221 results for "study_type:"exome sequencing" AND repository:ega"

in 5.73 milliseconds.

• Distinct genomic profiles and clinical outcomes in constitutional mismatch repair deficiency-associated high-grade gliomas: insights into mutational signatures and clonal evolution

  Constitutional mismatch repair deficiency (CMMRD) is a rare cancer-predisposition syndrome, yet the mutational processes and clonal evolution of CMMRD-associated high-grade gliomas (HGGs) remain incompletely understood. In this study, mutational signatures and tumor evolution were analyzed in 25 CMMRD-associated HGGs. Germline biallelic mutations were most frequently identified in MSH6 (56.0%), followed by PMS2 (36.0%) and MLH1 (8.0%). Affected patients showed very early disease onset (mean 5.8 years) and poor clinical outcomes, with a mean progression-free survival of 16 months. Distinct genomic and clinical differences were observed between MSH6- and PMS2-associated tumors. MSH6-deficient HGGs were enriched for SBS6, whereas PMS2-deficient tumors showed predominance of SBS21, and these mutational signatures were correlated with prognosis. Clonal evolution analyses revealed early involvement of POLE/POLD1 mutations and persistence of the founding clone at recurrence. Overall, the study highlights the importance of mutational signatures and clonal evolution in shaping tumor behavior and clinical outcomes in CMMRD-associated HGGs.

  Study EGAS50000001506

• Rare Germline Variants in CDKN2A-Negative Children and Adolescents with Cutaneous Melanoma

  Cutaneous melanoma is a complex disease influenced by both environmental and genetic factors. Inherited susceptibility plays a significant role, involving a combination of high-, intermediate-, and low-penetrance genes. Melanoma in children and adolescents has been speculated to have a stronger genetic component due to the early onset. This study investigates germline variants in early-onset melanoma through exome sequencing of 154 patients in Australia diagnosed with cutaneous melanoma before the age of 20.

  Study EGAS50000001311

• ERDERA Diagnostic Research Workstream - WES reanalysis (distributed approach)

  The ERDERA Diagnostic Research Workstream – WES reanalysis (distributed approach) aims to improve diagnostic yield by systematically reanalyzing existing whole exome sequencing (WES) data from rare disease cases. The goal is to apply updated bioinformatics pipelines, novel variant interpretation tools, and the latest reference databases to detect clinically relevant variants that may have been missed in earlier analyses. By using a distributed approach across multiple expert groups, the project fosters collaborative interpretation and knowledge sharing to enhance diagnostic outcomes for patients.

  Study EGAS50000001514

• Whole Exome Sequencing of monomorphic epitheliotropic intestinal T-cell lymphoma and enteropathy associated T-cell lymphoma

  Background : Enteropathy-associated T-cell lymphoma (EATL) and monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) are aggressive malignancies with limited treatment options and poor prognosis. Our research on MEITL has uncovered its genetic portrait including hallmark SEDT2 mutations, expanded its pathological spectrum, and identified molecular biomarkers influencing patients’ outcome. In this study, we aimed to establish and clarify the similar and diverging features of EATL. Methods : A large combined cohort of patients with EATL (n=30) and MEITL (n=52) was assembled and tumor samples were used for whole-exome and RNA sequencing profiling.

  Study EGAS50000001126

• A human induced pluripotent stem cell toolbox for studying sex chromosome effects-Whole exome seq

  To generate autosomaly isogenic hiPSCs with various chromosome complement, we use Klinefelter syndrome patient skin fibroblasts. These cells harbour XXY sex chromosomes, which can be lost during the reprogramming event and generate cells which are autosomaly identical to each other but differ in sex chromosome complement. We use state of the art reprogramming methods to generate panels of isogenic XXY, XX and XY iPSCs from XXY patient fibroblasts. We have performed Whole exome sequencing on Klinefelter syndrome patient's skin fibroblasts in order to check if two X chromosomes are identical and to see if we can distinguish which X chromosome is more likely to be lost during the reprogramming event in XY cell lines.

  Study EGAS50000000930

• Mutational analysis reveals the origin and therapy-driven evolution of recurrent glioma

  Tumor recurrence is a leading cause of cancer mortality. Therapies for recurrent disease may fail, at least in part, because the genomic alterations driving the growth of recurrences are distinct from those in the initial tumor. To explore this hypothesis, we sequenced the exomes of 23 initial low-grade gliomas and recurrent tumors resected from the same patients. In 43% of cases, at least half of the mutations in the initial tumor were undetected at recurrence, including driver mutations inTP53, ATRX, SMARCA4, and BRAF; this suggests that recurrent tumors are often seeded by cells derived from the initial tumor at a very early stage of their evolution. Notably, tumors from 6 of 10 patients treated with the chemotherapeutic drug temozolomide (TMZ) followed an alternative evolutionary path to high-grade glioma. At recurrence, these tumors were hypermutated and harbored driver mutations in the RB (retinoblastoma) and Akt-mTOR (mammalian target of rapamycin) pathways that bore the signature of TMZ-induced mutagenesis.

