiloide/patología , Centenarios , Enfermedad de Alzheimer/patología , Encéfalo/patología
9.
Alzheimers Dement ; 19(6): 2265-2275, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36453627

RESUMEN

INTRODUCTION: There are limited data on prevalence of dementia in centenarians and near-centenarians (C/NC), its determinants, and whether the risk of dementia continues to rise beyond 100. METHODS: Participant-level data were obtained from 18 community-based studies (N = 4427) in 11 countries that included individuals ≥95 years. A harmonization protocol was applied to cognitive and functional impairments, and a meta-analysis was performed. RESULTS: The mean age was 98.3 years (SD = 2.67); 79% were women. After adjusting for age, sex, and education, dementia prevalence was 53.2% in women and 45.5% in men, with risk continuing to increase with age. Education (OR 0.95;0.92-0.98) was protective, as was hypertension (odds ratio [OR] 0.51;0.35-0.74) in five studies. Dementia was not associated with diabetes, vision and hearing impairments, smoking, and body mass index (BMI). DISCUSSION: Among the exceptional old, dementia prevalence remains higher in the older participants. Education was protective against dementia, but other factors for dementia-free survival in C/NC remain to be understood.


Asunto(s)
Centenarios , Cognición , Masculino , Anciano de 80 o más Años , Humanos , Femenino , Índice de Masa Corporal , Escolaridad
10.
Nat Genet ; 54(12): 1786-1794, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36411364

RESUMEN

Alzheimer's disease (AD), the leading cause of dementia, has an estimated heritability of approximately 70%1. The genetic component of AD has been mainly assessed using genome-wide association studies, which do not capture the risk contributed by rare variants2. Here, we compared the gene-based burden of rare damaging variants in exome sequencing data from 32,558 individuals-16,036 AD cases and 16,522 controls. Next to variants in TREM2, SORL1 and ABCA7, we observed a significant association of rare, predicted damaging variants in ATP8B4 and ABCA1 with AD risk, and a suggestive signal in ADAM10. Additionally, the rare-variant burden in RIN3, CLU, ZCWPW1 and ACE highlighted these genes as potential drivers of respective AD-genome-wide association study loci. Variants associated with the strongest effect on AD risk, in particular loss-of-function variants, are enriched in early-onset AD cases. Our results provide additional evidence for a major role for amyloid-ß precursor protein processing, amyloid-ß aggregation, lipid metabolism and microglial function in AD.


Asunto(s)
Transportador 1 de Casete de Unión a ATP , Adenosina Trifosfatasas , Enfermedad de Alzheimer , Exosomas , Humanos , Adenosina Trifosfatasas/genética , Enfermedad de Alzheimer/genética , Transportador 1 de Casete de Unión a ATP/genética , Estudio de Asociación del Genoma Completo , Factores de Riesgo , Exosomas/genética
11.
Alzheimers Res Ther ; 14(1): 77, 2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35650585

RESUMEN

BACKGROUND: Many families with clinical early-onset Alzheimer's disease (EOAD) remain genetically unexplained. A combination of genetic factors is not standardly investigated. In addition to monogenic causes, we evaluated the possible polygenic architecture in a large series of families, to assess if genetic testing of familial EOAD could be expanded. METHODS: Thirty-six pedigrees (77 patients) were ascertained from a larger cohort of patients, with relationships determined by genetic data (exome sequencing data and/or SNP arrays). All families included at least one AD patient with symptom onset <70 years. We evaluated segregating rare variants in known dementia-related genes, and other genes or variants if shared by multiple families. APOE was genotyped and duplications in APP were assessed by targeted test or using SNP array data. We computed polygenic risk scores (PRS) compared with a reference population-based dataset, by imputing SNP arrays or exome sequencing data. RESULTS: In eight families, we identified a pathogenic variant, including the genes APP, PSEN1, SORL1, and an unexpected GRN frameshift variant. APOE-ε4 homozygosity was present in eighteen families, showing full segregation with disease in seven families. Eight families harbored a variant of uncertain significance (VUS), of which six included APOE-ε4 homozygous carriers. PRS was not higher in the families combined compared with the population mean (beta 0.05, P = 0.21), with a maximum increase of 0.61 (OR = 1.84) in the GRN family. Subgroup analyses indicated lower PRS in six APP/PSEN1 families compared with the rest (beta -0.22 vs. 0.10; P = 0.009) and lower APOE burden in all eight families with monogenic cause (beta 0.29 vs. 1.15, P = 0.010). Nine families remained without a genetic cause or risk factor identified. CONCLUSION: Besides monogenic causes, we suspect a polygenic disease architecture in multiple families based on APOE and rare VUS. The risk conveyed by PRS is modest across the studied families. Families without any identified risk factor render suitable candidates for further in-depth genetic evaluation.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Apolipoproteínas E/genética , Estudios de Cohortes , Heterocigoto , Humanos , Proteínas Relacionadas con Receptor de LDL/genética , Proteínas de Transporte de Membrana/genética , Secuenciación del Exoma
12.
Alzheimers Dement (Amst) ; 13(1): e12229, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34541285

