3246 results for "*geneti*"

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• Geographical structure and differential natural selection among North European populations

  European populations and epidemiological cohorts are of special significance in the current era of genomic research aiming to characterize the background of common human diseases. The genome sequence, detailed information of genetic variations between individuals, high-throughput molecular technologies and novel statistical strategies create new possibilities to define genetic and life-style risk factors behind common health problems. Studies of large population cohorts are needed to transform the genetic information to detailed understanding of the predisposing factors in diseases affecting most human populations. European twin cohorts provide a unique competitive advantage for investigations of the role of genetics and environment or life style in the etiology of common diseases. This project will apply and develop new molecular and statistical strategies to analyze unique European twin and other population cohorts to define and characterise the genetic, environmental and life-style components in the background of health problems like obesity, migraine, coronary heart disease and stroke, representing major health care problems worldwide.

  Study EGAS00000000033

• Carbamazepine-induced hypersensitivity reactions in Europeans

  An antiepileptic drug carbamazepine is well tolerated by the majority of patients, but can cause severe and potentialy fatal hypersensitivity reactions in a small number of individuals. The aim of this study was to identify genetic predictors of hypersensitivity reactions to carbamazepine. We undertook a genome-wide association study (GWAS) in 22 patients of European ancestry with carbamazepine-induced hypersensitivity syndrome (HSS) and compared our data with genotypes from a healthy population within the WTCCC. We performed imputation of classical HLA alleles according to a recently described method (Science. 2010 Dec 10;330(6010):1551-7. Epub 2010 Nov 4). GWAS statistical analysis was performed using logistic regression with an additive model of inheritance.

  Study EGAS00000000037

• Procardis study on novel susceptibility genes for coronary artery disease (CAD)

  An increased level of Lp(a) lipoprotein has been identified as a risk factor for coronary artery disease that is highly heritable. The genetic determinants of the Lp(a) lipoprotein level and their relevance for the risk of coronary disease are incompletely understood. METHODS: We used a novel gene chip containing 48,742 single-nucleotide polymorphisms (SNPs) in 2100 candidate genes to test for associations in 3145 case subjects with coronary disease and 3352 control subjects. Replication was tested in three independent populations involving 4846 additional case subjects with coronary disease and 4594 control subjects. RESULTS: Three chromosomal regions (6q26-27, 9p21, and 1p13) were strongly associated with the risk of coronary disease. The LPA locus on 6q26-27 encoding Lp(a) lipoprotein had the strongest association. We identified a common variant (rs10455872) at the LPA locus with an odds ratio for coronary disease of 1.70 (95% confidence interval [CI], 1.49 to 1.95) and another independent variant (rs3798220) with an odds ratio of 1.92 (95% CI, 1.48 to 2.49). Both variants were strongly associated with an increased level of Lp(a) lipoprotein, a reduced copy number in LPA (which determines the number of kringle IV-type 2 repeats), and a small Lp(a) lipoprotein size. Replication studies confirmed the effects of both variants on the Lp(a) lipoprotein level and the risk of coronary disease. A meta-analysis showed that with a genotype score involving both LPA SNPs, the odds ratios for coronary disease were 1.51 (95% CI, 1.38 to 1.66) for one variant and 2.57 (95% CI, 1.80 to 3.67) for two or more variants. After adjustment for the Lp(a) lipoprotein level, the association between the LPA genotype score and the risk of coronary disease was abolished. CONCLUSIONS: We identified two LPA variants that were strongly associated with both an increased level of Lp(a) lipoprotein and an increased risk of coronary disease. Our findings provide support for a causal role of Lp(a) lipoprotein in coronary disease.

  Study EGAS00000000055

• Genome-wide association study in multiple human prion diseases suggests genetic risk factors additional to PRNP

  We conducted GWAS of sporadic CJD, variant CJD, iatrogenic CJD, inherited prion disease, kuru and resistance to kuru despite attendance at mortuary feasts. After quality control we analysed 2000 samples and 6015 control individuals (provided by the Wellcome Trust Case Control Consortium and KORA-gen), for 491032-511862 SNPs in the European study. Association studies were done in each geographical and aetiological group followed by several combined analyses.

