1,487 research outputs found
Type 2 Diabetes Risk Alleles Are Associated With Reduced Size at Birth
OBJECTIVE: Low birth weight is associated with an increased risk of type 2 diabetes. The mechanisms underlying this association are unknown and may represent intrauterine programming or two phenotypes of one genotype. The fetal insulin hypothesis proposes that common genetic variants that reduce insulin secretion or action may predispose to type 2 diabetes and also reduce birth weight, since insulin is a key fetal growth factor. We tested whether common genetic variants that predispose to type 2 diabetes also reduce birth weight. RESEARCH DESIGN AND METHODS: We genotyped single-nucleotide polymorphisms (SNPs) at five recently identified type 2 diabetes loci (CDKAL1, CDKN2A/B, HHEX-IDE, IGF2BP2, and SLC30A8) in 7,986 mothers and 19,200 offspring from four studies of white Europeans. We tested the association between maternal or fetal genotype at each locus and birth weight of the offspring. RESULTS: We found that type 2 diabetes risk alleles at the CDKAL1 and HHEX-IDE loci were associated with reduced birth weight when inherited by the fetus (21 g [95% CI 11-31], P = 2 x 10(-5), and 14 g [4-23], P = 0.004, lower birth weight per risk allele, respectively). The 4% of offspring carrying four risk alleles at these two loci were 80 g (95% CI 39-120) lighter at birth than the 8% carrying none (P(trend) = 5 x 10(-7)). There were no associations between birth weight and fetal genotypes at the three other loci or maternal genotypes at any locus. CONCLUSIONS: Our results are in keeping with the fetal insulin hypothesis and provide robust evidence that common disease-associated variants can alter size at birth directly through the fetal genotype
A model-based assessment of the cost-utility of strategies to identify Lynch syndrome in early-onset colorectal cancer patients.
This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.BACKGROUND: Lynch syndrome is an autosomal dominant cancer predisposition syndrome caused by mutations in the DNA mismatch repair genes MLH1, MSH2, MSH6 and PMS2. Individuals with Lynch syndrome have an increased risk of colorectal cancer, endometrial cancer, ovarian and other cancers. Lynch syndrome remains underdiagnosed in the UK. Reflex testing for Lynch syndrome in early-onset colorectal cancer patients is proposed as a method to identify more families affected by Lynch syndrome and offer surveillance to reduce cancer risks, although cost-effectiveness is viewed as a barrier to implementation. The objective of this project was to estimate the cost-utility of strategies to identify Lynch syndrome in individuals with early-onset colorectal cancer in the NHS. METHODS: A decision analytic model was developed which simulated diagnostic and long-term outcomes over a lifetime horizon for colorectal cancer patients with and without Lynch syndrome and for relatives of those patients. Nine diagnostic strategies were modelled which included microsatellite instability (MSI) testing, immunohistochemistry (IHC), BRAF mutation testing (methylation testing in a scenario analysis), diagnostic mutation testing and Amsterdam II criteria. Biennial colonoscopic surveillance was included for individuals diagnosed with Lynch syndrome and accepting surveillance. Prophylactic hysterectomy with bilateral salpingo-oophorectomy (H-BSO) was similarly included for women diagnosed with Lynch syndrome. Costs from NHS and Personal Social Services perspective and quality-adjusted life years (QALYs) were estimated and discounted at 3.5% per annum. RESULTS: All strategies included for the identification of Lynch syndrome were cost-effective versus no testing. The strategy with the greatest net health benefit was MSI followed by BRAF followed by diagnostic genetic testing, costing £5,491 per QALY gained over no testing. The effect of prophylactic H-BSO on health-related quality of life (HRQoL) is uncertain and could outweigh the health benefits of testing, resulting in overall QALY loss. CONCLUSIONS: Reflex testing for Lynch syndrome in early-onset colorectal cancer patients is predicted to be a cost-effective use of limited financial resources in England and Wales. Research is recommended into the cost-effectiveness of reflex testing for Lynch syndrome in other associated cancers and into the impact of prophylactic H-BSO on HRQoL.NIH
Genetic variation at CHRNA5-CHRNA3-CHRNB4 interacts with smoking status to influence body mass index
Cigarette smoking is associated with lower body mass index (BMI), and a commonly cited reason for unwillingness to quit smoking is a concern about weight gain. Common variation in the CHRNA5-CHRNA3-CHRNB4 gene region (chromosome 15q25) is robustly associated with smoking quantity in smokers, but its association with BMI is unknown. We hypothesized that genotype would accurately reflect smoking exposure and that, if smoking were causally related to weight, it would be associated with BMI in smokers, but not in never smokers
Simulated distributions from negative experiments highlight the importance of the body mass index distribution in explaining depression–body mass index genetic risk score interactions
This is the final version. Available on open access from Oxford University Press via the DOI in this record. Data availability:
All data from UK Biobank are publicly available; the negative
experiments algorithm can be found here https://github.com/drar
wood/gags.Abstract.
Background:
Depression and obesity are complex global health problems. Recent studies suggest a
genetic predisposition to obesity might be accentuated in people with depression, but these
analyses are prone to bias. Here, we tested the hypothesis that depression accentuates
genetic susceptibility to obesity and applied negative control experiments to test whether any
observed interactions were real or driven by confounding and statistical biases.
Methods:
We used data from upto 378,000 Europeans in UK Biobank, a 73 variant Body Mass Index
(BMI) genetic risk score, 2 depression measures (depressive symptoms (DS), major
depression (MD)) and an antidepressant usage variable available. We tested whether a)
depression and b) antidepressant treatment accentuated genetic susceptibility to obesity.
