Methods and Results— Clinical evaluation was performed according to the Task Force Criteria (TFC). We analyzed the genes in (a) 57 patients who fulfilled the ARVD/C TFC (TFC+), (b) 28 patients with probable ARVD/C (1 major and 1 minor, or 3 minor criteria), and (c) 31 patients with 2 minor or 1 major criteria. In the TFC+ ARVD/C group, 23 patients (40%) had PKP2 mutations, 4 (7%) had DSG2 mutations, and 1 patient (2%) carried a mutation in DSC2, whereas 1 patient (2%) had a mutation in both DSG2 and DSC2. Among the DSG2 and DSC2 mutation-positive TFC+ ARVD/C probands, 2 carried compound heterozygous mutations and 1 had digenic mutations. In probable ARVD/C patients and those with 2 minor or 1 major criteria for ARVD/C, mutations were less frequent and they were all heterozygous. Negative T waves in the precordial leads were observed more (P<0.002) among mutation carriers than noncarriers and in particular in PKP2 mutation carriers.

Conclusions— Mutations in DSG2 and DSC2 are together less prevalent (10%) than PKP2 mutations (40%) in Dutch TFC+ ARVD/C patients. Interestingly, biallelic or digenic DSC2 and/or DSG2 mutations are frequently identified in TFC+ ARVD/C patients, suggesting that a single mutation is less likely to cause a full-blown ARVD/C phenotype. Negative T waves on ECG were prevalent among mutation carriers (P<0.002).

Methods and Results— In 82 individuals with ARVD/C and 18 people with suspected ARVD/C, DNA sequence analysis was performed on PKP2, DSG2, DSP, DSC2, and JUP. In those with ARVD/C, 52% harbored a desmosome mutation. A majority of these mutations occurred in PKP2. Notably, 3 of the individuals studied have a mutation in more than 1 gene. Patients with a desmosome mutation were more likely to have experienced ventricular tachycardia (73% versus 44%), and they presented at a younger age (33 versus 41 years) compared with those without a desmosome mutation. Men with ARVD/C were more likely than women to carry a desmosome mutation (63% versus 38%). A mutation was identified in 5 of 18 patients (28%) with suspected ARVD. In this smaller subgroup, there were no significant phenotypic differences identified between individuals with a desmosome mutation compared with those without a mutation.

Conclusions— Our study shows that in 52% of North Americans with ARVD/C a mutation in one of the cardiac desmosome genes can be identified. Compared with those without a desmosome gene mutation, individuals with a desmosome gene mutation had earlier-onset ARVD/C and were more likely to have ventricular tachycardia.

Methods and Results— Seventy-nine consecutive patients diagnosed with HCM aged 13 years or younger underwent detailed clinical and genetic evaluation. The protein-coding sequences of 9 sarcomere protein genes (MYH7, MYBPC3, TNNI3, TNNT2, TPM1, MYL2, MYL3, ACTC, and TNNC1), the genes encoding desmin (DES), and the -2 subunit of AMP kinase (PRKAG2) were screened for mutations. A family history of HCM was present in 48 patients (60.8%). Forty-seven mutations (15 novel) were identified in 42 (53.2%) patients (5 patients had 2 mutations). The genes most commonly implicated were MYH7 (48.9%) and MYBPC3 (36.2%); mutations in TNNT2, ACTC, MYL3, and TNNI3 accounted for <5% of cases each. A total of 16.7% patients with sarcomeric mutations were diagnosed before 1 year of age. There were no differences in clinical and echocardiographic features between those children with sarcomere protein gene mutations and those without or between patients with 2 mutations and those with 1 or no mutations.

Conclusions— This study shows that familial disease is common among infants and children with HCM and that, in most cases, disease is caused by mutations in cardiac sarcomere protein genes. The major implication is that all first-degree relatives of any child diagnosed with HCM should be offered screening. Furthermore, the finding that one sixth of patients with sarcomeric disease were diagnosed in infancy suggests that current views on pathogenesis and natural history of familial HCM may have to be revised.

Methods and Results— We used clinically available genetic testing on 3 cases referred for evaluation of left ventricular dysfunction and noncompaction of the left ventricle and found that all 3 individuals carried sarcomere mutations. The first patient presented with neonatal heart failure and was referred for left ventricular noncompaction cardiomyopathy. Genetic testing found 2 different mutations in MYBPC3 in trans. The first mutation, 3776delA, Q1259fs, rendered a frame shift at 1259 of cardiac myosin-binding protein C and the second mutation was L1200P. The frameshift mutation was also found in this mother who displayed mild echocardiographic features of cardiomyopathy, with only subtle increase in trabeculation and an absence of hypertrophy. A second pediatric patient presented with heart failure and was found to carry a de novo MYH7 R369Q mutation. The third case was an adult patient with dilated cardiomyopathy referred for ventricular hypertrabeculation. This patient had a family history of congestive heart failure, including pediatric onset cardiomyopathy where 3 individuals in the family were found to have the MYH7 mutation R1250W.

Conclusion— Genetic testing should be considered for cardiomyopathy with hypertrabeculation.

Methods and Results— To determine the disease incidence in the Taiwan Chinese population, a Fabry disease newborn screening study was initiated. A total of 110 027 newborns were screened by assaying the -galactosidase A (-Gal A) activity using dry blood spots. Low plasma -Gal A activity and presence of a Fabry mutation was demonstrated in 45 neonates (3 females). Eight different mutations were identified, including 3 known missense mutations (R112H, A143T, and R356W), 4 novel missense mutations (G104V, M296L, G360C, and K391T), and one known intronic mutation (IVS4+919G->A). The IVS4+919G->A mutation was most common (82% of patients). A total of 20 maternal grandparents of infants harboring this intronic mutation were evaluated by echocardiography, mutation analysis and -Gal A activity assay. The intronic mutation was found in 9 grandfathers and 11 grandmothers. Of these grandparents, 3 grandfathers (33%) but none of the grandmothers had hypertrophic cardiomyopathy. Additionally, 16 males who had been diagnosed with idiopathic hypertrophic cardiomyopathy were screened by mutation analysis and -Gal A activity; 4 (25%) showed deficient plasma -Gal A activity in combination with the intronic mutation.

Conclusion— We found an unexpected high prevalence of the cardiac variant Fabry mutation IVS4+919G->A among both newborns (1 in 1600 males) and patients with idiopathic hypertrophic cardiomyopathy in the Taiwan Chinese population. The early identification of undiagnosed patients allows timely therapeutic intervention providing a better clinical outcome.

Methods and Results— To distinguish the direct effects of ₂R302Q expression from later compensatory alterations in signaling, we used transgenic mice expressing either the wild-type AMPK₂ subunit (TG₂WT) or the mutated form (TG₂R302Q), in combination with acute expression of these proteins in neonatal rat cardiomyocytes. Although acute expression of ₂R302Q induces AMPK activation and upregulation of glycogen synthase and AS160, with an associated increase in glycogen content, AMPK activity, glycogen synthase activity, and AS160 expression are reduced in hearts from TG₂R302Q mice, likely in response to the existing 37-fold increase in glycogen. Interestingly, ₂WT expression has similar, yet less marked effects than ₂R302Q expression in both cardiomyocytes and hearts.

