4078 results for "*geneti*"

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• Complex genotype-phenotype relationships shape the response to treatment of Down Syndrome Childhood Acute Lymphoblastic Leukaemia

  Extensive genetic and epigenetic variegation has been demonstrated in many malignancies. Importantly, their interplay has the potential to contribute to disease progression and treatment resistance. To shed light on the complex relationships between these different sources of intra-tumour heterogeneity, we explored their relative contributions to the evolutionary dynamics of Acute Lymphoblastic Leukaemia (ALL) in children with Down syndrome, which has particularly poor prognosis. We quantified the tumour propagating potential of genetically distinct sub-clones using serial transplantation assays and SNP-arrays. While most leukaemias were characterized by a single dominant subclone, others were highly heterogeneous. Importantly, we provide clear and direct evidence that genotypes and phenotypes with functional relevance to leukemic progression and treatment resistance can co-segregate within the disease. Hence, individual genetic lesions can be restricted to well-defined cell immunophenotypes, corresponding to different stages of the leukemic differentiation hierarchy and varied proliferation potentials. As a result of this difference in fitness, which can be accurately quantified via competitive transplantation assays, matching diagnostic, post-treatment, and relapse leukaemias can be dominated by different genotypes, including pre-leukemic clones persisting throughout the disease progression and treatment. Intriguingly, plasticity also appears to be a temporally defined property that can segregate with genotype. These results suggest that Down Syndrome ALL should be viewed as a complex matrix of cells exhibiting genetic and epigenetic heterogeneity that foster extensive clonal evolution and competition. Therapeutic intervention reshapes this ‘eco-system’ and may provide the right conditions for the preferential expansion of selected compartments and subsequently relapse.

  Study EGAS50000001287

• Identification Of Pathogenic Mutations And Application Of Polygenic Risk Scores In Early-Onset Diabetes Patients

  Maturity-onset Diabetes of the Young (MODY) presents a diagnostic challenge. In this study we investigate the genetic background of Latvian early-onset diabetes patients, using whole-genome sequencing data. Additionally, we investigate the utility of previously published and available type 1 diabetes (T1D) and type 2 diabetes (T2D) polygenic risk scores in differentiating monogenic diabetes (MODY) from T1D and T2D cases.

  Study EGAS50000000991

• Genetic differences between primary colorectal cancer and its paired synchronous and metachronous metastases

  In this study we present for the first time the genetic differences associated with different chronicity of colorectal cancer liver metastases identified by whole-exome sequencing of 210 CRC samples. We focus on differences in primary tumors as we hypothesize that these are the cause of the differences in the time course of the disease. The results suggest that distinct tumor progression pathways account for different chronicity outcomes with ultimate impact on patient’s prognosis

  Study EGAS50000000996

• Mechanisms of active DNA demethylation in human monocytes

  Study EGAS00001004784

• A prospective study identifies MisMatch Repair genes as candidate predisposing genes for uveal melanoma.

  Objective: The aim of this study is to identify new predisposing genes for uveal melanoma (UM), the most common intraocular malignancy in adults. Design: Prospective cohort study from Institut Curie. Participants: 381 unselected patients diagnosed with UM between July 2021 and February 2023 at Institut Curie. Methods: All patients received genetic counseling and consented to extended genetic testing. A panel of 122 genes was analyzed by targeted sequencing on germline DNA from these patients. Main outcomes measures: UM was diagnosed by ophthalmologists at Institut Curie, and a senior pathologist confirmed the diagnosis when tumor or biopsy was available. Classification of the germline genetic variants was performed according to the ACMG guidelines. Results: We identified at least one pathogenic variant (PV) in 79 patients. Among those variants, 20 were found in clinically relevant genes for the patient’s follow-up and genetic counseling. We found a significant enrichment of germline pathogenic variants in Mismatch Repair (MMR) MLH1, MSH2 and MSH6 genes in this UM cohort, suggesting that MMR germline alterations could predispose to UM. From this cohort, one tumor was available from a patient carrying a MLH1 germline mutation. The tumor was characterized by a monosomy 3, in line with a loss of heterozygosity (LOH) of MLH1, located on chromosome 3. Loss of expression of MLH1 and PMS2 was observed by immunohistochemistry, and MMR mutational signatures SBS6, ID1 and ID2 were identified from the whole genome sequencing of the tumor. These data suggest that MLH1 is implicated in the oncogenesis of this UM. Conclusions: This study is the largest prospective constitutional study performed on UM patients, and the first demonstrating that MMR germline alterations are significantly enriched among these patients. Further analyses will be needed to estimate the risk of developing UM for patients with Lynch syndrome

