3931 results for "*geneti*"

in 20.47 milliseconds.

• High-resolution analyses of human sperm dynamic methylome reveals thousands of novel age-related epigenetic alterations

  Age-dependent modifications of the germ cells epigenome remain poorly understood. Our objective was to assess the DNA methylation profile of human spermatozoa during aging. A cohort study was designed to investigate the effects of age and fertility status on sperm DNA methylation.

  Study EGAS00001004168

• Study on the consequences of prenatal famine exposure on DNA methylation.

  The potential of the epigenome to undergo environmentally-induced changes during early development is central to its postulated role in human disease. Here, we report a genome-scale view of DNA methylation differences after early gestational malnutrition that was caused by the Dutch Hunger Winter, a severe famine at the end of World War II. We adopted an annotation guided analysis of reduced-representation bisulfite sequencing data generated in 24 middle-aged individuals who had been exposed to famine in utero and 24 unexposed sibling controls. We observed differential DNA methylation primarily at genomic regions with regulatory potential, including enhancers active during early development. In-depth annotation of 181 prenatally-induced differentially methylated regions (P-DMRs) showed that they were predominantly located in gene bodies and co-occurred with histone marks denoting an active state. In line with the early gestational timing of the exposure, the P-DMRs mapped to genes that were enriched for differential expression patterns during blastocyst development and early organogenesis. Validation and further explorative analyses of 6 P-DMRs mapping to SMAD7, CDH23, INSR, RFTN1, CPT1A and KLF13 highlighted the critical role of gestational timing, indicated that differential methylation extended along pathways involved in growth, development and metabolism, and suggested associations with birth weight and serum LDL cholesterol in adulthood and confirmed an enhancer function for the INSR and CPT1A P-DMRs. Our results point toward a link between prenatal malnutrition and epigenetic modulation of growth and lipid metabolism that may underlie the adverse metabolic phenotype of exposed individuals in later life.

  Study EGAS00001000668

• Whole exome sequencing of 49 tumor-blood pairs and transcriptome sequencing of 44 tumors for adrenocortical tumors

  Adrenal Cushing syndrome, which leads to type 2 diabetes, obesity and hypertension, is caused by ACTH-independent production of glucocorticoid by adrenocortical tumors. To investigate the genetic origins of cortisol-producing adrenocortical tumors, we performed whole exome sequencing of 49 tumor-blood pairs and transcriptome sequencing of 44 tumors

  Study EGAS00001000712

• Detection of mutational patterns in cell free DNA (cfDNA) of colorectal cancer by custom amplicon sequencing

  Monitoring the mutational patterns of solid tumors during cancer therapy is a major challenge in oncology. Analysis of mutations in cell free (cf) DNA offers a non-invasive approach to detect mutations that may be prognostic for disease survival or predictive for primary or secondary drug resistance. A main challenge for the application of cfDNA as a diagnostic tool is the diverse mutational landscape of cancer. Here, we developed a flexible end-to-end experimental and bioinformatics workflow to analyze mutations in cfDNA using custom amplicon sequencing. Our approach relies on open software tools to select primers suitable for multiplex PCR using minimal cfDNA as input. In addition, we developed a robust linear model to identify specific genetic alterations from sequencing data of cfDNA. We used our method to design a custom amplicon panel suitable for detection of hotspot mutations relevant for colorectal cancer and analyzed mutations in serial cfDNA samples from 34 patients with advanced colorectal cancer. Our data demonstrates that recurrent and patient-specific mutational patterns can be reliably detected for the majority of patients. Furthermore, we show that the allele frequency of mutations in cfDNA correlates well with disease progression. Finally, we demonstrate that monitoring of cfDNA can outperform the predictive power of currently used tumor markers and reveal mechanisms of resistance to anti-EGFR antibody treatment.