Conclusions— Using acute and chronic models of ₂R302Q expression, we have differentiated the direct effects of the ₂R302Q mutation from eventual compensatory modifications. Our data suggest that expression of ₂R302Q induces AMPK activation and the eventual increase in glycogen content, a finding that is masked in hearts from transgenic adult mice. These findings are the first to highlight temporal differences in the effects of the PRKAG2 R302Q mutation on cardiac metabolic signaling events.

Methods and Results— Haplotypes at the PCSK5 locus were examined in 9 multigenerational families that included 60 individuals with HDL-C <10th percentile. Segregation with low HDL-C in 1 family was found. Sequencing of the PCSK5 gene in 12 probands with HDL-C <5th percentile identified 7 novel variants. Using a 2-stage design, we first genotyped these single-nucleotide polymorphisms (SNPs) along with 163 tagSNPs and 12 additional SNPs (n=182 total) in 457 individuals with documented coronary artery disease. We identified 9 SNPs associated with HDL-C (P<0.05), with the strongest results for rs11144782 and rs11144766 (P=0.002 and P=0.005, respectively). The SNP rs11144782 was also associated with very low-density lipoprotein (P=0.039), triglycerides (P=0.049), and total apolipoprotein levels (P=0.022). In stage 2, we replicated the association of rs11144766 with HDL-C (P=0.014) in an independent sample of Finnish low HDL-C families. In a combined analysis of both stages (n=883), region-wide significance of rs11144766 and low HDL-C was observed (unadjusted P=1.86x10^–4 and Bonferroni-adjusted P=0.031).

Conclusions— We conclude that variability at the PCSK5 locus influences HDL-C levels, possibly through the inactivation of endothelial lipase activity, and, consequently, atherosclerotic cardiovascular disease risk.

Methods and Results— Eight haplotype-tagging SNPs spanning 29 kb were tested for association with ICH presentation in 146 white patients with BAVM (phase I: 56 ICH, 90 non-ICH) using allelic, haplotypic, and principal components analysis. Associated SNPs were then genotyped in 102 additional cases (phase II: 37 ICH, 65 non-ICH), and data were combined for multivariable logistic regression. Minor alleles of 2 SNPs were associated with reduced risk of ICH presentation (rs314313_C, P=0.005; rs314308_T, P=0.0004). Overall, haplotypes were also significantly associated with ICH presentation (²=17.24, 6 df, P=0.008); 2 haplotypes containing the rs314308 T allele (GCCTGGGT, P=0.003; GTCTGGGC, P=0.036) were associated with reduced risk. In principal components analysis, 2 components explained 91% of the variance and complemented haplotype results by implicating 4 SNPs at the 5' end, including rs314308 and rs314313. These 2 SNPs were replicated in the phase II cohort, and combined data resulted in greater significance (rs314313, P=0.0007; rs314308, P=0.00008). SNP association with ICH presentation persisted after adjusting for age, sex, BAVM size, and deep venous drainage.

Conclusions— EPHB4 polymorphisms are associated with risk of ICH presentation in patients with BAVM, warranting further study.

Methods and Results— For each subject, the genome-wide variations were measured using the Affymetrix 6.0 chip that includes measurements of 906 000 single-nucleotide polymorphisms and 946 000 CNV probes. The gene expression profiles of the transformed B lymphocytes were measured for the same subjects. Among the 210 subjects, we identified 1529 CNV regions on 22 autosomes. By testing the association between CNVs and the gene expression levels in each racial group using linear regression, we identified 4 statistically significant CNV associations in all 3 groups (=0.05). The strongest association was between a 66 kbp CNV region located on chromosome 6 and endothelin-1 (EDN1) expression. The effects of the CNV-EDN1 association in the 3 racial groups were in the same direction and explained 7% to 14% of the variation in EDN1 expression.

Conclusions— Although the biological function of the chromosome 6 CNV is unclear, the significant and consistent association found in 3 racial groups suggests that CNVs may contribute to variation in underlying risks of common disease through their effects on key molecular signaling pathways.

Methods and Results— A large-scale quantitative measurements of gene expression was performed on 5 normal and 5 AS valves using Affymetrix GeneChips. A total of 409 and 306 genes were significantly up- and downregulated in AS valves, respectively. The 2 most highly upregulated genes were matrix metalloproteinase 12 and chitinase 3-like 1. The upregulation of these 2 biologically relevant genes in AS was validated by real-time polymerase chain reaction in 38 aortic valves (12 normal and 26 AS). To provide a global biological validation of the whole-genome gene expression analysis, the microarray experiment was repeated in a second set of aortic valves with (n=5) or without (n=5) AS. There was an overrepresentation of small P values among genes claimed significant in the first microarray experiment. A total of 223 genes were replicated (P<0.05 and fold change >1.2), including matrix metalloproteinase 12 and chitinase 3-like 1.

Conclusions— This study reveals many unrecognized genes potentially implicated in the pathogenesis of AS. These new genes were overlaid on known pathological pathways leading to AS to refine our molecular understanding of this disease.

Methods and Results— Two prospectively collected cohorts of patients undergoing coronary artery bypass graft surgery, with or without concurrent valve surgery, at 3 US centers. From a discovery cohort of 959 patients, clinical and genomic multivariate predictors of postoperative AF were identified by genotyping 45 single-nucleotide polymorphisms (SNPs) encompassing the 4q25 locus. Three SNPs were then assessed in a separately collected validation cohort of 494 patients. After adjustment for clinical predictors of postoperative AF and multiple comparisons, rs2200733, rs13143308, and 5 other linked SNPs independently predicted postoperative AF in the discovery cohort. Additive odds ratios for the 7 associated 4q25 SNPs ranged between 1.57 and 2.17 (P=8.0x10^–4 to 3.4x10^–6). Association with postoperative AF were measured and replicated for rs2200733 and rs13143308 in the validation cohort.

Conclusions— In 2 independently collected cardiac surgery cohorts, noncoding SNPs within the chromosome 4q25 region are independently associated with postoperative AF after coronary artery bypass graft surgery after adjusting for clinical covariates and multiple comparisons.

Methods and Results— We used information on 9584 men and women from the Danish general population in the Copenhagen City Heart Study. During follow-up, from 1991 to 2007, 663 incident cases of myocardial infarction occurred. We observed that increasing alcohol intake was associated with decreasing risk of myocardial infarction, decreasing low-density lipoprotein cholesterol and fibrinogen, increasing diastolic and systolic blood pressure and high-density lipoprotein cholesterol, and with U-shaped nonfasting triglycerides. In contrast, ADH1B and ADH1C genotypes were not associated with risk of myocardial infarction or with any of the cardiovascular biochemical risk factors, and there was no indication that associations between alcohol intake and myocardial infarction and between alcohol intake and risk factors were modified by genotypes.

