Publications by authors named "Amanda J Myers"

While there are currently over 40 replicated genes with mapped risk alleles for Late Onset Alzheimer's disease (LOAD), the Apolipoprotein E locus E4 haplotype is still the biggest driver of risk, with odds ratios for neuropathologically confirmed E44 carriers exceeding 30 (95% confidence interval 16.59-58.75).

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While there are currently over 40 replicated genes with mapped risk alleles for Late Onset Alzheimer's disease (LOAD), the E locus E4 haplotype is still the biggest driver of risk, with odds ratios for neuropathologically confirmed E44 carriers exceeding 30 (95% confidence interval 16.59-58.75).

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Article Synopsis
  • - The study addresses the issue of limited ancestral diversity in genome-wide association studies (GWAS), which makes it hard to find genetic risk variants in non-European ancestry groups, focusing on Alzheimer's Disease (AD).
  • - Researchers analyzed a multi-ancestry GWAS dataset within the Alzheimer's Disease Genetics Consortium (ADGC) involving individuals from various ancestries, identifying 13 shared risk loci and 3 ancestry-specific loci, highlighting the benefits of diverse samples.
  • - The findings underscore the importance of including underrepresented populations in genetic research, suggesting that even smaller sample sizes can lead to the discovery of novel genetic variants related to AD and implicating specific biological pathways like amyloid regulation and neuronal development.
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Introduction: Both late-onset Alzheimer's disease (AD) and ageing have a strong genetic component. In each case, many associated variants have been discovered, but how much missing heritability remains to be discovered is debated. Variability in the estimation of SNP-based heritability could explain the differences in reported heritability.

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Biomarkers that predict symptom trajectories after trauma can facilitate early detection or intervention for posttraumatic stress disorder (PTSD) and may also advance our understanding of its biology. Here, we aimed to identify trajectory-based biomarkers using blood transcriptomes collected in the immediate aftermath of trauma exposure. Participants were recruited from an Emergency Department in the immediate aftermath of trauma exposure and assessed for PTSD symptoms at baseline, 1, 3, 6, and 12 months.

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Posttraumatic stress disorder (PTSD) is a debilitating syndrome with substantial morbidity and mortality that occurs in the aftermath of trauma. Symptoms of major depressive disorder (MDD) are also a frequent consequence of trauma exposure. Identifying novel risk markers in the immediate aftermath of trauma is a critical step for the identification of novel biological targets to understand mechanisms of pathophysiology and prevention, as well as the determination of patients most at risk who may benefit from immediate intervention.

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Objective: We describe herein a bioinformatics approach that leverages gene expression data from brain homogenates to derive cell-type specific differential expression results.

Results: We found that differentially expressed (DE) cell-specific genes were mostly identified as neuronal, microglial, or endothelial in origin. However, a large proportion (75.

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Each additional copy of the apolipoprotein E4 (APOE4) allele is associated with a higher risk of Alzheimer's dementia, while the APOE2 allele is associated with a lower risk of Alzheimer's dementia, it is not yet known whether APOE2 homozygotes have a particularly low risk. We generated Alzheimer's dementia odds ratios and other findings in more than 5,000 clinically characterized and neuropathologically characterized Alzheimer's dementia cases and controls. APOE2/2 was associated with a low Alzheimer's dementia odds ratios compared to APOE2/3 and 3/3, and an exceptionally low odds ratio compared to APOE4/4, and the impact of APOE2 and APOE4 gene dose was significantly greater in the neuropathologically confirmed group than in more than 24,000 neuropathologically unconfirmed cases and controls.

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Article Synopsis
  • An amendment to the original paper has been released.
  • You can find the amendment through a link provided at the top of the paper.
  • This update may contain important changes or additional information related to the original content.
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It was recently suggested that beta-site amyloid precursor protein (APP)-cleaving enzyme 2 (BACE2) functions as an amyloid beta (Aβ)-degrading enzyme; in addition to its better understood role as an APP secretase. Due to this finding we sought to understand the possible genetic risk contributed by the BACE2 locus to the development of late-onset Alzheimer's disease (AD). In this study, we report that common single nucleotide polymorphism (SNP) variation in BACE2 is associated with altered AD risk in apolipoprotein E gene (APOE) epsilon 4 variant (ε4) non-carriers.

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In humans, a first-degree family history of dementia (FH) is a well-documented risk factor for Alzheimer's disease (AD); however, the influence of FH on cognition across the lifespan is poorly understood. To address this issue, we developed an internet-based paired-associates learning (PAL) task and tested 59,571 participants between the ages of 18-85. FH was associated with lower PAL performance in both sexes under 65 years old.

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Genetic case-control association studies are often based on clinically ascertained cases and population or convenience controls. It is known that some of the controls will contain cases, as they are usually not screened for the disease of interest. However, even clinically assessed cases and controls can be misassigned.

