3613 results for "*geneti*"

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• Genetic Studies of Homologous Recombination Deficiency in Hispanic Gastric Cancer

  Approximately 10% of gastric cancer cases show familial clustering and a hereditary cause is likely, however, only 1-3% cases result from known hereditary syndromes – which are predominantly associated with CDH1 and CTNNA1 genes. Hispanics are > 2 times more likely to be diagnosed and to die from gastric cancer compared to non-Hispanic whites. Not only does gastric cancer precision medicine lag behind other cancers – there is an urgent need to understand its etiology. Germline mutations in homologous recombination genes have been implicated as important risk factors for gastric cancer. The purpose of this study is to continue to generate knowledge to improve gastric cancer outcomes and disparities by 1) characterizing prevalence of germline mutations in homologous recombination genes and identify new genes associated with gastric cancer 2) perform molecular characterization of gastric tumors in Hispanic patients. Participants for germline analysis were enrolled from Chile, Colombia, Mexico, Portugal, Spain, Uruguay.Whole exome sequence capture was performed for all germline and somatic samples using Agilent SureSelect Human All Exon v7 Kit. All sequencing was performed on an Illumina NovaSeq 6000. Germline Analysis: Whole exome sequencing was performed on 536 Hispanic patients (290 males, 246 female)

  Study phs003251

• Feasibility of Circulating 5-Hydroxymethylcytosine Profiling in Osteosarcoma

  Aims: To examine the utility and performance of 5-hydroxymethycytosine (5-hmC) profiling of cell-free DNA (cfDNA) as a biomarker of disease in patients with osteosarcoma. Population: A Discovery cohort consisting of 5 patients with primary, localized osteosarcoma and an independent Validation cohort consisting of 17 patients with osteosarcoma. Serial cfDNA samples were collected for the majority of patients.Molecular Technologies Employed: Nano-hmC-Seal libraries were constructed from 1-10 ng of cfDNA. Briefly, cfDNA 5-hmC marks were subjected to enzymatic modification with UDP-N3-glucose, followed by chemical modification with biotin. Biotin-labeled cfDNA fragments were then pulled down using streptavidin beads, and PCR amplified to construct sequencing libraries. Findings: Using genes with differential 5-hmC deposition between osteosarcoma patients at diagnosis in the Discovery cohort and well children, hierarchal clustering identified two clusters of samples in the Validation cohort that were associated with disease status. Using a semi-quantitative osteosarcoma signature scoring system, the sensitivity and specificity to identify patients with active disease were 65% and 64%, respectively. Lung/soft tissue metastases were not readily identified. Despite limitations, 5-hmC profiling of cfDNA is feasible as a technique and further investigation with larger patient cohorts is warranted.

  Study phs003842

• CIDR NICHD Genetic Basis of Recessive Pediatric Brain Diseases - Group 4

  The purpose of this study is to identify new genetic causes of recessive forms of pediatric neurodevelopmental disorders (NDDs) including Cerebellar hypoplasia (CBH), Lissencephaly (LIS), Microcephaly (MIC), Corpus callosum hypoplasia (CCH), Pontocerebellar hypoplasia (PCH), Pontine tegmental cap dysplasia (PTCD), and Aicardi syndrome among many others. Using whole exome sequencing (WES) on one or two affected members per family, we are able to identify many pathogenic genes for these families. Using Human SNP Linkage Scans, which takes advantage of the Illumina HumanCore Array, and parametric linkage analysis software (Genehunter, Allegro, and others), we seek to identify pathogenic loci utilizing 60-70 families per year. Through the combination of parametric linkage analysis with exome sequencing and bioinformatics approaches, we will refine our search for superior sensitivity and accuracy when investigating candidate genes and identifying causative mutations for disease.

  Study phs001822

• Genetic Markers of Caries Risk in Diverse Underserved Children: CIDR

  The study Predicting Caries Risk In Underserved Children, From Toddlers To The School-age Years In Primary Healthcare Settings, is a renewal of an initial project designed to develop a dental caries risk tool for use in primary medical and dental healthcare settings to identify high dental caries risk children, expanding from the toddler (1-4 years old, referred to as Stage 1 grant) to the school-age years (6-9 years old, referred to as Stage 2 grant); and to determine the relationships between dental caries risk profiles and dental caries disease patterns. 1326 children, 12 +/- 3 months of age, and their primary caregivers, were enrolled in the study. This cohort represents a diverse population, including ethnic and racial minorities and low socio-economic status groups. There are a total of six in-person visits (at child age 1, 2.5, 4, 6.5, 8 and 9.5 years), and at each one the primary caregiver (PCG) completes a dental caries risk questionnaire, and the child receives a detailed dental caries examination. Saliva samples were collected during the age 8 visit (2019-2020) from 1,059 racially and ethnically diverse individuals (543 children and 516 PCGs) for the purposes of human genetic testing, to study the genetics of dental caries experience of children and their primary caregivers.

