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Irene Pichler,
Fabiola Del Greco M,
Martin Gögele,
Christina M. Lill,
Lars Bertram,
Chuong B. Do,
Nicholas Eriksson,
Tatiana Foroud,
Richard H. Myers,
PD GWAS Consortium, [......],
Margaux F. Keller,
International Parkinson's Disease Genomics Consortium,
Wellcome Trust Case Control Consortium,
Beben Benyamin, John B. Whitfield,
Genetics of Iron Status Consortium,
Peter P. Pramstaller,
Andrew A. Hicks,
John R. Thompson,
Cosetta Minelli
PLoS Medicine 01/2013; · 16.27 Impact Factor
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Anna Köttgen,
Eva Albrecht,
Alexander Teumer,
Veronique Vitart,
Jan Krumsiek,
Claudia Hundertmark,
Giorgio Pistis,
Daniela Ruggiero,
Conall M O'Seaghdha,
Toomas Haller, [......],
Nicole Soranzo,
Daniela Toniolo,
Daniel I Chasman,
Olli Raitakari,
W H Linda Kao,
Marina Ciullo,
Caroline S Fox,
Mark Caulfield,
Murielle Bochud,
Christian Gieger
[show abstract]
[hide abstract]
ABSTRACT: Elevated serum urate concentrations can cause gout, a prevalent and painful inflammatory arthritis. By combining data from >140,000 individuals of European ancestry within the Global Urate Genetics Consortium (GUGC), we identified and replicated 28 genome-wide significant loci in association with serum urate concentrations (18 new regions in or near TRIM46, INHBB, SFMBT1, TMEM171, VEGFA, BAZ1B, PRKAG2, STC1, HNF4G, A1CF, ATXN2, UBE2Q2, IGF1R, NFAT5, MAF, HLF, ACVR1B-ACVRL1 and B3GNT4). Associations for many of the loci were of similar magnitude in individuals of non-European ancestry. We further characterized these loci for associations with gout, transcript expression and the fractional excretion of urate. Network analyses implicate the inhibins-activins signaling pathways and glucose metabolism in systemic urate control. New candidate genes for serum urate concentration highlight the importance of metabolic control of urate production and excretion, which may have implications for the treatment and prevention of gout.
Nature genetics. 01/2013; 45(2):145-54.
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Anna Köttgen,
Eva Albrecht,
Alexander Teumer,
Veronique Vitart,
Jan Krumsiek,
Claudia Hundertmark,
Giorgio Pistis,
Daniela Ruggiero,
Conall M O'Seaghdha,
Toomas Haller, [......],
Nicole Soranzo,
Daniela Toniolo,
Daniel I Chasman,
Olli Raitakari,
W H Linda Kao,
Marina Ciullo,
Caroline S Fox,
Mark Caulfield,
Murielle Bochud,
Christian Gieger
[show abstract]
[hide abstract]
ABSTRACT: Elevated serum urate concentrations can cause gout, a prevalent and painful inflammatory arthritis. By combining data from >140,000 individuals of European ancestry within the Global Urate Genetics Consortium (GUGC), we identified and replicated 28 genome-wide significant loci in association with serum urate concentrations (18 new regions in or near TRIM46, INHBB, SFMBT1, TMEM171, VEGFA, BAZ1B, PRKAG2, STC1, HNF4G, A1CF, ATXN2, UBE2Q2, IGF1R, NFAT5, MAF, HLF, ACVR1B-ACVRL1 and B3GNT4). Associations for many of the loci were of similar magnitude in individuals of non-European ancestry. We further characterized these loci for associations with gout, transcript expression and the fractional excretion of urate. Network analyses implicate the inhibins-activins signaling pathways and glucose metabolism in systemic urate control. New candidate genes for serum urate concentration highlight the importance of metabolic control of urate production and excretion, which may have implications for the treatment and prevention of gout.