  Study EGAS00000000097

• Identification of genetic etiology of CAMRQ2

  We aimed to identify genetic etiology of cerebellar ataxia, mental retardation, and disequilibrium syndrome (CAMRQ). Targeted sequencing of the entire CAMRQ2 locus, 7.1 Mb interval on chromosome 17p13, in three affected individuals and two obligate carriers uncovered the mutation associated with CAMRQ2.

  Study EGAS00000000099

• The complex SNP and CNV genetic architecture of the increased risk of congenital heart defects in Down syndrome

  Here we aimed to contribute to the description of the genetic architecture of Congenital heart defect (CHD) in Down syndrome (DS), and report the results of a genome-wide association study using samples from DS individuals with and without CHD. CHD is a common developmental defect of DS occurring in 40% of cases. This case-control GWAS includes 187 DS with CHD as cases, and 151 DS without CHD as controls.

  Study EGAS00000000129

• DAC_for_study___Screening_for_human_epigenetic_variation_at_CpG_islands

  Dac EGAC00001000043

• MRCA and MRCE SNP genotypes

  Gene expression levels can be an important link DNA between variation and phenotypic manifestations. Our previous map of global gene expression based on approximately 400K SNPs and 50K transcripts in 400 sib pairs from the MRCA family panel has been widely used to interpret the results of GWAS. Here, we more than double the size of our initial dataset with expression data on 550 additional individuals from the MRCE family panel using the Illumina whole genome expression array. We have used new statistical methods for dimension reduction to account for non-genetic effects in estimates of expression levels and we have also included SNPs imputed from the 1000 Genomes Project. Our methods reduced false discovery rates and increased the number of eQTLs mapped either locally or at a distance (i.e. in cis or trans) from 1,534 in the MRCA dataset to 4,452 (with <5% FDR). Imputation of 1000 Genomes SNPs further increased the number of eQTLs to 7,302. Using the same methods and imputed SNPs in the newly acquired MRCE dataset we identified eQTLs for 9000 genes. The combined results identify strong local and distant effects for transcripts from 14,177 genes. Our eQTL database (http://www.hsph.harvard.edu/faculty/liming-liang/software/eqtl/) based on these results is freely available to help define the function of disease-associated variants.

  Study EGAS00000000137

• Genetic_variation_in_Kuusamo

  The aim of this study is to characterize as completely as possible the genetic variation and structure of Kuusamo and surrounding regions. We will perform low coverage, whole genome sequencing in a relatively limited number (approximately 200) of individuals from the FINRISK study both of whose parents are born in Kuusamo, Posio or Taivalkoski. Sequencing will be performed at the Wellcome Trust Sanger Institute (WTSI). We have previously shown using simulations and genome wide SNP data that the genetic characteristics agree with known genealogical data, and that approximately 200 individuals suffice to capture the majority of the genetic variation in this population.We have also developed methods for long-range haplotyping and long-range imputation, which are more accurate than traditional methods. This will allow us to identify a majority of the founder haplotypes in this population. The information from the haplotypes identified in this study can be used in other studies to impute from genome-wide SNP data the full genome sequence of samples ascertained for specific phenotypes.

  Study EGAS00001000020

• An exome sequencing pilot study of HIV elite-long term non progressors and rapid progressors

  A pilot study examining genetic determinants associated with elite long term non progression and rapid progression using exome sequencing of individuals at the extremes of the distribution of HIV control and progression. Data can only be used for HIV related research.

