A single mutation can alter cellular and global homeostatic mechanisms and give rise to multiple clinical diseases. We hypothesized that these disease mechanisms could be identified using low minor allele frequency (MAF<0.1) non-synonymous SNPs (nsSNPs) associated with “mechanistic phenotypes”, comprised of collections of related diagnoses. We studied two mechanistic phenotypes: (1) thrombosis, evaluated in a population of 1,655 African Americans; and (2) four groupings of cancer diagnoses, evaluated in 3,009 white European Americans. We tested associations between nsSNPs represented on GWAS platforms and mechanistic phenotypes ascertained from electronic medical records (EMRs), and sought enrichment in functional ontologies across the top-ranked associations. We used a two-step analytic approach whereby nsSNPs were first sorted by the strength of their association with a phenotype. We tested associations using two reverse genetic models and standard additive and recessive models. In the second step, we employed a hypothesis-free ontological enrichment analysis using the sorted nsSNPs to identify functional mechanisms underlying the diagnoses comprising the mechanistic phenotypes. The thrombosis phenotype was solely associated with ontologies related to blood coagulation (Fisher's p = 0.0001, FDR p = 0.03), driven by the F5, P2RY12 and F2RL2 genes. For the cancer phenotypes, the reverse genetics models were enriched in DNA repair functions (p = 2×10−5, FDR p = 0.03) (POLG/FANCI, SLX4/FANCP, XRCC1, BRCA1, FANCA, CHD1L) while the additive model showed enrichment related to chromatid segregation (p = 4×10−6, FDR p = 0.005) (KIF25, PINX1). We were able to replicate nsSNP associations for POLG/FANCI, BRCA1, FANCA and CHD1L in independent data sets. Mechanism-oriented phenotyping using collections of EMR-derived diagnoses can elucidate fundamental disease mechanisms.
Paraoxonase 1 (PON1) is a cardioprotective, HDL-associated glycoprotein enzyme with broad substrate specificity. Our previous work found associations between dietary cholesterol and vitamin C with PON1 activity. The goal of this study was to determine the effect of specific dietary fatty acid (DFA) intake on PON1 activity.
1,548 participants with paraoxonase activity measures completed the Harvard Standardized Food Frequency Questionnaire to determine their daily nutrient intake over the past year. Eight saturated, 3 monounsaturated, and 6 polyunsaturated DFAs were measured by the questionnaire. To reduce the number of observations tested, only specific fatty acids that were not highly correlated (r < 0.8) with other DFAs or that were representative of other DFAs through high correlation within each respective group (saturated, monounsaturated, or polyunsaturated) were retained for analysis. Six specific DFA intakes – myristic acid (14 carbon atoms, no double bonds – 14:0), oleic acid (18:1), gadoleic acid (20:1), α-linolenic acid (18:3), arachidonic acid (20:4), and eicosapentaenoic acid (20:5) – were carried forward to stepwise linear regression, which evaluated the effect of each specific DFA on covariate-adjusted PON1 enzyme activity.
Four of the 6 tested DFA intakes – myristic acid (p = 0.038), gadoleic acid (p = 6.68 × 10-7), arachidonic acid (p = 0.0007), and eicosapentaenoic acid (p = 0.013) - were independently associated with covariate-adjusted PON1 enzyme activity. Myristic acid, a saturated fat, and gadoleic acid, a monounsaturated fat, were both positively associated with PON1 activity. Both of the tested polyunsaturated fats, arachidonic acid and eicosapentaenoic acid, were negatively associated with PON1 activity.
This study presents the largest cohort-based analysis of the relationship between dietary lipids and PON1 enzyme activity. Further research is necessary to elucidate and understand the specific biological mechanisms, whether direct or regulatory, through which DFAs affect PON1 activity.
Paraoxonase 1; Dietary fatty acid intake; Saturated fats; Monounsaturated fats; Polyunsaturated fats; ω-3 fatty acids; Cardiovascular disease
To promote effective genome-scale research, genomic and clinical data for large population samples must be collected, stored, and shared.
We conducted focus groups with 45 members of a Seattle-based integrated healthcare delivery system to learn about their views and expectations for informed consent in genome-scale studies.
