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Biomedical subjects

Lucia A Hindorff

Publications and source records attributed to Lucia A Hindorff.

11 recordsLinked to original sources

Genomic sequencing in diverse and underserved pediatric populations: Parent perspectives on understanding, uncertainty, psychosocial impact, and personal utility of results.

PURPOSE: Limited evidence evaluates parents' perceptions of their child's clinical genome-scale sequencing (GS) results, particularly among individuals from medically underserved groups. Five Clinical Sequencing Evidence-Generating Research consortium studies performed GS in children with suspected genetic conditions with high proportions of individuals from underserved groups to address this evidence gap. METHODS: Parents completed surveys of perceived understanding, personal utility, and test-related distress after GS result disclosure. We assessed outcomes' associations with child- and parent-related factors: child age; type of GS finding; and parent health literacy, numeracy, and education. RESULTS: A total of 1763 parents completed surveys; 83% met "underserved" criteria based on race, ethnicity, and risk factors for barriers to access. We observed high perceived understanding and personal utility and low test-related distress. Outcomes were associated with the type of GS finding; parents of children with a pathogenic or likely pathogenic finding endorsed higher personal utility and more test-related distress than those whose children had a variant of uncertain significance or normal finding. Personal utility was higher in parents who met the criteria for "underserved." CONCLUSION: Our findings shed light on correlates of parents' cognitive and emotional responses to their child's GS findings and emphasize the need for tailored support in disclosure discussions.

Humans↗

Association of polymorphisms in the CRP gene with circulating C-reactive protein levels and cardiovascular events.

CONTEXT: C-reactive protein (CRP) is an inflammation protein that may play a role in the pathogenesis of cardiovascular disease (CVD). OBJECTIVE: To assess whether polymorphisms in the CRP gene are associated with plasma CRP, carotid intima-media thickness (CIMT), and CVD events. DESIGN, SETTING, AND PARTICIPANTS: In the prospective, population-based Cardiovascular Health Study, 4 tag single-nucleotide polymorphisms (SNPs) (1919A/T, 2667G/C, 3872G/A, 5237A/G) were genotyped in 3941 white (European American) participants and 5 tag SNPs (addition of 790A/T) were genotyped in 700 black (African American) participants, aged 65 years or older, all of whom were without myocardial infarction (MI) or stroke before study entry. Median follow-up was 13 years (1989-2003). MAIN OUTCOME MEASURES: Baseline CIMT; occurrence of MI, stroke, and CVD mortality during follow-up. RESULTS: In white participants, 461 incident MIs, 491 incident strokes, and 490 CVD-related deaths occurred; in black participants, 67 incident MIs, 78 incident strokes, and 75 CVD-related deaths occurred. The 1919T and 790T alleles were associated with higher CRP levels in white and black participants, respectively. The 3872A allele was associated with lower CRP levels in both populations, and the 2667C allele was associated with lower CRP levels in white participants only. There was no association between CIMT and any CRP gene polymorphism in either population. In white participants, the 1919T allele was associated with increased risk of stroke for TT vs AA (hazard ratio [HR], 1.40; 95% confidence interval [CI], 1.06-1.87) and for CVD mortality (HR, 1.40; 95% CI, 1.10-1.90). In black participants, homozygosity for the 790T allele was associated with a 4-fold increased risk of MI compared with homozygosity for the 790A allele (95% CI, 1.58-10.53). The minor alleles of the 2 SNPs associated with lower plasma CRP concentration in white participants (2667C and 3872A) were associated with decreased risk of CVD mortality. CONCLUSIONS: Genetic variation in the CRP gene is associated with plasma CRP levels and CVD risk in older adults.

Aged↗

Common genetic variation in the prothrombin gene, hormone therapy, and incident nonfatal myocardial infarction in postmenopausal women.

