Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 134
Filtrar
1.
Am J Clin Nutr ; 109(2): 276-287, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30721968

RESUMO

Background: Lean body mass (LM) plays an important role in mobility and metabolic function. We previously identified five loci associated with LM adjusted for fat mass in kilograms. Such an adjustment may reduce the power to identify genetic signals having an association with both lean mass and fat mass. Objectives: To determine the impact of different fat mass adjustments on genetic architecture of LM and identify additional LM loci. Methods: We performed genome-wide association analyses for whole-body LM (20 cohorts of European ancestry with n = 38,292) measured using dual-energy X-ray absorptiometry) or bioelectrical impedance analysis, adjusted for sex, age, age2, and height with or without fat mass adjustments (Model 1 no fat adjustment; Model 2 adjustment for fat mass as a percentage of body mass; Model 3 adjustment for fat mass in kilograms). Results: Seven single-nucleotide polymorphisms (SNPs) in separate loci, including one novel LM locus (TNRC6B), were successfully replicated in an additional 47,227 individuals from 29 cohorts. Based on the strengths of the associations in Model 1 vs Model 3, we divided the LM loci into those with an effect on both lean mass and fat mass in the same direction and refer to those as "sumo wrestler" loci (FTO and MC4R). In contrast, loci with an impact specifically on LM were termed "body builder" loci (VCAN and ADAMTSL3). Using existing available genome-wide association study databases, LM increasing alleles of SNPs in sumo wrestler loci were associated with an adverse metabolic profile, whereas LM increasing alleles of SNPs in "body builder" loci were associated with metabolic protection. Conclusions: In conclusion, we identified one novel LM locus (TNRC6B). Our results suggest that a genetically determined increase in lean mass might exert either harmful or protective effects on metabolic traits, depending on its relation to fat mass.


Assuntos
Tecido Adiposo/metabolismo , Composição Corporal/genética , Compartimentos de Líquidos Corporais/metabolismo , Músculo Esquelético/metabolismo , Fenótipo , Polimorfismo de Nucleotídeo Único , Proteínas ADAMTS/genética , Absorciometria de Fóton , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Impedância Elétrica , Grupo com Ancestrais do Continente Europeu/genética , Proteínas da Matriz Extracelular/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Ligação a RNA/genética , Receptor Tipo 4 de Melanocortina/genética , Versicanas/genética , Adulto Jovem
2.
Am J Hum Genet ; 104(2): 260-274, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30639324

RESUMO

With advances in whole-genome sequencing (WGS) technology, more advanced statistical methods for testing genetic association with rare variants are being developed. Methods in which variants are grouped for analysis are also known as variant-set, gene-based, and aggregate unit tests. The burden test and sequence kernel association test (SKAT) are two widely used variant-set tests, which were originally developed for samples of unrelated individuals and later have been extended to family data with known pedigree structures. However, computationally efficient and powerful variant-set tests are needed to make analyses tractable in large-scale WGS studies with complex study samples. In this paper, we propose the variant-set mixed model association tests (SMMAT) for continuous and binary traits using the generalized linear mixed model framework. These tests can be applied to large-scale WGS studies involving samples with population structure and relatedness, such as in the National Heart, Lung, and Blood Institute's Trans-Omics for Precision Medicine (TOPMed) program. SMMATs share the same null model for different variant sets, and a virtue of this null model, which includes covariates only, is that it needs to be fit only once for all tests in each genome-wide analysis. Simulation studies show that all the proposed SMMATs correctly control type I error rates for both continuous and binary traits in the presence of population structure and relatedness. We also illustrate our tests in a real data example of analysis of plasma fibrinogen levels in the TOPMed program (n = 23,763), using the Analysis Commons, a cloud-based computing platform.