  Study EGAS50000000914

• PBAT sequencing of naïve human ESCs

  This project investigates the DNA methylation landscape of naïve human embryonic stem cells (hESCs) derived from human embryos, assessing the impact of ERK inhibition (ERKi). Naïve ESCs were cultured in UXGL or PXGL media. Post bisulphite adaptor tagging protocol was used to profile genome-wide DNA methylation.

  Study EGAS50000001006

• The circulating cell-free DNA landscape in sepsis is dominated by impaired liver clearance

  Circulating cell-free DNA (cfDNA) is a promising molecular biomarker. However, its utility in severe infection remains poorly understood. Here, we isolated cfDNA from sepsis patients and controls, demonstrating a 41-fold increase in the amount of cfDNA in circulation during disease. We used sequencing to reconstruct cfDNA methylomes, fragmentation profiles, and nucleosome footprints across 58 samples. We observed no difference in cfDNA composition between patients and controls, challenging the idea that cfDNA increases due to higher immune cell death during sepsis. Instead, we suggest that liver dysfunction prevents efficient clearance of cfDNA during disease. This was supported by fragmentation and end-motif patterns, both of which showed evidence of cfDNA being exposed to circulating nucleases for a prolonged period, proportionally to the extent of liver dysfunction. Variation in cfDNA of megakaryocyte-erythroid progenitor origin was also a significant contributor in sepsis, increasing over time. Moreover, we showed that cfDNA retains nucleosome footprints with cell type-specific gene activity information. We developed a novel approach to study nucleosome phasing that successfully recovers tissue-specific signatures. By combining this with single-cell data, we demonstrated that sepsis patients with liver dysfunction have higher amounts of cfDNA derived from Kupffer cells and the liver parenchyma. In conclusion, we present the first high-throughput multi-modal study of cfDNA during sepsis, which will serve as a reference point for future studies on the role of this biomarker in critical illness.

  Study EGAS50000001033

• South African Blood Regulatory (SABR) Resource

  Functional genomics resources are critical for interpreting human genetic studies, however they are predominantly from European-ancestry individuals. Here we present the South African Blood Regulatory (SABR) resource, a map of blood regulatory variation that includes three South Eastern Bantu-speaking groups. Using paired whole genome and blood transcriptome data from over 600 individuals, we map the genetic architecture of 40 blood cell traits derived from deconvolution analysis, as well as expression, splice, and cell type interaction quantitative trait loci (QTL).

  Study EGAS50000001008

• SCI-MAP: Single Cell Microgel embedded iPS-cells to map molecular variability of cell differentiation using a systems biology approach.

  In the SCI-MAP project we will map cell states encountered across a previously established 49 day in vitro chondrogenic differentiation protocol. We do this to optimise the differentiation process for therapeutic and in vitro modelling ends. We collect epigenetic open chromatin and phenotypic transcriptome data to determine cell states and so performed single nucleus sequencing in two modalities: RNA- and ATAC-sequencing. Data was collected in a time series experiment at 7 points: Days 0, 3, 6, 8, 14, 21, and 49, starting with the first pilot data from day 21 (D21).

  Study EGAS50000001041

• Jeju Genome Project

  The Jeju Genome Project (JGP) is a multi-omics resource for precision medicine in a geographically distinct South Korean population. It comprises 5,309 participants (3,001 community-based; 2,308 hospital-based) with data spanning Whole-Genome Sequencing (WGS) and genotyping arrays. The hospital cohort is specifically enriched for neurological and rheumatic diseases and malignancies. By providing a population-specific reference panel, JGP enables high-resolution genetic architecture analysis, risk stratification, and the discovery of rare variants relevant to Jeju and broader East Asian populations.

  Study EGAS50000001706