Participants viewed information about study purpose, aims, and how and by whom study data could be used to be at least as important as information about risks and possible harms. They generally supported a tiered consent approach for specific issues, including research purpose, data sharing, and access to individual research results. Participants expressed a continuum of opinions with respect to the acceptability of broad consent, ranging from completely acceptable to completely unacceptable. Older participants were more likely to view the consent process in relational – rather than contractual – terms, compared with younger participants. The majority of participants endorsed seeking study subjects’ permission regarding material changes in study purpose and data sharing.
Although this study sample was limited in terms of racial and socioeconomic diversity, our results suggest a strong positive interest in genomic research on the part of at least some prospective participants and indicate a need for increased public engagement, as well as strategies for ongoing communication with study participants.
Informed consent; participant views; genomic research; biobank; research ethics
The era of “Personalized Medicine,” guided by individual molecular variation in DNA, RNA, expressed proteins and other forms of high volume molecular data brings new requirements and challenges to the design and implementation of Electronic Health Records (EHRs). In this article we describe the characteristics of biomolecular data that differentiate it from other classes of data commonly found in EHRs, enumerate a set of technical desiderata for its management in healthcare settings, and offer a candidate technical approach to its compact and efficient representation in operational systems.
Electronic Health Records; Genomics; Knowledge representation; Data compression
Genome-wide association studies (GWAS) are a useful approach in the study of the genetic components of complex phenotypes. Aside from large cohorts, GWAS have generally been limited to the study of one or a few diseases or traits. The emergence of biobanks linked to electronic medical records (EMRs) allows the efficient re-use of genetic data to yield meaningful genotype-phenotype associations for multiple phenotypes or traits. Phase I of the electronic MEdical Records and GEnomics (eMERGE-I) Network is a National Human Genome Research Institute (NHGRI)-supported consortium composed of five sites to perform various genetic association studies using DNA repositories and EMR systems. Each eMERGE site has developed EMR-based algorithms to comprise a core set of fourteen phenotypes for extraction of study samples from each site’s DNA repository. Each eMERGE site selected samples for a specific phenotype, and these samples were genotyped at either the Broad Institute or at the Center for Inherited Disease Research (CIDR) using the Illumina Infinium BeadChip technology. In all, approximately 17,000 samples from across the five sites were genotyped. A unified quality control (QC) pipeline was developed by the eMERGE Genomics Working Group and used to ensure thorough cleaning of the data. This process includes examination of sample quality, marker quality, and various batch effects. Upon completion of the genotyping and QC analyses for each site’s primary study, the eMERGE Coordinating Center merged the datasets from all five sites. This larger merged dataset re-entered the established eMERGE QC pipeline. Based on lessons learned during the process, additional analyses and QC checkpoints were added to the pipeline to ensure proper merging. Here we explore the challenges associated with combining datasets from different genotyping centers and describe the expansion to the eMERGE QC pipeline for merged datasets. These additional steps will be useful as the eMERGE project expands to include additional sites in eMERGE-II and also serve as a starting point for investigators merging multiple genotype data sets accessible through the National Center for Biotechnology Information (NCBI) in the database of Genotypes and Phenotypes (dbGaP). Our experience demonstrates that merging multiple datasets after additional QC can be an efficient use of genotype data despite new challenges that appear in the process.
quality control; genome-wide association (GWAS); eMERGE; dbGaP; merging datasets
To identify common genetic variants influencing red blood cell (RBC) traits.
Patients and Methods
We performed a genomewide association study from June 2008 through July 2011 of hemoglobin, hematocrit, RBC count, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration in 12,486 patients of European ancestry from the electronic MEdical Records and Genomics (eMERGE) network. We developed an electronic medical record–based algorithm that included individuals who had RBC measurements obtained for clinical care and excluded values measured in the setting of hematopoietic disorders, comorbid conditions, or medications known to affect RBC production or a recent history of blood loss.