3.
PLoS Genet ; 14(4): e1007222, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29608557

RESUMO

Human GWAS of obesity have been successful in identifying loci associated with adiposity, but for the most part, these are non-coding SNPs whose function, or even whose gene of action, is unknown. To help identify the genes on which these human BMI loci may be operating, we conducted a high throughput screen in Drosophila melanogaster. Starting with 78 BMI loci from two recently published GWAS meta-analyses, we identified fly orthologs of all nearby genes (± 250KB). We crossed RNAi knockdown lines of each gene with flies containing tissue-specific drivers to knock down (KD) the expression of the genes only in the brain and the fat body. We then raised the flies on a control diet and compared the amount of fat/triglyceride in the tissue-specific KD group compared to the driver-only control flies. 16 of the 78 BMI GWAS loci could not be screened with this approach, as no gene in the 500-kb region had a fly ortholog. Of the remaining 62 GWAS loci testable in the fly, we found a significant fat phenotype in the KD flies for at least one gene for 26 loci (42%) even after correcting for multiple comparisons. By contrast, the rate of significant fat phenotypes in RNAi KD found in a recent genome-wide Drosophila screen (Pospisilik et al. (2010) is ~5%. More interestingly, for 10 of the 26 positive regions, we found that the nearest gene was not the one that showed a significant phenotype in the fly. Specifically, our screen suggests that for the 10 human BMI SNPs rs11057405, rs205262, rs9925964, rs9914578, rs2287019, rs11688816, rs13107325, rs7164727, rs17724992, and rs299412, the functional genes may NOT be the nearest ones (CLIP1, C6orf106, KAT8, SMG6, QPCTL, EHBP1, SLC39A8, ADPGK /ADPGK-AS1, PGPEP1, KCTD15, respectively), but instead, the specific nearby cis genes are the functional target (namely: ZCCHC8, VPS33A, RSRC2; SPDEF, NUDT3; PAGR1; SETD1, VKORC1; SGSM2, SRR; VASP, SIX5; OTX1; BANK1; ARIH1; ELL; CHST8, respectively). The study also suggests further functional experiments to elucidate mechanism of action for genes evolutionarily conserved for fat storage.


Assuntos
Índice de Massa Corporal , Cruzamentos Genéticos , Drosophila melanogaster/genética , Estudo de Associação Genômica Ampla , Obesidade/genética , Interferência de RNA , Tecido Adiposo , Animais , Humanos , Camundongos , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas
4.
N Engl J Med ; 378(12): 1096-1106, 2018 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-29562163

RESUMO

BACKGROUND: Elucidation of the genetic factors underlying chronic liver disease may reveal new therapeutic targets. METHODS: We used exome sequence data and electronic health records from 46,544 participants in the DiscovEHR human genetics study to identify genetic variants associated with serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Variants that were replicated in three additional cohorts (12,527 persons) were evaluated for association with clinical diagnoses of chronic liver disease in DiscovEHR study participants and two independent cohorts (total of 37,173 persons) and with histopathological severity of liver disease in 2391 human liver samples. RESULTS: A splice variant (rs72613567:TA) in HSD17B13, encoding the hepatic lipid droplet protein hydroxysteroid 17-beta dehydrogenase 13, was associated with reduced levels of ALT (P=4.2×10-12) and AST (P=6.2×10-10). Among DiscovEHR study participants, this variant was associated with a reduced risk of alcoholic liver disease (by 42% [95% confidence interval {CI}, 20 to 58] among heterozygotes and by 53% [95% CI, 3 to 77] among homozygotes), nonalcoholic liver disease (by 17% [95% CI, 8 to 25] among heterozygotes and by 30% [95% CI, 13 to 43] among homozygotes), alcoholic cirrhosis (by 42% [95% CI, 14 to 61] among heterozygotes and by 73% [95% CI, 15 to 91] among homozygotes), and nonalcoholic cirrhosis (by 26% [95% CI, 7 to 40] among heterozygotes and by 49% [95% CI, 15 to 69] among homozygotes). Associations were confirmed in two independent cohorts. The rs72613567:TA variant was associated with a reduced risk of nonalcoholic steatohepatitis, but not steatosis, in human liver samples. The rs72613567:TA variant mitigated liver injury associated with the risk-increasing PNPLA3 p.I148M allele and resulted in an unstable and truncated protein with reduced enzymatic activity. CONCLUSIONS: A loss-of-function variant in HSD17B13 was associated with a reduced risk of chronic liver disease and of progression from steatosis to steatohepatitis. (Funded by Regeneron Pharmaceuticals and others.).


Assuntos
17-Hidroxiesteroide Desidrogenases/genética , Fígado Gorduroso/genética , Predisposição Genética para Doença , Hepatopatias/genética , Mutação com Perda de Função , 17-Hidroxiesteroide Desidrogenases/metabolismo , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Biomarcadores/sangue , Doença Crônica , Progressão da Doença , Feminino , Variação Genética , Genótipo , Humanos , Modelos Lineares , Fígado/patologia , Hepatopatias/patologia , Masculino , Análise de Sequência de RNA , Sequenciamento Completo do Exoma
6.
Nat Commun ; 8(1): 80, 2017 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-28724990

RESUMO

Lean body mass, consisting mostly of skeletal muscle, is important for healthy aging. We performed a genome-wide association study for whole body (20 cohorts of European ancestry with n = 38,292) and appendicular (arms and legs) lean body mass (n = 28,330) measured using dual energy X-ray absorptiometry or bioelectrical impedance analysis, adjusted for sex, age, height, and fat mass. Twenty-one single-nucleotide polymorphisms were significantly associated with lean body mass either genome wide (p < 5 × 10-8) or suggestively genome wide (p < 2.3 × 10-6). Replication in 63,475 (47,227 of European ancestry) individuals from 33 cohorts for whole body lean body mass and in 45,090 (42,360 of European ancestry) subjects from 25 cohorts for appendicular lean body mass was successful for five single-nucleotide polymorphisms in/near HSD17B11, VCAN, ADAMTSL3, IRS1, and FTO for total lean body mass and for three single-nucleotide polymorphisms in/near VCAN, ADAMTSL3, and IRS1 for appendicular lean body mass. Our findings provide new insight into the genetics of lean body mass.Lean body mass is a highly heritable trait and is associated with various health conditions. Here, Kiel and colleagues perform a meta-analysis of genome-wide association studies for whole body lean body mass and find five novel genetic loci to be significantly associated.