Nature Genetics 12/2012; · 35.53 Impact Factor
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Pim van der Harst,
Weihua Zhang,
Irene Mateo Leach,
Augusto Rendon,
Niek Verweij,
Joban Sehmi,
Dirk S Paul,
Ulrich Elling,
Hooman Allayee,
Xinzhong Li, [......],
Manuel A Ferreira,
Serena Sanna,
Manuela Uda,
Andrew A Hicks,
Josef Martin Penninger,
Christian Gieger,
Jaspal S Kooner,
Willem H Ouwehand,
Nicole Soranzo,
John C Chambers
[show abstract]
[hide abstract]
ABSTRACT: Anaemia is a chief determinant of global ill health, contributing to cognitive impairment, growth retardation and impaired physical capacity. To understand further the genetic factors influencing red blood cells, we carried out a genome-wide association study of haemoglobin concentration and related parameters in up to 135,367 individuals. Here we identify 75 independent genetic loci associated with one or more red blood cell phenotypes at P < 10(-8), which together explain 4-9% of the phenotypic variance per trait. Using expression quantitative trait loci and bioinformatic strategies, we identify 121 candidate genes enriched in functions relevant to red blood cell biology. The candidate genes are expressed preferentially in red blood cell precursors, and 43 have haematopoietic phenotypes in Mus musculus or Drosophila melanogaster. Through open-chromatin and coding-variant analyses we identify potential causal genetic variants at 41 loci. Our findings provide extensive new insights into genetic mechanisms and biological pathways controlling red blood cell formation and function.
Nature 12/2012; · 36.28 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: BACKGROUND: Alcohol consumption has multiple biochemical consequences. Only a few of these are useful as diagnostic markers, but many reflect potentially harmful or beneficial effects of alcohol. Average consumption of 2 to 4 drinks per day is associated with lower overall or cardiovascular mortality risk than either lower or higher intake. We have analyzed the dose-response relationships between reported alcohol consumption and 17 biomarkers, with emphasis on intake of up to 3 drinks per day. METHODS: Biochemical tests were performed on serum from 8,396 study participants (3,750 men and 4,646 women, aged 51 ± 13 years, range 18 to 93) who had provided information on alcohol consumption in the week preceding blood collection. RESULTS: Gamma glutamyl transferase, alanine aminotransferase, aspartate aminotransferase, carbohydrate-deficient transferrin, urate, ferritin, and bilirubin showed little or no change with alcohol consumption below 2 to 3 drinks per day, but increased with higher intake. High-density lipoprotein cholesterol and albumin showed increasing results, and insulin showed decreasing results, across the entire range of alcohol use. Biphasic responses, where subjects reporting 1 to 2 drinks per day had lower results than those reporting either more or less alcohol use, occurred for triglycerides, glucose, C-reactive protein, alkaline phosphatase, and butyrylcholinesterase. Increasing alcohol use was associated with decreasing low-density lipoprotein cholesterol (LDL-C) in younger women, but higher LDL-C in older men. CONCLUSIONS: Some markers show threshold relationships with alcohol, others show continuous ones, and a third group show biphasic or U-shaped relationships. Overall, the biochemical sequelae of low-to-moderate alcohol use are consistent with the epidemiological evidence on morbidity and mortality.
Alcoholism Clinical and Experimental Research 11/2012; · 3.34 Impact Factor
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Folkert W Asselbergs,
Yiran Guo,
Erik P A van Iperen,
Suthesh Sivapalaratnam,
Vinicius Tragante,
Matthew B Lanktree,
Leslie A Lange,
Berta Almoguera,
Yolande E Appelman,
John Barnard, [......],
Nilesh J Samani,
Alex P Reiner,
Robert A Hegele,
John J P Kastelein,
Aroon D Hingorani,
Philippa J Talmud,
Hakon Hakonarson,
Clara C Elbers,
Brendan J Keating,
Fotios Drenos
[show abstract]
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ABSTRACT: Genome-wide association studies (GWASs) have identified many SNPs underlying variations in plasma-lipid levels. We explore whether additional loci associated with plasma-lipid phenotypes, such as high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglycerides (TGs), can be identified by a dense gene-centric approach. Our meta-analysis of 32 studies in 66,240 individuals of European ancestry was based on the custom ∼50,000 SNP genotyping array (the ITMAT-Broad-CARe array) covering ∼2,000 candidate genes. SNP-lipid associations were replicated either in a cohort comprising an additional 24,736 samples or within the Global Lipid Genetic Consortium. We identified four, six, ten, and four unreported SNPs in established lipid genes for HDL-C, LDL-C, TC, and TGs, respectively. We also identified several lipid-related SNPs in previously unreported genes: DGAT2, HCAR2, GPIHBP1, PPARG, and FTO for HDL-C; SOCS3, APOH, SPTY2D1, BRCA2, and VLDLR for LDL-C; SOCS3, UGT1A1, BRCA2, UBE3B, FCGR2A, CHUK, and INSIG2 for TC; and SERPINF2, C4B, GCK, GATA4, INSR, and LPAL2 for TGs. The proportion of explained phenotypic variance in the subset of studies providing individual-level data was 9.9% for HDL-C, 9.5% for LDL-C, 10.3% for TC, and 8.0% for TGs. This large meta-analysis of lipid phenotypes with the use of a dense gene-centric approach identified multiple SNPs not previously described in established lipid genes and several previously unknown loci. The explained phenotypic variance from this approach was comparable to that from a meta-analysis of GWAS data, suggesting that a focused genotyping approach can further increase the understanding of heritability of plasma lipids.
