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Ganesh S.K.,University of Michigan | Chasman D.I.,Brigham and Womens Hospital | Chasman D.I.,Harvard University | Larson M.G.,U.S. National Institutes of Health | And 62 more authors.
American Journal of Human Genetics | Year: 2014

Blood pressure (BP) is a heritable, quantitative trait with intraindividual variability and susceptibility to measurement error. Genetic studies of BP generally use single-visit measurements and thus cannot remove variability occurring over months or years. We leveraged the idea that averaging BP measured across time would improve phenotypic accuracy and thereby increase statistical power to detect genetic associations. We studied systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP) averaged over multiple years in 46,629 individuals of European ancestry. We identified 39 trait-variant associations across 19 independent loci (p < 5 × 10 -8); five associations (in four loci) uniquely identified by our LTA analyses included those of SBP and MAP at 2p23 (rs1275988, near KCNK3), DBP at 2q11.2 (rs7599598, in FER1L5), and PP at 6p21 (rs10948071, near CRIP3) and 7p13 (rs2949837, near IGFBP3). Replication analyses conducted in cohorts with single-visit BP data showed positive replication of associations and a nominal association (p < 0.05). We estimated a 20% gain in statistical power with long-term average (LTA) as compared to single-visit BP association studies. Using LTA analysis, we identified genetic loci influencing BP. LTA might be one way of increasing the power of genetic associations for continuous traits in extant samples for other phenotypes that are measured serially over time. © 2014 The American Society of Human Genetics. Source

Luzum J.A.,Ohio State University | Theusch E.,Childrens Hospital Oakland Research Institute | Taylor K.D.,Institute for Translational Genomics and Population science | Taylor K.D.,University of California at Los Angeles | And 6 more authors.
Journal of Cardiovascular Pharmacology | Year: 2015

Our objective was to evaluate the associations of genetic variants affecting simvastatin (SV) and simvastatin acid (SVA) metabolism [the gene encoding cytochrome P450, family 3, subfamily A, polypeptide 4 (CYP3A4)∗22 and the gene encoding cytochrome P450, family 3, subfamily A, polypeptide 5 (CYP3A5)∗3] and transport [the gene encoding solute carrier organic anion transporter family member 1B1 (SLCO1B1) T521C] with 12-hour plasma SV and SVA concentrations. The variants were genotyped, and the concentrations were quantified by high performance liquid chromatography-tandem mass spectrometry in 646 participants of the Cholesterol and Pharmacogenetics clinical trial of 40 mg/d SV for 6 weeks. The genetic variants were tested for association with 12-hour plasma SV, SVA, or the SVA/SV ratio using general linear models. CYP3A5∗3 was not significantly associated with 12-hour plasma SV or SVA concentration. CYP3A4∗1/∗22 participants had 58% higher 12-hour plasma SV concentration compared with CYP3A4∗1/∗1 participants (P 0.006). SLCO1B1 521T/C and 521C/C participants had 71% (P < 0.001) and 248% (P < 0.001) higher 12-hour plasma SVA compared with SLCO1B1 521T/T participants, respectively. CYP3A4 and SLCO1B1 genotypes combined categorized participants into low (<1), intermediate (≈1), and high (>1) SVA/SV ratio groups (P 0.001). In conclusion, CYP3A4∗22 and SLCO1B1 521C were significantly associated with increased 12-hour plasma SV and SVA concentrations, respectively. CYP3A5∗3 was not significantly associated with 12-hour plasma SV or SVA concentrations. The combination of CYP3A4∗22 and SLCO1B1 521C was significantly associated with SVA/SV ratio, which may translate into different clinical SV risk/benefit profiles. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. Source

Verhaaren B.F.J.,University of Texas Health Science Center at Houston | Smith J.A.,Medical Informatics | Adams H.H.,Clinical Chemistry | Beecham A.H.,Erasmus University Rotterdam | And 80 more authors.
Circulation: Cardiovascular Genetics | Year: 2015

Background-The burden of cerebral white matter hyperintensities (WMH) is associated with an increased risk of stroke, dementia, and death. WMH are highly heritable, but their genetic underpinnings are incompletely characterized. To identify novel genetic variants influencing WMH burden, we conducted a meta-analysis of multiethnic genome-wide association studies. Methods and Results-We included 21 079 middle-aged to elderly individuals from 29 population-based cohorts, who were free of dementia and stroke and were of European (n=17 936), African (n=1943), Hispanic (n=795), and Asian (n=405) descent. WMH burden was quantified on MRI either by a validated automated segmentation method or a validated visual grading scale. Genotype data in each study were imputed to the 1000 Genomes reference. Within each ethnic group, we investigated the relationship between each single-nucleotide polymorphism and WMH burden using a linear regression model adjusted for age, sex, intracranial volume, and principal components of ancestry. A meta-analysis was conducted for each ethnicity separately and for the combined sample. In the European descent samples, we confirmed a previously known locus on chr17q25 (P=2.7×10-19) and identified novel loci on chr10q24 (P=1.6×10-9) and chr2p21 (P=4.4×10-8). In the multiethnic meta-analysis, we identified 2 additional loci, on chr1q22 (P=2.0×10-8) and chr2p16 (P=1.5×10-8). The novel loci contained genes that have been implicated in Alzheimer disease (chr2p21 and chr10q24), intracerebral hemorrhage (chr1q22), neuroinflammatory diseases (chr2p21), and glioma (chr10q24 and chr2p16). Conclusions-We identified 4 novel genetic loci that implicate inflammatory and glial proliferative pathways in the development of WMH in addition to previously proposed ischemic mechanisms. © 2015 American Heart Association, Inc. Source

