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Tuomas O Kilpeläinen,
M Carola Zillikens,
Alena Stančákova,
Francis M Finucane,
Janina S Ried,
Claudia Langenberg,
Weihua Zhang,
Jacques S Beckmann,
Jian'an Luan,
Liesbeth Vandenput, [......],
Joel N Hirschhorn,
Kari Stefansson,
H-Erich Wichmann,
Claes Ohlsson,
Stephen O'Rahilly,
Nicholas J Wareham,
Elizabeth K Speliotes,
Caroline S Fox,
Markku Laakso,
Ruth J F Loos
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ABSTRACT: Genome-wide association studies have identified 32 loci influencing body mass index, but this measure does not distinguish lean from fat mass. To identify adiposity loci, we meta-analyzed associations between ∼2.5 million SNPs and body fat percentage from 36,626 individuals and followed up the 14 most significant (P < 10(-6)) independent loci in 39,576 individuals. We confirmed a previously established adiposity locus in FTO (P = 3 × 10(-26)) and identified two new loci associated with body fat percentage, one near IRS1 (P = 4 × 10(-11)) and one near SPRY2 (P = 3 × 10(-8)). Both loci contain genes with potential links to adipocyte physiology. Notably, the body-fat-decreasing allele near IRS1 is associated with decreased IRS1 expression and with an impaired metabolic profile, including an increased visceral to subcutaneous fat ratio, insulin resistance, dyslipidemia, risk of diabetes and coronary artery disease and decreased adiponectin levels. Our findings provide new insights into adiposity and insulin resistance.
Nature Genetics 06/2011; 43(8):753-60. · 35.53 Impact Factor
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Haiqing Shen,
Lawrence F Bielak,
Jane F Ferguson,
Elizabeth A Streeten,
Laura M Yerges-Armstrong,
Jie Liu,
Wendy Post, Jeffery R O'Connell,
James E Hixson,
Sharon L R Kardia, [......],
Nehal N Mehta,
Mingyao Li,
Daniel L Koller,
Hakan Hakonarson,
Brendan J Keating,
Daniel J Rader,
Alan R Shuldiner,
Patricia A Peyser,
Muredach P Reilly,
Braxton D Mitchell
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ABSTRACT: The vitamin D endocrine system is essential for calcium homeostasis, and low levels of vitamin D metabolites have been associated with cardiovascular disease risk. We hypothesized that DNA sequence variation in genes regulating vitamin D metabolism and signaling pathways might influence variation in coronary artery calcification (CAC).
We genotyped single-nucleotide polymorphisms (SNPs) in GC, CYP27B1, CYP24A1, and VDR and tested their association with CAC quantity, as measured by electron beam computed tomography. Initial association studies were carried out in a discovery sample comprising 697 Amish subjects, and SNPs nominally associated with CAC quantity (4 SNPs in CYP24A1, P=0.008 to 0.00003) were then tested for association with CAC quantity in 2 independent cohorts of subjects of white European ancestry (Genetic Epidemiology Network of Arteriopathy study [n=916] and the Penn Coronary Artery Calcification sample [n=2061]). One of the 4 SNPs, rs2762939, was associated with CAC quantity in both the Genetic Epidemiology Network of Arteriopathy (P=0.007) and Penn Coronary Artery Calcification (P=0.01) studies. In all 3 populations, the rs2762939 C allele was associated with lower CAC quantity. Metaanalysis for the association of this SNP with CAC quantity across all 3 studies yielded a P value of 2.9×10(-6).
A common SNP in the CYP24A1 gene was associated with CAC quantity in 3 independent populations. This result suggests a role for vitamin D metabolism in the development of CAC quantity.
Arteriosclerosis Thrombosis and Vascular Biology 12/2010; 30(12):2648-54. · 6.37 Impact Factor
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ABSTRACT: Migraine with aura is a risk factor for ischemic stroke, but the mechanism by which these disorders are associated remains unclear. Both disorders exhibit familial clustering, which may imply a genetic influence on migraine and stroke risk. Genes encoding for endothelial function are promising candidate genes for migraine and stroke susceptibility because of the importance of endothelial function in regulating vascular tone and cerebral blood flow.
Using data from the Stroke Prevention in Young Women study, a population-based case-control study including 297 women aged 15 to 49 years with ischemic stroke and 422 women without stroke, we evaluated whether polymorphisms in genes regulating endothelial function, including endothelin-1 (EDN), endothelin receptor type B (EDNRB), and nitric oxide synthase-3 (NOS3), confer susceptibility to migraine and stroke.