Assuntos
Estudo de Associação Genômica Ampla , Magreza/genética , 17-Hidroxiesteroide Desidrogenases/genética , Proteínas ADAMTS/genética , Aldeído Oxirredutases/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Composição Corporal , Proteínas da Matriz Extracelular/genética , Humanos , Proteínas Substratos do Receptor de Insulina/genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Elementos Reguladores de Transcrição , Versicanas/genética
7.
Circ Res ; 121(1): 81-88, 2017 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-28506971

RESUMO

RATIONALE: Therapies that inhibit CETP (cholesteryl ester transfer protein) have failed to demonstrate a reduction in risk for coronary heart disease (CHD). Human DNA sequence variants that truncate the CETP gene may provide insight into the efficacy of CETP inhibition. OBJECTIVE: To test whether protein-truncating variants (PTVs) at the CETP gene were associated with plasma lipid levels and CHD. METHODS AND RESULTS: We sequenced the exons of the CETP gene in 58 469 participants from 12 case-control studies (18 817 CHD cases, 39 652 CHD-free controls). We defined PTV as those that lead to a premature stop, disrupt canonical splice sites, or lead to insertions/deletions that shift frame. We also genotyped 1 Japanese-specific PTV in 27561 participants from 3 case-control studies (14 286 CHD cases, 13 275 CHD-free controls). We tested association of CETP PTV carrier status with both plasma lipids and CHD. Among 58 469 participants with CETP gene-sequencing data available, average age was 51.5 years and 43% were women; 1 in 975 participants carried a PTV at the CETP gene. Compared with noncarriers, carriers of PTV at CETP had higher high-density lipoprotein cholesterol (effect size, 22.6 mg/dL; 95% confidence interval, 18-27; P<1.0×10-4), lower low-density lipoprotein cholesterol (-12.2 mg/dL; 95% confidence interval, -23 to -0.98; P=0.033), and lower triglycerides (-6.3%; 95% confidence interval, -12 to -0.22; P=0.043). CETP PTV carrier status was associated with reduced risk for CHD (summary odds ratio, 0.70; 95% confidence interval, 0.54-0.90; P=5.1×10-3). CONCLUSIONS: Compared with noncarriers, carriers of PTV at CETP displayed higher high-density lipoprotein cholesterol, lower low-density lipoprotein cholesterol, lower triglycerides, and lower risk for CHD.


Assuntos
Proteínas de Transferência de Ésteres de Colesterol/genética , Doença das Coronárias/diagnóstico , Doença das Coronárias/genética , Variação Genética/genética , Adulto , Idoso , Estudos de Casos e Controles , Proteínas de Transferência de Ésteres de Colesterol/sangue , Doença das Coronárias/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
8.
JAMA ; 317(9): 937-946, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28267856

RESUMO

Importance: The activity of lipoprotein lipase (LPL) is the rate-determining step in clearing triglyceride-rich lipoproteins from the circulation. Mutations that damage the LPL gene (LPL) lead to lifelong deficiency in enzymatic activity and can provide insight into the relationship of LPL to human disease. Objective: To determine whether rare and/or common variants in LPL are associated with early-onset coronary artery disease (CAD). Design, Setting, and Participants: In a cross-sectional study, LPL was sequenced in 10 CAD case-control cohorts of the multinational Myocardial Infarction Genetics Consortium and a nested CAD case-control cohort of the Geisinger Health System DiscovEHR cohort between 2010 and 2015. Common variants were genotyped in up to 305 699 individuals of the Global Lipids Genetics Consortium and up to 120 600 individuals of the CARDIoGRAM Exome Consortium between 2012 and 2014. Study-specific estimates were pooled via meta-analysis. Exposures: Rare damaging mutations in LPL included loss-of-function variants and missense variants annotated as pathogenic in a human genetics database or predicted to be damaging by computer prediction algorithms trained to identify mutations that impair protein function. Common variants in the LPL gene region included those independently associated with circulating triglyceride levels. Main Outcomes and Measures: Circulating lipid levels and CAD. Results: Among 46 891 individuals with LPL gene sequencing data available, the mean (SD) age was 50 (12.6) years and 51% were female. A total of 188 participants (0.40%; 95% CI, 0.35%-0.46%) carried a damaging mutation in LPL, including 105 of 32 646 control participants (0.32%) and 83 of 14 245 participants with early-onset CAD (0.58%). Compared with 46 703 noncarriers, the 188 heterozygous carriers of an LPL damaging mutation displayed higher plasma triglyceride levels (19.6 mg/dL; 95% CI, 4.6-34.6 mg/dL) and higher odds of CAD (odds ratio = 1.84; 95% CI, 1.35-2.51; P < .001). An analysis of 6 common LPL variants resulted in an odds ratio for CAD of 1.51 (95% CI, 1.39-1.64; P = 1.1 × 10-22) per 1-SD increase in triglycerides. Conclusions and Relevance: The presence of rare damaging mutations in LPL was significantly associated with higher triglyceride levels and presence of coronary artery disease. However, further research is needed to assess whether there are causal mechanisms by which heterozygous lipoprotein lipase deficiency could lead to coronary artery disease.