  Study EGAS00001000057

• Contribution of allelic imbalance to colorectal cancer

  Point mutations in cancer have been extensively studied but chromosomal gains and losses have been more challenging to interpret due to their unspecific nature. Here we examine high-resolution allelic imbalance (AI) landscape in 1699 colorectal cancers, 256 of which have been whole genome sequenced (WGSed). The imbalances pinpoint 38 genes as plausible AI targets based on previous knowledge, and unbiased CRISPR-Cas9 knockout and activation screens identified altogether 79 genes within AI peaks regulating cell growth. Genetic and functional data implicates loss of TP53 as a sufficient driver of AI. The WGS highlights an influence of copy number aberrations on the rate of detected somatic point mutations. Importantly, the data reveal several associations between AI target genes, suggesting a role for a network of lineage-determining transcription factors in colorectal tumorigenesis. Overall, the results unravel the contribution of AI in colorectal cancer and provide a plausible explanation why so few genes are commonly affected by point mutations in cancers.

  Study EGAS00001002966

• Determination of the molecular nature of the Vel blood group by exome sequencing

  The genetic basis of the Vel group is yet to be determined. We have collected DNA samples from about 90 Vel negative blood donors by phenotyping 270,000 donors. Understanding the genetic basis of the Vel group could have clinical significance as transfusion of Vel positive blood to Vel negative recipients with anti-Vel can cause severe and acute haemolytic transfusion reactions.

  Study EGAS00001000069

• Screening_for_human_epigenetic_variation_at_CpG_islands

  Many human characteristics, including susceptibility to disease, are determined genetically. An unexplored alternative to such genetic determination concerns epigenetic mechanisms such as DNA methylation. CpG islands (CGIs) are generally constitutively hypomethylated, however there are circumstances in which they become heavily methylated and, when coincident with a gene promoter, this invariably causes transcriptional silencing. CGI methylation occurs in normal tissues during processes such as X-inactivation, but abnormal patterns of methylation have also been implicated in disease. The vast majority of evidence relates to cancer, where silencing of multiple genes in this way appears to be a causal contributor to the cancer state. To address the role and extent of CGI methylation in ‘normal’ and diseased cells we applied MBD-affinity purification in conjunction with next generation sequencing in a panel of human brain autopsy samples. These samples represent a panel of individuals as well as specific brain regions and neurological pathologies.

  Study EGAS00001000074

• Functional_characterisation_of_CpG_islands_in_human_and_mouse_tissues

  Tissue-specific methylation patterns suggest a role for CpG island (CGI) methylation in differentiation and cell-type-specific gene regulation. We have applied CXXC affinity purification (CAP), MBD affinity purification (MAP) and chromatin immunoprecipitation (ChIP) in combination with solexa sequencing to investigate the extent and functional significance of CGI methylation in sperm, blood, cerebellum and ES cells for both human and mouse.

  Study EGAS00001000075

• Screening_for_abnormal_CGI_methylation_in_primary_colorectal_tumours

  A common hallmark of neoplastic cells is abnormal acquisition of CpG island (CGI) methylation and the silencing of associated gene promoters. To determine the extent and distribution of CGI methylation in colorectal cancer, we solexa sequenced MBD affinity purified DNA prepared from five colorectal tumours and matched colon mucosa from the same individuals.

  Study EGAS00001000076

• Novel regional age-associated DNA methylation changes within human common disease-associated loci

  Background: Advancing age progressively impacts on risk and severity of chronic disease. It also modifies the epigenome, with changes in DNA methylation, due to both random drift and variation within specific functional loci. Results: In a discovery set of 2,238 peripheral-blood genome-wide DNA methylomes (MeDIP-seq) aged 19-82 years, we identified 71 age-associated Differentially Methylated Regions (a-DMRs, p &lt; 1.85 x 10-8) within the Linkage Disequilibrium (LD) blocks of the NIH Catalogue of published GWAS SNPs. This included 52 novel regions, 29 within loci not covered by 450k or 27k Illumina array, and with marked enrichment for Poised Promoters and Enhancers across multiple cell types. In a replication set of 2,084 DNA methylomes, 95.7% of the a-DMRs showed the same direction of ageing effect, with 80.3% and 53.3% replicated to p &lt; 0.05 and p &lt; 1.85 x 10-8, respectively. Conclusion: By analysing the functionally enriched disease and trait-associated regions of the human genome, we identified novel epigenetic ageing changes, which could be useful biomarkers or provide mechanistic insights into age-related common diseases.

