3456 results for "*geneti*"

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• Sweden-Schizophrenia Population-Based Case-Control Exome Sequencing

  Current findings of the genetic risk of schizophrenia and bipolar disorder emerging from genome wide association studies (GWAS) support a highly polygenic model displaying the full spectrum of causal alleles that includes the extremes of rare, penetrant alleles as well as common alleles of small effect. Lower frequency polymorphism, rare variants and private mutations have eluded measurement by GWAS studies and thus association with disease. In order to create a comprehensive catalogue of low frequency or rare coding variation in individuals with psychiatric disease and to build a foundation for future genetic studies of schizophrenia and bipolar disorder, we have obtained whole exome DNA sequence from a population-based schizophrenia and bipolar disorder Swedish case-control cohort.

  Study phs000473

• A Genome-Wide Association Study of Fuchs' Endothelial Corneal Dystrophy (FECD)

  Fuchs' Endothelial Corneal Dystrophy (FECD) is a common disease that results in loss of vision associated with progressive corneal edema and loss of corneal transparency. In the initial stages of the disease, excrescences on Descemet's membrane with the appearance of an abnormal posterior collagenous layer, result in the clinical and pathologic appearance of guttae. Corneal edema ensues as endothelial function is compromised that may result in stromal edema, epithelial edema, and painful bullous keratopathy. Penetrating or endothelial keratoplasty is the only definitive treatment, with palliative care the only option prior to surgery. The pathophysiology underlying FECD, particularly in the common cases that affect older individuals, remains unknown, with a genetic predisposition being reported as the single best predictor of disease. Three independent groups funded by the National Eye Institute (NEI), with well-established programs in the genetics of FECD, conducted a genome-wide association study of FECD. The collaboration comprised investigators from Case Western University (CWRU), Duke University (DUEC), and Johns Hopkins University (JHU). CWRU and DUEC contributed samples that were genotyped at CIDR for the GWAS. Johns Hopkins University (JHU) provided samples for the replication phase of the study, where their data are not listed in dbGaP. Cohorts of FECD cases and controls were assembled. Synchronization of clinical and coded data was performed to unify the information across centers. The family history, clinical, demographic information, and genome-wide genotype data for samples from CWRU and DUEC were deposited in dbGaP.

  Study phs000421

• Altered chromosomal topology drives oncogenic programs in gastrointestinal stromal tumors

  Metabolic lesions with pleiotropic effects on epigenetic regulation and other cellular processes are widely implicated in cancer, yet their oncogenic mechanisms remain poorly understood. Succinate dehydrogenase (SDH) deficiency causes a subset of gastrointestinal stromal tumors (GISTs) with DNA hyper-methylation. Here we associate this hyper-methylation with changes in chromosome topology that activate oncogenic programs. To investigate epigenetic alterations in this disease, we systematically mapped DNA methylation, CTCF insulators, enhancers and chromosome topology in KIT-mutant, PDGFRA-mutant and SDH-deficient GISTs. Although these respective subtypes share similar enhancer landscapes, we identified hundreds of putative insulators where DNA methylation replaced CTCF binding in SDH-deficient GISTs. We focused on disrupted insulators that partitions super-enhancers from FGF3, FGF4 and the KIT oncogene. Recurrent loss of this insulator alters locus topology in SDH-deficient GISTs, allowing aberrant physical interaction between enhancers and oncogenes. CRISPR-mediated excision of the corresponding CTCF motif in an SDH-intact model disrupted the boundary and up-regulated FGFs and KIT expression. Our findings reveal how a metabolic lesion destabilizes chromatin structure to facilitate the initiation and selection of epigenetic alterations that drive oncogenic programs in the absence of canonical mutations.

  Study phs001906

• T2D-GENES Project 2: San Antonio Mexican American Family Studies

  The Type 2 Diabetes (T2D) Genetic Exploration by Next-generation sequencing in Ethnic Samples (T2D-GENES) Consortium is a collaborative international effort to identify genes influencing susceptibility to T2D in multiple ethnic groups using next generation sequencing. T2D-GENES Project 2 is a complex pedigree-based study designed to identify low frequency or rare variants influencing susceptibility to T2D, using whole genome sequence (WGS) information from 1,043 individuals in 20 Mexican American T2D-enriched pedigrees from San Antonio, Texas. The major objectives of this study are to identify low frequency or rare variants in and around known common variant signals for T2D, as well as to find novel low frequency or rare variants influencing susceptibility to T2D. The sampled individuals are obtained from two studies: the San Antonio Family Heart Study (SAFHS) and the San Antonio Family Diabetes/Gallbladder Study (SAFDGS), collectively referred to as the San Antonio Mexican American Family Studies (SAMAFS). The strategy is to sequence approximately 600 individuals at an average of 50x coverage across the entire genome, then impute genome wide genotypes for about 440 additional family members. The 600 sequenced individuals are specifically chosen for their value in imputing sequence information into other family members. By studying large pedigrees, we expect to find multiple individuals carrying each genetic variant, even if this variant is very rare in the population at large. Thus, a pedigree-based approach provides an excellent opportunity for identifying rare novel variants influencing risk of T2D and quantitative variation in T2D-related phenotypes. The whole genome sequencing has been done commercially by Complete Genomics, Inc. (CGI). The final data set includes whole genome sequence data for 607 individuals. After quality control, 585 sequenced individuals provide data for family based imputation, using Merlin linkage analysis software, into approximately 440 additional family members for whom chip based genotypes are available to indicate which parental haplotype is transmitted. Extensive phenotype data is provided for 1048 individuals. These include 5 sequenced individuals who do not belong to any of the 20 large pedigrees. Phenotype information was collected between 1991 and 2011 in the two contributing longitudinal studies. SAFHS participants may have information from up to 5 visits, and SAFDGS participants may have up to 4 visits. The clinical variables reported are coordinated with T2D-GENES Project 1 (multi-ethnic exome sequencing) and include T2D status and age at diagnosis, glycemic traits (fasting and 2 hour glucose and insulin), blood pressure, blood lipids (total cholesterol, HDL cholesterol, calculated LDL cholesterol and triglycerides), clinical chemistry (cystatin c, glutamic acid decarboxylase antibody titer (GadAb), creatinine, adiponectin and leptin). Glycated hemoglobin (HbA1c) was not measured for these individuals and insulin C-peptide is not included in this data set. Additional phenotype data include the medication status at each visit, classified in four categories as any current use of diabetes, hypertension or lipid-lowering medications, and, for females, current use of female hormones. Anthropometric measurements include age, sex, height, weight, hip circumference, waist circumference and derived ratios. Each phenotype variable has an initial summary column containing the most recent non-missing measurement for each individual, followed by the five potential time points for each individual, the number of non-missing measurements, and the age and year for the most recent non-missing measurement. For historical reasons, the order in which variables are presented on the dbGaP web site differs from their order in the data download file. When reading the comment fields for each variable, please note that commas are omitted to support data exchange in .csv format.

  Study phs000462

• Genomic Changes in Breast Cancer Among Chinese Women in Hong Kong

  Recently, tumor sequencing and profiling analyses have improved molecular classification and refined existing breast cancer subtypes. However, epidemiologic data are absent in most somatic profiling studies even in extensively studied Western populations. The expansion of genomic studies to understudied populations with the integration of etiologic factors will allow the capture of a much wider range of genetic structure and mutagenic exposures associated with breast cancer risk. We therefore conducted a detailed molecular characterization of paired breast tumor/normal tissues using fresh frozen tissues collected from breast cancer cases in an ongoing breast cancer case-control study in Hong Kong. These analyses included whole exome sequencing, RNA sequencing, and genome-wide methylation profiling analyses.

  Study phs001870

• Clinical Resistance to Crenolanib in Acute Myeloid Leukemia Due to Diverse Molecular Mechanisms

  FLT3 mutations are commonly detected in Acute Myeloid Leukemia (AML) patients and are associated with poor prognosis. Crenolanib, a potent type I pan-FLT3 (GeneID:2322) inhibitor, is effective against both internal tandem duplications (ITD) and resistance-conferring tyrosine kinase domain (TKD) mutations. While crenolanib monotherapy has demonstrated significant clinical benefit in heavily pretreated relapsed/refractory AML patients, responses are transient and relapse eventually occurs. To investigate the mechanisms of crenolanib resistance, we performed whole exome sequencing of AML patient samples before and after crenolanib treatment (122 samples from 59 patients). Unlike other FLT3 inhibitors, crenolanib did not induce FLT3 activation loop mutations, and mutations of the FLT3 "gatekeeper" residue were infrequent. Instead, mutations of NRAS (GeneID:4893) and IDH2 (GeneID:3418) arose, mostly as FLT3-independent subclones, while TET2 (GeneID:54790) and IDH1 (GeneID:3417) predominantly co-occurred with the FLT3-mutant clone and were enriched in crenolanib poor-responders. The remaining patients exhibited post-crenolanib expansion of mutations associated with epigenetic regulators, transcription factors, and cohesion factors, suggesting diverse non-FLT3 genetic/epigenetic mechanisms of crenolanib resistance. Drug combinations in experimental models restored crenolanib sensitivity.

  Study phs001628

• Consanguinity and rare mutations outside of MCCC genes underlie non-specific phenotypes of MCC Deficiency

  3-Methylcrotonyl-CoA Carboxylase Deficiency (MCCD) is an autosomal recessive disorder of leucine catabolism, which has a highly variable clinical phenotype, ranging from acute metabolic acidosis to non-specific symptoms such as developmental delay, failure to thrive, hemiparesis, muscular hypotonia, and multiple sclerosis. Implementation of newborn screening for MCCD has resulted in broadening the range of phenotypic expression to include asymptomatic adults. The purpose of this study was to identify factors underlying the varying phenotypes of MCCD. We performed exome sequencing on DNA from 107 healthy controls and 33 cases. We examined these data for associations between either MCC mutational status, genetic ancestry or consanguinity and the absence or presence/specificity of clinical symptoms in MCCD cases. We determined that individuals with non-specific clinical phenotypes are highly inbred compared to cases that are asymptomatic and healthy controls. For five of these individuals we discovered a homozygous damaging mutation in a disease gene that is likely to underlie their non-specific clinical phenotypes previously attributed to MCCD.

  Study phs000776

• Genomics and Modification of Pain: A peripheral component identified using iPSCs with the S241T mutation

  We have capitalized on inherited erythromelalgia (IEM) as a well-characterized genetic model of chronic pain, and studied IEM patients carrying Nav1.7 mutations which affect channel activation and often produce hyperexcitability of DRG neurons. Whole exome sequencing was used to discover multiple gene variants that might contribute to neuronal excitability and that might serve as modifiers of sensory neuron firing, and identified the Kv7.2 channel as a contributor to differences in pain profiles between individuals.

  Study phs001724

• A Population Genomics Study Using a Disease-Targeted Cell model: Integration of

  The common genetic variants associated with complex traits typically lie in non-coding DNA and may alter gene regulation in a cell type-specific manner. Consequently, the choice of tissue or cell model in the dissection of disease associations is important. We carried out an expression quantitative trait loci (eQTL) study of primary human osteoblasts (HOb) derived from 95 unrelated donors of Swedish origin, each represented by two independently derived primary lines to provide biological replication. We combined our data with publicly available information from a genome-wide association study (GWAS) of bone mineral density (BMD). The top 2000 BMD-associated SNPs were tested for cis-association of gene expression in HObs and in lymphoblastoid cell lines (LCLs) using publicly available data and showed that HObs have a significantly greater enrichment (threefold) of converging cis-eQTLs as compared to LCLs. The top 10 BMD loci with SNPs showing strong cis-effects on gene expression in HObs were selected for further validation using a staged design in two cohorts of Caucasian male subjects. All 10 variants were tested in the Swedish MrOS Cohort (n = 3014), providing evidence for two novel BMD loci (SRR and MSH3). These variants were then tested in the Rotterdam Study (n = 2090), yielding converging evidence for BMD association at the 17p13.3 SRR locus. The cis-regulatory effect was further fine-mapped to the proximal promoter of the SRR gene (rs3744270). Our results suggest that primary cells relevant to disease phenotypes complement traditional approaches for prioritization and validation of GWAS hits for follow-up studies. Reprinted from Grundberg E, Kwan T, Ge B et al., Genome Res Nov 2009, with permission from Genome Research, Cold Spring Harbor Press, PMID:19654370.

  Study phs000225

• Determinants of Asthma Following RSV Bronchiolitis in Early Life

  The goal of the RSV Bronchiolitis in Early Life (RBEL) study is to determine how specific genetic, biologic, and immunologic characteristics interact to predispose individuals to develop asthma. Participants were carefully recruited by selecting a prospective cohort of 206 infants with severe respiratory syncytial virus (RSV) bronchiolitis who were at substantial risk of developing asthma.

  Study phs001009