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1.
Sci Rep ; 9(1): 1193, 2019 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-30718923

RESUMO

Short sleep duration or insomnia may lead to an increased risk of various psychiatric and cardio-metabolic conditions. Since DNA methylation plays a critical role in the regulation of gene expression, studies of differentially methylated positions (DMPs) might be valuable for understanding the mechanisms underlying insomnia. We performed a cross-sectional genome-wide analysis of DNA methylation in relation to self-reported insufficient sleep in individuals from a community-based sample (79 men, aged 39.3 ± 7.3), and in relation to shift work disorder in an occupational cohort (26 men, aged 44.9 ± 9.0). The analysis of DNA methylation data revealed that genes corresponding to selected DMPs form a distinctive pathway: "Nervous System Development" (FDR P value < 0.05). We found that 78% of the DMPs were hypomethylated in cases in both cohorts, suggesting that insufficient sleep may be associated with loss of DNA methylation. A karyoplot revealed clusters of DMPs at various chromosomal regions, including 12 DMPs on chromosome 17, previously associated with Smith-Magenis syndrome, a rare condition comprising disturbed sleep and inverse circadian rhythm. Our findings give novel insights into the DNA methylation patterns associated with sleep loss, possibly modifying processes related to neuroplasticity and neurodegeneration. Future prospective studies are needed to confirm the observed associations.

2.
Biomark Med ; 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-30191727

RESUMO

AIM: The aim of the study was to explore the effects of variants at 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and kinesin family member 6 (KIF6) loci on a range of cardio-metabolic phenotypes. METHODS: We analyzed the range of variants within Genetics in Brisighella Health Study and KIF6 genes using an additive genetic model on 18 cardiometabolic phenotypes in a sample of 1645 individuals from the Genetics in Brisighella Health Study and replicated in 10,662 individuals from the Estonian Genome Center University of Tartu. RESULTS: We defined directly the effects of rs3846662:C>A at HMGCR on apoB levels. The analysis also confirmed effects of on low-density lipoprotein-cholesterol and total cholesterol levels. Variants in KIF6 gene did not reveal any associations with cardiometabolic phenotypes. CONCLUSION: This study highlights effect of HMGCR locus on assay-determined apoB levels, an infrequent measure of blood lipids in large studies.

3.
Mol Psychiatry ; 2018 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-29988085

RESUMO

Macronutrient intake, the proportion of calories consumed from carbohydrate, fat, and protein, is an important risk factor for metabolic diseases with significant familial aggregation. Previous studies have identified two genetic loci for macronutrient intake, but incomplete coverage of genetic variation and modest sample sizes have hindered the discovery of additional loci. Here, we expanded the genetic landscape of macronutrient intake, identifying 12 suggestively significant loci (P < 1 × 10-6) associated with intake of any macronutrient in 91,114 European ancestry participants. Four loci replicated and reached genome-wide significance in a combined meta-analysis including 123,659 European descent participants, unraveling two novel loci; a common variant in RARB locus for carbohydrate intake and a rare variant in DRAM1 locus for protein intake, and corroborating earlier FGF21 and FTO findings. In additional analysis of 144,770 participants from the UK Biobank, all identified associations from the two-stage analysis were confirmed except for DRAM1. Identified loci might have implications in brain and adipose tissue biology and have clinical impact in obesity-related phenotypes. Our findings provide new insight into biological functions related to macronutrient intake.

4.
Eur J Hum Genet ; 25(11): 1179-1180, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29023438
5.
Diabetes ; 66(11): 2888-2902, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28566273