  Study EGAS00001001910

• Dilgom_Exome

  The Finrisk sample sets are part of the National FINRISK Study. It is a large population survey on risk factors of chronic, noncommunicable diseases. The survey is carried out since 1972 every five years using independent, random and representative population samples from different parts of Finland. The main results from the previous FINRISK 2007 survey are published.The National FINRISK Study Survey was carried out in 5 areas in Finland and 2000 inhabitants aged 25-75 years were invited to participate in each year. Among findings were that Finns continue to gain weight.Data from FINRISK surveys are used for many different research projects and for national health monitoring needs. The recent research activities deal, in addition to cardiovascular diseases and the classical risk factors, also with e.g. asthma and allergy, alcohol, socioeconomic factors and genetic epidemiology.The FINRISK study is part of the MORGAM Project (MONICA Risk, Genetics, Archiving and Monigraph), sponsored by the EU and MDECODE (Molecular Diversity and Epidemiology of Common Disease) program coordinated by the University of Michigan.The exome sequencing study will be part of the Dilgom study, which is a part of the larger Finrisk population based health study performed in Finland. It consists of 5000 individuals with a prospective aspect of metabolic traits. The cohort has been extensively phenotyped for their cardiovascular and metabolic status. So far, we have performed a 660K Illumina GWAS and a full genome wide expression study from peripheral blood cells of 500 individuals. The cohort has also been in total genotyped by the cardiometabochip

  Study EGAS00001000086

• Unraveling_the_genetic_basis_of_a_collagen_migration_defect_in_patients_with_a_combined__platelet_dysfunction_and_reduced_bone_density

  In this project we study cases from unrelated pedigrees that present at a young age with a phenotype which inludes hypotonia and hypodensity of bones, a chronic elevation of some liver and muscle enzymes as well as abnormal platelet number and volume. We aim to use exome sequencing to discover the causative variants reponsible for these defects.

  Study EGAS00001000093

• Exome sequencing

  Human telomere biology disorders (TBD), a heterogeneous group of disorders characterized by telomere attrition and premature aging phenotypes, are caused by inherited loss-of-function mutations in telomere-associated genes. Here, we identify three germline heterozygous missense variants in RPA1 gene in four unrelated probands presenting with short telomeres and varying clinical features of TBD including bone marrow failure, myelodysplastic syndrome, T- and B-cell lymphopenia, pulmonary fibrosis, and skin manifestations. All variants cluster to DNA binding domain A of RPA1 protein. RPA1 is an essential single-strand DNA-binding protein essential for DNA replication and repair. RPA1 has been implicated in telomere maintenance but the mechanism remains elusive. Thus far, no genetic disorder had been linked to RPA1. Using FRET assays, we showed that RPA1E240K and RPA1V227A exhibit increased binding to single-strand and telomeric DNA, implying a gain in DNA-binding function while RPA1T270A has binding properties similar to wild type. To study the mutational effect, RPA1E240K, with the highest binding capacity, was knocked-in iPSCs using CRISPR/Cas9, which showed severe telomere shortening and impaired hematopoietic differentiation. Furthermore, in the RPA1E240K patient, stable blood counts over two decades due coincided with clonal rescue hematopoiesis with an RNA-degrading truncating RPA1 mutation and a uniparental isodisomy 17p with loss of RPA1E240K allele. Using single cell DNA sequencing, the two somatic genetic rescue events were proven to be independently acquired in hematopoietic stem cells. In summary, we describe the first human disease caused by germline RPA1 variants in individuals with TBD.

  Study EGAS00001005761

• Genetic_factors_underlying_premature_coronary_heart_disease_in_patients_with_normal_coronary_arteries

  The study will analyse by exome sequencing 42 Greek patients with premature MI and no vessel disease to identify genetic factors underlying this condition.