RESUMEN

INTRODUCTION: We investigated relationships among genetic determinants of Alzheimer's disease (AD), amyloid/tau/neurodegenaration (ATN) biomarkers, and risk of dementia. METHODS: We studied cognitively normal individuals with subjective cognitive decline (SCD) from the Amsterdam Dementia Cohort and SCIENCe project. We examined associations between genetic variants and ATN biomarkers, and evaluated their predictive value for incident dementia. A polygenic risk score (PRS) was calculated based on 39 genetic variants. The APOE gene was not included in the PRS and was analyzed separately. RESULTS: The PRS and APOE ε4 were associated with amyloid-positive ATN profiles, and APOE ε4 additionally with isolated increased tau (A-T+N-). A high PRS and APOE ε4 separately predicted AD dementia. Combined, a high PRS increased while a low PRS attenuated the risk associated with ε4 carriers. DISCUSSION: Genetic variants beyond APOE are clinically relevant and contribute to the pathophysiology of AD. In the future, a PRS might be used in individualized risk profiling.

13.
Transl Psychiatry ; 11(1): 451, 2021 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-34475377

RESUMEN

Genetic factors play a major role in frontotemporal dementia (FTD). The majority of FTD cannot be genetically explained yet and it is likely that there are still FTD risk loci to be discovered. Common variants have been identified with genome-wide association studies (GWAS), but these studies have not systematically searched for rare variants. To identify rare and new common variant FTD risk loci and provide more insight into the heritability of C9ORF72-related FTD, we performed a GWAS consisting of 354 FTD patients (including and excluding N = 28 pathological repeat carriers) and 4209 control subjects. The Haplotype Reference Consortium was used as reference panel, allowing for the imputation of rare genetic variants. Two rare genetic variants nearby C9ORF72 were strongly associated with FTD in the discovery (rs147211831: OR = 4.8, P = 9.2 × 10-9, rs117204439: OR = 4.9, P = 6.0 × 10-9) and replication analysis (P < 1.1 × 10-3). These variants also significantly associated with amyotrophic lateral sclerosis in a publicly available dataset. Using haplotype analyses in 1200 individuals, we showed that these variants tag a sub-haplotype of the founder haplotype of the repeat expansion that was previously found to be present in virtually all pathological C9ORF72 G4C2 repeat lengths. This new risk haplotype was 10 times more likely to contain a C9ORF72 pathological repeat length compared to founder haplotypes without one of the two risk variants (~22% versus ~2%; P = 7.70 × 10-58). In haplotypes without a pathologic expansion, the founder risk haplotype had a higher number of repeats (median = 12 repeats) compared to the founder haplotype without the risk variants (median = 8 repeats) (P = 2.05 × 10-260). In conclusion, the identified risk haplotype, which is carried by ~4% of all individuals, is a major risk factor for pathological repeat lengths of C9ORF72 G4C2. These findings strongly indicate that longer C9ORF72 repeats are unstable and more likely to convert to germline pathological C9ORF72 repeat expansions.


Asunto(s)
Proteína C9orf72/genética , Demencia Frontotemporal , Estudio de Asociación del Genoma Completo , Expansión de las Repeticiones de ADN/genética , Demencia Frontotemporal/genética , Haplotipos , Humanos
14.
Nucleic Acids Res ; 49(W1): W603-W612, 2021 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-34048563

RESUMEN

Genetic association studies are frequently used to study the genetic basis of numerous human phenotypes. However, the rapid interrogation of how well a certain genomic region associates across traits as well as the interpretation of genetic associations is often complex and requires the integration of multiple sources of annotation, which involves advanced bioinformatic skills. We developed snpXplorer, an easy-to-use web-server application for exploring Single Nucleotide Polymorphisms (SNP) association statistics and to functionally annotate sets of SNPs. snpXplorer can superimpose association statistics from multiple studies, and displays regional information including SNP associations, structural variations, recombination rates, eQTL, linkage disequilibrium patterns, genes and gene-expressions per tissue. By overlaying multiple GWAS studies, snpXplorer can be used to compare levels of association across different traits, which may help the interpretation of variant consequences. Given a list of SNPs, snpXplorer can also be used to perform variant-to-gene mapping and gene-set enrichment analysis to identify molecular pathways that are overrepresented in the list of input SNPs. snpXplorer is freely available at https://snpxplorer.net. Source code, documentation, example files and tutorial videos are available within the Help section of snpXplorer and at https://github.com/TesiNicco/snpXplorer.


