4078 results for "*geneti*"

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• Capturing the Genetic Diversity of the Himba Population

  The Himba people are a semi-nomadic, Bantu-speaking pastoralist group from the northwestern Kunene region of Namibia. Because of their limited population size, restricted geographic distribution, and endogamy, founder populations represent an ideal system for genetic analyses due to reduction of the confounding environmental and cultural variables. The original study used genotype data and demographic interview data to understand family dynamics and ancestry in a population of Himba pastoralists. HLA allele calls and genome-wide methylation array data were later generated for a subset of the initial dataset for 2 additional studies. These 3 molecular datasets, available through dbGaP, are relevant to broader studies of ancestry, allele frequencies and the relationship of Himba to other ethnic groups in sub-Saharan Africa. The Himba population provides a unique opportunity to study questions regarding extra-pair paternity and mate selection because Himba culture allows both men and women, married and not, to take multiple partners. Previous estimates of extra-pair paternity rates in human populations have been very low, but these estimates lack global and cultural diversity in population representation. Thus, investigating the rate of extra-pair paternity in the Himba greatly aids in understanding the global variation in non-paternity rates among human populations. Saliva samples were collected from parents and children, and were genotyped on Illumina SNP array platforms (MEGAex and H3Africa). In total, 678 individuals' genotype array data are deposited. Paternity results were de-identified and protected by a double blind protocol (no researcher has full knowledge of individual paternity results). Due to the sensitive nature of this study, paternity assertions are not available for access. For a subset of 360 individuals, HLA class 1 (A, B, C) and class 2 (DPA1, DPB1, DQA1, DQB1, DRB1) genes were targeted for DNA sequencing using a probe-based capture method. HLA alleles at the four field resolution were determined from the sequence capture using the consensus calls obtained from two algorithms: NGSengine® 2.10.0 (GenDX, Utrecht, the Netherlands) and HLA Explore™ (Omixon Biocomputing Ltd. Budapest, Hungary). These data were used to investigate evidence for mate selection based on HLA dissimilarity in the Himba. Himba cultural norms permit concurrent arranged marriages and chosen sexual partnerships allowing us to directly test for evidence of disassortative mate selection based on HLA genotype. Due to the sensitive nature of this study, partnership data are not available for access.For a subset of 51 Himba individuals methylation array data was generated from the saliva-derived DNA. These data were generated in order to investigate the accuracy of epigenetic age predictors in this population and to construct population-specific epigenetic age predictors in a subsequent publication. Chronological ages are available for these 51 individuals.

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• Epi4K: Gene Discovery in 4,000 Epilepsy Genomes

  The Epi4K project began in 2011 as an international, multi-center study that seeks to identify and characterize the genetic bases of complex epilepsies. The Center without Walls Epi4K project includes three cores and four scientific projects, as well as a steering committee comprised of the primary study investigators and representatives from the National Institute of Neurological Disorders and Stroke (NINDS). The three cores include: (1) The Administrative Core which handles the overall coordination of Epi4K activities; (2) The Sequencing, Biostatistics and Bioinformatics Core which is responsible for generating the next-generation sequence data, inferring the genetic variation in each of the study participants, and performing the primary analyses to identify epilepsy genes; and (3) The Phenotyping and Clinical Informatics Core which verifies and archives all the phenotypic data from each study participant. The proposed number of patients to be sequenced and analyzed in the scientific projects is a minimum of 4,000; thus the Center was named "Epi4K: Gene Discovery in 4,000 Genomes". Project 1 addresses the genetics of rare and severe childhood epilepsies, including epileptic encephalopathies (infantile spasms and Lennox-Gastaut syndrome), and malformations of cortical development (periventricular nodular heterotopia and polymicrogyria). Exome and genome sequence data generated from DNA collected from patients will be screened for mutations (single nucleotide substitutions, small insertion-deletions, and copy number variations) that cause or contribute to the diseases. Project 2 is focused on genetic discovery in multiplex families. This study will use next-generation sequencing to identify genomic variation that influences risk for common subtypes of epilepsy including idiopathic generalized epilepsy and nonlesional focal epilepsy. Project 3 seeks to identify genetic determinants of prognosis in patients with a range of epilepsy disorders. This study will study established epilepsy cohorts with well-characterized data on seizure outcome to look for relationships between genetic variation and pharmacological control of seizures. Project 4 will use next-generation sequencing data (exome and genome) to screen for epilepsy-associated copy number variation across all Epi4K projects using novel computational algorithms.

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• Genetic Modifiers of Duchenne Muscular Dystrophy

  The primary determinant of disease severity in patients with severe Duchenne muscular dystrophy (DMD) or milder Becker muscular dystrophy (BMD) is whether their dystrophin gene (DMD) mutation disrupts the mRNA reading frame or permits the expression of a partially functional protein. However, even in the complete absence of dystrophin, variability in disease severity is observed, with candidate gene studies implicating several genes as potential DMD modifiers. This study undertakes a comprehensive genome-wide search for modifier loci influencing disease severity in DMD patients. The availability of subjects for such studies remains limited, resulting in modest sample sizes that challenge the GWAS design. To address this, we have implemented measures to minimize heterogeneity within the dataset at the dystrophin (DMD) gene itself, adopting a conservative approach to DMD mutation classification to limit the possibility of residual dystrophin expression. Additionally, the study employed statistical methods that are well-suited to smaller sample sizes, including the use of a novel linear regression-like residual for time to ambulatory loss and the application of evidential statistics, specifically the Posterior Probability of Linkage Disequilibrium (PPLD), to assess trait-SNP associations in the GWAS framework. With a sample size of 419 patients, this study has identified multiple candidate genetic modifier loci. The molecular data available in dbGaP includes 2,562,265 directly genotyped variants in 419 people using the Illumina Infinium Omni2.5Exome-8 Beadchip assay, achieving a genotyping rate of 0.998. The phenotypic data comprises age at ambulatory loss, steroid status, DMD gene mutation, and the PPLD value from the time-to-event (TE) phenotype.

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• Somatic Mutations and Their Etiological Determinants for Breast Cancer in African American Women (B-CAUSE Study)

  The breast cancer health disparity between women of African ancestry (AA) and European ancestry (EA) remains a major public health challenge in the United States. AA women are afflicted by higher rate of triple-negative breast cancer (TNBC) and bear the highest mortality rate of all populations from the disease. Even within TNBC, some data suggest that AA women have poorer outcomes than EA women. Mounting evidence points to population differences in cancer biology, a fundamental question that remains unsettled. The disparity also manifests in representativeness in tumor sequencing projects, due to the low inclusion of AAs in genomic studies. A recent analysis of The Cancer Genome Atlas (TCGA) data revealed that the number of AA cases sequenced was sufficient only for studying frequently mutated genes (≥10%), and the power was worse for TNBC as a separate disease entity. As a result, the breast tumor mutational landscape elucidated to date is derived mostly from EA cases, and may not necessarily represent AA cancer genomes. Moreover, as discovery potential for new driver genes has come close to a plateau, cancer in AAs derived from distinct genetic and environmental contexts may provide a powerful venue for discovering mutations that are rare in EA cases. This is showcased in recent studies in colon and prostate cancer. Thus, we carried out a collaborative project, B-CAUSE, to characterize the mutational landscape of AA breast cancer genomes by pooling resources from five established studies, including the Women's Circle of Health Study (WCHS), the Black Women's Health Study (BWHS), the Southern Community Cohort Study (SCCS), the Nashville Breast Health Study (NBHS), and the Southern Tri-State Breast Health Study (STSBHS). This effort has created the largest AA-specific breast tumor mutation dataset to date in an efficient manner. The data deposited here are from the whole-exome sequencing (WES) of matched tumor-normal pairs of 462 TNBC in AA women from the B-CAUSE Study.

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• Kids First: Genetics of Pediatric Germ Cell Tumors

  The Gabriella Miller Kids First Pediatric Research Program (Kids First) is a trans-NIH effort initiated in response to the 2014 Gabriella Miller Kids First Research Act and supported by the NIH Common Fund. This program focuses on gene discovery in pediatric cancers and structural birth defects and the development of the Gabriella Miller Kids First Pediatric Data Resource (Kids First Data Resource). All of the genomic and phenotypic data from this study are accessible through dbGaP. The data is also available at the Kids First Portal, where other Kids First datasets can also be accessed in the cloud for data analysis, data visualization, collaboration and interoperability, open to all researchers and developers.Pediatric malignant germ cell tumors (GCTs) represent approximately 6% of childhood cancers, including 3% of tumors in children aged 0-14 years and 15% of tumors in adolescents. GCTs are heterogeneous and grouped together due to the presumed common cell of origin, the primordial germ cell (PGC). GCTs typically occur in the testes or ovaries; however, extragonadal GCTs can occur and are likely a result of abnormal germ cell migration during development. Evidence suggests that GCTs, including those diagnosed in adults, are initiated in utero. Thus, alterations in normal embryonic development are likely to be especially relevant to GCT etiology. Germline susceptibility has not been evaluated in an agnostic fashion in pediatric GCT, mainly due to a lack of an adequate number of samples; however, emerging evidence supports a genetic etiology.In the two Kids First GCT projects, we will evaluate genetic susceptibility to intracranial and extracranial GCT by sequencing probands and their unaffected parents. The goals of the project are to: 1) evaluate the contribution of rare genetic variants in GCT through the use of aggregate burden tests, focusing on genes and established regulatory regions; 2) identify de novo SNVs and CNVs in pediatric GCT using a case-parent triad design; and 3) identify molecular signatures in GCT tumor specimens, overall and by age group and tumor characteristics. Whole Genome Sequencing (WGS) data generated through the Gabriella Miller Kids First Pediatric Research Program will provide an opportunity to investigate the genetic origins of GCT in a diverse set of samples. Given the limited knowledge of GCT etiology and biology, the results of the proposed analyses are likely to have a big impact on the field.

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• Study on the Genetics of Alcoholism (COGA): Smoke Screen and Exome Sequencing

  This is a family study of alcoholism, in which the subjects have been drawn from the Collaborative Study on the Genetics of Alcoholism (COGA), a large, ongoing family-based study that includes subjects from seven sites around the US. COGA has gathered detailed, standardized data on study participants, including diagnostic and neurophysiological assessments. This project has already proved successful in identifying several genes that influence the risk for alcoholism and neurophysiological endophenotypes, which have been independently replicated. COGA data were included as part of two Genetic Analysis Workshops, and the phenotypes are familiar to the genetics community. Alcoholic probands were recruited from treatment facilities, assessed by personal interview, and after securing permission, other family members were also assessed. A set of comparison families was drawn from the same communities as the families recruited through an alcoholic proband. Assessment involved a detailed personal interview developed for this project, the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), which gathers detailed information on alcoholism related symptoms along with other drugs and psychiatric symptoms. Many participants also came to the laboratories for electroencephalographic studies. Neurophysiological features that have been shown to be useful endophenotypes for which we have linkage and in some cases association results are included on a subset of the case-control sample: the beta power of the resting electroencephalogram (EEG), the P3(00) amplitude of the visual event-related potential (ERP), and the theta and delta event-related oscillations (EROs) underlying the P3.

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• Genomic Sequencing of Ewing Sarcoma

  Pediatric Ewing sarcoma is a pediatric cancer that primarily arises from the bone. It is characterized by chimeric fusions of the EWS gene and an ETS family transcription factor. In this study, we performed massively parallel sequencing of a larger collection of Ewing sarcoma tumors to define the genomic landscape of this disease. We found that these tumors are among of the most genetically normal cancers currently characterized. There was also a marked absence of recurrent mutations in immediately targetable signaling transduction pathway genes. In this study we answer outstanding questions about ETS transcription factor expression, effects of treatment on mutational burden in Ewing sarcoma tumors, and describe patterns of tumor evolution. We also found that loss-of-function mutations in STAG2 were present in approximately 15% of Ewing sarcoma tumors and loss of STAG2 expression was associated with disease metastasis in this patient cohort.

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• Genetic and Hormonal Contributions to Gene Expression in Immune Cells

  The origins of sex differences in human disease are elusive, in part because of difficulties in separating the effects of sex hormones and sex chromosomes. To isolate the effects of testosterone, estradiol, and sex chromosome complement (XX or XY) in humans, we implemented a four-state, cross-sectional study design of trans- and cisgender individuals, the former receiving exogenous testosterone or estradiol for at least a year as part of their gender-affirming medical care. This study design allowed us to compare four combinations of sex hormones and sex chromosomes in humans: XX individuals treated with exogenous testosterone (n=21), XY individuals treated with exogenous estradiol (n=13), untreated XX individuals (n=20), and untreated XY individuals (n=15). We chose to focus on the human immune system because it displays an impressively broad range of sex-differential biology. We collected blood samples from each individual and isolated PBMCs the same day. We performed 10X Genomics 3' single-cell RNA-sequencing (scRNA-seq) on PBMCs from the 69 individuals. We generated 150-bp paired end reads from a total of 358,426 cells (with an average of 48,007 reads/cell) and identified 18 distinct immune cell types. We found that testosterone, estradiol, and sex chromosome complement have unique, non-overlapping effects on PBMC cell abundances and gene expression.

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• Childhood Cancer Data Initiative (CCDI): NCI-COG Pediatric MATCH Precision Medicine Clinical Trial

  The National Cancer Institute-Children's Oncology Group (NCI-COG) Pediatric Molecular Analysis for Therapy Choice (MATCH) trial provides a framework for biomarker-driven early phase trials of targeted therapies in pediatric and young adult cancer patients across the United States. Pediatric MATCH enrolled more than 1,300 patients with treatment-refractory cancers, offering access to molecular screening and investigational targeted therapies. To further advance this, matched diagnostic, refractory tumor, and normal samples from Pediatric MATCH cases were molecularly characterized, creating one of the largest comprehensive data sets available for childhood cancers. This analysis has the potential to provide novel insights into the genetics of refractory pediatric, adolescent, and young adult cancers, as well as inform potential therapeutic strategies. The following molecular characterization assays were performed: Tumor whole exome sequencing (WES) Tumor whole genome sequencing (WGS) Tumor RNA sequencing (RNA-seq) Blood whole exome sequencing (WES) Blood whole genome sequencing (WGS)

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• dbGaP Collection: NIH Autism -omics Studies

  Autism Spectrum Disorders (ASD) are early onset neurodevelopmental syndromes characterized by impairments in reciprocal social interaction and communication, accompanied by restricted and repetitive behaviors. ASDs afflict ~1% of the human population, and represent a major public health burden. Evidence for the etiology of ASD has consistently pointed to a strong genetic component, though the genetic architecture is indisputably complex. This dbGaP Collection consists of studies that include GWAS, sequencing (targeted, exome, whole genome), transcriptomics, etc, across many different cohorts. Many of the datasets have been curated and harmonized with NDAR prior to submission to dbGaP. Researchers who request and are approved to access this collection will be granted access to all related substudies in dbGaP as well as all NDAR data. Individual level genomics data will only be available for download through dbGaP along with minimal phenotype and pedigree information. Detailed phenotype and available imaging data related to these same research subjects are available for query and download within NDAR. The NDAR GUID will allow individual genomic data to be associated with all NDAR data collected for those subjects.

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