Assuntos
Doença da Artéria Coronariana/genética , Lipase Lipoproteica/genética , Mutação , Adulto , Idade de Início , Estudos de Casos e Controles , Estudos Transversais , Feminino , Genótipo , Heterozigoto , Humanos , Lipoproteínas/sangue , Masculino , Pessoa de Meia-Idade , Razão de Chances , Triglicerídeos/sangue
9.
Nat Genet ; 49(1): 125-130, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27918534

RESUMO

Variation in body fat distribution contributes to the metabolic sequelae of obesity. The genetic determinants of body fat distribution are poorly understood. The goal of this study was to gain new insights into the underlying genetics of body fat distribution by conducting sample-size-weighted fixed-effects genome-wide association meta-analyses in up to 9,594 women and 8,738 men of European, African, Hispanic and Chinese ancestry, with and without sex stratification, for six traits associated with ectopic fat (hereinafter referred to as ectopic-fat traits). In total, we identified seven new loci associated with ectopic-fat traits (ATXN1, UBE2E2, EBF1, RREB1, GSDMB, GRAMD3 and ENSA; P < 5 × 10-8; false discovery rate < 1%). Functional analysis of these genes showed that loss of function of either Atxn1 or Ube2e2 in primary mouse adipose progenitor cells impaired adipocyte differentiation, suggesting physiological roles for ATXN1 and UBE2E2 in adipogenesis. Future studies are necessary to further explore the mechanisms by which these genes affect adipocyte biology and how their perturbations contribute to systemic metabolic disease.


Assuntos
Adipócitos/citologia , Distribuição da Gordura Corporal , Diferenciação Celular , Loci Gênicos/genética , Marcadores Genéticos/genética , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único/genética , Adipócitos/metabolismo , Animais , Estudos de Coortes , Grupos Étnicos/genética , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/genética , Fenótipo
10.
Science ; 354(6319)2016 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-28008010

RESUMO

Familial hypercholesterolemia (FH) remains underdiagnosed despite widespread cholesterol screening. Exome sequencing and electronic health record (EHR) data of 50,726 individuals were used to assess the prevalence and clinical impact of FH-associated genomic variants in the Geisinger Health System. The estimated FH prevalence was 1:256 in unselected participants and 1:118 in participants ascertained via the cardiac catheterization laboratory. FH variant carriers had significantly increased risk of coronary artery disease. Only 24% of carriers met EHR-based presequencing criteria for probable or definite FH diagnosis. Active statin use was identified in 58% of carriers; 46% of statin-treated carriers had a low-density lipoprotein cholesterol level below 100 mg/dl. Thus, we find that genomic screening can prompt the diagnosis of FH patients, most of whom are receiving inadequate lipid-lowering therapy.


Assuntos
Corantes/uso terapêutico , Uso de Medicamentos/estatística & dados numéricos , Testes Genéticos , Hiperlipoproteinemia Tipo II/epidemiologia , Hiperlipoproteinemia Tipo II/genética , Doença da Artéria Coronariana/epidemiologia , Assistência à Saúde , Registros Eletrônicos de Saúde , Exoma/genética , Heterozigoto , Humanos , Hiperlipoproteinemia Tipo II/diagnóstico , Lipoproteínas LDL/sangue , Prevalência , Estados Unidos/epidemiologia
11.
Science ; 354(6319)2016 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-28008009

RESUMO

The DiscovEHR collaboration between the Regeneron Genetics Center and Geisinger Health System couples high-throughput sequencing to an integrated health care system using longitudinal electronic health records (EHRs). We sequenced the exomes of 50,726 adult participants in the DiscovEHR study to identify ~4.2 million rare single-nucleotide variants and insertion/deletion events, of which ~176,000 are predicted to result in a loss of gene function. Linking these data to EHR-derived clinical phenotypes, we find clinical associations supporting therapeutic targets, including genes encoding drug targets for lipid lowering, and identify previously unidentified rare alleles associated with lipid levels and other blood level traits. About 3.5% of individuals harbor deleterious variants in 76 clinically actionable genes. The DiscovEHR data set provides a blueprint for large-scale precision medicine initiatives and genomics-guided therapeutic discovery.


