A genetic instrument for Mendelian randomization of fibrinogen

Mendelian randomization studies on fibrinogen commonly use a single genetic variant as an instrument, but this may explain only a small proportion of the total phenotypic variance. We examined the contribution of multiple common single nucleotide polymorphisms (SNPs) and haplotypes in the entire fibrinogen gene cluster to plasma fibrinogen levels in two prospective cohorts, for use as instruments in future Mendelian randomization studies. Genotypes for 20 SNPs were determined in 2,778 middle-age (49–64 years) men from the Second-Northwick-Park-Heart Study (NPHS-II). These were replicated in 3,705 men from the Whitehall-II study (WH-II). Plasma fibrinogen levels were determined six times in NPHS-II and three times in WH-II. The minor alleles of four SNPs from the FGB gene, two from the FGA gene, and one from the FGG gene were associated with higher plasma fibrinogen levels. SNP rs1800790 (−455G > A) commonly used in Mendelian randomization studies was associated with R2 = 1.22% of the covariate adjusted residual variance in fibrinogen level. A variable selection procedure identified one additional SNP: rs2070011 (FGA) altogether explaining R2 = 1.45% of the residual variance in fibrinogen level. Using these SNPs no evidence for causality between the fibrinogen levels and coronary heart diseases was found in instrumental variables analysis. In the replication cohort, WH-II, the effects of the two SNPs on fibrinogen levels were consistent with the NPHS-II results. There is statistical evidence for several functional sites in the fibrinogen gene cluster that determine an individual’s plasma fibrinogen levels. Thus, a combination of several SNPs will provide a stronger instrument for fibrinogen Mendelian randomization studies.

[1]  A. Hamsten,et al.  Two common, functional polymorphisms in the promoter region of the beta-fibrinogen gene contribute to regulation of plasma fibrinogen concentration. , 1999, Arteriosclerosis, thrombosis, and vascular biology.

[2]  Peter Donnelly,et al.  A comparison of bayesian methods for haplotype reconstruction from population genotype data. , 2003, American journal of human genetics.

[3]  A. Hamsten,et al.  The association between fibrinogen haplotypes and myocardial infarction in men is partly mediated through pleiotropic effects on the serum IL‐6 concentration , 2007, Journal of internal medicine.

[4]  C. Carlson,et al.  Associations between common fibrinogen gene polymorphisms and cardiovascular disease in older adults , 2008, Thrombosis and Haemostasis.

[5]  Andres Metspalu,et al.  Fibrinogen beta variants confer protection against coronary artery disease in a Greek case-control study , 2010, BMC Medical Genetics.

[6]  J. Houwing-Duistermaat,et al.  Genetic variation in the fibrinogen gamma gene increases the risk for deep venous thrombosis by reducing plasma fibrinogen gamma' levels. , 2005, Blood.

[7]  G. Davey Smith,et al.  Fibrinogen, C-reactive protein and coronary heart disease: does Mendelian randomization suggest the associations are non-causal? , 2004, QJM : monthly journal of the Association of Physicians.

[8]  A. Evans,et al.  β Fibrinogen Gene Polymorphisms Are Associated With Plasma Fibrinogen and Coronary Artery Disease in Patients With Myocardial Infarction , 1996 .

[9]  Y. Friedlander,et al.  Genetic and environmental sources of fibrinogen variability in Israeli families: the Kibbutzim Family Study. , 1995, American journal of human genetics.

[10]  Frank Windmeijer,et al.  Instrumental Variable Estimators for Binary Outcomes , 2009 .

[11]  Per Eriksson,et al.  Epistatic and pleiotropic effects of polymorphisms in the fibrinogen and coagulation factor XIII genes on plasma fibrinogen concentration, fibrin gel structure and risk of myocardial infarction , 2006, Thrombosis and Haemostasis.

[12]  S. Humphries,et al.  ROLE OF GENETIC VARIATION AT THE FIBRINOGEN LOCUS IN DETERMINATION OF PLASMA FIBRINOGEN CONCENTRATIONS , 1987, The Lancet.

[13]  D. Kromhout,et al.  Correcting for multivariate measurement error by regression calibration in meta‐analyses of epidemiological studies , 2009, Statistics in medicine.