RESUMO

To characterize type 2 diabetes (T2D)-associated variation across the allele frequency spectrum, we conducted a meta-analysis of genome-wide association data from 26,676 T2D case and 132,532 control subjects of European ancestry after imputation using the 1000 Genomes multiethnic reference panel. Promising association signals were followed up in additional data sets (of 14,545 or 7,397 T2D case and 38,994 or 71,604 control subjects). We identified 13 novel T2D-associated loci (P < 5 × 10-8), including variants near the GLP2R, GIP, and HLA-DQA1 genes. Our analysis brought the total number of independent T2D associations to 128 distinct signals at 113 loci. Despite substantially increased sample size and more complete coverage of low-frequency variation, all novel associations were driven by common single nucleotide variants. Credible sets of potentially causal variants were generally larger than those based on imputation with earlier reference panels, consistent with resolution of causal signals to common risk haplotypes. Stratification of T2D-associated loci based on T2D-related quantitative trait associations revealed tissue-specific enrichment of regulatory annotations in pancreatic islet enhancers for loci influencing insulin secretion and in adipocytes, monocytes, and hepatocytes for insulin action-associated loci. These findings highlight the predominant role played by common variants of modest effect and the diversity of biological mechanisms influencing T2D pathophysiology.


Assuntos
Diabetes Mellitus Tipo 2/genética , Grupo com Ancestrais do Continente Europeu , Regulação da Expressão Gênica/fisiologia , Estudo de Associação Genômica Ampla , Variação Genética , Humanos
6.
Nature ; 533(7604): 539-42, 2016 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-27225129

RESUMO

Educational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals. Here we report the results of a genome-wide association study (GWAS) for educational attainment that extends our earlier discovery sample of 101,069 individuals to 293,723 individuals, and a replication study in an independent sample of 111,349 individuals from the UK Biobank. We identify 74 genome-wide significant loci associated with the number of years of schooling completed. Single-nucleotide polymorphisms associated with educational attainment are disproportionately found in genomic regions regulating gene expression in the fetal brain. Candidate genes are preferentially expressed in neural tissue, especially during the prenatal period, and enriched for biological pathways involved in neural development. Our findings demonstrate that, even for a behavioural phenotype that is mostly environmentally determined, a well-powered GWAS identifies replicable associated genetic variants that suggest biologically relevant pathways. Because educational attainment is measured in large numbers of individuals, it will continue to be useful as a proxy phenotype in efforts to characterize the genetic influences of related phenotypes, including cognition and neuropsychiatric diseases.


Assuntos
Encéfalo/metabolismo , Escolaridade , Feto/metabolismo , Regulação da Expressão Gênica/genética , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único/genética , Doença de Alzheimer/genética , Transtorno Bipolar/genética , Cognição , Biologia Computacional , Interação Gene-Ambiente , Humanos , Anotação de Sequência Molecular , Esquizofrenia/genética , Reino Unido
7.
Epigenomics ; 8(6): 789-99, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27004446

RESUMO

Genomic imprinting is an epigenetic feature characterized by parent-specific monoallelic gene expression. The aim of this study was to compare the DNA methylation status of imprinted genes and imprinting control regions (ICRs), harboring differentially methylated regions (DMRs) in a comprehensive panel of 18 somatic tissues. The germline DMRs analyzed were divided into ubiquitously imprinted and placenta-specific DMRs, which show identical and different methylation imprints in adult somatic and placental tissues, respectively. We showed that imprinted genes and ICR DMRs maintain methylation patterns characterized by intermediate methylation levels in somatic tissues, which are pronounced in a specific region of the promoter area, located 200-1500 bp from the transcription start site. This intermediate methylation is concordant with gene expression from a single unmethylated allele and silencing of a reciprocal parental allele through DNA methylation. The only exceptions were seen for ICR DMRs of placenta-specific imprinted genes, which showed low levels of methylation, suggesting that these genes escape parent-specific epigenetic regulation in somatic tissues.


Assuntos
Metilação de DNA , Impressão Genômica , Adulto , Ilhas de CpG , Feminino , Expressão Gênica , Células Germinativas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Especificidade de Órgãos , Placenta/metabolismo , Gravidez , Regiões Promotoras Genéticas
8.
Nat Genet ; 47(11): 1294-1303, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26414677