Assuntos
Prestação Integrada de Cuidados de Saúde , Doença/genética , Registros Eletrônicos de Saúde , Exoma/genética , Sequenciamento de Nucleotídeos em Larga Escala , Adulto , Desenho de Drogas , Frequência do Gene , Genômica , Humanos , Hipolipemiantes/farmacologia , Mutação INDEL , Lipídeos/sangue , Terapia de Alvo Molecular , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA
12.
Circ Cardiovasc Genet ; 9(6): 511-520, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27872105

RESUMO

BACKGROUND: The burden of subclinical atherosclerosis in asymptomatic individuals is heritable and associated with elevated risk of developing clinical coronary heart disease. We sought to identify genetic variants in protein-coding regions associated with subclinical atherosclerosis and the risk of subsequent coronary heart disease. METHODS AND RESULTS: We studied a total of 25 109 European ancestry and African ancestry participants with coronary artery calcification (CAC) measured by cardiac computed tomography and 52 869 participants with common carotid intima-media thickness measured by ultrasonography within the CHARGE Consortium (Cohorts for Heart and Aging Research in Genomic Epidemiology). Participants were genotyped for 247 870 DNA sequence variants (231 539 in exons) across the genome. A meta-analysis of exome-wide association studies was performed across cohorts for CAC and carotid intima-media thickness. APOB p.Arg3527Gln was associated with 4-fold excess CAC (P=3×10-10). The APOE ε2 allele (p.Arg176Cys) was associated with both 22.3% reduced CAC (P=1×10-12) and 1.4% reduced carotid intima-media thickness (P=4×10-14) in carriers compared with noncarriers. In secondary analyses conditioning on low-density lipoprotein cholesterol concentration, the ε2 protective association with CAC, although attenuated, remained strongly significant. Additionally, the presence of ε2 was associated with reduced risk for coronary heart disease (odds ratio 0.77; P=1×10-11). CONCLUSIONS: Exome-wide association meta-analysis demonstrates that protein-coding variants in APOB and APOE associate with subclinical atherosclerosis. APOE ε2 represents the first significant association for multiple subclinical atherosclerosis traits across multiple ethnicities, as well as clinical coronary heart disease.


Assuntos
Grupo com Ancestrais do Continente Africano/genética , Doenças das Artérias Carótidas/etnologia , Doenças das Artérias Carótidas/genética , Doença da Artéria Coronariana/etnologia , Doença da Artéria Coronariana/genética , Grupo com Ancestrais do Continente Europeu/genética , Exoma , Apolipoproteína B-100/genética , Apolipoproteína E2/genética , Doenças Assintomáticas , Doenças das Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , LDL-Colesterol/sangue , Angiografia por Tomografia Computadorizada , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Frequência do Gene , Marcadores Genéticos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Razão de Chances , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , Prognóstico , Medição de Risco , Fatores de Risco , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/etnologia , Calcificação Vascular/genética
13.
J Lipid Res ; 57(12): 2176-2184, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27729386

RESUMO

Cluster of differentiation 36 (CD36) variants influence fasting lipids and risk of metabolic syndrome, but their impact on postprandial lipids, an independent risk factor for cardiovascular disease, is unclear. We determined the effects of SNPs within a ∼410 kb region encompassing CD36 and its proximal and distal promoters on chylomicron (CM) remnants and LDL particles at fasting and at 3.5 and 6 h following a high-fat meal (Genetics of Lipid Lowering Drugs and Diet Network study, n = 1,117). Five promoter variants associated with CMs, four with delayed TG clearance and five with LDL particle number. To assess mechanisms underlying the associations, we queried expression quantitative trait loci, DNA methylation, and ChIP-seq datasets for adipose and heart tissues that function in postprandial lipid clearance. Several SNPs that associated with higher serum lipids correlated with lower adipose and heart CD36 mRNA and aligned to active motifs for PPARγ, a major CD36 regulator. The SNPs also associated with DNA methylation sites that related to reduced CD36 mRNA and higher serum lipids, but mixed-model analyses indicated that the SNPs and methylation independently influence CD36 mRNA. The findings support contributions of CD36 SNPs that reduce adipose and heart CD36 RNA expression to inter-individual variability of postprandial lipid metabolism and document changes in CD36 DNA methylation that influence both CD36 expression and lipids.


