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

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• Germline Aberrations of PAX5 Cause Susceptibility to pre-B cell Acute Lymphoblastic Leukemia

  A novel heterozygous germline variant, c.547G>A (p.Gly183Ser), in the paired box protein encoding gene, PAX5, was found to segregate with disease in two unrelated kindreds with autosomal dominant pre-B cell acute lymphoblastic leukemia (ALL). Leukemic cells from both families exhibited 9p deletion, with loss-of-heterozygosity and retention of the mutant PAX5 allele at 9p13 . Two additional sporadic ALL cases with 9p loss demonstrated PAX5 Gly183 substitution in the leukemic cells. Functional analysis of the PAX5 germline variants demonstrated reduced transcriptional activity, as well as decreased interaction with Groucho-4. These data extend the role of PAX5 alterations in the pathogenesis of pre-B ALL, and implicate PAX5 in a novel syndrome of germline susceptibility to pre-B cell neoplasia.

  Study EGAS00001000447

• A Cancer Cell-Line Titration Series for Evaluating Somatic Classification

  Accurate detection of somatic single nucleotide variants and small insertions and deletions from DNA sequencing experiments of tumour-normal pairs is a challenging task. Tumour samples are often contaminated with normal cells confounding the available evidence for the somatic variants. Furthermore, tumours are heterogeneous so sub-clonal variants are observed at reduced allele frequencies. We present here a cell-line titration series dataset that can be used to evaluate somatic variant calling pipelines with the goal of reliably calling true somatic mutations at low allele frequencies. Cell-line DNA was mixed with matched normal DNA at 8 different ratios to generate samples with known tumour cellularities, and exome sequenced on Illumina HiSeq to depths of >300x. The data was processed with several different variant calling pipelines and verification experiments were performed to assay >1,500 somatic variant candidates using Ion Torrent PGM as an orthogonal technology. By examining the variants called at varying cellularities and depths of coverage, we show that the best performing pipelines are able to maintain a high level of precision at any cellularity. In addition, we estimate the number of true somatic variants undetected as cellularity and coverage decrease. Our cell-line titration series dataset, along with the associated verification results, is effective for this evaluation and will serve as a valuable dataset for future somatic calling algorithm development.

  Study EGAS00001001016

• Whole exome sequencing of Zimbabwean patients with suspected Mendelian disorders

  This study presents whole exome sequencing data from Zimbabwean individuals with suspected Mendelian disorders, including sickle cell disease, Fanconi anemia, haemophilia, and muscular dystrophy. The dataset includes both affected individuals and family members to support inheritance-based analyses. Variant calling was performed using the Illumina DRAGEN pipeline, with downstream variant prioritisation and interpretation conducted using the Zi-Mendelian bioinformatics pipeline. This study supports rare disease genomics and precision medicine efforts in African populations.

  Study EGAS50000001708

• Proteomic Characterization of Intrahepatic Cholangiocarcinoma Identifies Risk-Stratifying Subgroups, Proteins Associated with Time-To-Recurrence, and mTOR Effector Molecule EIF4A1 as a Druggable Therapeutic Target

  Using mass spectrometry-based proteomics, we analyzed two independent cohorts comprising 80 and 62 treatment-naive ICC tumors, 67 adjacent non-malignant tissues, and 9 patient-derived xenografts (PDX). In the first cohort, we identifed two subclusters with distinct times-to-recurrence (TTR). A 4-protein classifier trained on our data cohort accurately stratifies these ICC clusters in the Dong et al. dataset (2022) and in our independent second cohort, revealing similar associations between proteomic motifs and clinical outcomes. The Translation regulator EIF4A1 emerges as a therapeutic target, as its inhibition with novel drug eFT226 significantly reduces tumor growth in an ICC PDX model.

  Study EGAS50000001343

• Pancreatic Cancer Sequencing Initiative

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

  Study EGAS00001000343

• 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

• 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

• 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

• 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

• UK10K_NEURO_ASD_FI

  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.These samples are a subset of a nationwide collection of Finnish autism spectrum disorder (ASD) samples. The samples have been collected from Central Hospitals across Finland in collaboration with the University of Helsinki. The samples consist of 93 individuals with a diagnosis of autistic disorder or Asperger syndrome from 36 families with at least two affected individuals. Of these individuals, 16 can be genealogically connected to form two large pedigrees originating from Central Finland, suggesting possible genetic risk factors shared identical by descent within the pedigrees. All diagnoses are based on ICD-10 and DSM-IV diagnostic criteria for ASDs. Additional phenotypic data is available for a subset of the individuals.For further information with regard to this cohort please contact Aarno Palotie (Aarno.palotie@helsinki.fi).

  Study EGAS00001000110