  Study EGAS00001003382

• Illumina Human OmniExpress genotyping data from the Cretan Greek isolate collection HELIC MANOLIS

  Isolated populations can empower the identification of rare variation associated with complex traits through next generation association studies. Here we have genotyped individuals from a Greek population isolate on the Illumina Human OmniExpress BeadChip array. The HELIC (Hellenic Isolated Cohorts) MANOLIS (Minoan Isolates) collection focuses on Anogia and surrounding Mylopotamos villages. Recruitment of this population-based sample was primarily carried out at the village medical centres. All individuals were older than 17 years and had to have at least one parent from the Mylopotamos area. www.helic.org **The data may not be used for population genetics analyses**

  Study EGAS00001000687

• Autozygosity_pilot___QMUL

  The offspring of first cousin marriages have ~6% of their genome autozygous, i.e. homozygous identical by descent, or even more if there was further consanguinity in their ancestry. In the UK there are large populations with very high first cousin marriage rates of 20-50%. Sequencing the exomes of a sample of these individuals has the potential both to support genetic health programmes in these populations, and to provide genetic research information about rare loss of function mutations. This pilot study based on existing British-Pakistani cohort samples will identify homozygous individuals for almost all variants down to an allele frequency around 1%, plus individuals carrying hundreds of new homozygous rare loss-of-function variants, and will support development of community relations and ethics for a wider study currently being designed. The data deposited in the EGA consists of low coverage whole exome sequencing on these samples.

  Study EGAS00001000717

• Germline and somatic SMARCA4 mutations characterize small-cell carcinoma of the ovary, hypercalcemic type.

  Small-cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is the most common undifferentiated ovarian malignancy in women under 40 years1. We sequenced the exomes of six individuals from three SCCOHT families. After discovering segregating deleterious germline mutations in SMARCA4 in all three families, we tested DNA from a fourth family, which also possessed a segregating SMARCA4 germline mutation. All familial tumors sequenced harboured either a somatic mutation or loss of the wild-type allele. Immunohistochemical (IHC) analysis of these and additional familial and non-familial cases showed loss of the SMARCA4 protein (BRG1) in 38/40 tumors overall. Sequencing of cases with available DNA revealed at least one germline or somatic deleterious SMARCA4 mutation in 30/32 cases. Additionally, the SCCOHT cell line BIN-67 contained bi-allelic deleterious mutations in SMARCA4. Our findings identify alterations in SMARCA4 as the major cause of SCCOHT, which could lead to genetic counseling and new treatment approaches.

  Study EGAS00001000721

• ESGI_Exome_sequencing_in_Circulating_Tumor_Cells_to_determine_therapy_related_markers_____

  The objectives of this project are the identification of markers related to cancer therapy resistance in the blood of breast cancer patients and to study the genetic changes in cancer cells during this development of resistance. Whole genome amplified DNA from Circulating Tumor Cells (CTCs), selected during the course of systemic treatment from blood of metastatic breast cancer patients, will be exome sequenced . The patients selected for this study did not respond to therapy.

  Study EGAS00001000747

• 16S-based fecal microbiota composition of the Milieu Intérieur Cohort

  The Milieu Intérieur project is a population-based study coordinated by the Institut Pasteur, Paris. The objective is to dissect the interplay between genetics and environment and their impact on the immune system. One of the primary goals of the project is to ascertain the role of the microbiota in regulating immune programs.

  Study EGAS00001003419

• Integrated genetic and epigenetic analysis defines novel molecular clusters in rhabdomyosarcoma

  Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in childhood. To unravel the genetic/epigenetic basis of RMS, we studied 60 RMS cases using whole exome/transcriptome sequencing, copy number (CN) profiling, and DNA methylome analysis. Based on DNA methylation patterns, RMS was clustered into 4 distinct subtypes, which exhibited remarkable correlation with mutation/CN profiles, histological phenotypes, and clinical behaviors. A1 and A2 subtypes, especially A1, largely corresponded to alveolar histology with frequent PAX3/7 fusions and alterations in cell cycle regulators. In contrast, mostly showing embryonal histology, both E1 and E2 subtypes were characterized by high frequency of CN alterations and/or allelic imbalances, FGFR4/RAS/AKT pathway mutations and PTEN mutations/methylation and in E2, also by p53 inactivation. Despite generally poor prognosis in RMS, patients in E1 cluster exceptionally showed excellent prognosis. Our results highlight the close relationship between DNA methylation status and gene mutations and biological behavior in RMS.

  Study EGAS00001000884