Assuntos
Antígenos CD36/genética , Remanescentes de Quilomícrons/sangue , Lipoproteínas LDL/sangue , Adulto , Ilhas de CpG , Metilação de DNA , Feminino , Expressão Gênica , Frequência do Gene , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/metabolismo , Especificidade de Órgãos , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Triglicerídeos/sangue
14.
PLoS One ; 11(10): e0165488, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27792787

RESUMO

DNA methylation at CpG sites is both heritable and influenced by environment, but the relative contributions of each to DNA methylation levels are unclear. We conducted a heritability analysis of CpG methylation in human CD4+ cells across 975 individuals from 163 families in the Genetics of Lipid-lowering Drugs and Diet Network (GOLDN). Based on a broad-sense heritability (H2) value threshold of 0.4, we identified 20,575 highly heritable CpGs among the 174,445 most variable autosomal CpGs (SD > 0.02). Tests for associations of heritable CpGs with genotype at 2,145,360 SNPs using 717 of 975 individuals showed that ~74% were cis-meQTLs (< 1 Mb away from the CpG), 6% of CpGs exhibited trans-meQTL associations (>1 Mb away from the CpG or located on a different chromosome), and 20% of CpGs showed no strong significant associations with genotype (based on a p-value threshold of 1e-7). Genes proximal to the genotype independent heritable CpGs were enriched for functional terms related to regulation of T cell activation. These CpGs were also among those that distinguished T cells from other blood cell lineages. Compared to genes proximal to meQTL-associated heritable CpGs, genotype independent heritable CpGs were moderately enriched in the same genomic regions that escape erasure during primordial germ cell development and could carry potential for generational transmission.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Metilação de DNA , Linhagem , Ilhas de CpG/genética , Feminino , Humanos , Masculino , Anotação de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas/genética
15.
Cancer Epidemiol Biomarkers Prev ; 25(11): 1456-1463, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27486019

RESUMO

BACKGROUND: Common variants have been associated with prostate cancer risk. Unfortunately, few are reproducibly linked to aggressive disease, the phenotype of greatest clinical relevance. One possible explanation is that rare genetic variants underlie a significant proportion of the risk for aggressive disease. METHOD: To identify such variants, we performed a two-stage approach using whole-exome sequencing followed by targeted sequencing of 800 genes in 652 aggressive prostate cancer patients and 752 disease-free controls in both African and European Americans. In each population, we tested rare variants for association using two gene-based aggregation tests. We established a study-wide significance threshold of 3.125 × 10-5 to correct for multiple testing. RESULTS: TET2 in African Americans was associated with aggressive disease, with 24.4% of cases harboring a rare deleterious variant compared with 9.6% of controls (FET P = 1.84 × 10-5, OR = 3.0; SKAT-O P = 2.74 × 10-5). We report 8 additional genes with suggestive evidence of association, including the DNA repair genes PARP2 and MSH6 Finally, we observed an excess of rare truncation variants in 5 genes, including the DNA repair genes MSH6, BRCA1, and BRCA2 This adds to the growing body of evidence that DNA repair pathway defects may influence susceptibility to aggressive prostate cancer. CONCLUSIONS: Our findings suggest that rare variants influence risk of clinically relevant prostate cancer and, if validated, could serve to identify men for screening, prophylaxis, and treatment. IMPACT: This study provides evidence that rare variants in TET2 may help identify African American men at increased risk for clinically relevant prostate cancer. Cancer Epidemiol Biomarkers Prev; 25(11); 1456-63. ©2016 AACR.


Assuntos
Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença , Polimorfismo Genético , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas/genética , Afro-Americanos/genética , Idoso , Proteína BRCA1/genética , Proteína BRCA2/genética , Análise Mutacional de DNA , Reparo do DNA , Grupo com Ancestrais do Continente Europeu/genética , Humanos , Masculino , Poli(ADP-Ribose) Polimerases/genética , Neoplasias da Próstata/genética
16.
Sci Transl Med ; 8(341): 341ra76, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27252175

RESUMO

Regulatory authorities have indicated that new drugs to treat type 2 diabetes (T2D) should not be associated with an unacceptable increase in cardiovascular risk. Human genetics may be able to guide development of antidiabetic therapies by predicting cardiovascular and other health endpoints. We therefore investigated the association of variants in six genes that encode drug targets for obesity or T2D with a range of metabolic traits in up to 11,806 individuals by targeted exome sequencing and follow-up in 39,979 individuals by targeted genotyping, with additional in silico follow-up in consortia. We used these data to first compare associations of variants in genes encoding drug targets with the effects of pharmacological manipulation of those targets in clinical trials. We then tested the association of those variants with disease outcomes, including coronary heart disease, to predict cardiovascular safety of these agents. A low-frequency missense variant (Ala316Thr; rs10305492) in the gene encoding glucagon-like peptide-1 receptor (GLP1R), the target of GLP1R agonists, was associated with lower fasting glucose and T2D risk, consistent with GLP1R agonist therapies. The minor allele was also associated with protection against heart disease, thus providing evidence that GLP1R agonists are not likely to be associated with an unacceptable increase in cardiovascular risk. Our results provide an encouraging signal that these agents may be associated with benefit, a question currently being addressed in randomized controlled trials. Genetic variants associated with metabolic traits and multiple disease outcomes can be used to validate therapeutic targets at an early stage in the drug development process.