Asunto(s)
Anotación de Secuencia Molecular , Polimorfismo de Nucleótido Simple , Programas Informáticos , Enfermedad de Alzheimer/genética , Expresión Génica , Estudios de Asociación Genética , Genómica , Humanos , Desequilibrio de Ligamiento , Sitios de Carácter Cuantitativo
15.
JAMA Netw Open ; 4(1): e2031654, 2021 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-33449094

RESUMEN

Importance: Understanding mechanisms associated with prolonged cognitive health in combination with exceptional longevity might lead to approaches to enable successful aging. Objective: To investigate trajectories of cognitive functioning in centenarians across domains, and to examine the association of these trajectories with factors underlying cognitive reserve, physical health, and postmortem levels of Alzheimer disease (AD)-associated neuropathology. Design, Setting, and Participants: This cohort study used neuropsychological test data and postmortem neuropathological reports from Dutch centenarians who were drawn from the 100-plus Study between January 2013 and April 2019. Eligible participants self-reported being cognitively healthy, which was confirmed by a proxy. Data analysis was performed between June 2019 and June 2020. Exposures: Age, sex, APOE ε genotype, factors of cognitive reserve, physical health, and AD-associated neuropathology (ie, amyloid-ß, neurofibrillary tangles, and neuritic plaques). Main Outcomes and Measures: In annual visits (until death or until participation was no longer possible), centenarians underwent an extensive neuropsychological test battery, from which an mean z score of global cognition, memory, executive functions, verbal fluency, visuospatial functions, and attention/processing speed was calculated. Linear mixed models with a random intercept and time as independent variable were used to investigate cognitive trajectories, adjusted for sex, age, education, and vision and hearing capacities. In a second step, linear mixed models were used to associate cognitive trajectories with factors underlying cognitive reserve, physical health at baseline, and AD-associated neuropathology. Results: Of the 1023 centenarians approached, 340 were included in the study. We analyzed 330 centenarians for whom cognitive tests were available at baseline (239 [72.4%] women; median [interquartile range] age of 100.5 [100.2-101.7] years), with a mean (SD) follow-up duration of 1.6 (0.8) years. We observed no decline across investigated cognitive domains, with the exception of a slight decline in memory function (ß, -0.10 SD per year; 95% CI, -0.14 to -0.05 SD; P < .001). Cognitive performance was associated with factors of physical health (eg, higher Barthel index: ß, 0.37 SD per year; 95% CI, 0.24-0.49; P < .001) and cognitive reserve (eg, higher education: ß, 0.41 SD per year; 95% CI, 0.29-0.53; P < .001), but none of these factors were associated with the rate of decline. Neuropathological reports were available for 44 participants. While centenarian brains revealed varying loads of postmortem neuropathological hallmarks of AD, this was not associated with cognitive performance or rate of decline. Conclusions and Relevance: While we observed a slight vulnerability for decline in memory function, centenarians maintained high levels of performance in all other investigated cognitive domains for up to 4 years despite the presence of risk factors of cognitive decline. These findings suggest that mechanisms of resilience may underlie the prolongation of cognitive health until exceptional ages.


Asunto(s)
Encéfalo , Cognición/fisiología , Disfunción Cognitiva , Anciano de 80 o más Años , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/fisiopatología , Autopsia , Encéfalo/patología , Encéfalo/fisiopatología , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/patología , Disfunción Cognitiva/fisiopatología , Femenino , Humanos , Masculino , Países Bajos , Pruebas Neuropsicológicas , Estudios Prospectivos , Factores de Riesgo
16.
J Gerontol A Biol Sci Med Sci ; 76(5): 750-759, 2021 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-33216869