The American Journal of Human Genetics 10/2012; · 10.60 Impact Factor
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Ida Surakka, John B Whitfield,
Markus Perola,
Peter M Visscher,
Grant W Montgomery,
Mario Falchi,
Gonneke Willemsen,
Eco J C de Geus,
Patrik K E Magnusson,
Kaare Christensen, [......],
Ann-Christine Syvänen,
Aarno Palotie,
Jaakko Kaprio,
Kirsten O Kyvik,
Nancy L Pedersen,
Dorret I Boomsma,
Tim Spector,
Nicholas G Martin,
Samuli Ripatti,
Leena Peltonen
[show abstract]
[hide abstract]
ABSTRACT: Genome-wide association analysis on monozygotic twin-pairs offers a route to discovery of gene-environment interactions through testing for variability loci associated with sensitivity to individual environment/lifestyle. We present a genome-wide scan of loci associated with intra-pair differences in serum lipid and apolipoprotein levels. We report data for 1,720 monozygotic female twin-pairs from GenomEUtwin project with 2.5 million SNPs, imputed or genotyped, and measured serum lipid fractions for both twins. We found one locus associated with intra-pair differences in high-density lipoprotein cholesterol, rs2483058 in an intron of SRGAP2, where twins carrying the C allele are more sensitive to environmental factors (P = 3.98 × 10-8). We followed up the association in further genotyped monozygotic twins (N = 1,261), which showed a moderate association for the variant (P = 0.200, same direction of an effect). In addition, we report a new association on the level of apolipoprotein A-II (P = 4.03 × 10-8).
Twin Research and Human Genetics 10/2012; · 1.70 Impact Factor
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Kuixing Zhang,
Fangwen Rao,
Jose Pablo Miramontes-Gonzalez,
C Makena Hightower,
Brian Vaught,
Yuhong Chen,
Tiffany A Greenwood,
Andrew J Schork,
Lei Wang,
Manjula Mahata, [......],
Jill Waalen,
Rita P Middelberg,
Andrew C Heath,
Grant W Montgomery,
Nicholas G Martin, John B Whitfield,
Dewleen G Baker,
Nicholas J Schork,
Caroline M Nievergelt,
Daniel T O'Connor
[show abstract]
[hide abstract]
ABSTRACT: This study sought to understand whether genetic variation at the Neuropeptide Y (NPY) locus governs secretion and stress responses in vivo as well as NPY gene expression in sympathochromaffin cells.
The NPY is a potent pressor peptide co-released with catecholamines during stress by sympathetic axons. Genome-wide linkage on NPY secretion identified a LOD (logarithm of the odds ratio) peak spanning the NPY locus on chromosome 7p15.
Our approach began with genomics (linkage and polymorphism determination), extended into NPY genetic control of heritable stress traits in twin pairs, established transcriptional mechanisms in transfected chromaffin cells, and concluded with observations on blood pressure (BP) in the population.
Systematic polymorphism tabulation at NPY (by re-sequencing across the locus: promoter, 4 exons, exon/intron borders, and untranslated regions; on 2n = 160 chromosomes of diverse biogeographic ancestries) identified 16 variants, of which 5 were common. We then studied healthy twin/sibling pairs (n = 399 individuals), typing 6 polymorphisms spanning the locus. Haplotype and single nucleotide polymorphism analyses indicated that proximal promoter variant ∇-880Δ (2-bp TG/-, Ins/Del, rs3037354) minor/Δ allele was associated with several heritable (h(2)) stress traits: higher NPY secretion (h(2) = 73 ± 4%) as well as greater BP response to environmental (cold) stress, and higher basal systemic vascular resistance. Association of ∇-880Δ and plasma NPY was replicated in an independent sample of 361 healthy young men, with consistent allelic effects; genetic variation at NPY also associated with plasma NPY in another independent series of 2,212 individuals derived from Australia twin pairs. Effects of allele -880Δ to increase NPY expression were directionally coordinate in vivo (on human traits) and in cells (transfected NPY promoter/luciferase reporter activity). Promoter -880Δ interrupts a novel glucocorticoid response element motif, an effect confirmed in chromaffin cells by site-directed mutagenesis on the transfected promoter, with differential glucocorticoid stimulation of the motif as well as alterations in electrophoretic mobility shifts. The same -880Δ allele also conferred risk for hypertension and accounted for approximately 4.5/approximately 2.1 mm Hg systolic BP/diastolic BP in a population sample from BP extremes.