  Study phs003280

• Diabetic Retinopathy Genomics Study (DRGen) - Genetic Biomarkers of Diabetic Retinopathy

  Using a well-defined, clinically supported phenotypic strategy, we seek to better understand the role of common and rare genetic variants in the progression of diabetic retinopathy (DR). Whole exome/whole genome sequencing (WES/WGS) was used to systematically search the human genome to detect DR susceptibility genes or genes that protect people from developing advanced DR. Clinical data and bio specimens were obtained from clinically defined DR phenotypes such as, (i) No/Mild NPDR (non-proliferative DR) with a subset of extreme phenotype, ii) Diabetic macular edema (DME) alone and iii) Proliferative diabetic retinopathy (PDR) alone. In this ongoing comprehensive genomic study, we wish to i) Identify potential common and rare variants that may influence the phenotypic differentiation of DR into DME or PDR, ii) Define genetic variants stratified based on the "extreme phenotype," and iii) Characterize genetic factors that determine the differential response to anti-VEGF drugs in DME patients. Definition of Diabetic Retinopathy and classification of groups Study 1. Proliferative diabetic retinopathy (PDR). Anybody showing evidence of retinal neovascularization on the disc (NVD) or elsewhere (NVE) with or without pre-retinal and vitreous hemorrhage will be considered PDR. We will include only those "active" PDR patients. The total number of consented subjects in this study is 182. Study 2. Isolated Phenotype: Varied response with anti-VEGF treatment is a significant limiting factor for better clinical outcomes. We quantify the response to anti-VEGF treatment based on visual acuity changes and anatomic features of DME assessed by optical coherence tomography (OCT). Depending on the response at one month following three monthly intravitreal anti-VEGF injections, we have observed two phenotypes: 1) Good responders: Participants were considered "good responders" if the anatomical outcome to anti-VEGF treatment resulted in a significant reduction of baseline central retinal thickness (CRT) > 25% after three anti-VEGF injections. 2) Poor Responders: Participants were classified as "poor responders" if the outcome of anti-VEGF treatment resulted in a reduction of CRT < 20% or in any increase in CRT after three monthly injections. The total number of consented subjects in this study is 17.

  Study phs002501

• CIDR: Whole Exome Sequencing of Multiple Myeloma

  This goal of this project is to perform systematic analyses of germline genetic alterations in sporadic and familial multiple myeloma (MM) to discover candidate genes from these exome data. In this proposal, we will build on our prior work and pre-existing genomic data to prioritize, identify and validate novel candidate genes conferring susceptibility to MM.

  Study phs002497

• Single-Cell Mitochondrial Mutation Lineage Tracing of Non-Dysplastic and Dysplastic Barrett's Esophagus

  This study addresses a critical knowledge gap in understanding Barrett's esophagus (BE), a common metaplastic condition and precursor to esophageal adenocarcinoma, by identifying lineage connections and cell states underlying its development and malignant transformation. We collected biopsies from 13 Barrett's esophagus patients undergoing routine surveillance endoscopy, sampling metaplastic tissue alongside normal squamous esophagus and gastric cardia tissues when clinically appropriate. Our novel approach integrated single-cell RNA sequencing of nearly 180,000 cells with mitochondrial DNA mutation analysis for lineage tracing, coupled with spatial transcriptomics and comprehensive whole-exome sequencing. For one patient with high-grade dysplasia, we performed detailed whole-exome sequencing analysis at 100x coverage on dissociated Barrett's esophagus cells alongside matched normal esophagus and gastric cardia tissues. This genomic profiling revealed critical genetic drivers of malignant transformation, including a truncating mutation in the mutation cluster region of APC (a negative WNT regulator), mutations in the tumor suppressor genes CDKN2A and TP53, and significant copy number alterations including loss of CDKN2A on chromosome 9. These genetic alterations corresponded with the transcriptional changes observed in our single-cell data, particularly WNT pathway dysregulation and the expansion of LGR5-expressing stem cells, providing molecular evidence for how single clones can initiate the dysplastic transformation. Data deposited in dbGaP consist specifically of the whole-exome sequencing raw files, processed variant calls, and copy number analyses from the single patient with high-grade dysplasia and matched normal esophagus and stomach control tissue. Whole exome sequencing was performed on an Illumina NovaSeq 6000. Sequencing data was preprocessed following the Genome Analysis Toolkit's (GATK) Best Practices. Sequencing data was analyzed with Mutect2 (GATK, v4.2.5.0) to identify short somatic mutations including single-nucleotide polymorphisms and insertions and deletions. The Barrett's esophagus sample was run with the two matched normals, as well as the publicly available germline resource somatic-hg38_af-only-gnomad.hg38.vcf.gz (GATK). Somatic variant calls were filtered using FilterMutectCalls (GATK) and loaded into the Integrative Genomics Viewer (v2.12.3) for identification of high-quality variants in known esophageal adenocarcinoma regulators. Copy number alterations in the Barrett's esophagus sample were estimated using CNVkit (v0.9.9). CNV, Mutect2, and SVC analyses will be made available through dbGAP. Copy number alterations in the Barrett's esophagus sample were estimated using CNVkit (v0.9.9) with the default run settings; a pooled reference was generated from the normal esophagus and stomach samples. Copy number results were plotted directly within CNVkit using the function scatter.