Conclusions— Increasing alcohol intake is associated with decreasing risk of myocardial infarction, decreasing low-density lipoprotein cholesterol and fibrinogen, increasing diastolic and systolic blood pressure and high-density lipoprotein cholesterol, and U-shaped nonfasting triglycerides. These associations were not modified by ADH1B and ADH1C are genotypes.

Methods and Results— A total of 1031 consecutive patients with coronary artery disease who were scheduled for elective percutaneous coronary interventions were enrolled. Platelet function was assessed by means of ADP-induced light-transmittance aggregometry and the VerifyNow P2Y12 assay. Six haplotype-tagging single nucleotide polymorphisms were carefully selected to comprehensively cover the total common variation in the P2RY12 gene and its flanking regulatory regions. Six common haplotypes were inferred from these haplotype-tagging single nucleotide polymorphisms (denoted A to F). Haplotype F was associated with significantly lower residual on-clopidogrel platelet reactivity compared with the reference haplotype A. The size of this effect per haplotype allele was approximately 5% aggregation in the ADP-induced light-transmittance aggregometry (P<0.05) and 11 P2Y12 reaction units in the VerifyNow P2Y12 assay (P<0.05).

Conclusions— Common variation in the P2RY12 gene is a significant determinant of the interindividual variability in residual on-clopidogrel platelet reactivity in patients with coronary artery disease.

Methods and Results— In this study, we aimed at describing the molecular mechanism through which the strongest associating intronic single-nucleotide polymorphism variant in USF1 is involved in the development of dyslipidemia. The effects of the risk variant on gene expression were studied in 2 relevant human tissues, fat and muscle. Global transcript profiles of 47 fat biopsies ascertained for carriership of the risk allele were tested for differential expression of known USF1 target genes as well as for broader effects on the transcript profile. Allelic imbalance of USF1 in fat was assessed using a quantitative sequencing approach. The possible allele-specific effect of insulin on the expression of USF1 was studied in 118 muscle biopsies before and after a euglycemic hyperinsulinemic clamp. The risk allele of single-nucleotide polymorphism rs2073658 seems to eradicate the inductive effect of insulin on the expression of USF1 in muscle and fat. The expression of numerous target genes is in turn perturbed in adipose tissue.

Conclusions— In risk allele carriers, a defective response of USF1 to insulin results in the suboptimal response of relevant target genes that contributes to the enhanced risk of developing dyslipidemia and coronary heart disease.

Methods and Results— We recently undertook bidirectional resequencing of TNNT2, the cardiac troponin T gene, in 313 probands with DCM. We identified 6 TNNT2 protein-altering variants in 9 probands, all who had early onset, aggressive disease. Additional family members of mutation carriers were then studied when available. Four of the 9 probands had DCM without a family history, and 5 probands had familial DCM. Only 1 mutation (Lys210del) could be attributed as definitively causative from previous reports. Four of the 5 missense mutations were novel (Arg134Gly, Arg151Cys, Arg159Gln, and Arg205Trp), and one was previously reported with hypertrophic cardiomyopathy (Glu244Asp). Based on the clinical, pedigree, and molecular genetic data, these 5 mutations were considered possibly or likely disease causing. To further clarify their potential pathophysiologic impact, we undertook functional studies of these mutations in cardiac myocytes reconstituted with mutant troponin T proteins. We observed decreased Ca²⁺ sensitivity of force development, a hallmark of DCM, in support of the conclusion that these mutations are disease causing.

Conclusions— We conclude that the combination of clinical, pedigree, molecular genetic, and functional data strengthen the interpretation of TNNT2 mutations in DCM.

Methods and Results— Comprehensive echocardiography with strain imaging was performed on 146 genotyped individuals with mutations in 5 sarcomere genes. Contractile parameters were compared in 68 preclinical (G+/LVH–), 40 overt (G+/LVH+) subjects with HCM, and 38 mutation (–) normal control relatives. All subjects had normal left ventricular ejection fraction. In preclinical HCM, global and regional peak systolic strain (_sys) and longitudinal systolic strain rate were not significantly different from controls, but early diastolic mitral annular velocity (Ea) was reduced by 13%. In overt HCM, there was a significant 27% and 14% decrease in global longitudinal _sys and systolic strain rate, respectively, compared with both preclinical HCM and controls (P<0.013 for all comparisons), and a 33% reduction in Ea.

Conclusions— Sarcomere mutations have disparate initial effects on diastolic and systolic functions. Preclinical HCM is characterized by impaired relaxation but preserved systolic strain. In contrast, both diastolic and longitudinal systolic abnormalities are present in overt disease despite normal ejection fraction. We propose that diastolic dysfunction is an early consequence of sarcomere mutations, whereas systolic dysfunction results from mutations combined with subsequent pathological remodeling. Identifying mechanistic pathways triggered by these mutations may begin to reshape the clinical paradigm for treatment, based on early diagnosis and disease prevention.

Methods and Results— We analyzed the heart rate at rest, measured as the RR interval, and the length of the corrected QT interval for association with 318 237 single-nucleotide polymorphisms. The RR interval was associated with common variants within GPR133, a G-protein–coupled receptor (rs885389, P=3.9x10^–8). The QT interval was associated with the earlier reported NOS1AP gene (rs2880058, P=2.00x10^–10) and with a region on chromosome 13 (rs2478333, P=4.34x10^–8), which is 100 kb from the closest known transcript LOC730174 and has previously not been associated with the length of the QT interval.

Conclusion— Our results suggested an association between the RR interval and GPR133 and confirmed an association between the QT interval and NOS1AP.

Methods and Results— We performed a genome-wide association analysis of circulating MMP-1 levels using 500 K single-nucleotide polymorphisms (SNPs) to identify genes influencing variation in serum MMP-1 levels in 778 healthy Amish adults. Serum MMP-1 levels, logarithm transformed, and adjusted for age and sex, were screened for association with SNPs using mixed-model variance components to account for familial relatedness. Median MMP-1 level was 3.05 ng/mL (interquartile range: 1.82 to 5.04 ng/mL) with an estimated heritability of 81% (P<0.0001). Serum MMP-1 levels were strongly associated with a cluster of 179 SNPs extending over an 11.5-megabase region on chromosome 11q. The peak association was with rs495366 (P=5.73x10^–34), located within the region between MMP-1 and MMP-3 and having a minor allele frequency of 0.36. Two other SNPs within the 11q region, rs12289128 and rs11226373, were strongly associated with MMP-1 levels after accounting for rs495366 (P≤10^–7). These 3 SNPs explained 31% of the variance in MMP-1 levels after adjusting for age and sex.

Conclusions— This study provides strong evidence that the serum MMP-1 level is highly heritable and that SNPs near MMPs on chromosome 11q explain a significant portion of the variation in MMP-1 levels. Identification of the genetic variants that influence MMP-1 levels may provide insights into genetic mechanisms of cardiovascular disease.