  Study EGAS00001000133

• 'Targeted High Throughput Sequencing in Clinical Cancer Settings: Formaldehyde fixed-paraffin embedded (FFPE) tumor tissues, input amount and tumor heterogeneity'

  "Background: Massively parallel sequencing technologies have brought an enormous increase in sequencing throughput. However, these technologies need to be further improved with regard to reproducibility and applicability to clinical samples and settings. Methods: Using identification of genetic variations in prostate cancer as an example we address three crucial challenges in the field of targeted re-sequencing: Small nucleotide variation (SNV) detection in samples of formalin-fixed paraffin embedded (FFPE) tissue material, minimal amount of input sample and sampling in view of tissue heterogeneity.Results: We show that FFPE tissue material can supplement for fresh frozen tissues for the detection of SNVs and that solution-based enrichment experiments can be accomplished with small amounts of DNA with only minimal effects on enrichment uniformity and data variance. Finally, we address the question whether the heterogeneity of a tumor is reflected by different genetic alterations, e.g. different foci of a tumor display different genomic patterns. We show that the tumor heterogeneity plays an important role for the detection of copy number variations, but is of minor importance for the detection of somatic variations.Conclusions: The application of high throughput sequencing technologies in cancer genomics opens up a new dimension for the identification of disease mechanisms. In particular the ability to use small amounts of FFPE samples available from surgical tumor resections and histopathological examinations facilitates the collection of precious tissue materials. However, care needs to be taken in regard to the locations of the biopsies taken, which can have an influence on the prediction of copy number variations. Bearing these technological challenges in mind will significantly improve many large-scale sequencing studies and will - on a long-range - result in a more reliable prediction of individual cancer therapies."

  Study EGAS00001000136

• ENGAGE___Amendment__500_genes_exon_sequencing_

  The ENGAGE project is a FP7 funded EU project aiming to combine genetic and phenotype information from European population based cohorts. In this sub-project we aim to do whole exome sequencing of individuals selected from Health 2000 and FINRISK cohorts. Individuals have been selected based on their metabolic trait phenotypes

  Study EGAS00001000137

• Genetic_background_for_the_major_psychiatric_disorders_in_the_general_Finnish_population

  Low coverage (4-6x) sequencing on samples from population cohorts (Finrisk, Health2000) will be done at Wellcome Trust Sanger Institute (WTSI) using Illumina HiSeq sequencing technology. We will produce 100bp paired end reads. Variants will be called using the 1000 Genomes Project pipeline. The samples have been selected from a national representative set of 8028 samples from persons of 30 years or older, which were screened for psychotic and bipolar disorders using the Composite International Diagnostic Interview, self-reported diagnoses, medical examination, and national registers.

  Study EGAS00001000162

• Genetic_background_for_cardio_vascular_disorders_in_the_general_Finnish_population

  Low coverage (4-6x) sequencing on samples from population cohorts (Finrisk, Health2000) will be done at Wellcome Trust Sanger Institute (WTSI) using Illumina HiSeq sequencing technology. We will produce 100bp paired end reads. Variants will be called using the 1000 Genomes Project pipeline. The samples have been selected from a national representative set of approximately 30,300 samples and comprises 500 individuals of each gender in the extreme tail of high density lipoprotein (HDL) concentrations. Included individuals were between 25 and 65 years of age. Individuals with a diagnosis of diabetes or BMI&gt;30 were excluded from the study.

  Study EGAS00001000229

• Integrative analysis of small cell lung cancer

  Small-cell lung cancer (SCLC) is an aggressive lung tumor subtype. We conducted integrated analysis of genome sequencing, transcriptome, and copy number analysis and found an extremely high mutation rate of 7.4±1 protein-changing mutations per million basepairs. Evidence for inactivation of TP53 and RB1 was found in all sequenced cases. Furthermore, we identified recurrent mutations in CREBBP, EP300, and MLL, observed mutations in PTEN, in SLIT2, and EPHA7, as well as focal amplifications of the FGFR1 locus. As a major feature of SCLC we found mutation in histone modifying genes, observed genome alterations that are therapeutically tractable, and provide a framework for identifying biologically relevant genes in the context of a high mutation rate. Peifer et al., 2012, Nature Genetics.

  Study EGAS00001000299