[14]  Y. Friedlander,et al.  Combined Segregation and Linkage Analysis of Fibrinogen Variability in Israeli Families: Evidence for Two Quantitative‐trait Loci, One of Which is Linked to a Functional Variant (−58G > A) in the Promoter of the α‐fibrinogen Gene , 2003, Annals of human genetics.

[15]  L. Cardon,et al.  Association study designs for complex diseases , 2001, Nature Reviews Genetics.

[16]  P. McKeigue,et al.  Problems of reporting genetic associations with complex outcomes , 2003, The Lancet.

[17]  D. Lawlor,et al.  Using genetic loci to understand the relationship between adiposity and psychological distress: a Mendelian Randomization study in the Copenhagen General Population Study of 53 221 adults , 2011, Journal of internal medicine.

[18]  Ronald J. Prineas,et al.  The Minnesota code manual of electrocardiographic findings : standards and procedures for measurement and classification , 1982 .

[19]  Michael Marmot,et al.  Cohort Profile: the Whitehall II study. , 2005, International journal of epidemiology.

[20]  M. McCarthy,et al.  An evaluation of HapMap sample size and tagging SNP performance in large-scale empirical and simulated data sets , 2005, Nature Genetics.

[21]  A. Clauss.  [Rapid physiological coagulation method in determination of fibrinogen]. , 1957, Acta haematologica.

[22]  James T. Elder,et al.  Genetic linkage and transmission disequilibrium of marker haplotypes at chromosome 1q41 in human systemic lupus erythematosus , 2001, Arthritis research.

[23]  Sarah Parish,et al.  Fibrinogen and coronary heart disease: test of causality by 'Mendelian randomization'. , 2006, International journal of epidemiology.

[24]  S. Humphries,et al.  Commentary: fibrinogen and coronary heart disease--test of causality by 'Mendelian' randomization by Keavney et al. , 2006, International journal of epidemiology.

[25]  F. Green,et al.  Linkage disequilibrium across the fibrinogen locus as shown by five genetic polymorphisms, G/A −455 (HaeIII), C/T −148 (HindIII/AluI), T/G+1689 (AvaII), and BclI (β‐fibrinogen) and TaqI (α‐fibrinogen), and their detection by PCR , 1994 .

[26]  Zhaohui S. Qin,et al.  A comparison of phasing algorithms for trios and unrelated individuals. , 2006, American journal of human genetics.

[27]  L. Smeeth,et al.  Integrated associations of genotypes with multiple blood biomarkers linked to coronary heart disease risk , 2009, Human molecular genetics.

[28]  D. Arveiler,et al.  Beta fibrinogen gene polymorphisms are associated with plasma fibrinogen and coronary artery disease in patients with myocardial infarction. The ECTIM Study. Etude Cas-Temoins sur l'Infarctus du Myocarde. , 1996, Circulation.

[29]  Mark I. McCarthy,et al.  Concept, Design and Implementation of a Cardiovascular Gene-Centric 50 K SNP Array for Large-Scale Genomic Association Studies , 2008, PloS one.

[30]  A. Henschen,et al.  Linkage disequilibrium relationships among four polymorphisms within the human fibrinogen gene cluster , 1994, Human Genetics.

[31]  A. Steptoe,et al.  Lack of association between depressive symptoms and markers of immune and vascular inflammation in middle-aged men and women , 2003, Psychological Medicine.

[32]  D. Balding.  A tutorial on statistical methods for population association studies , 2006, Nature Reviews Genetics.

[33]  P. Donnelly,et al.  A new statistical method for haplotype reconstruction from population data. , 2001, American journal of human genetics.

[34]  S. Rezende,et al.  Haemostatic Genetic Risk Factors in Arterial Thrombosis , 2001, Thrombosis and Haemostasis.

[35]  Anne Cambon-Thomsen,et al.  Assessing the impact of biobanks , 2003, Nature Genetics.

[36]  J. Loscalzo,et al.  Genetic Determinants of Arterial Thrombosis , 2004, Arteriosclerosis, thrombosis, and vascular biology.