Methods and Results— We performed a shared control-cases study using 15 tagging single-nucleotide polymorphisms and 2 previously reported susceptibility single-nucleotide polymorphisms spanning 58 kb of the chromosome of 9p21 in a set of 558 patients with ischemic stroke, 510 patients with CAD, and 557 unaffected participants (controls) in the Chinese Han population. The association analyses were performed at both SNP and haplotype levels. We further verified our findings in an independent cohort of 442 ischemic stroke cases and 502 control subjects. In the first study, rs2383206, rs1004638, and rs10757278 in block 3 were significantly associated with CAD but not with ischemic stroke independent of traditional cardiovascular risk factors in additive model (P=0.002 to 0.0001, q=0.026 to 0.004). Analysis from all blocks revealed that haplotype profiles of block 3 on 9p21 were significantly different between shared control and cases of CAD (P=1.3x10^–10, q=1.2x10^–9) and ischemic stroke (P=1.7x10^–6, q=7.7x10^–6). In the expanded second case-control study, block 3 on 9p21 remained associated with ischemic stroke (P=2.6x10^–4, q=6.3x10^–4).

Conclusions— Our results suggest for the first time that 9p21 is a shared susceptibility locus, strongly for CAD and weakly for ischemic stroke, in a Chinese Han population.

Methods and Results— We used data from the InCHIANTI, Baltimore Longitudinal Study of Aging, and Health, Aging, and Body Composition studies. In 2630 white individuals (mean age, 76.4 years), the C allele at rs1333049 was associated with lower mean ABI measures and with an increased prevalence of PAD. These associations remained after removal of baseline and incident myocardial infarction cases over a 6-year follow-up for both ABI (–0.017 ABI units; 95% CI, –0.03 to –0.01; P=1.3x10^–4) and PAD (per allele odds ratio, 1.29; 95% CI, 1.06 to 1.56; P=0.012). These associations also remained after adjustment for known atherosclerosis risk factors, including diabetes mellitus, smoking, hypercholesterolemia, and hypertension.

Conclusions— The C allele at rs1333049 is associated with an increased prevalence of PAD and lower mean ABI. This association was independent of the presence of diagnosed myocardial infarction and atherosclerotic risk factors in 3 older white populations.

Methods and Results— We investigated the associations of 6 PCSK9 variants with LDL-C over 20 years in 1750 blacks and 1828 whites from the Coronary Artery Risk Development In Young Adults study. Generalized estimating equations were used to assess longitudinal differences in LDL-C levels between genotype categories. For blacks, LDL-C levels at age 18 were significantly lower (P<0.001) among those with 3 genetic variants (L253F, C679X, and Y142X; 81.5 mg/dL) and A443T (95.5 mg/dL) compared with noncarriers (109.6 mg/dL). The difference in LDL-C levels from noncarriers tended to widen for those with the 3 variants only, by 0.24 mg/dL per year of age (P=0.14). For whites with the R46L variant, compared with noncarriers, LDL-C levels at age 18 were significantly lower (84.4 mg/dL versus 100.9 mg/dL; P<0.001), and the increase in LDL-C with age was similar to noncarriers. The 3 genetic variants and the A443T variant in black men were associated with lower carotid intima-media thickness and lower prevalence of coronary calcification measured at ages 38 to 50.

Conclusions— Our results suggest that participants with several genetic variants of PCSK9 have persistently lower serum LDL-C levels than noncarriers from ages 18 to 50. Such long-term reduction in LDL-C levels is associated with reduced subclinical atherosclerosis burden in black men.

Methods and Results— Resequencing of CACNA1C was performed followed by a nested case-control study of the INternational VErapamil SR/trandolapril STudy (INVEST) GENEtic Substudy (INVEST-GENES). Of 46 polymorphisms identified, 8 were assessed in the INVEST-GENES. Rs1051375 was found to have a significant interaction with treatment strategy (P=0.0001). Rs1051375 A/A genotype was associated with a 46% reduction in the primary outcome among those randomized to verapamil SR treatment, when compared with atenolol treatment (odds ratio 0.54 95% CI 0.32 to 0.92). In heterozygous A/G individuals, there was no difference in the occurrence of the primary outcome when randomized to verapamil SR versus atenolol treatment (odds ratio 1.47 95% CI 0.86 to 2.53), whereas homozygous G/G individuals had a greater than 4-fold increased risk of the primary outcome with verapamil treatment compared with those randomized to atenolol treatment (odds ratio 4.59 95% CI 1.67 to 12.67). We did not identify allelic expression imbalance or differences in mRNA expression in heart tissue by rs1051375 genotype.

Conclusions— Variation in CACNA1C is associated with treatment response among hypertensive patients with stable coronary artery disease. Our data suggest a genetically defined group of patients that benefit most from calcium channel blocker therapy, a group that benefits most from β-blocker therapy, and a third group in which calcium channel blocker and β-blocker therapy are equivalent.

Methods and Results— Adult dogs underwent left bundle branch ablation and right atrial pacing at 200 bpm for either 6 weeks (dyssynchronous heart failure, n=12) or 3 weeks, followed by 3 weeks of resynchronization by biventricular pacing at the same pacing rate (CRT, n=10). Control animals without left bundle branch block were not paced (n=13). At 6 weeks, RNA was isolated from the anterior and lateral left ventricular (LV) walls and hybridized onto canine-specific 44K microarrays. Echocardiographically, CRT led to a significant decrease in the dyssynchrony index, while dyssynchronous heart failure and CRT animals had a comparable degree of LV dysfunction. In dyssynchronous heart failure, changes in gene expression were primarily observed in the anterior LV, resulting in increased regional heterogeneity of gene expression within the LV. Dyssynchrony-induced expression changes in 1050 transcripts were reversed by CRT to levels of nonpaced hearts (false discovery rate <5%). CRT remodeled transcripts with metabolic and cell signaling function and greatly reduced regional heterogeneity of gene expression as compared with dyssynchronous heart failure.

Conclusions— Our results demonstrate a profound effect of electromechanical dyssynchrony on the regional cardiac transcriptome, causing gene expression changes primarily in the anterior LV wall. CRT corrected the alterations in gene expression in the anterior wall, supporting a global effect of biventricular pacing on the ventricular transcriptome that extends beyond the pacing site in the lateral wall.

Methods and Results— To obtain insights into the role of MPs in atherogenesis, MP proteins were identified by tandem mass spectrometry, metabolite profiles were determined by high-resolution nuclear magnetic resonance spectroscopy, and antibody reactivity was assessed against combinatorial antigen libraries. Plaque MPs expressed surface antigens consistent with their leukocyte origin, including major histocompatibility complex classes I and II, and induced a dose-dependent stimulatory effect on T-cell proliferation. Notably, taurine, the most abundant free organic acid in human neutrophils, which scavenges myeloperoxidase-catalyzed free radicals, was highly enriched in plaque MPs. Moreover, fluorescent labeling of proteins on the MP surface suggested immunoglobulins to be trapped inside, which was confirmed by flow cytometry analysis on permeabilized and nonpermeabilized plaque MPs. Colabeling for CD14 and IgG established that more than 90% of the IgG containing MPs were CD14⁺, indicating a macrophage origin. Screening against an antigen library revealed that the immunologic profiles of antibodies in MPs were similar to those found in plaques but differed profoundly from antibodies in plasma and unexpectedly, showed strong reactions with oligosaccharide antigens, in particular blood group antigen A.