  Study EGAS00001000579

• Whole-exome Sequencing Combined with Functional Genomics Reveals Novel Candidate Driver Cancer Genes in Endometrial Cancer

  Endometrial cancer is the most common gynecological malignancy, with more than 280,000 cases occurring annually worldwide. Although previous studies have identified important common somatic mutations in endometrial cancer, they have primarily focused on a small set of known cancer genes and have thus provided a limited view of the molecular basis underlying this disease. Here we developed an integrated systems biology approach to identifying novel cancer genes contributing to endometrial tumorigenesis. We first performed whole-exome sequencing on 13 endometrial cancers and matched normal samples, systematically identifying somatic alterations with high precision and sensitivity. We then combined bioinformatics prioritization with high-throughput screening (including both shRNA-mediated knockdown and expression of wild type and mutant constructs) in a highly sensitive cell viability assay. Our results revealed 12 potential driver cancer genes including 10 tumor suppressor candidates (ARID1A, INHBA, KMO, TTLL5, GRM8, IGFBP3, AKTIP, PHKA2, TRPS1 and WNT11) and two oncogene candidates (ERBB3 and RPS6KC1). The results in the “sensor” cell line were recapitulated by siRNA-mediated knockdown in endometrial cancer cell lines. Focusing on ARID1A, we integrated mutation profiles with functional proteomics in 222 endometrial cancer samples, demonstrating that ARID1A mutations frequently co-occur with mutations in the phosphatidylinositol 3-kinase (PI3K) pathway and are associated with PI3K pathway activation. siRNA knockdown in endometrial cancer cell lines increased AKT phosphorylation supporting ARID1A as a novel regulator of PI3K pathway activity. Our study presents the first unbiased view of somatic coding mutations in endometrial cancer and provides functional evidence for diverse driver genes and mutations in this disease.

  Study EGAS00001000318

• Ashkenazi Jewish Leukoencephalopathy

  Genetic leukoencephalopathies (gLEs) are a group of heterogeneous disorders with white matter abnormalities in the central nervous system (CNS). Patients affected with gLEs have brain white matter defects that can be seen in MRI and exhibit variable neurologic phenotypes including motor impairment, hypotonia, pyramidal dysfunction, dystonia and/or dyskinesias, ataxia, seizures, cortical blindness, optic atrophy, and impaired cognitive development. The exact causes in half of gLEs are unknown. We studied three unrelated families affected with an undiagnosed gLE and discovered a homozygous germline mutation c.2536T>G in VPS11 by whole exome sequencing, a gene involved in membrane trafficking and fusion of the lysosomes and endosomes, as a novel cause of a new gLE syndrome.

  Study EGAS00001001767

• Pancreatic Cancer Sequencing Initiative

  Pancreatic Cancer Sequencing Initiative for the International Cancer Genome Consortium at the Ontario Institute for Cancer Research.

  Study EGAS00001000343

• Characterization of a novel MEF2D-BCL9 fusion positive acute lymphoblastic leukemia cell line WXS

  Study EGAS00001006800

• UK10K_RARE_HYPERCHOL

  In the UK10K project we propose a series of complementary genetic approaches to find new low frequency/rare variants contributing to disease phenotypes. These will be based on obtaining the genome wide sequence of 4000 samples from the TwinsUK and ALSPAC cohorts (at 6x sequence coverage), and the exome sequence (protein coding regions and related conserved sequence) of 6000 samples selected for extreme phenotypes. Our studies will focus primarily on cardiovascular-related quantitative traits, obesity and related metabolic traits, neurodevelopmental disorders and a limited number of extreme clinical phenotypes that will provide proof-of-concept for future familial trait sequencing. We will analyse directly quantitative traits in the cohorts and the selected traits in the extreme samples, and also use imputation down to 0.1% allele frequency to extend the analyses to further sample sets with genome wide genotype data. In each case we will investigate indels and larger structural variants as well as SNPs, and use statistical methods that combine rare variants in a locus or pathway as well as single-variant approaches.Familial Hypercholesterolemia is a condition where the affected person has a consistently high level of LDL which can lead to early clogging of the coronary arteries. All patients selected for this study will have been found not to carry the common APOB and PCSK9 mutations, and to have no detectable LDLR mutations by testing for 18 common mutations. For further information with regard to this cohort please contact Steve Humphries(steve.humphries@ucl.ac.uk).

  Study EGAS00001000129