  Study phs003949

• The Contribution of De Novo Coding Mutations to Meningomyelocele

  Meningomyelocele (MM) is considered a genetically complex disease resulting from the failure of the neural tube to close; a neural tube defect (NTD). Patients display neuromotor disability and frequent hydrocephalus requiring ventricular shunting. A few genes have been proposed to contribute to disease susceptibility, but most risk remains unexplained. 851 MM trios were recruited and we found 187 likely gene disrupting or damaging missense de novo mutations (DNMs) that are estimated to contribute to disease risk. These DNMs collectively define networks including actin cytoskeleton and microtubule-based processes, axon guidance, and histone modification. Gene validation demonstrates partial or complete loss of function, impaired signaling and defective neural tube closure in Xenopus embryos. Our results suggest DNMs make key contributions to MM risk, and highlight critical pathways required for neural tube closure in human embryogenesis. Data for 245 WES trios and 1 quad are available through dbGaP.

  Study phs003746

• Integrative Omics Analysis of Human Cartilage in Aging and Osteoarthritis

  This study investigates the tissue- and cell-type-specific genetic regulatory architecture of human knee joint tissues to elucidate the molecular underpinnings of osteoarthritis (OA). Matched cartilage, meniscus, and synovium samples were obtained from unrelated donors, comprising healthy organ donors with macroscopically normal cartilage and patients undergoing total knee arthroplasty (TKA) for severe OA. We performed whole-genome sequencing (WGS), bulk RNA sequencing of cartilage (n=113), meniscus (n=112), and synovium (n=81), and single-nucleus multiome (joint snATAC-seq + snRNA-seq) profiling on a subset of donors. By integrating these datasets, we performed cis-eQTL mapping in bulk and deconvolved cell-type-specific contexts across all three tissues, colocalization analysis with OA GWAS summary statistics (Regulatory Trait Concordance and coloc), rare variant promoter analysis, and chromatin-informed fine-mapping.In this updated version, the study has been expanded to a total of 220 unrelated donors. We added whole-genome sequencing (WGS) for 102 additional donors; small RNA sequencing (Illumina) of cartilage (n=92) and meniscus (n=88) to profile microRNA regulation; and long-read RNA sequencing (Oxford Nanopore PromethION P2) of cultured cartilage, meniscus, and synovium cells with and without interleukin-1β (IL-1β) stimulation (n=31) to capture full-length transcript isoforms of the inflammatory response.The data available through dbGaP include raw WGS sequence (FASTQ/CRAM), bulk RNA-seq sequence (FASTQ) from cartilage, meniscus, and synovium, small RNA-seq sequence (FASTQ), long-read RNA-seq (unaligned BAM), associated metadata, and donor phenotypic information.

  Study phs004730

• The Formation and Propagation of Human Robertsonian Chromosomes

  Robertsonian chromosomes are a type of variant chromosome found commonly in nature. Present in one in 800 humans, these chromosomes can underlie infertility, trisomies, and increased cancer incidence. Recognized cytogenetically for more than a century, their origins have remained mysterious. Recent advances in genomics have allowed us to assemble three human Robertsonian chromosomes completely. We identify a common breakpoint and epigenetic changes in centromeres that provide insight into the formation and propagation of common Robertsonian translocations. Further investigation of the assembled genomes of chimpanzee and bonobo highlights the structural features of the human genome that uniquely enable the specific crossover event that creates these chromosomes. Resolving the structure and epigenetic features of human Robertsonian chromosomes at a molecular level will pave the way to understanding how chromosomal structural variation occurs more generally, and how chromosomes evolve.

  Study phs003920