Assuntos
Doença das Coronárias/genética , Receptor do Peptídeo Semelhante ao Glucagon 1/genética , Alelos , Diabetes Mellitus Tipo 2/genética , Dipeptidil Peptidase 4/genética , Genótipo , Humanos , Obesidade/genética , Receptor CB2 de Canabinoide/genética , Receptor 5-HT2C de Serotonina/genética , Receptores de Somatostatina/genética , Transportador 1 de Glucose-Sódio/genética
17.
J Am Geriatr Soc ; 64(8): 1679-83, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27294813

RESUMO

OBJECTIVES: To investigate the association between mortality and heritability of a rescaled Fried frailty index, the Scale of Aging Vigor in Epidemiology (SAVE), to determine its value for genetic analyses. DESIGN: Longitudinal, community-based cohort study. SETTING: The Long Life Family Study (LLFS) in the United States and Denmark. PARTICIPANTS: Long-lived individuals (N = 4,875, including 4,075 genetically related individuals) and their families (N = 551). MEASUREMENTS: The SAVE was administered to 3,599 participants and included weight change, weakness (grip strength), fatigue (questionnaire), physical activity (days walked in prior 2 weeks), and slowness (gait speed); each component was scored 0, 1, or 2 using approximate tertiles, and summed (range 0 (vigorous) to 10 (frail)). Heritability was determined using a variance component-based family analysis using a polygenic model. Association with mortality in the proband generation (N = 1,421) was calculated using Cox proportional hazards mixed-effect models. RESULTS: Heritability of the SAVE was 0.23 (P < .001) overall (n = 3,599), 0.31 (P < .001) in probands (n = 1,479), and 0.26 (P < .001) in offspring (n = 2,120). In adjusted models, higher SAVE scores were associated with higher mortality (score 5-6: hazard ratio (HR) = 2.83, 95% confidence interval (CI) = 1.46-5.51; score 7-10: HR = 3.40, 95% CI = 1.72-6.71) than lower scores (0-2). CONCLUSION: The SAVE was associated with mortality and was moderately heritable in the LLFS, suggesting a genetic component to age-related vigor and frailty and supporting its use for further genetic analyses.


Assuntos
Idoso Fragilizado/estatística & dados numéricos , Genótipo , Longevidade/genética , Idoso de 80 Anos ou mais , Peso Corporal/genética , Estudos de Coortes , Comparação Transcultural , Dinamarca , Avaliação da Deficiência , Exercício , Feminino , Marcha/genética , Força da Mão , Nível de Saúde , Humanos , Estudos Longitudinais , Masculino , Herança Multifatorial/genética , Aptidão Física , Estatística como Assunto , Estados Unidos
18.
N Engl J Med ; 374(12): 1123-33, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-26933753

RESUMO

BACKGROUND: Higher-than-normal levels of circulating triglycerides are a risk factor for ischemic cardiovascular disease. Activation of lipoprotein lipase, an enzyme that is inhibited by angiopoietin-like 4 (ANGPTL4), has been shown to reduce levels of circulating triglycerides. METHODS: We sequenced the exons of ANGPTL4 in samples obtain from 42,930 participants of predominantly European ancestry in the DiscovEHR human genetics study. We performed tests of association between lipid levels and the missense E40K variant (which has been associated with reduced plasma triglyceride levels) and other inactivating mutations. We then tested for associations between coronary artery disease and the E40K variant and other inactivating mutations in 10,552 participants with coronary artery disease and 29,223 controls. We also tested the effect of a human monoclonal antibody against ANGPTL4 on lipid levels in mice and monkeys. RESULTS: We identified 1661 heterozygotes and 17 homozygotes for the E40K variant and 75 participants who had 13 other monoallelic inactivating mutations in ANGPTL4. The levels of triglycerides were 13% lower and the levels of high-density lipoprotein (HDL) cholesterol were 7% higher among carriers of the E40K variant than among noncarriers. Carriers of the E40K variant were also significantly less likely than noncarriers to have coronary artery disease (odds ratio, 0.81; 95% confidence interval, 0.70 to 0.92; P=0.002). K40 homozygotes had markedly lower levels of triglycerides and higher levels of HDL cholesterol than did heterozygotes. Carriers of other inactivating mutations also had lower triglyceride levels and higher HDL cholesterol levels and were less likely to have coronary artery disease than were noncarriers. Monoclonal antibody inhibition of Angptl4 in mice and monkeys reduced triglyceride levels. CONCLUSIONS: Carriers of E40K and other inactivating mutations in ANGPTL4 had lower levels of triglycerides and a lower risk of coronary artery disease than did noncarriers. The inhibition of Angptl4 in mice and monkeys also resulted in corresponding reductions in these values. (Funded by Regeneron Pharmaceuticals.).


