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- Chikowore, Tinashe, et al.
(author)
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GWAS transethnic meta-analysis of BMI in similar to 700k individuals reveals novel gene-smoking interaction in African populations
- 2020
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In: Genetic Epidemiology. - : John Wiley & Sons. - 0741-0395 .- 1098-2272. ; 44:5, s. 475-476
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Journal article (other academic/artistic)abstract
- Sixty two percent of the 1.12 billion obese people globally reside in low‐middle income countries, 77% of which are in Africa. There is paucity of data on gene‐lifestyle interactions associated with the increasing prevalence of obesity among Africans. We hypothesised that gene‐environment interacting (GEI) variants exhibit heterogenous effects on obesity in transethnic meta‐analysis of marginal SNP associations as a result of modification by an unknown exposure that varies across populations.Body mass index (BMI) genome‐wide association study (GWAS) summary statistics for 678,671 individuals representative of the major global ancestries were aggregated at 21,338,816 SNPs via fixed‐effects meta‐analysis. Lead SNPs attaining genome‐wide significance (P < 5 × 10−8) were tested for heterogeneity in effects between GWAS. Lead SNPs with significant evidence of heterogeneity after Bonferroni correction were then selected for interaction analysis with selected lifestyle factors in an independent AWI‐Gen study of 10,500 African participants. Significant interaction findings were then replicated in 3,177 individuals of African ancestry in the UK Biobank.Of 881 lead SNPs, five had significant heterogenous effects on BMI (P < 5.7 × 10−5). Rs471094, at the CDKAL1 locus had significant interaction with smoking status, which reduced the effect of the BMI raising allele in current smokers (Betaint = −0.949 kg/m2; P int = .002) compared with non‐smokers in AWI‐Gen. This finding was validated in the UK Biobank (Betaint = −1.471 kg/m2, P int = .020; meta‐analysis Betaint = −1.050 kg/m2, P int = .0002). Our results highlight the first gene‐lifestyle interaction on BMI in Africans and demonstrate the utility of transethnic meta‐analysis of GWAS for identifying GEI effects.
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| 2. |
- Mahmoodi, Bakhtawar K., et al.
(author)
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Association of Factor V Leiden With Subsequent Atherothrombotic Events A GENIUS-CHD Study of Individual Participant Data
- 2020
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In: Circulation. - : Ovid Technologies (Wolters Kluwer Health). - 0009-7322 .- 1524-4539. ; 142:6, s. 546-555
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Journal article (peer-reviewed)abstract
- Background: Studies examining the role of factor V Leiden among patients at higher risk of atherothrombotic events, such as those with established coronary heart disease (CHD), are lacking. Given that coagulation is involved in the thrombus formation stage on atherosclerotic plaque rupture, we hypothesized that factor V Leiden may be a stronger risk factor for atherothrombotic events in patients with established CHD.Methods: We performed an individual-level meta-analysis including 25 prospective studies (18 cohorts, 3 case-cohorts, 4 randomized trials) from the GENIUS-CHD (Genetics of Subsequent Coronary Heart Disease) consortium involving patients with established CHD at baseline. Participating studies genotyped factor V Leiden status and shared risk estimates for the outcomes of interest using a centrally developed statistical code with harmonized definitions across studies. Cox proportional hazards regression models were used to obtain age- and sex-adjusted estimates. The obtained estimates were pooled using fixed-effect meta-analysis. The primary outcome was composite of myocardial infarction and CHD death. Secondary outcomes included any stroke, ischemic stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality.Results: The studies included 69 681 individuals of whom 3190 (4.6%) were either heterozygous or homozygous (n=47) carriers of factor V Leiden. Median follow-up per study ranged from 1.0 to 10.6 years. A total of 20 studies with 61 147 participants and 6849 events contributed to analyses of the primary outcome. Factor V Leiden was not associated with the combined outcome of myocardial infarction and CHD death (hazard ratio, 1.03 [95% CI, 0.92-1.16];I-2=28%;P-heterogeneity=0.12). Subgroup analysis according to baseline characteristics or strata of traditional cardiovascular risk factors did not show relevant differences. Similarly, risk estimates for the secondary outcomes including stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality were also close to identity.Conclusions: Factor V Leiden was not associated with increased risk of subsequent atherothrombotic events and mortality in high-risk participants with established and treated CHD. Routine assessment of factor V Leiden status is unlikely to improve atherothrombotic events risk stratification in this population.
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| 3. |
- Surendran, Praveen, et al.
(author)
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Discovery of rare variants associated with blood pressure regulation through meta-analysis of 1.3 million individuals
- 2020
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In: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 52:12, s. 1314-1332
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Journal article (peer-reviewed)abstract
- Genetic studies of blood pressure (BP) to date have mainly analyzed common variants (minor allele frequency > 0.05). In a meta-analysis of up to similar to 1.3 million participants, we discovered 106 new BP-associated genomic regions and 87 rare (minor allele frequency <= 0.01) variant BP associations (P < 5 x 10(-8)), of which 32 were in new BP-associated loci and 55 were independent BP-associated single-nucleotide variants within known BP-associated regions. Average effects of rare variants (44% coding) were similar to 8 times larger than common variant effects and indicate potential candidate causal genes at new and known loci (for example, GATA5 and PLCB3). BP-associated variants (including rare and common) were enriched in regions of active chromatin in fetal tissues, potentially linking fetal development with BP regulation in later life. Multivariable Mendelian randomization suggested possible inverse effects of elevated systolic and diastolic BP on large artery stroke. Our study demonstrates the utility of rare-variant analyses for identifying candidate genes and the results highlight potential therapeutic targets.
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