| 1. |
- Bennet, Anna M, et al.
(författare)
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Genetic association of sequence variants near AGER/NOTCH4 and dementia.
- 2011
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Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908. ; 24:3, s. 475-84
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Tidskriftsartikel (refereegranskat)abstract
- We performed a survey of sequence variation in a series of 20 genes involved in inflammation-related pathways for association with dementia risk in twin and unrelated case-control samples consisting in total of 1462 Swedish dementia casesand 1929 controls. For a total of 218 tested genetic markers, strong evidence was obtained implicating a region near AGER and NOTCH4 on chromosome 6p with replication across both samples and maximum combined significance at marker rs1800625 (OR = 1.37, 95% CI 1.19–1.56, p = 1.36×10(–6)). Imputation of the associated genomic interval provided an improved signal atrs8365, near the 3UTR of AGER (p = 7.34×10(–7)). The associated region extends 120 kb encompassing 11 candidate genes.While AGER encodes a key receptor for amyloid-β protein, an analysis of network context based upon genes now confirmed to contribute to dementia risk (AβPP, PSEN1, PSEN2, CR1, CLU, PICALM, and APOE) suggested strong functional coupling to NOTCH4, with no significant coupling to the remaining candidates. The implicated region occurs in the broad HLA locus on chromosome 6p, but associated markers were not in strong LD with known variants that regulate HLA gene function, suggesting that this may represent a signal distinct from immune-system pathways.
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| 2. |
- Hong, Mun-Gwan, et al.
(författare)
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A genome-wide assessment of variability in human serum metabolism
- 2013
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Ingår i: Human Mutation. - : Hindawi Limited. - 1059-7794 .- 1098-1004. ; 34:3, s. 515-524
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Tidskriftsartikel (refereegranskat)abstract
- The study of the genetic regulation of metabolism in human serum samples can contribute to a better understanding of the intermediate biological steps that lead from polymorphism to disease. Here, we conducted a genome-wide association study (GWAS) to discover metabolic quantitative trait loci (mQTLs) utilizing samples from a study of prostate cancer in Swedish men, consisting of 402 individuals (214 cases and 188 controls) in a discovery set and 489 case-only samples in a replication set. A global nontargeted metabolite profiling approach was utilized resulting in the detection of 6,138 molecular features followed by targeted identification of associated metabolites. Seven replicating loci were identified (PYROXD2, FADS1, PON1, CYP4F2, UGT1A8, ACADL, and LIPC) with associated sequence variants contributing significantly to trait variance for one or more metabolites (P = 10(-13) -10(-91)). Regional mQTL enrichment analyses implicated two loci that included FADS1 and a novel locus near PDGFC. Biological pathway analysis implicated ACADM, ACADS, ACAD8, ACAD10, ACAD11, and ACOXL, reflecting significant enrichment of genes with acyl-CoA dehydrogenase activity. mQTL SNPs and mQTL-harboring genes were over-represented across GWASs conducted to date, suggesting that these data may have utility in tracing the molecular basis of some complex disease associations.
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| 3. |
- Hong, Mun-Gwan, et al.
(författare)
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Evidence that the gene encoding insulin degrading enzyme influences human lifespan.
- 2008
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Ingår i: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 17:15, s. 2370-8
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Tidskriftsartikel (refereegranskat)abstract
- Studies in model organisms have demonstrated that components of insulin and insulin-like signaling pathways are involved in the regulation of lifespan but the relevance of those findings to humans has remained obscure. Here we provide evidence suggesting that variants of the gene encoding insulin-degrading enzyme (IDE) may be influencing human lifespan. We have employed a variety of models and diverse samples that reproducibly indicate the relative change in IDE genotype frequency across the age spectrum as well as allow the detection of association with age-at-death. A tenable molecular basis of this is suggested by the observation of genetic association with both fasting plasma insulin levels and IDE mRNA expression. Across populations the emergent genetic model is indicative of over-dominance, where heterozygotes of critical markers have increased IDE mRNA expression and insulin levels, and this is reflected in diminished heterozygosity at advanced age. A critical and replicating feature of this study is that change in IDE genotype frequency with advancing age appears to be occurring only in men, and this is supported in that insulin levels are only associated with IDE in men. Results suggest a relationship between a gene that is intimately involved in insulin metabolism and the determination of lifespan in humans, but over-dominance and gender specificity will be important parameters to consider clarifying the biological importance of these findings.