Conclusions— This study provides the first evidence that immunoglobulins are present within MPs derived from plaque macrophages, that the portfolio of plaque antibodies is different from circulating antibodies in plasma, and that anticarbohydrate antibodies are retained in human atherosclerotic lesions.

Methods and Results— We performed a nested case-control study in the prospective EPIC-Norfolk cohort. Cases were apparently healthy men and women, aged 45 to 79 years, who developed fatal or nonfatal CAD (n=882). Controls remained free of CAD (n=1490). Overall, systemic prolactin levels did not differ between cases and controls, and people in the highest prolactin tertile did not have a significantly increased risk of developing future CAD (in men, odds ratio, 1.21; 95% CI, 0.92 to 1.61; in women, odds ratio, 1.12; 95% CI, 0.76 to 1.64). However, in a separate immunohistochemical study, the presence of prolactin receptors could be demonstrated in postmortem human coronary artery plaques (preliminary data).

Conclusions— Elevated systemic prolactin levels do not predict CAD in the general population. However, prolactin receptors were found in human coronary artery plaques. This observation may indicate a role of prolactin within atherosclerotic plaques. More studies are needed to define the possible role of prolactin in atherosclerotic plaque development.

Methods and Results— We studied the interaction of additive genetic effects and behavioral (physical activity, smoking, alcohol use) and socioeconomic (education) factors on BP in 3600 American Indian participants of the Strong Heart Family Study, using variance component models. The mean and SD of resting systolic and diastolic BPs were 123±17 and 76±11 mm Hg, respectively. We detected evidence for distinct genetic effects on diastolic BP among ever smokers compared with never smokers (P=0.01). For alcohol intake, we observed significant genotype-by-environment interactions on diastolic (g=0.10, P=0.0003) and on systolic BPs (g=0.59, P=0.0008) among current drinkers compared with former or never drinkers. We also detected genotype-by-physical activity interactions on diastolic BP (g=0.35, P=0.0004). Finally, there was evidence for distinct genetic effects on diastolic BP among individuals with less than high school education compared with those with 12 or more years of education (g=0.41, P=0.02).

Conclusions— Our findings suggest that behavioral and socioeconomic factors can modify the genetic effects on BP phenotypes. Accounting for context dependent factors may help us to better understand the complexities of the gene effects on BP and other complex phenotypes with high levels of genetic heterogeneity.

Methods and Results— RNA isolates from failing (n=86) and nonfailing (n=16) human hearts were hybridized with Affymetrix HU133A arrays. For each gene on the array, we determined conserved MEF2, NFAT, NKX , GATA , and FOX binding motifs within the –1-kb promoter region using human-murine sequence alignments and the TRANSFAC database. Across 9076 genes expressed in the heart, TF-binding motifs tended to cluster together in nonrandom patterns within promoters of specific genes (P values ranging from 10^–2 to 10^–21), suggesting coregulation. We then modeled differential expression as a function of TF combinations present in promoter regions. Several combinations predicted increased odds of differential expression in the failing heart, with the highest odds ratios noted for genes containing both MEF2 and NFAT binding motifs together in the same promoter region (peak odds ratio, 3.47; P=0.005).

Conclusions— These findings provide genomic evidence for coregulation of myocardial gene expression by MEF2 and NFAT in human heart failure. In doing so, they extend the paradigm of combinatorial regulation of gene expression to the human heart and identify new target genes for mechanistic study. More broadly, we demonstrate how integrating diverse sources of genomic data yields novel insight into human cardiovascular disorders.

Methods and Results— Female B6.apoE^–/– mice were crossed with male C3H.apoE^–/– mice to generate F₁s, which were intercrossed to generate 204 male F₂ progeny. At 10 weeks of age, F₂s underwent endothelium denudation injury to the left common carotid artery. Mice were fed a Western diet for 1 week before and 4 weeks after injury and analyzed for neointimal lesion size, plasma lipid, and membrane cofactor protein (MCP)-1 levels. One significant quantitative trait locus, named Nih1 (61 cM; LOD score, 5.02), on chromosome 12 and a suggestive locus on chromosome 13 (35 cM; LOD score, 2.67) were identified to influence lesion size. One significant quantitative trait locus on distal chromosome 1 accounted for major variations in plasma non–high-density lipoprotein cholesterol and triglyceride levels. Four suggestive quantitative trait locis on chromosomes 1, 2, and 3 were detected for circulating MCP-1 levels. No correlations were observed between neointimal lesion size and plasma lipid levels or between lesion size and plasma MCP-1 levels.

Conclusions— Neointimal formation is controlled by genetic factors independent of those affecting plasma lipid levels and circulating MCP-1 levels in the B6 and C3H mouse model.

Methods and Results— In offspring participants (n=3710), we examined 11 inflammatory biomarkers (CD40 ligand, C-reactive protein, intercellular adhesion molecule-1, interleukin-6, urinary isoprostanes, monocyte chemoattractant protein-1, myeloperoxidase, P-selectin, tumor necrosis factor-, tumor necrosis factor receptor II, fibrinogen). Heritability and bivariate genetic and environmental correlations were assessed by Sequential Oligogenic Linkage Analysis routines in 1012 family members. We examined 1943 tagging single-nucleotide polymorphisms in 233 inflammatory pathway genes with ≥5 minor allele carriers using a general genetic linear model. Clinical correlates explained 2.4% (CD40 ligand) to 28.5% (C-reactive protein) of the variability in inflammatory biomarkers. Estimated heritability ranged from 10.9% (isoprostanes) to 44.8% (P-selectin). Most correlations between biomarkers were weak although statistically significant. A total of 45 single-nucleotide polymorphism-biomarker associations met the q-value threshold of 0.25. Novel top single-nucleotide polymorphisms were observed in ICAM1 gene in relation to intercellular adhesion molecule-1 concentrations (rs1799969, P=1.32x10^–8) and MPO in relation to myeloperoxidase (rs28730837, P=1.9x10^–5). Lowest P values for trans-acting single-nucleotide polymorphisms were observed for APCS with monocyte chemoattractant protein-1 concentrations (rs1374486, P=1.01x10^–7) and confirmed for IL6R with interleukin-6 concentrations (rs8192284, P=3.36x10^–5). Novel potential candidates (APCS, MPO) need to be replicated.

Conclusions— Our community-based data support the relevance of clinical and genetic factors for explaining variation in inflammatory biomarker traits.