Genetic variants in coagulation factors are associated with myocardial infarction and may modify the association between hormone therapy and cardiovascular disease risk. This study assessed whether common variation in the prothrombin gene was associated with incident nonfatal myocardial infarction in postmenopausal women and whether this association differed according to current estrogen use. Eight variants representing 98% of common prothrombin variants were selected using publicly available genomic variation data. These variants and the functional G20210A variant were genotyped and used to infer haplotypes in a population-based Washington State case-control study of postmenopausal Caucasian women (1995-1999; 273 cases and 788 controls). Women carrying a nonsynonymous polymorphism in exon 6 (C5467T) had an increased risk of myocardial infarction (for each additional copy, relative to women with one fewer copy, odds ratio = 1.4, 95% confidence interval: 1.0, 1.8). Prothrombin haplotypes were also associated with myocardial infarction (with minimal adjustment, global p = 0.056; with full adjustment, p = 0.034). Associations between haplotypes and myocardial infarction were similar among users of hormone therapy and nonusers (global p = 0.61), though statistical power was limited. These preliminary results suggest that common genetic variants in the prothrombin gene or other variants in linkage disequilibrium are associated with myocardial infarction in postmenopausal women.

Aged↗

Simple estimates of haplotype relative risks in case-control data.

Methods of varying complexity have been proposed to efficiently estimate haplotype relative risks in case-control data. Our goal was to compare methods that estimate associations between disease conditions and common haplotypes in large case-control studies such that haplotype imputation is done once as a simple data-processing step. We performed a simulation study based on haplotype frequencies for two renin-angiotensin system genes. The iterative and noniterative methods we compared involved fitting a weighted logistic regression, but differed in how the probability weights were specified. We also quantified the amount of ambiguity in the simulated genes. For one gene, there was essentially no uncertainty in the imputed diplotypes and every method performed well. For the other, approximately 60% of individuals had an unambiguous diplotype, and approximately 90% had a highest posterior probability greater than 0.75. For this gene, all methods performed well under no genetic effects, moderate effects, and strong effects tagged by a single nucleotide polymorphism (SNP). Noniterative methods produced biased estimates under strong effects not tagged by an SNP. For the most likely diplotype, median bias of the log-relative risks ranged between -0.49 and 0.22 over all haplotypes. For all possible diplotypes, median bias ranged between -0.73 and 0.08. Results were similar under interaction with a binary covariate. Noniterative weighted logistic regression provides valid tests for genetic associations and reliable estimates of modest effects of common haplotypes, and can be implemented in standard software. The potential for phase ambiguity does not necessarily imply uncertainty in imputed diplotypes, especially in large studies of common haplotypes.

Algorithms↗

beta(2)-Adrenergic receptor polymorphisms and determinants of cardiovascular risk: the Cardiovascular Health Study.

BACKGROUND: Common Arg16Gly and Gln27Glu polymorphisms of the beta(2)-adrenergic receptor (beta(2)AR) have been associated with hypertension and coronary disease. This analysis of older adults in the Cardiovascular Health Study examined whether these polymorphisms were associated with blood pressure (BP), subclinical atherosclerosis, and, among treated hypertensive individuals, differences in coronary disease risk according to antihypertensive drug class. METHODS: Altogether, 5249 participants (4441 white and 808 African American, median follow-up time 10.2 years) were genotyped for both polymorphisms. Ankle-arm index (AAI), carotid intima-media thickness (IMT), and brachial flow-mediated dilation were measured cross-sectionally. All estimates were adjusted for ethnicity. RESULTS: Relative to Gln27 homozygotes, carrying the Glu27 allele was not associated with new-onset hypertension (hazard ratio [HR] = 1.01, 95% confidence interval [CI] = 0.87 to 1.16), BP control (odds ratio [OR] = 0.97, 95% CI = 0.89 to 1.06), AAI (mean difference 0.0042 +/- 0.0052), carotid IMT (mean difference 0.0044 +/- 0.02 mm), or brachial flow-mediated dilation (mean difference in baseline diameter -0.028 +/- 0.036 mm; the most marked of three measures). Among treated hypertensive individuals, coronary disease risk was similar in Glu27 carriers relative to Gln27 homozygotes in subgroups defined by use of beta-blockers (HR = 1.09, 95% CI = 0.64 to 1.87) or other antihypertensive medications (HR = 1.00, 95% CI = 0.78 to 1.28). Results were similar for the Arg16Gly polymorphism. CONCLUSIONS: The association of beta(2)AR genotype with coronary disease previously reported in this older adult population is not likely to be explained by BP levels, subclinical atherosclerosis, or antihypertensive treatment. Other measures of vascular response, gene-gene or gene-environment interactions, or characteristics developing earlier in life may mediate the association between beta(2)AR genotype and coronary disease and merit further research.