EDN SNP rs1800542 and rs10478723 were associated with increased stroke susceptibility in whites (OR, 2.1; 95% CI, 1.1-4.2 and OR, 2.2; 95% CI, 1.1-4.4; P=0.02 and 0.02, respectively), as were EDNRB SNP rs4885493 and rs10507875, (OR, 1.7; 95% CI, 1.1-2.7 and OR, 2.4; 95% CI, 1.4-4.3; P=0.01 and 0.002, respectively). Only 1 of the tested SNP (NOS3 rs3918166) was associated with both migraine and stroke.
In our study population, variants in EDN and EDNRB were associated with stroke susceptibility in white but not in black women. We found no evidence that these genes mediate the association between migraine and stroke.
Stroke 09/2009; 40(10):e550-7. · 5.73 Impact Factor
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ABSTRACT: Uric acid is the primary end product of purine metabolism. Increased serum uric acid levels have been associated with gouty arthritis as well as with a variety of cardiovascular-related phenotypes. This study was undertaken to investigate associations between uric acid levels and single-nucleotide polymorphisms (SNPs).
A 500,000-SNP genome-wide association study of serum uric acid levels was performed in a cohort of Old Order Amish from Lancaster County, Pennsylvania.
The scan confirmed a previously identified region on chromosome 4 to be strongly associated with uric acid levels (P = 4.2 x 10(-11) for rs10489070). Followup genotyping revealed that a nonsynonymous coding SNP (Val253Ile; rs16890979) in GLUT9 was most strongly associated with uric acid levels, with each copy of the minor allele associated with a decrease of 0.47 mg/dl in the uric acid level (95% confidence interval 0.31-0.63 [P = 1.43 x 10(-11)]). The effect of this variant tended to be stronger in women than in men (P = 0.16 for sex-genotype interaction). The genotype effect was not modified by the inclusion of several cardiovascular risk factors, suggesting that GLUT9 is directly related to uric acid homeostasis. The SNP identified in the genome-wide scan in the Amish population (rs10489070) was also significantly associated with gout in the Framingham Heart Study (P = 0.004).
Our findings indicate that GLUT9, which is expressed in the kidney, may be a novel regulator of uric acid elimination and that a common nonsynonymous variant in this gene contributes to abnormalities in uric acid homeostasis and gout.
Arthritis & Rheumatism 10/2008; 58(9):2874-81. · 7.87 Impact Factor
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Evadnie Rampersaud,
Braxton D Mitchell,
Toni I Pollin,
Mao Fu,
Haiqing Shen, Jeffery R O'Connell,
Julie L Ducharme,
Scott Hines,
Paul Sack,
Rosalie Naglieri,
Alan R Shuldiner,
Soren Snitker
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ABSTRACT: Common FTO (fat mass and obesity associated) gene variants have recently been associated with body mass index (BMI) and obesity in several large studies. The role of lifestyle factors (such as physical activity) in those with an underlying FTO genetic predisposition is unknown.
To determine if FTO variants are associated with BMI in Old Order Amish (OOA) individuals, and to further determine whether the detrimental associations of FTO gene variants can be lessened by increased physical activity, a total of 704 healthy OOA adults were selected from the Heredity and Phenotype Intervention (HAPI) Heart Study, an investigation of gene x environment interactions in cardiovascular disease, for whom objective quantified physical activity measurements were available and for whom 92 single-nucleotide polymorphisms (SNPs) in FTO were genotyped.
Twenty-six FTO SNPs were associated with BMI (P = .04 to <.001), including rs1477196 (P < .001) and rs1861868 (P < .001), 2 SNPs in moderate linkage disequilibrium in the OOA (D' = 0.82; r(2) = 0.36). Stratified analyses of rs1861868 revealed its association with BMI to be restricted entirely to those subjects with low sex- and age-adjusted physical activity scores (P < .001); in contrast, the SNP had no effect on those with above-average physical activity scores (P = .29), with the genotype x physical activity interaction achieving statistical significance (P = .01). Similar evidence for interaction was also obtained for rs1477196.
Our results strongly suggest that the increased risk of obesity owing to genetic susceptibility by FTO variants can be blunted through physical activity. These findings emphasize the important role of physical activity in public health efforts to combat obesity, particularly in genetically susceptible individuals.
Archives of internal medicine 09/2008; 168(16):1791-7. · 11.46 Impact Factor
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ABSTRACT: High blood pressure is a well established risk factor for morbidity and mortality acting through heart disease, stroke and cardiovascular disease. Genome wide scans have linked regions of nearly every human chromosome to blood pressure related traits. We have capitalized on beneficial qualities of the Old Order Amish of Lancaster, PA, a closed founder population with a relatively small number of founders, to perform a genome wide homozygosity by descent mapping scan. Each individual in the study has a non zero probability of consanguinity. Systolic and diastolic blood pressures are shown to have appreciable dominance variance components.