We conclude that common genetic variation at the NPY locus, especially in proximal promoter ∇-880Δ, disrupts glucocorticoid signaling to influence NPY transcription and secretion, raising systemic vascular resistance and early heritable responses to environmental stress, eventuating in elevated resting BP in the population. The results point to new molecular strategies for probing autonomic control of the human circulation and ultimately susceptibility to and pathogenesis of cardiovascular and neuropsychiatric disease states.
Journal of the American College of Cardiology 09/2012; 60(17):1678-89. · 14.16 Impact Factor
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Tanya M Teslovich,
Kiran Musunuru,
Albert V Smith,
Andrew C Edmondson,
Ioannis M Stylianou,
Masahiro Koseki,
James P Pirruccello,
Samuli Ripatti,
Daniel I Chasman,
Cristen J Willer, [......],
Heribert Schunkert,
L Adrienne Cupples,
Manjinder S Sandhu,
Paul M Ridker,
Daniel J Rader,
Cornelia M van Duijn,
Leena Peltonen,
Gonçalo R Abecasis,
Michael Boehnke,
Sekar Kathiresan
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Tanya M Teslovich,
Kiran Musunuru,
Albert V Smith,
Andrew C Edmondson,
Ioannis M Stylianou,
Masahiro Koseki,
James P Pirruccello,
Samuli Ripatti,
Daniel I Chasman,
Cristen J Willer, [......],
Heribert Schunkert,
L Adrienne Cupples,
Manjinder S Sandhu,
Paul M Ridker,
Daniel J Rader,
Cornelia M van Duijn,
Leena Peltonen,
Gonçalo R Abecasis,
Michael Boehnke,
Sekar Kathiresan
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[show abstract]
[hide abstract]
ABSTRACT: BACKGROUND: Variation in alcohol metabolism affects the duration of intoxication and alcohol use. While the majority of genetic association studies investigating variation in alcohol metabolism have focused on polymorphisms in alcohol or aldehyde dehydrogenases, we have now tested for association with genes in alternative metabolic pathways that catalyze the carbon skeleton of ethanol (EtOH) and NADH reoxidation. METHODS: Nine hundred fifty single nucleotide polymorphisms (SNPs) spanning 14 genes (ACN9, ACSS1, ACSS2, ALDH1A1, CAT, CYP2E1, GOT1, GOT2, MDH1, MDH2, SLC25A10, SLC25A11, SLC25A12, SLC25A13) were genotyped in 352 young adults who participated in an alcohol challenge study. Traits tested were blood alcohol concentration (BAC), breath alcohol concentration (BrAC), peak alcohol concentration, and rates of alcohol absorption and elimination. Allelic association was tested using quantitative univariate and multivariate methods. RESULTS: A CYP2E1 promoter SNP (rs4838767, minor allele frequency 0.008) exceeded the threshold for study-wide significance (4.01 × 10(-5) ) for 2 early BAC, 8 BrAC measures, and the peak BrAC. For each phenotype, the minor C allele was related to a lower alcohol concentration, most strongly for the fourth BrAC (p = 2.07 × 10(-7) ) explaining ~8% of the phenotypic variance. We also observed suggestive patterns of association with variants in ALDH1A1 and on chromosome 17 near SLC25A11 for aspects of blood and breath alcohol metabolism. An SNP upstream of GOT1 (rs2490286) reached study-wide significance for multivariate BAC metabolism (p = 0.000040). CONCLUSIONS: Overall, we did not find strong evidence that variation in genes coding for proteins that further metabolize the carbon backbone of acetaldehyde, or contribute to mechanisms for regenerating NAD from NADH, affects alcohol metabolism in our European-descent subjects. However, based on the breath alcohol data, variation in the promoter of CYP2E1 may play a role in preabsorptive or early hepatic alcohol metabolism, but more samples are required to validate this finding.