Black or African American↗

Beta2-adrenergic receptor polymorphisms and risk of incident cardiovascular events in the elderly.

BACKGROUND: Genetic polymorphisms at codons 16 and 27 of the beta2-adrenergic receptor have been associated with altered response to sympathetic stimulation. We examined these polymorphisms in relation to cardiovascular event risk in the Cardiovascular Health Study. METHODS AND RESULTS: A total of 808 black and 4441 white participants (mean age, 73 years) were genotyped for the Arg16Gly and Gln27Glu polymorphisms of the beta2-adrenergic receptor. There were 702 incident coronary events, 438 ischemic strokes, and 1136 combined cardiovascular events during 7 to 10 years of follow-up. Allele frequencies differed by race but not by age or hypertension status. Glu27 carriers had a lower risk of coronary events than Gln27 homozygotes (hazard ratio, 0.82; 95% CI, 0.70 to 0.95), and there was a suggestion of decreased risk among Gly16 carriers compared with Arg16 homozygotes (hazard ratio, 0.88; 95% CI, 0.72 to 1.07). There was no association of beta2-adrenergic receptor genotype with ischemic stroke or combined cardiovascular events. CONCLUSIONS: The Glu27 allele of the beta2-adrenergic receptor was associated with a lower risk of incident coronary events in this elderly population.

Aged↗

Family history of diabetes as a potential public health tool.

Given the substantial morbidity and mortality associated with type 2 diabetes, it is important that public health seek ways to delay or prevent the onset of this condition. Risk factors for type 2 diabetes are well established and include underlying genetic susceptibility. Despite this knowledge, as well as significant advances in understanding the human genome, the prevalence of type 2 diabetes continues to rise at an alarming rate. Because type 2 diabetes is a complex condition involving a combination of genetic and environmental factors, DNA testing for susceptibility genes is not yet warranted. However, because family history reflects genetic susceptibility in addition to other factors, it may be a useful public health tool for disease prevention. When evaluating family history as a public health tool, several important issues need to be considered, including the analytic and clinical validity and the clinical utility of using family history as a screening tool. These issues as well as a review of the epidemiologic evidence evaluating family history as a risk factor will be reviewed.Overall, a family history approach appears to be a promising new public health tool to fight the growing epidemic of diabetes in the United States. Adequate levels of funding to further evaluate this approach and to develop appropriate tools should be made available for research activities focused on this important area.

Diabetes Mellitus, Type 2↗

Expression of a cloned cyclopropane fatty acid synthase gene reduces solvent formation in Clostridium acetobutylicum ATCC 824.

The cyclopropane fatty acid synthase gene (cfa) of Clostridium acetobutylicum ATCC 824 was cloned and overexpressed under the control of the clostridial ptb promoter. The function of the cfa gene was confirmed by complementation of an Escherichia coli cfa-deficient strain in terms of fatty acid composition and growth rate under solvent stress. Constructs expressing cfa were introduced into C. acetobutylicum hosts and cultured in rich glucose broth in static flasks without pH control. Overexpression of the cfa gene in the wild type and in a butyrate kinase-deficient strain increased the cyclopropane fatty acid content of early-log-phase cells as well as initial acid and butanol resistance. However, solvent production in the cfa-overexpressing strain was considerably decreased, while acetate and butyrate levels remained high. The findings suggest that overexpression of cfa results in changes in membrane properties that dampen the full induction of solventogenesis. The overexpression of a marR homologous gene preceding the cfa gene in the clostridial genome resulted in reduced cyclopropane fatty acid accumulation.

1-Propanol↗

Genetic variants of coagulation factor XIII, postmenopausal estrogen therapy, and risk of nonfatal myocardial infarction.