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| 4. |
- Hong, Mun-Gwan, et al.
(författare)
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Genome-wide and gene-based association implicates FRMD6 in Alzheimer disease
- 2012
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Ingår i: Human Mutation. - : Hindawi Limited. - 1059-7794 .- 1098-1004. ; 33:3, s. 521-529
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) that allow for allelic heterogeneity may facilitate the discovery of novel genes not detectable by models that require replication of a single variant site. One strategy to accomplish this is to focus on genes rather than markers as units of association, and so potentially capture a spectrum of causal alleles that differ across populations. Here, we conducted a GWAS of Alzheimer disease (AD) in 2,586 Swedes and performed gene-based meta-analysis with three additional studies from France, Canada, and the United States, in total encompassing 4,259 cases and 8,284 controls. Implementing a newly designed gene-based algorithm, we identified two loci apart from the region around APOE that achieved study-wide significance in combined samples, the strongest finding being for FRMD6 on chromosome 14q (P = 2.6 × 10(-14)) and a weaker signal for NARS2 that is immediately adjacent to GAB2 on chromosome 11q (P = 7.8 × 10(-9)). Ontology-based pathway analyses revealed significant enrichment of genes involved in glycosylation. Results suggest that gene-based approaches that accommodate allelic heterogeneity in GWAS can provide a complementary avenue for gene discovery and may help to explain a portion of the missing heritability not detectable with single nucleotide polymorphisms (SNPs) derived from marker-specific meta-analysis.
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| 5. |
- Kumar, Jitender, et al.
(författare)
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Associations of Body Mass Index and Obesity-Related Genetic Variants with Serum Metabolites
- 2014
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Ingår i: Current Metabolomics. - 2213-235X. ; 2:1, s. 27-36-
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Body mass index (BMI) is one of the most important risk factors for different metabolic and cardiovascular disorders. Previously, both genetic and environmental agents associated with BMI have been described. The main focus of this exploratory study was to find the circulating metabolites associated with BMI utilizing an untargeted metabolomics approach. Additionally, significant metabolites identified were studied for their relation with BMIassociated single nucleotide polymorphisms (SNPs). Materials and Methods: A total of 971 individuals from the Cancer of the Prostate in Sweden study (discovery sample- 275 prostate cancers patients and 182 controls; replication sample- 514 prostate cancer patients) were utilized. Blood samples were collected and serum metabolic profiling was obtained using ultra-performance liquid chromatography followed by mass spectrometry. Genotyping data was available for 26 out of 32 SNPs (21 genotyped and 5 proxies) previously robustly associated with BMI in individuals of European descent. Weighted genetic risk score was generated using these SNPs and studied for its association with metabolites. Results: A total of 6138 and 5209 metabolite features were detected in discovery and replication samples, respectively. Out of 6138 metabolite features in discovery sample, 201 were found to be significantly associated with BMI (p<8.15*10-6) after multiple testing correction. These 201 features were further investigated in the replication samples and 16 were found to be significantly associated with BMI (p<2.49*10-4). Seven of these significant features were isotopes for four of the primary metabolites. Four metabolites were putatively identified: monoacylglyceride (18:1), diacylglyrcerol (32:1) and two phosphatidylcholines (34:0 and 36:0). Weighted genetic score of BMI-associated SNPs was not associated with these four metabolites. Conclusion: Four identifiable metabolites (monoacylglyceride, diacyclglyrcerol and two phosphatidylcholines) were found to be significantly associated with BMI in both discovery and replication samples. Common variants associated with BMI did not show association with these four metabolites. - See more at: http://www.eurekaselect.com/120422/article#sthash.PgqffHqv.dpuf
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| 6. |
- Reynolds, Chandra A, et al.
(författare)
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A survey of ABCA1 sequence variation confirms association with dementia.