Alcoholism Clinical and Experimental Research 05/2012; · 3.34 Impact Factor
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Zari Dastani,
Marie-France Hivert,
Nicholas Timpson,
John R B Perry,
Xin Yuan,
Robert A Scott,
Peter Henneman,
Iris M Heid,
Jorge R Kizer,
Leo-Pekka Lyytikäinen, [......],
Eric E Schadt,
David P Strachan,
Muredach P Reilly,
Nilesh J Samani,
Heribert Schunkert,
L Adrienne Cupples,
Manjinder S Sandhu,
Paul M Ridker,
Daniel J Rader,
Sekar Kathiresan
[show abstract]
[hide abstract]
ABSTRACT: Circulating levels of adiponectin, a hormone produced predominantly by adipocytes, are highly heritable and are inversely associated with type 2 diabetes mellitus (T2D) and other metabolic traits. We conducted a meta-analysis of genome-wide association studies in 39,883 individuals of European ancestry to identify genes associated with metabolic disease. We identified 8 novel loci associated with adiponectin levels and confirmed 2 previously reported loci (P = 4.5×10(-8)-1.2×10(-43)). Using a novel method to combine data across ethnicities (N = 4,232 African Americans, N = 1,776 Asians, and N = 29,347 Europeans), we identified two additional novel loci. Expression analyses of 436 human adipocyte samples revealed that mRNA levels of 18 genes at candidate regions were associated with adiponectin concentrations after accounting for multiple testing (p<3×10(-4)). We next developed a multi-SNP genotypic risk score to test the association of adiponectin decreasing risk alleles on metabolic traits and diseases using consortia-level meta-analytic data. This risk score was associated with increased risk of T2D (p = 4.3×10(-3), n = 22,044), increased triglycerides (p = 2.6×10(-14), n = 93,440), increased waist-to-hip ratio (p = 1.8×10(-5), n = 77,167), increased glucose two hours post oral glucose tolerance testing (p = 4.4×10(-3), n = 15,234), increased fasting insulin (p = 0.015, n = 48,238), but with lower in HDL-cholesterol concentrations (p = 4.5×10(-13), n = 96,748) and decreased BMI (p = 1.4×10(-4), n = 121,335). These findings identify novel genetic determinants of adiponectin levels, which, taken together, influence risk of T2D and markers of insulin resistance.
PLoS Genetics 03/2012; 8(3):e1002607. · 8.69 Impact Factor
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Rita P Middelberg,
Beben Benyamin,
Marleen H M de Moor,
Nicole M Warrington,
Scott Gordon,
Anjali K Henders,
Sarah E Medland,
Dale R Nyholt,
Eco J C de Geus,
Jouke J Hottenga, [......],
Lawrence J Beilin,
Trevor A Mori,
Margaret J Wright,
Andrew C Heath,
Pamela A F Madden,
Dorret I Boomsma,
Craig E Pennell,
Grant W Montgomery,
Nicholas G Martin, John B Whitfield
[show abstract]
[hide abstract]
ABSTRACT: Serum gamma-glutamyl transferase (GGT) activity is a marker of liver disease which is also prospectively associated with the risk of all-cause mortality, cardiovascular disease, type 2 diabetes and cancers. We have discovered novel loci affecting GGT in a genome-wide association study (rs1497406 in an intergenic region of chromosome 1, P = 3.9 × 10(-8); rs944002 in C14orf73 on chromosome 14, P = 4.7 × 10(-13); rs340005 in RORA on chromosome 15, P = 2.4 × 10(-8)), and a highly significant heterogeneity between adult and adolescent results at the GGT1 locus on chromosome 22 (maximum P(HET) = 5.6 × 10(-12) at rs6519520). Pathway analysis of significant and suggestive single-nucleotide polymorphism associations showed significant overlap between genes affecting GGT and those affecting common metabolic and inflammatory diseases, and identified the hepatic nuclear factor (HNF) family as controllers of a network of genes affecting GGT. Our results reinforce the disease associations of GGT and demonstrate that control by the GGT1 locus varies with age.
Human Molecular Genetics 01/2012; 21(2):446-55. · 7.64 Impact Factor
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Neda Jahanshad,
Omid Kohannim,
Derrek P Hibar,
Jason L Stein,
Katie L McMahon,
Greig I de Zubicaray,
Sarah E Medland,
Grant W Montgomery, John B Whitfield,
Nicholas G Martin,
Margaret J Wright,
Arthur W Toga,
Paul M Thompson
[show abstract]
[hide abstract]
ABSTRACT: Control of iron homeostasis is essential for healthy central nervous system function: iron deficiency is associated with cognitive impairment, yet iron overload is thought to promote neurodegenerative diseases. Specific genetic markers have been previously identified that influence levels of transferrin, the protein that transports iron throughout the body, in the blood and brain. Here, we discovered that transferrin levels are related to detectable differences in the macro- and microstructure of the living brain. We collected brain MRI scans from 615 healthy young adult twins and siblings, of whom 574 were also scanned with diffusion tensor imaging at 4 Tesla. Fiber integrity was assessed by using the diffusion tensor imaging-based measure of fractional anisotropy. In bivariate genetic models based on monozygotic and dizygotic twins, we discovered that partially overlapping additive genetic factors influenced transferrin levels and brain microstructure. We also examined common variants in genes associated with transferrin levels, TF and HFE, and found that a commonly carried polymorphism (H63D at rs1799945) in the hemochromatotic HFE gene was associated with white matter fiber integrity. This gene has a well documented association with iron overload. Our statistical maps reveal previously unknown influences of the same gene on brain microstructure and transferrin levels. This discovery may shed light on the neural mechanisms by which iron affects cognition, neurodevelopment, and neurodegeneration.
Proceedings of the National Academy of Sciences 01/2012; 109(14):E851-9. · 9.68 Impact Factor
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ABSTRACT: A recent meta-analysis of genome-wide association (GWA) studies identified 95 loci that influence lipid traits in the adult population and found that collectively these explained about 25-30% of heritability for each trait. Little is known about how these loci affect lipid levels in early life, but there is evidence that genetic effects on HDL- and LDL-cholesterol (HDL-C, LDL-C) and triglycerides vary with age. We studied Australian adults (N = 10,151) and adolescents (N = 2,363) who participated in twin and family studies and for whom we have lipid phenotypes and genotype information for 91 of the 95 genetic variants. Heterogeneity tests between effect sizes in adult and adolescent cohorts showed an excess of heterogeneity for HDL-C (p(Het)<0.05 at 5 out of 37 loci), but no more than expected by chance for LDL-C (1 out of 14 loci), or trigycerides (0 out 24). There were 2 (out of 5) with opposite direction of effect in adolescents compared to adults for HDL-C, but none for LDL-C. The biggest difference in effect size was for LDL-C at rs6511720 near LDLR, adolescents (0.021 ± 0.033 mmol/L) and adults (0.157 ± 0.023 mmol/L), p(Het) = 0.013; followed by ZNF664 (p(Het) = 0.018) and PABPC4 (p(Het) = 0.034) for HDL-C. Our findings suggest that some of the previously identified variants associate differently with lipid traits in adolescents compared to adults, either because of developmental changes or because of greater interactions with environmental differences in adults.
PLoS ONE 01/2012; 7(4):e35605. · 4.09 Impact Factor
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Joseph E Powell,
Anjali K Henders,
Allan F McRae,
Anthony Caracella,
Sara Smith,
Margaret J Wright, John B Whitfield,
Emmanouil T Dermitzakis,
Nicholas G Martin,
Peter M Visscher,
Grant W Montgomery
[show abstract]
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ABSTRACT: There is growing evidence that genetic risk factors for common disease are caused by hereditary changes of gene regulation acting in complex pathways. Clearly understanding the molecular genetic relationships between genetic control of gene expression and its effect on complex diseases is essential. Here we describe the Brisbane Systems Genetics Study (BSGS), a family-based study that will be used to elucidate the genetic factors affecting gene expression and the role of gene regulation in mediating endophenotypes and complex diseases.BSGS comprises of a total of 962 individuals from 314 families, for which we have high-density genotype, gene expression and phenotypic data. Families consist of combinations of both monozygotic and dizygotic twin pairs, their siblings, and, for 72 families, both parents. A significant advantage of the inclusion of parents is improved power to disentangle environmental, additive genetic and non-additive genetic effects of gene expression and measured phenotypes. Furthermore, it allows for the estimation of parent-of-origin effects, something that has not previously been systematically investigated in human genetical genomics studies. Measured phenotypes available within the BSGS include blood phenotypes and biochemical traits measured from components of the tissue sample in which transcription levels are determined, providing an ideal test case for systems genetics approaches.We report results from an expression quantitative trait loci (eQTL) analysis using 862 individuals from BSGS to test for associations between expression levels of 17,926 probes and 528,509 SNP genotypes. At a study wide significance level approximately 15,000 associations were observed between expression levels and SNP genotypes. These associations corresponded to a total of 2,081 expression quantitative trait loci (eQTL) involving 1,503 probes. The majority of identified eQTL (87%) were located within cis-regions.