[37]  A. Zwinderman,et al.  −455G/A Polymorphism of the β-Fibrinogen Gene is Associated With the Progression of Coronary Atherosclerosis in Symptomatic Men , 1998 .

[38]  Jacqueline P Mitchell,et al.  Comparison of Novel Hemostatic Factors and Conventional Risk Factors for Prediction of Coronary Heart Disease , 2000, Circulation.

[39]  A. Clauss,et al.  Gerinnungsphysiologische Schnellmethode zur Bestimmung des Fibrinogens , 1957 .

[40]  M. Stephens,et al.  Accounting for Decay of Linkage Disequilibrium in Haplotype Inference and Missing-data Imputation , 2022 .

[41]  A. Hofman,et al.  Fibrinogen gene haplotypes in relation to risk of coronary events and coronary and extracoronary atherosclerosis: The Rotterdam Study , 2007, Thrombosis and Haemostasis.

[42]  R. Collins,et al.  Blood pressure, stroke, and coronary heart disease Part 2, short-term reductions in blood pressure: overview of randomised drug trials in their epidemiological context , 1990, The Lancet.

[43]  R. Collins,et al.  Blood pressure, stroke, and coronary heart disease Part 1, prolonged differences in blood pressure: prospective observational studies corrected for the regression dilution bias , 1990, The Lancet.

[44]  J. Cooper,et al.  Increased Activation of the Haemostatic System in Men at High Risk of Fatal Coronary Heart Disease , 1996, Thrombosis and Haemostasis.

[45]  H Tunstall-Pedoe,et al.  Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis. , 2005, JAMA.

[46]  A. Hamsten,et al.  Contribution of haplotypes across the fibrinogen gene cluster to variation in risk of myocardial infarction , 2005, Thrombosis and Haemostasis.

[47]  Wiebe R. Pestman,et al.  Instrumental Variables: Application and Limitations , 2006, Epidemiology.

[48]  A. Kastrati,et al.  Fibrinogen Genes and Myocardial Infarction: A Haplotype Analysis , 2008, Arteriosclerosis, thrombosis, and vascular biology.

[49]  David Clayton,et al.  Epidemiological methods for studying genes and environmental factors in complex diseases , 2001, The Lancet.

[50]  J. Cooper,et al.  The Effects of Quality and Timing of Venepuncture on Markers of Blood Coagulation in Healthy Middle-aged Men , 1995, Thrombosis and Haemostasis.

[51]  M. Rieder,et al.  Association between patterns of nucleotide variation across the three fibrinogen genes and plasma fibrinogen levels: the Coronary Artery Risk Development in Young Adults (CARDIA) study , 2006, Journal of thrombosis and haemostasis : JTH.

[52]  S. Gabriel,et al.  Efficiency and power in genetic association studies , 2005, Nature Genetics.

[53]  David A. Jaeger,et al.  Problems with Instrumental Variables Estimation when the Correlation between the Instruments and the Endogenous Explanatory Variable is Weak , 1995 .

[54]  George Davey Smith,et al.  Mendelian randomization: Using genes as instruments for making causal inferences in epidemiology , 2008, Statistics in medicine.

[55]  A. Henschen,et al.  Human fibrinogen polymorphic site analysis by restriction endonuclease digestion and allele-specific polymerase chain reaction amplification: identification of polymorphisms at positions A alpha 312 and B beta 448. , 1993, Blood.

[56]  Fotios Drenos,et al.  Application of statistical and functional methodologies for the investigation of genetic determinants of coronary heart disease biomarkers: lipoprotein lipase genotype and plasma triglycerides as an exemplar , 2010, Human molecular genetics.

[57]  R. Kronmal,et al.  The Cardiovascular Health Study: design and rationale. , 1991, Annals of epidemiology.

[58]  J. Stock,et al.  Instrumental Variables Regression with Weak Instruments , 1994 .

[59]  Tom R. Gaunt,et al.  Gene-centric association signals for lipids and apolipoproteins identified via the HumanCVD BeadChip. , 2009, American journal of human genetics.

[60]  G. Crabtree,et al.  Evolution and organization of the fibrinogen locus on chromosome 4: gene duplication accompanied by transposition and inversion. , 1985, Proceedings of the National Academy of Sciences of the United States of America.