We hypothesized that possession of either of 2 functional coagulation factor XIII polymorphisms, one within subunit A (Val34Leu) and one within subunit B (His95Arg), might modulate the prothrombotic effects of estrogen and help to explain the variation in incidence of arterial thrombotic events among postmenopausal women using hormone replacement therapy. In a population-based case-control study of 955 postmenopausal women, we assessed the associations of factor XIII genotypes and their interactions with estrogen therapy on risk of nonfatal myocardial infarction (MI). The presence of the factor XIIIA Leu34 allele was associated with a reduced risk of MI (odds ratio [OR] = 0.70, 95% confidence interval [95% CI] = 0.51-0.95). The presence of the factor XIIIB Arg95 allele had little association with MI risk. Neither factor XIII polymorphism alone significantly modified the association between the risk of MI and current estrogen use. In exploratory analyses, however, there was a significant factor XIII subunit gene-gene interaction. Compared to women homozygous for both common factor XIII alleles, the Arg95 variant was associated with a reduced risk of MI in the presence of the Leu34 variant (OR = 0.36, 95% CI = 0.17-0.75) but not in the absence of the Leu34 variant (OR = 1.11, 95% CI = 0.69-1.79). Moreover, among women who had at least 2 copies of the variant factor XIII alleles and were current estrogen users, the risk of MI was reduced by 70% relative to estrogen nonusers with fewer than 2 factor XIII variant alleles (P value for interaction =.03). If confirmed, these findings may permit a better assessment of the cardiovascular risks and benefits associated with postmenopausal estrogen therapy.

Adult↗

Angiotensin II type 1 receptor polymorphisms in the cardiovascular health study: relation to blood pressure, ethnicity, and cardiovascular events.

BACKGROUND: The angiotensin II type 1 receptor A1166C polymorphism has been associated with increased risks of hypertension and myocardial infarction in several small studies. We examined the association between this polymorphism and new-onset hypertension, blood pressure (BP) control, and incident cardiovascular events in a large population-based cohort of older adults. METHODS: Eight hundred self-identified African Americans and 1,371 randomly selected white participants in the Cardiovascular Health Study were genotyped. The median duration of follow-up was 8.1 years. RESULTS: The A1166C polymorphism was not associated with new-onset hypertension, with BP control, or with incident cardiovascular events in the overall population. In white participants, the CC genotype was associated with higher baseline systolic BP and pulse pressure, compared to the AC or AA genotype. In whites with treated hypertension at baseline, compared to the AA genotype, the CC genotype was associated with increased risks of incident congestive heart failure (hazard ratio = 2.5, 95% confidence interval [CI] 1.3-4.9) and incident ischemic stroke (hazard ratio = 2.6, 95% CI 1.1-6.0). These associations were not observed among white participants without treated hypertension, but the interaction of genotype with treated hypertension on ischemic stroke and heart failure was only marginally significant. CONCLUSIONS: On the whole, in this large cohort of older adults, the A1166C polymorphism was not associated with BP control or incident cardiovascular events. The subgroup findings in treated hypertensives need to be confirmed in additional studies.

Aged↗

The association of PAI-1 promoter 4G/5G insertion/deletion polymorphism with myocardial infarction and stroke in young women.

BACKGROUND: The plasminogen activator inhibitor-1 (PAI-1) promoter 4G/5G insertion/deletion polymorphism has been associated with increased risk of myocardial infarction (MI) and decreased risk of cerebrovascular events. Whether these results apply to young women is not known. METHODS: We genotyped 78 MI cases, 106 stroke cases and 385 age-matched controls from a population-based case-control study of MI and stroke in women < 45 years old. RESULTS: The risk of MI was significantly decreased in carriers of the 4G allele compared with 5G/5G homozygotes, and the association persisted upon adjustment for other risk factors (age- and race-adjusted OR 0.50, 95% CI 0.29-0.85). Carrying the 4G allele was not associated with stroke, either overall or according to subtype. The association of this polymorphism with MI or stroke did not vary significantly by presence or absence of established cardiovascular risk factors, assessed on either an additive or multiplicative scale. CONCLUSIONS: These data suggest a decreased risk of MI among young women carrying the 4G allele of the PAI-1 4G/5G polymorphism. Although this result contrasts with those of previous studies of older adults and young men, it may highlight the influence of genetic factors on the development of MI within the context of particular hormonal or environmental influences.

Adult↗