We performed a meta-analysis of 14 genome-wide association studies of coronary artery disease (CAD) comprising 22,233 cases and 64,762 controls of European descent, followed by genotyping of top association signals in 60,738 additional individuals. This genomic analysis identified 13 novel loci harboring one or more SNPs that were associated with CAD at P<5×10−8 and confirmed the association of 10 of 12 previously reported CAD loci. The 13 novel loci displayed risk allele frequencies ranging from 0.13 to 0.91 and were associated with a 6 to 17 percent increase in the risk of CAD per allele. Notably, only three of the novel loci displayed significant association with traditional CAD risk factors, while the majority lie in gene regions not previously implicated in the pathogenesis of CAD. Finally, five of the novel CAD risk loci appear to have pleiotropic effects, showing strong association with various other human diseases or traits.

Abdominal aortic aneurysm (AAA) is a common cause of morbidity and mortality and has a significant heritability. We carried out a genome-wide association discovery study of 1866 patients with AAA and 5435 controls and replication of promising signals (lead SNP with a p value < 1 × 10(-5)) in 2871 additional cases and 32,687 controls and performed further follow-up in 1491 AAA and 11,060 controls. In the discovery study, nine loci demonstrated association with AAA (p < 1 × 10(-5)). In the replication sample, the lead SNP at one of these loci, rs1466535, located within intron 1 of low-density-lipoprotein receptor-related protein 1 (LRP1) demonstrated significant association (p = 0.0042). We confirmed the association of rs1466535 and AAA in our follow-up study (p = 0.035). In a combined analysis (6228 AAA and 49182 controls), rs1466535 had a consistent effect size and direction in all sample sets (combined p = 4.52 × 10(-10), odds ratio 1.15 [1.10-1.21]). No associations were seen for either rs1466535 or the 12q13.3 locus in independent association studies of coronary artery disease, blood pressure, diabetes, or hyperlipidaemia, suggesting that this locus is specific to AAA. Gene-expression studies demonstrated a trend toward increased LRP1 expression for the rs1466535 CC genotype in arterial tissues; there was a significant (p = 0.029) 1.19-fold (1.04-1.36) increase in LRP1 expression in CC homozygotes compared to TT homozygotes in aortic adventitia. Functional studies demonstrated that rs1466535 might alter a SREBP-1 binding site and influence enhancer activity at the locus. In conclusion, this study has identified a biologically plausible genetic variant associated specifically with AAA, and we suggest that this variant has a possible functional role in LRP1 expression.

Coronary artery disease (CAD) has a significant genetic contribution that is incompletely characterized. To complement genome-wide association (GWA) studies, we conducted a large and systematic candidate gene study of CAD susceptibility, including analysis of many uncommon and functional variants. We examined 49,094 genetic variants in ∼2,100 genes of cardiovascular relevance, using a customised gene array in 15,596 CAD cases and 34,992 controls (11,202 cases and 30,733 controls of European descent; 4,394 cases and 4,259 controls of South Asian origin). We attempted to replicate putative novel associations in an additional 17,121 CAD cases and 40,473 controls. Potential mechanisms through which the novel variants could affect CAD risk were explored through association tests with vascular risk factors and gene expression. We confirmed associations of several previously known CAD susceptibility loci (eg, 9p21.3:p<10−33; LPA:p<10−19; 1p13.3:p<10−17) as well as three recently discovered loci (COL4A1/COL4A2, ZC3HC1, CYP17A1:p<5×10−7). However, we found essentially null results for most previously suggested CAD candidate genes. In our replication study of 24 promising common variants, we identified novel associations of variants in or near LIPA, IL5, TRIB1, and ABCG5/ABCG8, with per-allele odds ratios for CAD risk with each of the novel variants ranging from 1.06–1.09. Associations with variants at LIPA, TRIB1, and ABCG5/ABCG8 were supported by gene expression data or effects on lipid levels. Apart from the previously reported variants in LPA, none of the other ∼4,500 low frequency and functional variants showed a strong effect. Associations in South Asians did not differ appreciably from those in Europeans, except for 9p21.3 (per-allele odds ratio: 1.14 versus 1.27 respectively; P for heterogeneity = 0.003). This large-scale gene-centric analysis has identified several novel genes for CAD that relate to diverse biochemical and cellular functions and clarified the literature with regard to many previously suggested genes.