Methods and Results— We genotyped index SNPs at 19 loci in the Third United States National Health and Nutrition Examination Survey (n=7159), a population-based probability sample of the United States comprised primarily of non-Hispanic blacks, Mexican Americans, and non-Hispanic whites. We constructed ethnic-specific residual blood lipid levels after adjusting for age and gender. Ethnic-specific linear regression was used to test the association of genotype with blood lipids. To summarize the statistical evidence across 3 racial groups, we conducted a fixed-effects variance-weighted meta-analysis. After exclusions, there were 1627 non-Hispanic blacks, 1659 Mexican Americans, and 2230 non-Hispanic whites. At 5 loci (1p13 near CELSR2/PSRC1/SORT1, HMGCR, CETP, LPL, and APOA5), the index SNP was associated with low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, or triglycerides in all 3 ethnic groups. At the remaining loci, there was mixed evidence by ethnic group. In meta-analysis, we found that, at 14 of the 19 loci, SNPs exceeded a nominal P<0.05.

Conclusions— At 5 loci including the recently discovered region on 1p13 near CELSR2/PSRC1/SORT1, the same SNP discovered in whites associates with blood lipids in non-Hispanic blacks and Mexican Americans. For the remaining loci, fine mapping and resequencing will be required to definitively evaluate the relevance of each locus in individuals of African and Hispanic ancestries.

Methods and Results— We assessed whether common variants of HNF1A are associated with C-reactive protein, -glutamyl transferase, and other atherosclerotic and metabolic risk factors, in the large, population-based Coronary Artery Risk Development in Young Adults Study of healthy young EA (n=2154) and African American (AA; n=2083) adults. The minor alleles of Ile27Leu (rs1169288) and Ser486Asn (rs2464196) were associated with 0.10 to 0.15 standard deviation units lower C-reactive protein and -glutamyl transferase levels in EA. The same HNF1A coding variants were associated with higher low-density lipoprotein cholesterol, apolipoprotein B, creatinine, and fibrinogen in EA. We replicated the associations between HNF1A coding variants and C-reactive protein, fibrinogen, low-density lipoprotein cholesterol, and renal function in a second population-based sample of EA adults 65 years and older from the Cardiovascular Health Study. The HNF1A Ser486Asn and/or Ile27Leu variants were also associated with increased risk of subclinical coronary atherosclerosis in Coronary Artery Risk Development in Young Adults and with incident coronary heart disease in Cardiovascular Health Study. The Ile27Leu and Ser486Asn variants were 3-fold less common in AA than in EA. There was little evidence of association between HNF1A genotype and atherosclerosis-related phenotypes in AA.

Conclusions— Common polymorphisms of HNF1A seem to influence multiple phenotypes related to cardiovascular risk in the general population of younger and older EA adults.

Methods and Results— FTO rs9939609 genotype was determined in 4897 patients with type 2 diabetes in the prospective Genetics of Diabetes Audit and Research Study in Tayside Scotland study. The A allele was associated with lower plasma high-density lipoprotein cholesterol (mean difference, 0.03 mmol/L; P=0.008), higher triglycerides (0.1 mmol/L, P=0.007), higher atherogenic index of plasma (0.03, P=0.003), and, as expected, increased body mass index (0.77 kg/m², P=8.8x10^–6). During a mean follow-up of 3.6 years, the A allele was also associated with increased risk (hazard ratio, 2.36; CI, 1.49 to 3.74; P=0.0002) of fatal and nonfatal myocardial infarction (total of 324 events) in a model, including baseline age, gender, prevalent myocardial infarction, smoking status, statin, and insulin use. This association diminished but remained significant when obesity-related traits, such as body mass index, glycohemoglobin, and lipid parameters, were also included (hazard ratio, 2.01; CI, 1.18 to 3.45, P=0.011). There was a strong interaction of FTO genotype and statin use and cardiovascular outcome (P=0.001), such that cardiovascular morbidity and mortality was completely abrogated in individuals who were prescribed statins.

Conclusion— The increased fat mass in carriers of the A allele of rs9939609 of FTO is associated not only with increased risk of type 2 diabetes, but also with an increase in atherogenic lipid profile and myocardial infarction in these patients. This variant may, therefore, in the future contribute to more effective targeting of specific preventative therapy.

Methods and Results— The primary study was carried out in 485 adolescents recruited from a French Canadian founder population who underwent detailed body-composition and cardiovascular phenotyping. Body fat was examined with MRI, bioimpedance, and anthropometry. BP was recorded beat to beat at rest and during physical and mental challenges. Sympathetic modulation of vasomotor tone was assessed with power spectral analysis of BP. We found that individuals with the FTO-risk genotype compared with those without it demonstrate greater adiposity, including the amount of intra-abdominal fat (by 38%). They also showed higher systolic BP throughout the entire protocol, with a maximum difference during a mental stress (6.4 [1.5 to 11.3] mm Hg). The difference in BP was accompanied by elevated index of sympathetic modulation of vasomotor tone. A replication in an independent sample of adults from the same founder population confirmed the association between FTO and BP.

Conclusions— These results suggest that, in a French Canadian founder population, FTO may increase not only risk for obesity, as demonstrated in other populations, but also for hypertension. The latter may be related, at least in part, to the regulation of sympathetic vasomotor tone.

Methods and Results— A 64-year-old white male displayed a type 1 ST-segment elevation in V1 and V2 during procainamide challenge. Polymerase chain reaction-based direct sequencing was performed using a candidate gene approach. A missense mutation (L10P) was detected in exon 1 of SCN3B, the β3 subunit of the cardiac sodium channel, but not in any other gene known to be associated with Brugada syndrome or in 296 controls. Wild-type (WT) and mutant genes were expressed in TSA201 cells and studied using whole-cell patch-clamp techniques. Coexpression of SCN5A/WT+SCN1B/WT+SCN3B/L10P resulted in an 82.6% decrease in peak sodium current density, accelerated inactivation, slowed reactivation, and a –9.6-mV shift of half-inactivation voltage compared with SCN5A/WT+SCN1B/WT+SCN3B/WT. Confocal microscopy revealed that SCN5A/WT channels tagged with green fluorescent protein are localized to the cell surface when coexpressed with WT SCN1B and SCN3B but remain trapped in intracellular organelles when coexpressed with SCN1B/WT and SCN3B/L10P. Western blot analysis confirmed the presence of Na_Vβ3 in human ventricular myocardium.

Conclusions— Our results provide support for the hypothesis that mutations in SCN3B can lead to loss of transport and functional expression of the hNa_v1.5 protein, leading to reduction in sodium channel current and clinical manifestation of a Brugada phenotype.