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Article Synopsis
  • Late-onset Alzheimer's disease (LOAD) is the most common type of dementia and is influenced by genetics.
  • Researchers studied a lot of people (94,437) to find specific genes that may increase the risk of developing LOAD, confirming 20 known ones and discovering 5 new ones.
  • They also found that certain genetic traits related to the immune system and how the brain processes proteins are linked to a higher risk of LOAD, suggesting there are more rare genes yet to be identified that could also play a role.
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Article Synopsis
  • The study investigates how changes in gene and protein expression contribute to the development of late-onset Alzheimer's disease.
  • Researchers utilized a robust analysis pipeline, including predicting gene expression, analyzing relationships between transcripts and proteins, and validating findings across two significant brain sample sets.
  • HSPA2, a specific protein, emerged as a key regulator linked to increased levels of amyloid-beta and tau proteins, highlighting its importance in late-onset Alzheimer's disease processes.
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Previous estimates of the utility of polygenic risk score analysis for the prediction of Alzheimer disease have given area under the curve (AUC) estimates of <80%. However, these have been based on the genetic analysis of clinical case-control series. Here, we apply the same analytic approaches to a pathological case-control series and show a predictive AUC of 84%.

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Article Synopsis
  • * Our research uncovered three significant variants: a protective variant in the PLCG2 gene and risk variants in ABI3 and TREM2, known for their roles in Alzheimer's susceptibility.
  • * The findings emphasize the importance of microglia, immune cells in the brain, suggesting that their genetic variations may contribute directly to the progression of Alzheimer's disease.
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Circadian rhythms modulate the biology of many human tissues, including brain tissues, and are driven by a near 24-hour transcriptional feedback loop. These rhythms are paralleled by 24-hour rhythms of large portions of the transcriptome. The role of dynamic DNA methylation in influencing these rhythms is uncertain.

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Background: Oxytocin is a neuropeptide that is involved in the regulation of mood, anxiety and social biology. Genetic variation in the oxytocin receptor gene (OXTR) has been implicated in anxiety, depression and related stress phenotypes. It is not yet known whether OXTR interacts with other risk factors such as early life trauma to heighten the severity of experienced anxiety and depression.

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Background And Methodology: UK regulations on managing fetal tissue after pregnancy loss, including abortion, are underscored by the concept of 'sensitive disposal'. This involves offering women burial or cremation and, when disposal is by the health care provider, separating fetal tissue from other clinical waste before incineration. We interviewed 23 women who had undergone one or more abortions about their understanding, attitudes and experiences of fetal tissue disposal and 'sensitive disposal'.

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Article Synopsis
  • The study investigates how known genetic risk factors for late-onset Alzheimer disease (LOAD) influence the age at which symptoms appear in affected individuals, particularly focusing on the APOE locus and other established risk loci.
  • Researchers utilized data from the Alzheimer Disease Genetics Consortium, analyzing 9,162 patients over several years, to determine the cumulative effects of these genetic factors on age at onset (AAO) of LOAD.
  • Results indicated that variants at the APOE locus are strongly associated with earlier onset of Alzheimer’s symptoms, with other loci like CR1, BIN1, and PICALM showing statistically significant effects as well, together explaining a portion of the AAO variation.
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Alzheimer's disease (AD) and related dementias are a major public health challenge and present a therapeutic imperative for which we need additional insight into molecular pathogenesis. We performed a genome-wide association study and analysis of known genetic risk loci for AD dementia using neuropathologic data from 4,914 brain autopsies. Neuropathologic data were used to define clinico-pathologic AD dementia or controls, assess core neuropathologic features of AD (neuritic plaques, NPs; neurofibrillary tangles, NFTs), and evaluate commonly co-morbid neuropathologic changes: cerebral amyloid angiopathy (CAA), Lewy body disease (LBD), hippocampal sclerosis of the elderly (HS), and vascular brain injury (VBI).

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Article Synopsis
  • This study aimed to find new genes linked to late-onset Alzheimer's disease by analyzing a large dataset from the International Genomics of Alzheimer's Project Consortium, which included over 25,000 Alzheimer's patients and around 48,000 controls.
  • Researchers discovered new significant genetic loci on chromosomes 8 and 14, expanding the understanding of genetic susceptibility to Alzheimer's beyond previously known genes.
  • The newly identified genes are involved in processes related to energy metabolism, protein degradation, and immune response, highlighting potential new targets for therapy in treating Alzheimer's disease.
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Recent years have seen the increasing understanding of the crucial role of RNA in the functioning of the eukaryotic genome. These discoveries, fueled by the achievements of the FANTOM, and later GENCODE and ENCODE consortia, led to the recognition of the important regulatory roles of natural antisense transcripts (NATs) arising from what was previously thought to be 'junk DNA'. Roughly defined as non-coding regulatory RNA transcribed from the opposite strand of a coding gene locus, NATs are proving to be a heterogeneous group with high potential for therapeutic application.

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The genetics of complex disease produce alterations in the molecular interactions of cellular pathways whose collective effect may become clear through the organized structure of molecular networks. To characterize molecular systems associated with late-onset Alzheimer's disease (LOAD), we constructed gene-regulatory networks in 1,647 postmortem brain tissues from LOAD patients and nondemented subjects, and we demonstrate that LOAD reconfigures specific portions of the molecular interaction structure. Through an integrative network-based approach, we rank-ordered these network structures for relevance to LOAD pathology, highlighting an immune- and microglia-specific module that is dominated by genes involved in pathogen phagocytosis, contains TYROBP as a key regulator, and is upregulated in LOAD.

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