Finally, we performed negative control experiments by sampling individuals at random so
that they had BMI distributions identical to depression cases and controls.
Results:
Depression was associated with an accentuation of an individuals genetic risk of obesity with
evidence of interactions for both DS and MD (Pinteraction=7x10-4 and 7x10-5 respectively).
Antidepressant usage within DS cases accentuated genetic obesity risk (Pinteraction=9x10-4),
but not for MD (Pinteraction=0.13). Negative control experiments suggested that the observed
interactions for MD (empirical-P =0.067) may be driven by statistical biases or confounding
factors but were not possible with the larger DS groups. Antidepressant usage interaction
also appears to be driven by statistical artefacts (empirical-P=0.510 using MD and 0.162
using DS).
Conclusion:
We have highlighted the importance of running negative experiments to confirm putative
interactions in gene-environment studies. We provide some tentative evidence that
depression accentuates an individual’s genetic susceptibility to higher BMI but demonstrated
that the BMI distributions within cases and controls might drive these interactions.Academy of Medical SciencesEuropean Research Council (ERC
A genome-wide association study identifies protein quantitative trait loci (pQTLs)
There is considerable evidence that human genetic variation influences gene expression. Genome-wide studies have revealed that mRNA levels are associated with genetic variation in or close to the gene coding for those mRNA transcripts - cis effects, and elsewhere in the genome - trans effects. The role of genetic variation in determining protein levels has not been systematically assessed. Using a genome-wide association approach we show that common genetic variation influences levels of clinically relevant proteins in human serum and plasma. We evaluated the role of 496,032 polymorphisms on levels of 42 proteins measured in 1200 fasting individuals from the population based InCHIANTI study. Proteins included insulin, several interleukins, adipokines, chemokines, and liver function markers that are implicated in many common diseases including metabolic, inflammatory, and infectious conditions. We identified eight Cis effects, including variants in or near the IL6R (p = 1.8×10 -57), CCL4L1 (p = 3.9×10-21), IL18 (p = 6.8×10-13), LPA (p = 4.4×10-10), GGT1 (p = 1.5×10-7), SHBG (p = 3.1×10-7), CRP (p = 6.4×10-6) and IL1RN (p = 7.3×10-6) genes, all associated with their respective protein products with effect sizes ranging from 0.19 to 0.69 standard deviations per allele. Mechanisms implicated include altered rates of cleavage of bound to unbound soluble receptor (IL6R), altered secretion rates of different sized proteins (LPA), variation in gene copy number (CCL4L1) and altered transcription (GGT1). We identified one novel trans effect that was an association between ABO blood group and tumour necrosis factor alpha (TNF-alpha) levels (p = 6.8×10-40), but this finding was not present when TNF-alpha was measured using a different assay , or in a second study, suggesting an assay-specific association. Our results show that protein levels share some of the features of the genetics of gene expression. These include the presence of strong genetic effects in cis locations. The identification of protein quantitative trait loci (pQTLs) may be a powerful complementary method of improving our understanding of disease pathways. © 2008 Melzer et al
Great art for everyone? Engagement and participation policy in the arts
New Labour began its administration with a commitment to bring democracy to culture. However, a decade later the Arts Council England (ACE)'s mission statement of "Great art for everyone" suggested a continued emphasis on access to mainstream culture rather than on cultural democracy. The argument in this paper is that Labour's vision has resulted in little change to the basis upon which arts institutions receive regular funding, or the social composition of those who participate in the arts in Britain today - who remain predominantly white and middle class. Public consultation through The arts debate provides evidence that the arts are still perceived as elitist, and policy too insular and self-reflective. The report clearly identified the public's desire for not only greater transparency in decisionmaking processes but also involvement in the decisions themselves, in order to democratise the arts. This paper draws on research investigating the extent to which participatory decisionmaking schemes affect cultural democracy and the subsequent impact on artistic policy and practice. In addition to documentary analysis, this study involved interviews with policymakers, practitioners and the public, focusing on two projects using participatory decision-making in England. © 2011 Copyright Taylor and Francis Group, LLC
Genetic predisposition to metabolically unfavourable adiposity and prostate cancer risk:A Mendelian randomization analysis
BACKGROUND
The associations of adiposity with aggressive prostate cancer risk are unclear. Using two-sample Mendelian randomization, we assessed the association of metabolically unfavourable adiposity (UFA), favourable adiposity (FA) and for comparison body mass index (BMI), with prostate cancer, including aggressive prostate cancer.
METHODS
We examined the association of these genetically predicted adiposity-related traits with risk of prostate cancer overall, aggressive and early onset disease using outcome summary statistics from the PRACTICAL consortium (including 15,167 aggressive cases).
RESULTS
In inverse-variance weighted models, there was little evidence that genetically predicted one standard deviation higher UFA, FA and BMI were associated with aggressive prostate cancer [OR: 0.85 (95% CI:0.61-1.19), 0.80 (0.53-1.23) and 0.97 (0.88-1.08), respectively]; these associations were largely consistent in sensitivity analyses accounting for horizontal pleiotropy. There was no strong evidence that genetically determined UFA, FA or BMI were associated with overall prostate cancer or early age of onset prostate cancer.
CONCLUSIONS
We did not find differences in the associations of UFA and FA with prostate cancer risk, which suggest that adiposity is unlikely to influence prostate cancer via the metabolic factors assessed; however, these did not cover some aspects related to metabolic health that may link obesity with aggressive prostate cancer, which should be explored in future studies
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