Methods and Results— Whites (n=9998) in the Atherosclerosis Risk in Communities study for whom the 9p21 genotype and traditional RF information was available were included. Using Cox proportional hazards models, the Atherosclerosis Risk in Communities Cardiovascular Risk Score, which is based on traditional RFs, was determined. A total of 1349 individuals (13.5%) developed incident CHD events during a period of 14.6 years. Adding the 9p21 allele to traditional RFs was associated with a hazard ratio of incident CHD of 1.2 per allele (P<0.000003) and a significant increase in the area under the curve of the receiver operating characteristic from 0.782 to 0.786 (95% CI, 0.001, 0.007). The 9p21 allele’s greatest influence to the Atherosclerosis Risk in Communities Cardiovascular Risk Score was observed in the intermediate-low (>5% to ≤10% 10-year CHD risk) and intermediate-high (>10% to ≤20% 10-year CHD risk) categories, with 12.1% and 12.6% reclassified, respectively. This may impact therapy because 90% of these reclassified individuals had low-density lipoprotein cholesterol >100 mg/dL.

Conclusion— Adding the 9p21 allele to traditional RFs in whites in the Atherosclerosis Risk in Communities study modestly improved CHD risk prediction in the intermediate categories.

Methods and Results— The circulating levels of GDF-15 were measured by immunoradiometric assay in patients with stable angina pectoris (n=1352) or acute coronary syndrome (n=877) who were followed up for a median of 3.6 years. Stable angina pectoris patients presenting with normal (<1200 ng/L), moderately elevated (1200 to 1800 ng/L), or markedly elevated (>1800 ng/L) GDF-15 levels had 3.6-year CHD mortality rates of 1.4%, 2.7%, and 15.0%, respectively (P<0.001). By backward stepwise Cox-regression analysis, which adjusted for age and gender, clinical variables, the number of diseased vessels, renal function, the levels of C-reactive protein, cardiac troponin I, and N-terminal pro-B-type natriuretic peptide, GDF-15 remained an independent predictor of CHD mortality (P<0.001). Addition of GDF-15 improved the prognostic accuracy of a clinical risk prediction model concerning CHD mortality (c-statistic, 0.84 versus 0.74; P=0.005). Analysis of the acute coronary syndrome part of the study population confirmed GDF-15 as an independent predictor of CHD mortality (P<0.001). The circulating levels of GDF-15 did not predict the future risk of nonfatal myocardial infarction in patients with stable angina pectoris or acute coronary syndrome.

Conclusion— This study identifies GDF-15 as a strong and independent predictor of CHD mortality across the broad spectrum of patients with stable and unstable CHD.

Methods and Results— In a population-based study (Oxford Vascular Study) of all patients with acute coronary syndromes (ACS), irrespective of age, family history of all acute vascular events and related risk factors were analyzed by sex and age of both probands and first-degree relatives. Premature events were categorized as occurring at age <65 years. Of 835 probands with 1 or more ACS, 623 (420 men) had incident events and complete family history data. In probands with premature ACS, maternal history of both MI and of all vascular events were more common in female than male probands (odds ratio [OR], 2.25; 95% CI, 1.02 to 4.94; P=0.04 and OR, 3.03; 95% CI, 1.47 to 6.26; P=0.002, respectively). No such effect existed for paternal history (OR, 1.00; 95% CI, 0.46 to 2.10; P=0.99 and OR, 1.19; 95% CI, 0.58 to 2.43; P=0.63, respectively). Age at ACS in probands was highly correlated with age at MI in mothers (r=0.46, P<0.001), regardless of the proband’s sex. Consequently, history of premature maternal MI was strongly associated with premature ACS and premature MI in female (OR, 10.52; 95% CI, 2.17 to 56.6; P=0.001 and OR, 7.31; 95% CI, 1.55 to 34.6; P=0.004, respectively) and male probands (OR, 3.88; 95% CI, 1.20 to 12.6; P=0.01 and OR, 3.63; 95% CI, 1.13 to 11.60; P=0.02, respectively).

Conclusions— Important sex-of-parent/sex-of-proband interactions exist in the family history of MI in patients with ACS. Greater emphasis should be placed on maternal than paternal history of MI, particularly in women aged <65 years.

Methods and Results— We used renal gene-expression profiling across 3 distinct SHR lines to identify genes that show different expression in SHR than in the genetically related normotensive control strain, Wistar-Kyoto. To ensure robust discovery of genes showing SHR-specific expression differences, we considered only those genes in which differential expression is replicated in multiple animals of each of multiple hypertensive rat lines at multiple time points during the ontogeny of hypertension. Mutation analysis was performed on the identified genes to uncover allelic variation. We identified those genes in which all SHR lines share a single allele of the gene when normotensive controls (Wistar-Kyoto) have fixed the alternative allele. We then identified which of the differentially expressed genes show expression that is controlled by the alleleic variation present in and around the gene. Allelic expression was demonstrated by observing the effect on gene expression of alleles inherited in the freely segregating F₂ progeny of a cross between SHR and Wistar-Kyoto animals.

Conclusions— The result of these studies is the identification of several genes (Ptprj, Ela1, Dapk-2, and Gstt2) in which each of 4 SHR lines examined have fixed the same allele and in which each of 2 Wistar-Kyoto lines have a contrasting allele for which the inherited allele influences the level of gene expression. We further show that alleles of these genes lie in extensive haplotype blocks that have been inherited identical by descent in the hypertensive lines.

Methods and Results— Generic hypertrophy-associated genes were identified and distinguished from stimulus-dependent transcripts by coupling a metric of cardiac growth with a dynamic time-warping algorithm to align transcriptome changes with respect to the hypertrophy response. The major differences in expression between the adaptive and maladaptive hypertrophy models were centered around the genes involved in metabolism, fibrosis, and immune response. Conversely, transcripts with common expression patterns in both hypertrophy models were associated with signal transduction, cytoskeletal development, and muscle contraction. Thus, despite the apparent differences in the expression response of the heart to either athletic conditioning or pressure overload, there is a set of genes that displays similar expression profiles.

Conclusions— This finding lends support to the notion of a generalized cardiac growth mechanism that is activated in response to mechanical perturbation. The common and unique genetic signatures of adaptive and maladaptive hypertrophy may be useful in the diagnosis and treatment of pathological myocardial remodeling.

Methods and Results— We conducted a genome-wide association analysis on 6 population-based studies, the Rotterdam Study, the Framingham Heart Study, the Cardiovascular Health Study, the Atherosclerosis Risk in Communities Study, the Monitoring of Trends and Determinants in Cardiovascular Disease/KORA Augsburg Study, and the British 1958 Birth Cohort Study, including 22 096 participants of European ancestry. Four loci were marked by 1 or more single-nucleotide polymorphisms that demonstrated genome-wide significance (P<5.0x10^–8). These included a single-nucleotide polymorphism located in the fibrinogen β chain (FGB) gene and 3 single-nucleotide polymorphisms representing newly identified loci. The high-signal single-nucleotide polymorphisms were rs1800789 in exon 7 of FGB (P=1.8x10^–30), rs2522056 downstream from the interferon regulatory factor 1 (IRF1) gene (P=1.3x10^–15), rs511154 within intron 1 of the propionyl coenzyme A carboxylase (PCCB) gene (P=5.9x10^–10), and rs1539019 on the NLR family pyrin domain containing 3 isoforms (NLRP3) gene (P=1.04x10^–8).

Conclusions— Our findings highlight biological pathways that may be important in regulation of inflammation underlying cardiovascular disease.

Methods and Results— To address this issue, we undertook a genome-wide association study evaluating the potential relationships between 337 343 single-nucleotide polymorphisms (SNPs) and plasma fibrinogen levels among 17 686 apparently healthy women participating in the Women’s Genome Health Study. As C-reactive protein is also an inflammatory marker known to predict cardiovascular diseases, we compared the determinants of fibrinogen levels with those of C-reactive protein. Four novel loci were identified, in addition to the fibrinogen gene cluster, which were associated with fibrinogen levels at genome-wide levels of significance (range of probability values from 8.82x10^–09 to 8.04x10^–39). Two of the loci are related to common chronic inflammatory diseases: the first, at locus 5q31.1 (SLC22A5, SLC22A4, IRF1), lies immediately adjacent to a locus linked to Crohn disease (P value for lead SNP, 1.24x10^–12) and the second, at locus 17q25.1 (CD300LF, SLC9A3R1, NAT9), has been associated with psoriasis (P value for lead SNP, 7.72x10^–11). A third locus at 1q21.3 (IL6R) lies within the interleukin 6 receptor gene, a critical component of the inflammatory cascade (P value for lead SNP, 1.80x10^–11). A novel locus at 2q34 (CPSI) participates in the urea cycle (P=8.82x10^–09). The majority of implicated SNPs showed little evidence of dual association with C-reactive protein levels.

Conclusions— A genome-wide survey of the human genome identifies novel loci related to common chronic inflammatory diseases as genetic determinants of fibrinogen levels, in addition to loci that relate to the inflammatory cascade, the urea cycle, and the fibrinogen gene cluster.

Methods and Results— To address this issue comprehensively, we performed a genome-wide association analysis, testing 336 469 single-nucleotide polymorphisms in 13 974 healthy white women. Although we confirm association with MTHFR (1p36.22; rs1801133; P=8.1x10^–35) and CBS (21q22.3; rs6586282; P=3.2x10^–10), we found novel associations with CPS1 (2q34; rs7422339; P=1.9x10^–11), MUT (6p12.3; rs4267943; P=2.0x10^–9), NOX4 (11q14.3; rs11018628; P=9.6x10^–12), and DPEP1 (16q24.3; rs1126464; P=1.2x10^–12). The associations at MTHFR, DPEP1, and CBS were replicated in an independent sample from the PROCARDIS study, whereas the association at CPS1 was only replicated among the women.

Conclusions— These associations offer new insight into the biochemical pathways involved in homocysteine metabolism and provide opportunities to better delineate the role of homocysteine in health and disease.

Methods and Results— The study cohort included participants from the SardiNIA study for whom PWV measures were available. Genotyping was performed in 4221 individuals, using either the Affymetrix 500K or the Affymetrix 10K mapping array sets (with imputation of the missing genotypes). Associations with PWV were evaluated using an additive genetic model that included age, age², and sex as covariates. The findings were tested for replication in an independent internal Sardinian cohort of 1828 individuals, using a custom chip designed to include the top 43 nonredundant SNPs associated with PWV. Of the loci that were tested for association with PWV, the nonsynonymous SNP rs3742207 in the COL4A1 gene on chromosome 13 and SNP rs1495448 in the MAGI1 gene on chromosome 3 were successfully replicated (P=7.08x10^–7 and P=1.06x10^–5, respectively, for the combined analyses). The association between rs3742207 and PWV was also successfully replicated (P=0.02) in an independent population, the Old-Order Amish, leading to an overall P=5.16x10^–8.

Conclusions— A genome-wide association study identified a SNP in the COL4A1 gene that was significantly associated with PWV in 2 populations. Collagen type 4 is the major structural component of basement membranes, suggesting that previously unrecognized cell-matrix interactions may exert an important role in regulating arterial stiffness.

Methods and Results— We genotyped 6 common genetic variants on chromosome 9p21, previously associated with coronary artery disease in genome-wide association studies, in 2 population-based studies in southern Sweden, the Lund Stroke Register (n=1837 cases, 947 controls) and the Malmö Diet and Cancer study (MDC; n=888 cases, 893 controls). We examined association in each study and in the pooled dataset. Adjustments were made for cardiovascular risk factors and further for previous myocardial infarction in MDC. We found a modest increase in ischemic stroke risk for 2 common (minor allele frequencies 0.46 to 0.49) variants, rs2383207 (P=0.04 in Lund Stroke Register, P=0.01 in MDC) and rs10757274 (P=0.03 in Lund Stroke Register, P=0.03 in MDC), in each sample independently. The strength of the association increased when samples were pooled with an odds ratio of 1.15 (95% CI, 1.05 to 1.25; P=0.002) for the strongest variant rs2383207. Results were similar after adjustment for clinical covariates. rs1333049 also showed significant association in MDC, which increased in the pooled sample (P=0.004).

Conclusions— In this large sample (n=4565), we detected common genetic determinants for ischemic stroke on chromosome 9p21. Our findings indicate that ischemic stroke shares pathophysiological determinants with coronary heart disease and other arterial diseases and highlight the need for large sample sizes in stroke genetics.

Methods and Results— Mutational screening of exon 8 (containing all so-far reported point mutations) disclosed 5 novel and 2 previously described missense mutations. Microsatellite genotyping and sequencing revealed the presence of the 21-bp deletion (located in exon 12) in 5 cases and in none of the controls. Functional studies on mutant proteins showed no alteration, neither in the transactivating properties (all mutants) nor in the nuclear localization (21-bp deletion). Furthermore, an association analysis performed using 3 microsatellites at the MEF2A locus showed no significant association with MI. These results were confirmed in a replication study performed on an independent Italian population with coronary artery disease.

Conclusions— All together, our data do not support MEF2A as a susceptibility gene for coronary artery disease/MI in the Italian population.

Methods and Results— A total of 291 988 single-nucleotide polymorphisms (SNPs) from 1984 individuals were analyzed for association with statin response, followed by genotyping top hits in 3761 additional individuals. None was significant at the whole-genome level in either the initial or follow-up test sets for association with low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, or triglyceride response. In addition to the whole-genome platform, 23 candidate genes previously associated with statin response were analyzed in these 5745 individuals. Three SNPs in apoE were most highly associated with low-density lipoprotein cholesterol response, followed by 1 in PCSK9 with a similar effect size. At the candidate gene level, SNPs in HMGCR were also significant though the effect was less than with those in apoE and PCSK9. rs7412/apoE had the most significant association (P=6x10^–30), and its high significance in the whole-genome study (P=4x10^–9) confirmed the suitability of this population for detecting effects. Age and gender were found to influence low-density lipoprotein cholesterol response to a similar extent as the most pronounced genetic effects.

Conclusions— Among SNPs tested with an allele frequency of at least 5%, only SNPs in apoE are found to influence statin response significantly. Less frequent variants in PCSK9 and smaller effect sizes in SNPs in HMGCR were also revealed.