RESUMEN

Studying the genome of centenarians may give insights into the molecular mechanisms underlying extreme human longevity and the escape of age-related diseases. Here, we set out to construct polygenic risk scores (PRSs) for longevity and to investigate the functions of longevity-associated variants. Using a cohort of centenarians with maintained cognitive health (N = 343), a population-matched cohort of older adults from 5 cohorts (N = 2905), and summary statistics data from genome-wide association studies on parental longevity, we constructed a PRS including 330 variants that significantly discriminated between centenarians and older adults. This PRS was also associated with longer survival in an independent sample of younger individuals (p = .02), leading up to a 4-year difference in survival based on common genetic factors only. We show that this PRS was, in part, able to compensate for the deleterious effect of the APOE-ε4 allele. Using an integrative framework, we annotated the 330 variants included in this PRS by the genes they associate with. We find that they are enriched with genes associated with cellular differentiation, developmental processes, and cellular response to stress. Together, our results indicate that an extended human life span is, in part, the result of a constellation of variants each exerting small advantageous effects on aging-related biological mechanisms that maintain overall health and decrease the risk of age-related diseases.


Asunto(s)
Estudio de Asociación del Genoma Completo , Longevidad/genética , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/genética , Apolipoproteínas E/genética , Estudios de Casos y Controles , Estudios de Cohortes , Inhibidor p15 de las Quinasas Dependientes de la Ciclina/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple
17.
Front Genet ; 12: 748781, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34992629

RESUMEN

Human longevity is influenced by the genetic risk of age-related diseases. As Alzheimer's disease (AD) represents a common condition at old age, an interplay between genetic factors affecting AD and longevity is expected. We explored this interplay by studying the prevalence of AD-associated single-nucleotide-polymorphisms (SNPs) in cognitively healthy centenarians, and replicated findings in a parental-longevity GWAS. We found that 28/38 SNPs that increased AD-risk also associated with lower odds of longevity. For each SNP, we express the imbalance between AD- and longevity-risk as an effect-size distribution. Based on these distributions, we grouped the SNPs in three groups: 17 SNPs increased AD-risk more than they decreased longevity-risk, and were enriched for ß-amyloid metabolism and immune signaling; 11 variants reported a larger longevity-effect compared to their AD-effect, were enriched for endocytosis/immune-signaling, and were previously associated with other age-related diseases. Unexpectedly, 10 variants associated with an increased risk of AD and higher odds of longevity. Altogether, we show that different AD-associated SNPs have different effects on longevity, including SNPs that may confer general neuro-protective functions against AD and other age-related diseases.

19.
Transl Psychiatry ; 10(1): 332, 2020 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-32994401

RESUMEN

Developing Alzheimer's disease (AD) is influenced by multiple genetic variants that are involved in five major AD-pathways. Per individual, these pathways may differentially contribute to the modification of the AD-risk. The pathways involved in the resilience against AD have thus far been poorly addressed. Here, we investigated to what extent each molecular mechanism associates with (i) the increased risk of AD and (ii) the resilience against AD until extreme old age, by comparing pathway-specific polygenic risk scores (pathway-PRS). We used 29 genetic variants associated with AD to develop pathway-PRS for five major pathways involved in AD. We developed an integrative framework that allows multiple genes to associate with a variant, and multiple pathways to associate with a gene. We studied pathway-PRS in the Amsterdam Dementia Cohort of well-phenotyped AD patients (N = 1895), Dutch population controls from the Longitudinal Aging Study Amsterdam (N = 1654) and our unique 100-plus Study cohort of cognitively healthy centenarians who avoided AD (N = 293). Last, we estimated the contribution of each pathway to the genetic risk of AD in the general population. All pathway-PRS significantly associated with increased AD-risk and (in the opposite direction) with resilience against AD (except for angiogenesis, p < 0.05). The pathway that contributed most to the overall modulation of AD-risk was ß-amyloid metabolism (29.6%), which was driven mainly by APOE-variants. After excluding APOE variants, all pathway-PRS associated with increased AD-risk (except for angiogenesis, p < 0.05), while specifically immune response (p = 0.003) and endocytosis (p = 0.0003) associated with resilience against AD. Indeed, the variants in these latter two pathways became the main contributors to the overall modulation of genetic risk of AD (45.5% and 19.2%, respectively). The genetic variants associated with the resilience against AD indicate which pathways are involved with maintained cognitive functioning until extreme ages. Our work suggests that a favorable immune response and a maintained endocytosis pathway might be involved in general neuro-protection, which highlight the need to investigate these pathways, next to ß-amyloid metabolism.


Asunto(s)
Enfermedad de Alzheimer , Anciano de 80 o más Años , Envejecimiento , Enfermedad de Alzheimer/genética , Cognición , Endocitosis , Humanos , Inmunidad
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