Fu Y.,Cedars Sinai Medical Center | Shaw S.A.,Cedars Sinai Medical Center | Naami R.,Cedars Sinai Medical Center | Vuong C.L.,Cedars Sinai Medical Center | And 3 more authors.
Circulation | Year: 2016

The key pathophysiology of human acquired heart failure is impaired calcium transient, which is initiated at dyads consisting of ryanodine receptors (RyRs) at sarcoplasmic reticulum apposing CaV1.2 channels at t-tubules. Sympathetic tone regulates myocardial calcium transients through β-adrenergic receptor (β-AR)-mediated phosphorylation of dyadic proteins. Phosphorylated RyRs (P-RyR) have increased calcium sensitivity and open probability, amplifying calcium transient at a cost of receptor instability. Given that bridging integrator 1 (BIN1) organizes t-tubule microfolds and facilitates CaV1.2 delivery, we explored whether β-AR-regulated RyRs are also affected by BIN1. Methods and Results-Isolated adult mouse hearts or cardiomyocytes were perfused for 5 minutes with the β-AR agonist isoproterenol (1 μmol/L) or the blockers CGP+ICI (baseline). Using biochemistry and superresolution fluorescent imaging, we identified that BIN1 clusters P-RyR and CaV1.2. Acute β-AR activation increases coimmunoprecipitation between P-RyR and cardiac spliced BIN1+13+17 (with exons 13 and 17). Isoproterenol redistributes BIN1 to t-tubules, recruiting P-RyRs and improving the calcium transient. In cardiac-specific Bin1 heterozygote mice, isoproterenol fails to concentrate BIN1 to t-tubules, impairing P-RyR recruitment. The resultant accumulation of uncoupled P-RyRs increases the incidence of spontaneous calcium release. In human hearts with end-stage ischemic cardiomyopathy, we find that BIN1 is also 50% reduced, with diminished P-RyR association with BIN1. Conclusions-On β-AR activation, reorganization of BIN1-induced microdomains recruits P-RyR into dyads, increasing the calcium transient while preserving electric stability. When BIN1 is reduced as in human acquired heart failure, acute stress impairs microdomain formation, limiting contractility and promoting arrhythmias. © 2016 American Heart Association, Inc. Source

Cornes B.K.,Massachusetts General Hospital | Cornes B.K.,Harvard University | Brody J.A.,Cardiovascular Health Research Unit | Nikpoor N.,McGill University | And 34 more authors.
Circulation: Cardiovascular Genetics | Year: 2014

Background-Common variation at the 11p11.2 locus, encompassing MADD, ACP2, NR1H3, MYBPC3, and SPI1, has been associated in genome-wide association studies with fasting glucose and insulin (FI). In the Cohorts for Heart and Aging Research in Genomic Epidemiology Targeted Sequencing Study, we sequenced 5 gene regions at 11p11.2 to identify rare, potentially functional variants influencing fasting glucose or FI levels. Methods and Results-Sequencing (mean depth, 38×) across 16.1 kb in 3566 individuals without diabetes mellitus identified 653 variants, 79.9% of which were rare (minor allele frequency <1%) and novel. We analyzed rare variants in 5 gene regions with FI or fasting glucose using the sequence kernel association test. At NR1H3, 53 rare variants were jointly associated with FI (P=2.73×10-3); of these, 7 were predicted to have regulatory function and showed association with FI (P=1.28×10-3). Conditioning on 2 previously associated variants at MADD (rs7944584, rs10838687) did not attenuate this association, suggesting that there are >2 independent signals at 11p11.2. One predicted regulatory variant, chr11:47227430 (hg18; minor allele frequency=0.00068), contributed 20.6% to the overall sequence kernel association test score at NR1H3, lies in intron 2 of NR1H3, and is a predicted binding site for forkhead box A1 (FOXA1), a transcription factor associated with insulin regulation. In human HepG2 hepatoma cells, the rare chr11:47227430 A allele disrupted FOXA1 binding and reduced FOXA1-dependent transcriptional activity. Conclusions-Sequencing at 11p11.2-NR1H3 identified rare variation associated with FI. One variant, chr11:47227430, seems to be functional, with the rare A allele reducing transcription factor FOXA1 binding and FOXA1- dependenttranscriptional activity. © 2014 American Heart Association, Inc. Source

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