Assuntos
Angiopoietinas/genética , Doença da Artéria Coronariana/genética , Inativação Gênica , Mutação , Idoso , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas/antagonistas & inibidores , Animais , Colesterol/sangue , Modelos Animais de Doenças , Feminino , Heterozigoto , Humanos , Macaca mulatta , Masculino , Camundongos , Pessoa de Meia-Idade , Fatores de Risco , Triglicerídeos/sangue
19.
Genet Epidemiol ; 40(3): 244-52, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27027517

RESUMO

For complex traits, most associated single nucleotide variants (SNV) discovered to date have a small effect, and detection of association is only possible with large sample sizes. Because of patient confidentiality concerns, it is often not possible to pool genetic data from multiple cohorts, and meta-analysis has emerged as the method of choice to combine results from multiple studies. Many meta-analysis methods are available for single SNV analyses. As new approaches allow the capture of low frequency and rare genetic variation, it is of interest to jointly consider multiple variants to improve power. However, for the analysis of haplotypes formed by multiple SNVs, meta-analysis remains a challenge, because different haplotypes may be observed across studies. We propose a two-stage meta-analysis approach to combine haplotype analysis results. In the first stage, each cohort estimate haplotype effect sizes in a regression framework, accounting for relatedness among observations if appropriate. For the second stage, we use a multivariate generalized least square meta-analysis approach to combine haplotype effect estimates from multiple cohorts. Haplotype-specific association tests and a global test of independence between haplotypes and traits are obtained within our framework. We demonstrate through simulation studies that we control the type-I error rate, and our approach is more powerful than inverse variance weighted meta-analysis of single SNV analysis when haplotype effects are present. We replicate a published haplotype association between fasting glucose-associated locus (G6PC2) and fasting glucose in seven studies from the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium and we provide more precise haplotype effect estimates.


Assuntos
Estudos de Associação Genética , Haplótipos/genética , Metanálise como Assunto , Envelhecimento , Estudos de Coortes , Jejum/metabolismo , Feminino , Variação Genética/genética , Glucose/metabolismo , Glucose-6-Fosfatase/genética , Coração , Humanos , Análise dos Mínimos Quadrados , Masculino , Modelos Genéticos , Epidemiologia Molecular , Análise Multivariada , Proteínas de Neoplasias/genética , Fenótipo , Reprodutibilidade dos Testes , Projetos de Pesquisa
20.
Pharmacogenet Genomics ; 26(7): 324-33, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27002377

RESUMO

BACKGROUND: Fibrates are commonly prescribed for hypertriglyceridemia, but they also lower LDL cholesterol and increase HDL cholesterol. Large interindividual variations in lipid response suggest that some patients may benefit more than others and genetic studies could help identify such patients. METHODS: We carried out the first genome-wide association study of lipid response to fenofibrate using data from two well-characterized clinical trials: the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) Study and the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Study. Genome-wide association study data from both studies were imputed to the 1000 Genomes CEU reference panel (phase 1). Lipid response was modeled as the log ratio of the post-treatment lipid level to the pretreatment level. Linear mixed models (GOLDN, N=813 from 173 families) and linear regression models (ACCORD, N=781) adjusted for pretreatment lipid level, demographic variables, clinical covariates, and ancestry were used to evaluate the association of genetic markers with lipid response. Among Caucasians, the results were combined using inverse-variance weighted fixed-effects meta-analyses. The main findings from the meta-analyses were examined in other ethnic groups from the HyperTG study (N=267 Hispanics) and ACCORD (N=83 Hispanics, 138 African Americans). RESULTS: A known lipid locus harboring the pre-B-cell leukemia homeobox 4 (PBX4) gene on chromosome 19 is important for LDL cholesterol response to fenofibrate (smallest P=1.5×10). The main results replicated with nominal statistical significance in Hispanics from ACCORD (P<0.05). CONCLUSION: Future research should evaluate the usefulness of this locus to refine clinical strategies for lipid-lowering treatments.


Assuntos
Fenofibrato/uso terapêutico , Estudo de Associação Genômica Ampla , Hipertrigliceridemia/tratamento farmacológico , Hipertrigliceridemia/genética , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Lipídeos/sangue , Ensaios Clínicos como Assunto , Grupo com Ancestrais do Continente Europeu , Feminino , Marcadores Genéticos , Genótipo , Humanos , Hipolipemiantes/uso terapêutico , Masculino , Metanálise como Assunto , Pessoa de Meia-Idade , Avaliação de Resultados (Cuidados de Saúde)
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA