3855 results for "*geneti*"

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• Relationship between low LDL cholesterol concentrations not due to statin therapy and risk of type 2 diabetes: a US-based cross-sectional observational study using electronic medical records

  Lipid lowering therapy using HMG-CoA reductase inhibitors (statins) is associated with an approximately 9-12% increase in the risk of new-onset type 2 diabetes (T2DM). The risk of diabetes could be increased by statins directly; however, genetic approaches have also implicated low LDL cholesterol (LDL-C) concentrations as a risk factor for T2DM. Mendelian randomization studies using functional variants in both HMGCR (GeneID:3156) and PCSK9 (GeneID:255738) genes found a higher risk of T2DM in individuals with variants associated with lower LDL-C concentrations. Since PCSK9 and HMGCR are involved in lipid metabolism through distinct molecular pathways, the altered glycemic effect associated with variants in both genes is likely to be the result of their common effect on LDL-C concentrations. Despite the findings from statin clinical trials and genetic studies, there is little direct evidence implicating low LDL-C concentrations with increased risk of T2DM. Individuals who have very low LDL-C concentrations not due to lipid lowering therapy can provide insights into the relationship between low LDL-C concentrations and T2DM. Here, we used de-identified electronic health records (EHRs) to test the hypothesis that low LDL-C concentrations are associated with T2DM.

  Study phs001588

• Characterizing Disease-Causing Variants Using Personal Genomes with Large Recurrent Deletions

  Individuals with recurrent genomic deletions are known to present variable clinical phenotypes, despite the apparent identical range of the genomic segments being affected in their genomes. We propose to study the phenotypic variability and the molecular polymorphism in individuals with the recurrent 17q12 deletions or the recurrent 1q21.1 deletions, with the objective to establish causal relationship between the genotypes and the incompletely penetrant clinical phenotypes. Genome sequencing and phenotypic data from individuals with the deletions and their relatives are included in this submission.

  Study phs002613

• Genetics of Pigmentation in Eastern and Southern African Populations Study

  The goal of this study was to identify genes and loci associated with pigmentation in African populations. It comprises 1,593 participants from Ethiopia, Tanzania, and Botswana. Sexes are evenly represented (768 males and 825 females) and self reported ages ranged from 18 to 103. Mean age was used for individuals without ages. For each participant, a DSM II color meter was used to measure underarm skin reflectance in triplicate. These measures averaged and converted to a melanin index (MI = 100 x log10(1/(x/255)). All individuals were included in a genome wide scan that accounted for age, sex, and genetic relatedness.

  Study phs001396

• National Cancer Institute (NCI) Head and Neck Cancer Study

  Head and neck cancers have well-documented associations with tobacco and alcohol exposure, but the disease develops in only a small fraction of users, which implies an important role for genetic susceptibility. Therefore, head and neck cancers are an excellent model for studying genetic susceptibility to environmental carcinogens. The primary goal of this study is to perform a comprehensive two-stage, high-density, genome-wide single-nucleotide polymorphism (SNP) analysis of head and neck cancer cases and corresponding frequency matched controls to identify novel genetic risk factors for head and neck cancer. In the study, we genotyped 2242 head and neck cancer cases and 1198 controls using Illumina HumanOmniExpress-12v1 BeadChip.

  Study phs001173

• Identification of ALS Associated Genes Using Whole Genome Sequencing

  The overall aim of this study is to discover of novel genetic elements associated with amyotrophic lateral sclerosis (ALS). Towards this goal, we have performed exome and whole genome sequencing for over 2000 samples. This data will be process and harmonized to yield high quality variant calling. These variants will be combined with control cohorts to identify novel genetic elements associated with ALS through case: control analyses.

  Study phs001585

• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): Identification of VUR genes by exome sequencing

  Primary vesicoureteric reflux (PVUR), or non-syndromic VUR, is the most common type of congenital anomaly of the kidney and the urinary tract (CAKUT). PVUR is the single most important risk factor for pyelonephritis and renal parenchymal scarring in the pediatric age group. Renal parenchymal scarring due to PVUR is referred to as reflux nephropathy and is a major cause of end stage kidney disease requiring dialysis and kidney transplantation in children. PVUR shows familial aggregation; however, the specific genetic cause(s) of PVUR is unknown despite a number of linkage studies. Reasons for this include: variable expression of the disease, difficulty with case ascertainment, genetic heterogeneity and lack of large pedigrees that can facilitate locus identification. We have ascertained a large 97 member PVUR kindred spanning five generations. We performed a genome-wide linkage study (GWLS) on this family and obtained a significant genome-wide LOD score of 3.3 on chromosome 6p. We performed exome sequencing on affected individuals in the family and identified mutations in tenascin XB (TNXB) as a cause of familial VUR. The proposed studies have the following specific objectives: a) to define the role of tenascin genes in the etiology of PVUR, and b) to identify new PVUR causative genes. Our specific aims are (1) To perform mutation analysis in TNXB and other tenascins in a cohort of 200 individuals with familial and sporadic PVUR and define genotype/phenotype correlations. (2) To perform sequential genome wide linkage studies (GWLS) and whole exome/targeted sequencing in families with PVUR. Impact on public health: Identification of PVUR genes may provide a novel non-invasive diagnostic tool for a subset of children with PVUR. Furthermore, this research will provide insights into the pathogenesis of PVUR and further elucidate the pathways involved in the development of the kidney and genitourinary tract. Future studies will define the role of the genes in the etiology of other malformations of the kidney and urinary tract and also seek to unravel the mechanisms by which the identified gene causes PVUR and other malformations of the kidney and the urinary tract.

  Study phs000778

• ADHD Genomic Association Study

  Studies at Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands, has recruited participants with ADHD and participants without ADHD, which included matched healthy controls and family members of participants with ADHD. ADHD participants met DSM-IV-TR criteria for ADHD. DNAs of these participants, 1005 samples, were anonymously genotyped with Illumina PsychArray. These samples were not part of the PGC-ADHD group. After removing family members, 820 case/control independent samples, including 211 ADHD cases, went through genomic association analyses. Results of ADHD risk genetic markers were compared with genetic markers associated with brain structure alterations in ADHD in adults and adolescents.

  Study phs001869

• Genomic Predictors of Combat Stress Vulnerability and Resilience

  The Genomic Predictors of Combat Stress Vulnerability and Resilience Study was designed to probe the likely hereditary basis for risk or resilience to develop PTSD and other trauma spectrum disorders. The overall guiding hypothesis was that genomic variation gives rise to risk/susceptibility traits that, when actuated by traumatic environmental stimuli, such as combat, give rise to PTSD and other stress-related phenotypes. Two studies designed to identify risk and resilience factors for combat-induced, stress-related symptoms are being conducted by our group: The Marine Resiliency Study (MRS) is a prospective PTSD study with longitudinal follow-up (pre- and post-exposure to combat stress) of US Marines bound for deployment to Iraq or Afghanistan. Extensive phenotyping includes 3 domains: Psychosocial, Psychophysiologic, and Biophysiologic. The biological and physiological measures collected were chosen in part due to their potential to serve as intermediate phenotypes for stress-related disorders. A second, cross-sectional study involves a cohort of combat-exposed active duty or previously deployed service members (CAVC), including PTSD cases and controls with comparable psychosocial and clinical phenotypes. Little information is available about the factors that explain why some trauma survivors develop stress disorders and some do not. It is hoped that the insights gained from this approach will improve understanding of the genetic contributors to PTSD, and potentially provide novel diagnostic tests and therapeutic approaches to this currently enigmatic and difficult-to-manage condition.

  Study phs000864

• Genetic Analysis of the Chiari I Malformation

  This study used whole exome sequencing (WES) on families affected with Chiari I Malformation (CM1). Individuals were recruited from the Republic of Tartarstan in the Russian Federation, where CM1 has a high prevalence (approximately 413 out of 100,000). At least one-third of these affected individuals have an affected relative. In collaboration with Dr. Enver Bogdanov of Kazan State Medical University, seven extended families affected with CM1 were identified. Eligible participants for this study were required to 1) have CM1 and a family member with syringomyelia or CM1, or 2) be a family member of a patient with CM1 and have at least two immediate family members diagnosed with CM1. Adults and minors were eligible for this study and recruitment was through self and physician referral. Patients were excluded if they had a contraindication to MRI scanning, were unable to understand the risks of testing, were under one year of age, or could not undergo MRI scanning without sedation. Study participants underwent SPGR (Spoiled Gradient Recalled) and T1-weighted MR-imaging of the brain and cervical spinal cord to assess the volume of the posterior fossa, as well as the presence of CM1. Individuals were defined as having CM1 if the inferior aspect of the cerebellar tonsils were lying ≥=2 mm caudal to the foramen magnum. Individuals were defined as having a small posterior fossa volume if the ratio of the posterior fossa volume to the supratentorial volume was < 0.15. Sixty-two patients (both cases and controls) from the seven extended families had DNA extracted from blood lymphocytes contained in 10 milliliters of stored blood. Whole exome sequencing (WES) was performed by the National Intramural Sequencing Center (NISC). These genotype data, as well as the case-control phenotype data on CM1 diagnosis and small posterior fossa diagnosis, were made available to dbGaP.

  Study phs001795

• Genetics of Disorders Affecting Tooth Structure, Number, Morphology and Eruption

  The long-term objective of this research project is to discover the complete spectrum of genes that contribute to the etiologies of genetic disorders of dentition. Inherited tooth defects can be isolated (the only symptom) or syndromic (having additional symptoms), and can be caused by mutations in many different genes. Clinically, it can be difficult to distinguish among the diverse forms. Making an accurate diagnosis would be greatly improved if reliable tests could identify the specific genetic defect that causes the disease in each case. Current technology can identify the numerous sequence variations throughout a patient's exome, but the disease-causing variation among them cannot be identified unless it is already on the list of genes that potentially cause the disease. A diagnosis based upon the genetic defect that causes the disorder distinguishes between isolated and syndromic tooth defects. A precise diagnosis permits formulation of a more accurate prognosis, which informs treatment decisions. The benefits of accomplishing our aims are to 1) enable genetic testing to achieve a precise and accurate diagnosis, and thereby optimize treatment, and 2) improve our understanding of normal and pathological tooth formation, leading to future improvements in treatment and eventually cures. Our short-term objectives are to 1) recruit kindreds with inherited disorders affecting their dentition, characterize their dental phenotype (and non-dental phenotypes when applicable) and the distribution of the disorder throughout the family, and 2) determine the genetic etiology of their disorders.

  Study phs001491