We identified 4 new genetic loci and replicated 11 loci previously reported to be associated with one or more RBC traits in individuals of European ancestry. Notably, genes present in 3 of the 4 newly identified loci (THRB, PTPLAD1, CDT1) and in 6 of the 11 replicated loci (KLF1, ALDH8A1, CCND3, SPTA1, FBXO7, TFR2/EPO) are implicated in erythroid differentiation and regulation of cell cycle in hematopoietic stem cells.
Genes in the erythroid differentiation and cell cycle regulation pathways influence interindividual variation in RBC indices. Our results provide insights into the molecular basis underlying variation in RBC traits.
eMERGE, electronic MEdical Records and GEnomics; EMMAX, mixed-model association-expedited; EMR, electronic medical record; eQTL, expression quantitative trait locus; GHC, Group Health Cooperative--University of Washington; GWAS, genomewide association study; HCT, hematocrit; HGB, hemoglobin; IBS, identity-by-state; LD, linkage disequilibrium; MC, Marshfield Clinic; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; MCV, mean corpuscular volume; MIM, Mendelian Inheritance of Man; NU, Northwestern University; RBC, red blood cell; SNP, single-nucleotide polymorphism; VUMC, Vanderbilt University Medical Center
hyperlipidemia; hypercholesterolemia; LDL-receptor; mutations
Background. Paraoxonase 1 (PON1) enzymatic activity has been consistently predictive of cardiovascular disease, while the genotypes at the four functional polymorphisms at PON1 have not. The goal of this study was to identify additional variation at the PON gene cluster that improved prediction of PON1 activity and determine if these variants predict carotid artery disease (CAAD). Methods. We considered 1,328 males in a CAAD cohort. 51 tagging single-nucleotide polymorphisms (tag SNPs) across the PON cluster were evaluated to determine their effects on PON1 activity and CAAD status. Results. Six SNPs (four in PON1 and one each in PON2/3) predicted PON1 arylesterase (AREase) activity, in addition to the four previously known functional SNPs. In total, the 10 SNPs explained 30.1% of AREase activity, 5% of which was attributable to the six identified predictive SNPs. We replicate rs854567 prediction of 2.3% of AREase variance, the effects of rs3917510, and a PON3 haplotype that includes rs2375005. While AREase activity strongly predicted CAAD, none of the 10 SNPs predicting AREase predicted CAAD. Conclusions. This study identifies new genetic variants that predict additional PON1 AREase activity. Identification of SNPs associated with PON1 activity is required when evaluating the many phenotypes associated with genetic variation near PON1.
The purpose of this study was to assess deep hypothermic circulatory arrest (DHCA) as a modifier of neurodevelopmental (ND) outcomes in preschool children after cardiac surgery in infancy for repair of congenital heart defects (CHD).
This is a planned analysis of infants enrolled in a prospective study of apolipoprotein E polymorphisms and ND outcome after cardiac surgery. The effect of DHCA was assessed in patients with single or biventricular CHD without aortic arch obstruction. Neurodevelopmental assessment at 4 years of age included cognition, language, attention, impulsivity, executive function, social competence, and visual-motor and fine-motor skills. Patient and procedural variables were evaluated in univariate and multivariate models.
Neurodevelopmental testing was completed in 238 of 307 eligible patients (78%). Deep hypothermic circulatory arrest was used at the discretion of the surgeon at least once in 92 infants (38.6%) with a median cumulative duration of 36 minutes (range, 1 to 132 minutes). By univariate analysis, DHCA patients were more likely to have single-ventricle CHD (p = 0.013), lower socioeconomic status (p < 0.001), a higher incidence of preoperative ventilation (p < 0.001), and were younger and smaller at the first surgery (p < 0.001). By multivariate analysis, use of DHCA was not predictive of worse performance for any ND outcome.
In this cohort of children undergoing repair of CHD in infancy, patients who underwent DHCA had risk factors associated with worse ND outcomes. Despite these, use of DHCA for repair of single-ventricle and biventricular CHD without aortic arch obstruction was not predictive of worse performance for any ND domain tested at 4 years of age.
To determine whether a cardiac diagnosis is a predictor of neurodevelopmental outcomes after infant cardiac surgery.
