| 1. |
- 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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| 2. |
- 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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