RESUMO

Menopause timing has a substantial impact on infertility and risk of disease, including breast cancer, but the underlying mechanisms are poorly understood. We report a dual strategy in ∼70,000 women to identify common and low-frequency protein-coding variation associated with age at natural menopause (ANM). We identified 44 regions with common variants, including two regions harboring additional rare missense alleles of large effect. We found enrichment of signals in or near genes involved in delayed puberty, highlighting the first molecular links between the onset and end of reproductive lifespan. Pathway analyses identified major association with DNA damage response (DDR) genes, including the first common coding variant in BRCA1 associated with any complex trait. Mendelian randomization analyses supported a causal effect of later ANM on breast cancer risk (∼6% increase in risk per year; P = 3 × 10(-14)), likely mediated by prolonged sex hormone exposure rather than DDR mechanisms.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Reparo do DNA , Predisposição Genética para Doença/genética , Hipotálamo/metabolismo , Transdução de Sinais/genética , Adulto , Fatores Etários , Envelhecimento/genética , Feminino , Redes Reguladoras de Genes/genética , Variação Genética , Estudo de Associação Genômica Ampla/métodos , Genômica/métodos , Genótipo , Humanos , Menopausa/genética , Pessoa de Meia-Idade , Modelos Genéticos , Fenótipo , Reprodução/genética
9.
Nat Genet ; 47(10): 1121-1130, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26343387

RESUMO

Existing knowledge of genetic variants affecting risk of coronary artery disease (CAD) is largely based on genome-wide association study (GWAS) analysis of common SNPs. Leveraging phased haplotypes from the 1000 Genomes Project, we report a GWAS meta-analysis of ∼185,000 CAD cases and controls, interrogating 6.7 million common (minor allele frequency (MAF) > 0.05) and 2.7 million low-frequency (0.005 < MAF < 0.05) variants. In addition to confirming most known CAD-associated loci, we identified ten new loci (eight additive and two recessive) that contain candidate causal genes newly implicating biological processes in vessel walls. We observed intralocus allelic heterogeneity but little evidence of low-frequency variants with larger effects and no evidence of synthetic association. Our analysis provides a comprehensive survey of the fine genetic architecture of CAD, showing that genetic susceptibility to this common disease is largely determined by common SNPs of small effect size.


Assuntos
Doença da Artéria Coronariana/genética , Genoma Humano , Estudo de Associação Genômica Ampla , Humanos , Fenótipo
10.
PLoS Genet ; 11(7): e1005230, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26132169

RESUMO

Reference panels from the 1000 Genomes (1000G) Project Consortium provide near complete coverage of common and low-frequency genetic variation with minor allele frequency ≥0.5% across European ancestry populations. Within the European Network for Genetic and Genomic Epidemiology (ENGAGE) Consortium, we have undertaken the first large-scale meta-analysis of genome-wide association studies (GWAS), supplemented by 1000G imputation, for four quantitative glycaemic and obesity-related traits, in up to 87,048 individuals of European ancestry. We identified two loci for body mass index (BMI) at genome-wide significance, and two for fasting glucose (FG), none of which has been previously reported in larger meta-analysis efforts to combine GWAS of European ancestry. Through conditional analysis, we also detected multiple distinct signals of association mapping to established loci for waist-hip ratio adjusted for BMI (RSPO3) and FG (GCK and G6PC2). The index variant for one association signal at the G6PC2 locus is a low-frequency coding allele, H177Y, which has recently been demonstrated to have a functional role in glucose regulation. Fine-mapping analyses revealed that the non-coding variants most likely to drive association signals at established and novel loci were enriched for overlap with enhancer elements, which for FG mapped to promoter and transcription factor binding sites in pancreatic islets, in particular. Our study demonstrates that 1000G imputation and genetic fine-mapping of common and low-frequency variant association signals at GWAS loci, integrated with genomic annotation in relevant tissues, can provide insight into the functional and regulatory mechanisms through which their effects on glycaemic and obesity-related traits are mediated.


Assuntos
Mapeamento Cromossômico , Predisposição Genética para Doença , Índice Glicêmico/genética , Obesidade/genética , Locos de Características Quantitativas/genética , Índice de Massa Corporal , Frequência do Gene/genética , Estudo de Associação Genômica Ampla , Glucose-6-Fosfatase/genética , Humanos , Polimorfismo de Nucleotídeo Único/genética , Proteínas Serina-Treonina Quinases/genética , Trombospondinas/genética
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