Infants with ventricular septal defect (VSD), tetralogy of Fallot (TOF), transposition of the great arteries (TGA), and hypoplastic left heart syndrome (HLHS) in a study of apolipoprotein E (APOE) polymorphisms, and neurodevelopmental outcome underwent neurodevelopmental and genetic evaluation at 4 years of age. The domains tested included cognition, language, speech, memory, executive function, visual-motor, fine motor, and reading and math skills.
Testing was completed in 178 patients with normal genetic evaluations: VSD (n = 26), TOF (n = 44), TGA (n = 41), and HLHS (n = 67). No differences were found in gestational age, ethnicity, APOE genotype, socioeconomic status, or maternal education among groups. Patient age at the first surgery was significantly lower for patients with TGA and HLHS compared with those with TOF and VSD. The postoperative length of stay was significantly longer for HLHS than all other groups and for TGA compared with TOF and VSD. HLHS correlated significantly with the use of deep hypothermic circulatory arrest and multiple operations. The mean scores for each domain were within normal limits for all groups. Compared with the other patients, those with HLHS had significantly lower scores for cognition, fine motor skills, executive function, and math skills. No significant differences were found among the TGA, TOF or VSD patients for any domain. Significant impairments in at least 1 domain were identified in 8% (2/25) of patients with VSD, 20% (8/41) with TOF, 17% (7/41) with TGA, and 18% (12/65) with HLHS. After correction for the demographic, preoperative, and operative variables, no significant differences were found among the groups for any domain.
The mean scores for the neurodevelopmental outcomes domains tested were in the normal range for preschool children with no recognized genetic syndromes after surgery for VSD, TOF, TGA, and HLHS. In each diagnostic group, the number of children with impairments in at least 1 domain increased compared with the general population. Unadjusted neurodevelopmental outcomes for HLHS were lower for cognition, fine motor skills, executive function, and math skills compared with the other patients. After correction for the demographic, preoperative, and operative variables, no significant differences were found among the groups for any domain. The specific cardiac diagnosis determines a large portion of the variation in these covariates. Therefore, although HLHS did predict for poorer outcomes in some domains, it did not add predictive power to the other factors considered.
Background and Purpose
Lipoprotein(a) level (Lp(a)) is an established risk factor for coronary artery disease and has been implicated in carotid artery disease (CAAD). The relationship between genetic variation in the LPA gene region and CAAD risk remains unknown.
We genotyped single nucleotide polymorphisms (SNPs) in the LPAL2, LPA, and PLG region in 530 individuals with severe CAAD and 770 controls and kringle IV type 2 (KIV2) repeat length in a subset of 90 individuals.
Nine SNPs collectively accounted for 30% of the variance in Lp(a) level. Six SNPs were associated with Lp(a) level after accounting for KIV2 copy number, and the dominant KIV2 allele combined with these markers explained 60% of the variance in Lp(a) level. Five SNPs, including rs10455872, which had an odds ratio of 2.1 per minor allele, and haplotypes formed by rs10455872, rs6919346, and rs3123629 were significant predictors of CAAD. After accounting for Lp(a) level, all evidence of CAAD-genotype association in the LPA region was eliminated.
LPA region SNPs capture some but not all of the effect of KIV2 repeat length on Lp(a) level. There are associations between LPA region SNPs and CAAD which appear to be due to effects on Lp(a) level.
Carotid stenosis; atherosclerosis; lipoprotein(a); genomics; risk factors
The Alzheimer Disease Genetics Consortium (ADGC) performed a genome-wide association study (GWAS) of late-onset Alzheimer disease (LOAD) using a 3 stage design consisting of a discovery stage (Stage 1) and two replication stages (Stages 2 and 3). Both joint and meta-analysis analysis approaches were used. We obtained genome-wide significant results at MS4A4A [rs4938933; Stages 1+2, meta-analysis (PM) = 1.7 × 10−9, joint analysis (PJ) = 1.7 × 10−9; Stages 1–3, PM = 8.2 × 10−12], CD2AP (rs9349407; Stages 1–3, PM = 8.6 × 10−9), EPHA1 (rs11767557; Stages 1–3 PM = 6.0 × 10−10), and CD33 (rs3865444; Stages 1–3, PM = 1.6 × 10−9). We confirmed that CR1 (rs6701713; PM = 4.6×10−10, PJ = 5.2×10−11), CLU (rs1532278; PM = 8.3 × 10−8, PJ = 1.9×10−8), BIN1 (rs7561528; PM = 4.0×10−14; PJ = 5.2×10−14), and PICALM (rs561655; PM = 7.0 × 10−11, PJ = 1.0×10−10) but not EXOC3L2 are LOAD risk loci1–3.