Areas of two chromosomes were identified as suggestive of linkage to SBP and 5 areas to DBP in either the overall or sex specific analyses. The strongest evidence for linkage in the overall sample was to Chromosome 18q12 (LOD = 2.6 DBP). Sex specific analyses identified a linkage on Chromosome 4p12-14 (LOD in men only = 3.4 SBP). At Chromosome 2q32-33, an area where we previously reported significant evidence for linkage to DBP using a conventional identity by descent approach, the LOD was 1.4; however an appreciable sex effect was observed with men accounting for most of the linkage (LOD in men only = 2.6).
These results add evidence to a sex specific genetic architecture to blood pressure related traits, particularly in regions of linkage on chromosome 2, 4 and 18.
BMC Genetics 02/2007; 8:66. · 2.47 Impact Factor
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ABSTRACT: Using autosome-wide linkage analysis in 964 Amish, strong evidence was found for the presence of genes affecting hip and spine BMD in men on chromosomes 7q31 and 21q22 (LOD = 4.15 and 3.36, respectively).
BMD is highly heritable, with genetic factors accounting for 60-88% of variation. The goal of this study was to localize genes contributing to BMD variation.
The Amish Family Osteoporosis Study was designed to identify genes affecting bone health. The Amish are a genetically closed population with a homogeneous lifestyle. BMD was measured at the spine, hip, and radius using DXA in 964 participants (mean age, 50.2 +/- 16.3 [SD] years; range, 18-99 years) from large multigenerational families. Genotyping of 731 highly polymorphic microsatellite markers (average spacing of 5.4 cM) and autosome-wide multipoint linkage analysis were performed.
In the overall study population, no strong evidence for linkage was detected to any chromosomal region (peak LOD: 2.11 for radius BMD on chromosome 3q26). In a subgroup analysis of men (n = 371), strong evidence was detected for a quantitative trait locus (QTL) influencing BMD variation on chromosome 7q31 at the total hip (LOD = 4.15) and femoral neck (LOD = 3.09) and for a second QTL influencing spine BMD at 21q22 (LOD = 3.36). Suggestive evidence of linkage was found in men for a QTL at 12q24 affecting total hip BMD (LOD = 2.60) and at 18p11 for femoral neck (LOD = 2.07), and in women (n = 593) at 1p36 for femoral neck BMD (LOD = 2.02) and at 1q21 for spine BMD (LOD = 2.11). In age subgroup analyses, suggestive evidence for linkage was found for those <50 years of age (n = 521) on chromosomes 11q22 and 14q23 (LODs = 2.11 and 2.16, respectively) and for those >50 years of age (n = 443) on 3p25.2 (LOD = 2.32).
These results strongly suggest the presence of genes affecting hip and spine BMD in men on chromosomes 7q31 and 21q22. Modest evidence was found for genes affecting BMD in women on chromosomes 1p36 and 1q21 and in men at 12q24, replicating results from other populations.
Journal of Bone and Mineral Research 10/2006; 21(9):1433-42. · 6.37 Impact Factor
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ABSTRACT: Pseudohypoparathyroidism (PHP) is characterized by biochemical hypoparathyroidism with elevated parathyroid hormone levels owing to reduced target tissue responsiveness to parathyroid hormone. Patients with PHP la have somatic defects termed Albright's hereditary osteodystrophy (AHO) and exhibit resistance to additional hormones because of heterozygous mutations in the GNAS1 gene that lead to a generalized deficiency of the a subunit of Gs, the heterotrimeric G protein that couples receptors to adenylyl cyclase. By contrast, patients with PHP 1b lack AHO and have selective parathyroid hormone (PTH) resistance, presumably because of an imprinting defect that impairs expression of G(s)alpha in the proximal renal tubule. Although an epigenetic defect in GNAS1 has been identified in subjects with PHP1b, the genetic defect is unknown. To define the genetic defect in PHP 1b, we performed a genome-wide linkage analysis in five multi-generational PHP lb families. Of the 408 polymorphic microsatellite markers examined, markers located on chromosome 20q13.3, the region containing GNAS1, demonstrated linkage to PHP lb. Fine-mapping and multipoint linkage analysis of this region demonstrated linkage to a 5.7-cM region between 907rep2 and the telomere. Haplotype analysis established that affected individuals shared a 5-cM region including part of the GNAS1 gene to the telomere. Our data confirm that PHP1b is linked to a region that includes GNAS1, and further refine the locus, although the primary genetic mutation(s) that causes defective imprinting of GNAS1 remains undefined.
Journal of Bone and Mineral Research 04/2003; 18(3):424-33. · 6.37 Impact Factor