PLoS ONE 01/2012; 7(4):e35430. · 4.09 Impact Factor
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John C Chambers,
Weihua Zhang,
Joban Sehmi,
Xinzhong Li,
Mark N Wass,
Pim Van der Harst,
Hilma Holm,
Serena Sanna,
Maryam Kavousi,
Sebastian E Baumeister, [......],
Caroline S Fox,
Mika Ala-Korpela,
Kari Stefansson,
Peter Vollenweider,
Henry Völzke,
Eric E Schadt,
James Scott,
Marjo-Riitta Järvelin,
Paul Elliott,
Jaspal S Kooner
[show abstract]
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ABSTRACT: Concentrations of liver enzymes in plasma are widely used as indicators of liver disease. We carried out a genome-wide association study in 61,089 individuals, identifying 42 loci associated with concentrations of liver enzymes in plasma, of which 32 are new associations (P = 10(-8) to P = 10(-190)). We used functional genomic approaches including metabonomic profiling and gene expression analyses to identify probable candidate genes at these regions. We identified 69 candidate genes, including genes involved in biliary transport (ATP8B1 and ABCB11), glucose, carbohydrate and lipid metabolism (FADS1, FADS2, GCKR, JMJD1C, HNF1A, MLXIPL, PNPLA3, PPP1R3B, SLC2A2 and TRIB1), glycoprotein biosynthesis and cell surface glycobiology (ABO, ASGR1, FUT2, GPLD1 and ST3GAL4), inflammation and immunity (CD276, CDH6, GCKR, HNF1A, HPR, ITGA1, RORA and STAT4) and glutathione metabolism (GSTT1, GSTT2 and GGT), as well as several genes of uncertain or unknown function (including ABHD12, EFHD1, EFNA1, EPHA2, MICAL3 and ZNF827). Our results provide new insight into genetic mechanisms and pathways influencing markers of liver function.
Nature Genetics 11/2011; 43(11):1131-8. · 35.53 Impact Factor
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Ida Surakka,
Aaron Isaacs,
Lennart C Karssen,
Pirkka-Pekka P Laurila,
Rita P S Middelberg,
Emmi Tikkanen,
Janina S Ried,
Claudia Lamina,
Massimo Mangino,
Wilmar Igl, [......],
H-Erich Wichmann,
Christian Gieger,
Marjo-Riitta Järvelin,
Nicholas G Martin,
Albert Hofman,
Mark I McCarthy,
Leena Peltonen,
Cornelia M van Duijn,
Yurii S Aulchenko,
Samuli Ripatti
[show abstract]
[hide abstract]
ABSTRACT: Recent genome-wide association (GWA) studies described 95 loci controlling serum lipid levels. These common variants explain ∼25% of the heritability of the phenotypes. To date, no unbiased screen for gene-environment interactions for circulating lipids has been reported. We screened for variants that modify the relationship between known epidemiological risk factors and circulating lipid levels in a meta-analysis of genome-wide association (GWA) data from 18 population-based cohorts with European ancestry (maximum N = 32,225). We collected 8 further cohorts (N = 17,102) for replication, and rs6448771 on 4p15 demonstrated genome-wide significant interaction with waist-to-hip-ratio (WHR) on total cholesterol (TC) with a combined P-value of 4.79×10(-9). There were two potential candidate genes in the region, PCDH7 and CCKAR, with differential expression levels for rs6448771 genotypes in adipose tissue. The effect of WHR on TC was strongest for individuals carrying two copies of G allele, for whom a one standard deviation (sd) difference in WHR corresponds to 0.19 sd difference in TC concentration, while for A allele homozygous the difference was 0.12 sd. Our findings may open up possibilities for targeted intervention strategies for people characterized by specific genomic profiles. However, more refined measures of both body-fat distribution and metabolic measures are needed to understand how their joint dynamics are modified by the newly found locus.