Sharing study data within the research community generates tension between two important goods: promoting scientific goals and protecting the privacy interests of study participants. The present study was designed to explore the perceptions, beliefs, and attitudes of research participants and possible future participants regarding genome-wide association studies (GWAS) and repository-based research.
Focus group sessions with (1) current research participants, (2) surrogate decision-makers, and (3) three age-defined cohorts (18–34 years, 35–50, >50).
Participants expressed a variety of opinions about the acceptability of wide sharing of genetic and phenotypic information for research purposes through large, publicly accessible data repositories. Most believed that making de-identified study data available to the research community is a social good that should be pursued. Privacy and confidentiality concerns were common, though they would not necessarily preclude participation. Many participants voiced reservations about sharing data with for-profit organizations.
Trust is central in participants’ views regarding GWAS data sharing. Further research is needed to develop governance models that enact the values of stewardship.
data sharing; genetics; electronic medical records; privacy; participant perspectives
No consensus exists about when researchers need additional participant consent (re-consent) to submit existing data to the federal database of Genotypes and Phenotypes (dbGaP). Reconsent for submission of their data to dbGaP was sought from 1,340 study participants, 1,159 (86%) of whom agreed. We invited the first 400 of those who agreed to complete a telephone survey about their reasoning for their consent decision and their satisfaction with the re-consent process; 365 participants completed the survey. Respondents reported that it was very (69%) or somewhat (21%) important that they were asked for their permission. Many respondents considered alternatives to consent, such as notification-only or opt-out, to be unacceptable (67% and 40%, respectively). These results suggest that re-consent for dbGaP deposition may be advisable in certain cases to anticipate and honor participant preferences.
informed consent; data sharing; dbGaP
The National Heart, Lung, and Blood Institute convened working group to provide basic and clinical research recommendations to the National Heart, Lung, and Blood Institute on the development of an integrated approach for identifying those individuals who are at high risk for cardiovascular event such as acute coronary syndromes (ACS) or sudden cardiac death in the “near term.” The working group members defined near-term as occurring within 1 year of the time of assessment. The participants reviewed current clinical cardiology practices for risk assessment and state-of-the-science techniques in several areas, including biomarkers, proteomics, genetics, psychosocial factors, imaging, coagulation, and vascular and myocardial susceptibility. This report presents highlights of these reviews and a summary of suggested research directions.
cardiovascular diseases; death, sudden; myocardial infarction; risk factors; risk prediction
Increases in throughput and affordability of genotyping products have led to large sample sizes in genetic studies, increasing the likelihood that incidental genetic findings may occur. We set out to survey potential notifiable variants on arrays used in genome-wide association studies and in direct-to-consumer genetic services.
We used multiple bioinformatics strategies to identify and map variants tested for genetic disorders in ≥2 CLIA-approved labs (based on the GeneTests database). We subsequently surveyed 18 commercial SNP arrays and HapMap for these variants.
Of 1,362 genes tested according to GeneTests, we identified 298 specific targeted mutations measured in ≥2 labs, encompassing 56 disorders. Only 88 of 298 mutations could be identified as known SNPs in genomic databases. We found 18 of 88 SNPs present in HapMap or on commercial SNP arrays. Homozygotes for rare alleles of some variants were identified in the Framingham Heart Study, an active GWAS cohort (n=8,410).
Variants in genes including APOE, F5, HFE, CYP21A2, MEFV, SPINK1, BTD, GALT, and G6PD were found on SNP arrays or in the HapMap. Some of these variants may warrant further review to determine their likelihood to trigger incidental findings in the course of GWAS or DTC testing.