Over 1.7 million Virginians rely on private water systems to supply household water. The heaviest reliance on these systems occurs in rural areas, which are often underserved in terms of financial resources and access to environmental health education. As the Safe Drinking Water Act (SDWA) does not regulate private water systems, it is the sole responsibility of the homeowner to maintain and monitor these systems.Previous limited studies indicate that microbial contamination of drinking water from private wells and springs is far from uncommon, ranging from 10% to 68%, depending on type of organism and geological region. With the exception of one thirtyyear old government study on rural water supplies, there have been no documented investigations of links between private system water contamination and household demographic characteristics, making the design of effective public health interventions, very difficult.The goal of the present study is to identify potential associations between concentrations of fecal indicator bacteria (e.g. coliforms, E. coli) in 831 samples collected at the point-of-use in homes with private water supply systems and homeowner-provided demographic data (e.g. homeowner age, household income, education, water quality perception). Household income and the education of the perceived head of household were determined to have an association with bacteria concentrations. However, when a model was developed to evaluate strong associations between total coliform presence and potential predictors, no demographic parameters were deemed significant enough to be included in the final model. Of the 831 samples tested, 349 (42%) of samples tested positive for total coliform and 55 (6.6%) tested positive for E. coli contamination. Chemical and microbial source tracking efforts using fluorometry and qPCR suggested possible E. coli contamination from human septage in 21 cases. The findings of this research can ultimately aid in determining effective strategies for public health intervention and gain a better understanding of interactions between demographic data and private system water quality.iii ACKNOWLEDGMENTS

Background: Genetic tests for diagnosis of clotting disorders and monitoring their treatment are based on identification of single nucleotide polymorphisms (SNPs) that are related respectively to clotting and to drug metabolism crucial to the effectiveness of therapy. Thrombophilia, an inherited condition which predisposes to thromboembolism, is due in part to genetic factors, such as the presence of SNPs in the genes encoding clotting factors. Hyperhomocysteinemia, which poses an extremely elevated risk of thromboembolism to the patient, can be caused by certain mutations to the MTHFR (677CT, 1298AC) gene; genotyping all genes involved in thrombophilia concurrently can offer a more complete picture of the genetic component of thrombophilic risk. Warfarin is the most frequently used oral anticoagulant for treatment and prevention of thromboembolism and requires careful adjustment of therapeutic dose and close monitoring because of its narrow therapeutic index and wide individual variability in response and therapeutic dose. Genetic variations in two genes, CYP2C9 and vitamin K epoxide reductase (VKORC1), have been shown to have a profound effect on warfarin sensitivity. Using genetic tests for identification of these variants clinicians to better estimate the appropriate starting dose for therapy, which may improve drug safety. Currently a number of test systems detect these SNPs. Use of a well-characterized independent quality control sample is important to monitor the accuracy and reproducibility of these tests. We have developed multi-analyte quality controls that contain major SNP variants for both thrombophilia MTHFR and warfarin sensitivity. Methods: PBMCs from multiple donors were screened for mutations for MTHFR for Thrombophilia and for CYP2C9 and VKORC1 for warfarin sensitivity. Mutations were identified using the Third Wave Technologies INVADER® and Autogenomics INFINITI™ platforms; and ABI TaqMan® SNP assay. All mutations were confirmed by sequencing on an ABI 3130 instrument. Results: PBMC samples were screened for CYP2C9, VKORC1, and MTHFR mutations. The mutation frequency for CYP2C9*2, CYP2C9*3 and VKORC1 1639GA variants was 28%, 7% and 63% respectively. 100% genotyping concordance was observed in all testing. In addition, heterozygotes for additional VKORC1 SNPs 5808TG, 6484CT, 6853GC, 7566CT, and 9041GA were present in one sample bearing VKORC -1639GA. The mutation frequency for MTHFR 677CT and 1298AC was 17% wt and 29% het for both SNPs. The identification of heterozygotes in several SNPs allowed development of multi-analyte controls for both genes. Data showing reproducibility and accuracy in SNP call rate on various test platforms will be presented. Conclusion: We have developed multi-analyte controls for thrombophilia and warfarin sensitivity that can monitor extraction, amplification and detection, and evaluated their performance with several test methods.