PLoS Genetics 10/2011; 7(10):e1002333. · 8.69 Impact Factor
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[show abstract]
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ABSTRACT: Genome-wide association studies (GWAS) have become a major strategy for genetic dissection of human complex diseases. Analysing multiple phenotypes jointly may improve both our ability to detect genetic variants with multiple effects and our understanding of their common features. Allelic associations for multiple biochemical traits (serum alanine aminotransferase, aspartate aminotransferase, butrylycholinesterase (BCHE), C-reactive protein (CRP), ferritin, gamma glutamyltransferase (GGT), glucose, high-density lipoprotein cholesterol (HDL), insulin, low-density lipoprotein cholesterol (LDL), triglycerides and uric acid), and body-mass index, were examined.
We aimed to identify common genetic variants affecting more than one of these traits using genome-wide association analysis in 2548 adolescents and 9145 adults from 4986 Australian twin families. Multivariate and univariate associations were performed.
Multivariate analyses identified eight loci, and univariate association analyses confirmed two loci influencing more than one trait at p < 5 × 10-8. These are located on chromosome 8 (LPL gene affecting HDL and triglycerides) and chromosome 19 (TOMM40/APOE-C1-C2-C4 gene cluster affecting LDL and CRP). A locus on chromosome 12 (OASL gene) showed effects on GGT, LDL and CRP. The loci on chromosomes 12 and 19 unexpectedly affected LDL cholesterol and CRP in opposite directions.
We identified three possible loci that may affect multiple traits and validated 17 previously-reported loci. Our study demonstrated the usefulness of examining multiple phenotypes jointly and highlights an anomalous effect on CRP, which is increasingly recognised as a marker of cardiovascular risk as well as of inflammation.
BMC Medical Genetics 09/2011; 12:123. · 2.33 Impact Factor
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Fangwen Rao,
Stephane Chiron,
Zhiyun Wei,
Maple M Fung,
Yuqing Chen,
Gen Wen,
Srikrishna Khandrika,
Michael G Ziegler,
Beben Benyamin,
Grant Montgomery, John B Whitfield,
Nicholas G Martin,
Jill Waalen,
Bruce A Hamilton,
Sushil K Mahata,
Daniel T O'Connor
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ABSTRACT: The cardiometabolic syndrome comprised of multiple correlated traits, but its origin is incompletely understood. Chromogranin A (CHGA) is required for formation of the catecholamine secretory pathway in sympathochromaffin cells. In twin pair studies, we found that CHGA traits aggregated with body mass index (BMI), as well as its biochemical determinant leptin. METHODS Here we used the twin method to probe the role of heredity in generating such risk traits, and then investigated the role of risk-trait-associated CHGA promoter genetic variation in transfected chromaffin cells. Trait heritability (h(2)) and shared genetic determination among traits (pleiotropy, genetic covariance, ρ(G)) were estimated by variance components in twin pairs.
CHGA, BMI, and leptin each displayed substantial h(2), and the traits also aggregated with several features of the metabolic syndrome (e.g., insulin resistance, blood pressure (BP), hypertension, catecholamines, and C-reactive protein (CRP)). Twin studies demonstrated genetic covariance (pleiotropy, ρ(G)) for CHGA, BMI, and leptin with other metabolic traits (insulin resistance, BP, and CRP). We therefore investigated the CHGA locus for mechanisms of codetermination with such metabolic traits. A common functional variant in the human CHGA promoter (G-462A, rs9658634, minor allele frequency ~21%) was associated with leptin and CRP secretion, as well as BMI, especially in women; marker-on-trait effects on BMI were replicated across twin populations on two continents. In CHGA promoter/luciferase reporter plasmids transfected into chromaffin cells, G-462A alleles differed markedly in reporter expression. The G-462A variant disrupted predicted transcriptional control by a PPARγ/RXRα motif and costimulation by PPARγ/RXRα and their cognate ligands, differentially activated the two alleles. During chromatin immunoprecipitation, endogenous PPARγ bound the motif.
Multiple features of the metabolic syndrome are thus under joint (pleiotropic) genetic determination, with CHGA as one such contributory locus: a common polymorphism in the promoter (G-462A) of CHGA predicts such heritable metabolic traits as BMI and leptin. CHGA promoter variant G-462A was not only associated with such metabolic traits but also disrupted a PPARγ/RXRα motif and responded differentially to characteristic trans-activators of that motif. The results suggest novel links between the catecholaminergic system and risk for the metabolic syndrome as well as systemic hypertension.
American Journal of Hypertension 09/2011; 25(1):29-40. · 3.18 Impact Factor