SNP; GWAS; incidental finding; return of results; genetic
Paraoxonase 1 (PON1) hydrolyzes a number of organophosphorus (OP) compounds including insecticides and nerve agents. The in vivo efficacy of PON1 to protect against a specific OP exposure depends on the catalytic efficiency of hydrolysis. The Q192R polymorphism affects the catalytic efficiency of hydrolysis of some substrates and not others. While PON1R192 hydrolyzes paraoxon approximately 9-times as efficiently as PON1Q192, the efficiency is insufficient to provide in vivo protection against paraoxon/parathion exposure. The two PON1192 alloforms have nearly equivalent but higher catalytic efficiencies for hydrolyzing diazoxon (DZO) and provide equivalent in vivo protection against DZO exposures. On the other hand, PON1R192 is significantly more efficient in hydrolyzing chlorpyrifos oxon (CPO) than PON1Q192 and provides better protection against CPO exposure. Thus, for some exposures it is only the level of plasma PON1 that is important, whereas for others it is both plasma level and the PON1192 alloform(s) present in plasma that are important. In no case is the plasma level of PON1 unimportant, provided that the catalytic efficiency is sufficient to protect against the exposure. Two-substrate enzyme assay/analysis protocols that reveal both PON1 plasma levels and PON1192 phenotype (QQ; QR; RR) are designed to optimize the separation of PON1192 phenotypes; however, they have not been optimized for evaluating in vivo rates of OP detoxication. This study describes the adaptation of a non-OP, two-substrate determination of PON1 status to the conversion of the PON1 status data to physiologically relevant rates of DZO and CPO detoxication. Conversion factors were generated for rates of hydrolysis of different substrates.
paraoxonase 1; PON1 polymorphism; chlorpyrifos; chlorpyrifos oxon; diazinon; diazoxon; pharmacogenetics
enzymes; genetics; lipoproteins; pharmacokinetics
The eMERGE (electronic MEdical Records and GEnomics) Network is an NHGRI-supported consortium of five institutions to explore the utility of DNA repositories coupled to Electronic Medical Record (EMR) systems for advancing discovery in genome science. eMERGE also includes a special emphasis on the ethical, legal and social issues related to these endeavors.
The five sites are supported by an Administrative Coordinating Center. Setting of network goals is initiated by working groups: (1) Genomics, (2) Informatics, and (3) Consent & Community Consultation, which also includes active participation by investigators outside the eMERGE funded sites, and (4) Return of Results Oversight Committee. The Steering Committee, comprised of site PIs and representatives and NHGRI staff, meet three times per year, once per year with the External Scientific Panel.
The primary site-specific phenotypes for which samples have undergone genome-wide association study (GWAS) genotyping are cataract and HDL, dementia, electrocardiographic QRS duration, peripheral arterial disease, and type 2 diabetes. A GWAS is also being undertaken for resistant hypertension in ≈2,000 additional samples identified across the network sites, to be added to data available for samples already genotyped. Funded by ARRA supplements, secondary phenotypes have been added at all sites to leverage the genotyping data, and hypothyroidism is being analyzed as a cross-network phenotype. Results are being posted in dbGaP. Other key eMERGE activities include evaluation of the issues associated with cross-site deployment of common algorithms to identify cases and controls in EMRs, data privacy of genomic and clinically-derived data, developing approaches for large-scale meta-analysis of GWAS data across five sites, and a community consultation and consent initiative at each site.
Plans are underway to expand the network in diversity of populations and incorporation of GWAS findings into clinical care.
By combining advanced clinical informatics, genome science, and community consultation, eMERGE represents a first step in the development of data-driven approaches to incorporate genomic information into routine healthcare delivery.
We sought to identify clinical and/or plaque characteristics that affect atherosclerotic disease progression and arterial remodeling in the carotid artery with subclinical stenosis.
Increasing severity of stenosis has been associated with a higher risk of stroke. Factors that drive subclinical lesions to become stenotic plaques remain ambiguous. Carotid magnetic resonance imaging (MRI) has been validated with histology to accurately quantify in vivo arterial morphology and plaque composition.