- 2009
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Ingår i: Human mutation. - : Hindawi Limited. - 1098-1004 .- 1059-7794. ; 30:9, s. 1348-54
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Tidskriftsartikel (refereegranskat)abstract
- We and others have conducted targeted genetic association analyses of ABCA1 in relation to Alzheimer disease risk with a resultant mixture of both support and refutation, but all previous studies have been based upon only a few markers. Here, a detailed survey of genetic variation in the ABCA1 region has been performed in a total of 1,567 Swedish dementia cases (including 1,275 with Alzheimer disease) and 2,203 controls, providing evidence of association with maximum significance at marker rs2230805 (odds ratio [OR]=1.39; 95% confidence interval [CI] 1.23-1.57, p=7.7x10(-8)). Haplotype-based tests confirmed association of this genomic region after excluding rs2230805, and imputation did not reveal additional markers with greater support. Significantly associating markers reside in two distinct linkage disequilibrium blocks with maxima near the promoter and in the terminal exon of a truncated ABCA1 splice form. The putative risk allele of rs2230805 was also found to be associated with reduced cerebrospinal fluid levels of beta-amyloid. The strongest evidence of association was obtained when all forms of dementia were considered together, but effect sizes were similar when only confirmed Alzheimer disease cases were assessed. Results further implicate ABCA1 in dementia, reinforcing the putative involvement of lipid transport in neurodegenerative disease.
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| 7. |
- Reynolds, Chandra A, et al.
(författare)
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Analysis of lipid pathway genes indicates association of sequence variation near SREBF1/TOM1L2/ATPAF2 with dementia risk.
- 2010
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Ingår i: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 19:10, s. 2068-2078
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Tidskriftsartikel (refereegranskat)abstract
- We conducted dense linkage disequilibrium mapping of a series of 25 genes putatively involved in lipid metabolism in 1567 dementia cases (including 1270 with Alzheimer disease) and 2203 Swedish controls. Across a total of 448 tested genetic markers, the strongest evidence of association was as anticipated for APOE (rs429358 at p approximately 10(-72)) followed by a previously reported association of ABCA1 (rs2230805 at p approximately 10(-8)). In the present study we report two additional markers near the SREBF1 locus on chromosome 17p that were also significant after multiple testing correction (best p=3.1 x 10(-6) for marker rs3183702). There was no convincing evidence of association for remaining genes, including candidates highlighted from recent genome-wide association studies of plasma lipids (CELSR2/PSRC1/SORT1, MLXIPL, PCSK9, GALNT2, and GCKR). The associated markers near SREBF1 reside in a large linkage disequilibrium block, extending more than 400kb across 7 candidate genes. Secondary analyses of gene expression levels of candidates spanning the LD region together with an investigation of gene network context highlighted two possible susceptibility genes including ATPAF2 and TOM1L2. Several markers in strong LD (r(2)>0.7) with rs3183702 were found to be significantly associated with AD risk in recent genome-wide association studies with similar effect sizes, providing independent support of the current findings.
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| 8. |
- Reynolds, Chandra A, et al.
(författare)
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Sequence variation in SORL1 and dementia risk in Swedes.
- 2010
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Ingår i: Neurogenetics. - : Springer Science and Business Media LLC. - 1364-6753 .- 1364-6745. ; 11:1, s. 139-42
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Tidskriftsartikel (refereegranskat)abstract
- The gene encoding the neuronal sortilin-related receptor SORL1 has been claimed to be associated with Alzheimer's disease (AD) by independent groups and across various human populations. We evaluated six genetic markers in SORL1 in a sample of 1,558 Swedish dementia cases (including 1,270 AD cases) and 2,179 controls. For both single-marker-based and haplotype-based analyses, we found no strong support for SORL1 as a dementia or AD risk-modifying gene in our sample in isolation nor did we observe association with AD/dementia-related traits, including cerebrospinal fluid beta-amyloid(1-42), tau levels, or age at onset. However, meta-analyses of markers in this study together with previously published studies on SORL1 encompassing in excess of 13,000 individuals does suggest significant association with AD (best odds ratio = 1.097; 95% confidence interval = 1.038-1.158, p = 0.001). All six markers were significant in meta-analyses and it is notable that they occur in two distinct linkage disequilibrium blocks. These data are consistent with either allelic heterogeneity or the existence of as yet untested functional variants and these will be important considerations in further attempts to evaluate the importance of sequence variation in SORL1 with AD risk.
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