A total of 67 asymptomatic participants with 16% to 49% carotid stenosis as demonstrated by duplex ultrasonography were imaged at 1.5-T with a carotid MRI protocol at baseline and at 18-month follow-up. Clinical and/or intra-arterial metrics with a significant association with change in plaque burden during multivariate analysis were evaluated for effects on lumen, wall, and total vessel volume.
From multiple regression analysis, intraplaque hemorrhage (IPH) (p < 0.001) and statin therapy (p = 0.015) were identified as key determinants of change in plaque burden. The group with IPH compared with the group without IPH demonstrated luminal narrowing, with a mean ± SD decrease in lumen volume (−24.9 ± 21.1 mm3/year vs. −0.5 ± 26.9 mm3/year; p = 0.005), a larger increase in wall volume (44.1 ± 36.1 mm3/year vs. 0.8 ± 34.5 mm3/year; p < 0.001), and no difference in total vessel volume (19.3 ± 27.4 mm3/year vs. 0.4 ± 42.4 mm3/year; p = 0.15). The nonstatin group compared with the statin group demonstrated outward remodeling, with an increase in wall volume (22.4 ± 35.6 mm3/year3/year vs. 0.9 ± 38.0 mm3/year; p = 0.026) and total vessel volume (19.2 ± 36.9 mm3/year vs. −4.9 ± 40.4 mm3/year; p = 0.019) and no difference in lumen volume (−5.8 ± 26.6 mm3/year vs. −3.2 ± 29.5 mm3/year; p = 0.72).
IPH may represent an indication of accelerated plaque growth and impending luminal compromise in the subclinical carotid artery. Statin therapy may stabilize lesions by slowing or halting lesion progression. This phase of plaque stenosis (16% to 49%) may be a critical stage for intrinsic and extrinsic factors to affect the atherosclerotic disease process.
atherosclerosis; carotid arteries; magnetic resonance imaging; remodeling
Since inflammation is an important contributor to atherosclerosis, gene variants mediating inflammation are of interest. We investigated gene variants in acute phase serum amyloid-A (SAA), a sensitive indicator of inflammatory activity, and their associations with cardiovascular disease (CVD) and HDL cholesterol. Interaction of the SAA genes with genetic variants of their regulators, IL-1, IL-6 and TNF-α in influencing CVD was also explored.
SNPs characterizing common variation in the SAA1 and SAA2 genes were genotyped in European-(EA) and African-American (AA) participants (n=3969 and n=719) of the Cardiovascular Health Study. Using linear and Cox proportional hazards regression, we assessed associations of SNPs with baseline carotid artery intima-media thickness (cIMT) and risk of incident myocardial infarction, ischemic stroke, total CVD events or mortality during ~14 years of follow-up.
No associations between SAA SNPs and outcomes were observed in EA, with the exception of total CVD events; each rs4638289 minor allele was associated with an increased risk in obese individuals, HR=1.2 (95%CI: 0.98-1.4; p=0.086) and decreased risk among non-obese, HR=0.9 (95%CI: 0.8-0.99; p=0.026). In AA, we observed modest associations between SAA SNPs and cIMT, potentially modified by HDL. SAA SNPs were also associated with lower HDL in EA and AA. Suggestive gene-gene interaction findings for cIMT in AA and CVD mortality in EA were not significant in subsequent model selection tests.
Associations of SAA SNPs with cIMT, HDL and total CVD events were identified, unadjusted for multiple testing. These findings should be regarded as hypothesis-generating until confirmed by other studies.
acute phase reactants; carotid IMT; myocardial infarction; ischemic stroke; genetic variants
The prevalence of perioperative stroke in infants undergoing operations for congenital heart disease has not been well described. The objectives of this study were to determine the prevalence of stroke as assessed by postoperative brain magnetic resonance imaging (MRI), characterize the neuroanatomic features of focal ischemic injury, and identify risk factors for its development.
Brain MRI was performed in 122 infants 3 to 14 days after cardiac operation with cardiopulmonary bypass, with or without deep hypothermic circulatory arrest. Preoperative, intraoperative, and postoperative data were collected. Risk factors were tested by logistic regression for univariate and multivariate associations with stroke.
Stroke was identified in 12 of 122 patients (10%). Strokes were preoperative in 6 patients and possibly intraoperative or postoperative in the other 6 patients, and were clinically silent except in 1 patient who had clinical seizures. Arterial-occlusive and watershed infarcts were identified with equal distribution in both hemispheres. Multivariate analysis identified lower birth weight, preoperative intubation, lower intraoperative hematocrit, and higher blood pressure at admission to the cardiac intensive care unit postoperatively as significant factors associated with stroke. Prematurity, younger age at operation, duration of cardiopulmonary bypass, and use of deep hypothermic circulatory arrest were not significantly associated with stroke.
The prevalence of stroke in infants undergoing operations for congenital heart disease was 10%, half of which occurred preoperatively. Most were clinically silent and undetected without neuroimaging. Mechanisms included thromboembolism and hypoperfusion, with patient-specific, procedure-specific, and postoperative contributions to increased risk.
The goal was to evaluate polymorphisms of the APOE gene as modifiers of neurobehavioral outcomes for preschool-aged children with congenital heart defects, after cardiac surgery.
A prospective observational study with neurodevelopmental evaluation between the fourth and fifth birthdays was performed. Attention and behavioral skills were assessed through parental report.
Parents of 380 children completed the neurobehavioral measures. Child Behavior Checklist scores for the pervasive developmental problem scale were in the at-risk or clinically significant range for 15% of the cohort, compared with 9% for the normative data (P < .00001). Attention problem scores were in the at-risk or clinically significant range for 12% of the cohort, compared with 7% for the normative data (P = .0002). The Attention-Deficit/Hyperactivity Disorder Rating Scale-IV, Preschool Version, was completed for 378 children; 30% scored in the clinically significant range for inattention and 22% for impulsivity. After adjustment for covariates, the APOE ε2 allele was significantly associated with higher scores (worse problems) for multiple Child Behavior Checklist indices, including somatic complaints (P = .009), pervasive developmental problems (P = .032), and internalizing problems (P=.009). In each case, the ε4 allele was associated with a better outcome. APOE ε2 carriers had impaired social skills, compared with ε4 carriers (P = .009).
For preschool-aged children with congenital heart defects requiring surgery, parental rating scales showed an increased prevalence of restricted behavior patterns, inattention, and impaired social interactions. The APOE ε2 allele was associated with increased behavior problems, impaired social interactions, and restricted behavior patterns.
congenital heart defects; genetic predisposition to disease; apolipoprotein E; behavioral symptoms; attention-deficit/hyperactivity disorder; impulsive behavior; autistic disorder
Human paraoxonase 1 (PON1) has broad substrate specificity and has been shown to protect against exposure to some organophosphorus (OP) insecticides due to its ability to hydrolyze toxic metabolites of some organophosphorothioate insecticides. PON1 status has been shown to be important in protecting against vascular disease, presumably due to the not-as-yet fully characterized role of the three PON proteins in modulating oxidative stress. More recently, all three PONs (1, 2, and 3) have been shown to inactivate the quorum sensing factor N-(3-oxododecanoyl)-L-homoserine lactone (3OC12-HSL) of Pseudomonas. Expression of human PON1 in Drosophila demonstrated the importance of PON1 in resistance to Pseudomonas infection. Many studies have examined only DNA single nucleotide polymorphisms as possible risk factors for disease or exposures. For all of the known functions of PON1, the level of PON1 enzyme is important and, in some cases, also the Q192R polymorphism. A simple high throughput two-substrate assay/analysis, plotting rates of diazoxon hydrolysis vs. paraoxon hydrolysis, provided both PON1 levels and functional Q192R phenotype/genotype. We have developed a new two-substrate assay/analysis protocol that provides PON1 status without use of toxic OP substrates. Factors were determined for inter-converting rates of hydrolysis of different substrates.
PON1 status; Paraoxonase; Diazoxon; Diazinon; Chlorpyrifos; Chlorpyrifos oxon; Carotid artery disease; Quorum sensing factor; OP exposure