22959 results for "ega"

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• RNA-sequencing data from 195 B-cell precursor acute lymphoblastic leukemias and mate pair whole genome sequencing data from 15 B-cell precursor acute lymphoblastic leukemias

  Fusion genes are potent driver mutations in cancer. In this study, we delineate the fusion gene landscape in a consecutive series of 195 pediatric B-cell precursor acute lymphoblastic leukemia (BCP ALL). Using RNA-sequencing, we find in-frame fusion genes in 127 (65%) cases, including 27 novel fusions. We describe a new subtype characterized by recurrent IGH-DUX4 or ERG-DUX4 fusions, representing 4% of cases, leading to overexpression of DUX4 and frequently co-occurring with intragenic ERG deletions. Furthermore, we identify a subtype characterized by an ETV6-RUNX1-like gene expression profile and coexisting ETV6 and IKZF1 alterations. Taken together, this study provides a detailed overview of fusion genes in pediatric BCP ALL and adds new pathogenetic insights, which may improve risk stratification and provide novel therapeutic options in this disease.

  Study EGAS00001001795

• Genomic and transcriptional landscape of P2RY8-CRLF2-positive childhood acute lymphoblastic leukemia

  The mutational and transcriptional landscape of P2RY8-CRLF2-positive ALL was defined in 41 major clone fusion-positive cases including 19 matched diagnosis and relapse pairs by an integrated analysis of whole-exome and RNA sequencing. We detected a variety of frequently subclonal and highly unstable JAK/STAT but also RTK/Ras pathway activating mutations in 76% of cases at diagnosis and virtually all relapses. Unlike P2RAY8-CRLF2 that was lost in 32% of relapses, all other genomic deletions affecting lymphoid development and cell cycle remained stable. Only IKZF1 alterations predominated in relapsing cases and increased from initially 36 to 58% in matched cases. IKZF1¹s transcriptional signature revealed compromised stem cell features with signs of impaired lymphoid differentiation, enhanced focal adhesion, activated hypoxia pathway, deregulated cell cycle and increased drug resistance.

  Study EGAS00001001847

• Molecular dissection of germline chromothripsis in a developmental context

  Complex germline genomic rearrangements can affect many genes and regulatory elements, but the precise mechanisms that caused the phenotype of patients with such rearrangements are often unknown. To dissect the impact of germline chromothripsis in a relevant developmental context, we performed trio-based RNA expression analysis on blood cells,induced pluripotent stem (iPS) cells and iPS-cell derived neuronal cells from a patient with de novo germline chromothripsis and both healthy parents. In addition, we performed Hi-C on iPS cell-derived neural progenitors of the patient and the father to study the effects of the chromothripsis rearrangements on the architecture of the derivative chromosomes. We demonstrate that a combination of patient-derived iPS cell differentiation and trio-based molecular profiling is a powerful approach to improve the interpretation of pathogenic complex genomic rearrangements.

  Study EGAS00001001896

• Exome sequencing of samples taken at multipl time points to monitor therapy response in AML

  As part of our individualized systems medicine program, personalized treatment options are identified and administered to chemorefractory AML patients based on exome sequencing and ex-vivo drug sensitivity and resistance testing data. In this study, we developed this approach further to take into account clonal heterogeneity and analyzed responses of 13 AML patients to chemotherapy and six patients to targeted treatments by using exome and ultra-deep amplicon resequencing. The data submitted includes fastq files from exome sequencing of multiple time-point samples collected from the 13 patients. In this study we identified rare subclonal variants present at diagnosis or later relapse samples and developed a correlation-based method to compare subclonal responses in serial samples across multiple time-points. Significant subclone-specific responses were observed subsequent to chemotherapy and specifically to targeted therapy in five patients.

  Study EGAS00001001948

• The Simons Genome Diversity Project: 300 genomes from 142 diverse populations

  Here we report the Simons Genome Diversity Project data set: high quality genomes from 300 individuals from 142 diverse populations. These genomes include at least 5.8 million base pairs that are not present in the human reference genome. Our analysis reveals key features of the landscape of human genome variation, including that the rate of accumulation of mutations has accelerated by about 5% in non-Africans compared to Africans since divergence. We show that the ancestors of some pairs of present-day human populations were substantially separated by 100,000 years ago, well before the archaeologically attested onset of behavioural modernity. We also demonstrate that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans; instead, their modern human ancestry is consistent with coming from the same source as that in other non- Africans.

  Study EGAS00001001959

• Germline MBD4 Mutations and Predisposition to Uveal Melanoma

  Uveal melanoma (UM) arises from malignant transformation of melanocytes from the uveal tract. This rare tumor has a poor outcome with frequent liver metastases and primary resistance to treatment1. The only strong predisposing condition for UM is the BAP1 tumor predisposition syndrome due to germline BAP1 deleterious mutations. UMs are generally characterized by a very low tumor mutation burden (TMB). However, some UMs display a high level of CpG to TpG mutations associated with MBD4 inactivation. Here, we explored the incidence of germline MBD4 variants in a consecutive series of 1, 099 primary UMs, and identified 8 deleterious MBD4 mutations, an aprox 10-fold increased incidence compared with the general population. These mutations were associated with a high TMB in tested UMs. We thus demonstrated that MBD4 is the second major predisposing gene for UM.

  Study EGAS00001003941

• A Unifying Paradigm for Transcriptional Heterogeneity and Squamous Features in Pancreatic Ductal Adenocarcinoma

  Pancreatic cancer expression profiles largely reflect a classical or basal-like phenotype. The extent to which these profiles vary within a patient is unknown. We integrated evolutionary analysis and expression profiling in multiregion sampled metastatic pancreatic cancers, finding that squamous features are the histologic correlate of an RNA-seq defined basal-like subtype. In patients with coexisting basal/squamous and classical/glandular morphology, phylogenetic studies revealed that squamous morphology represented a subclonal population in an otherwise classical/glandular tumor. Cancers with squamous features were significantly more likely to have clonal mutations in chromatin modifiers, intercellular heterogeneity for MYC amplification, and entosis. These data provide a unifying paradigm for integrating basal-type expression profiles, squamous histology, and somatic mutations in chromatin modifier genes in the context of clonal evolution of pancreatic cancer.  

  Study EGAS00001003974

• Measuring the level of relatedness between NGS datasets

  Sequencing technologies are providing increasingly detailed insight in genetic makeup are paving their way into molecular diagnostics. The field will benefit from rigorous and bias-free measures for the quality of sequence data and for the proper representation of the complexity of the original samples. While current methodologies rely on the availability of a well-characterized reference genome, we propose kMer profiling for alignment-free assessment of the quality, comparability, and complexity of sequencing datasets. We show that kMer detects technical artefacts such as high duplication rates, library chimaeras, and differences in library preparation protocols in whole-genome, whole-exome, and RNA sequencing data. Additionally, it successfully captures the complexity and diversity of microbiomes. Thus, kMer allows for a robust evaluation of the quality and complexity of sequencing data without relying on any prior information and opens the way to a more reliable biological reasoning.

  Study EGAS00001000600

• Reconstructing the dispersals and adaptive history of Bantu-speaking populations in Africa and North America

  Bantu languages are spoken by ~310 million Africans, yet the genetic history of Bantu-speaking populations remains largely unexplored. We generated genomic data for 1,318 individuals from 35 populations in western central Africa, where Bantu languages originated. We found that early Bantu speakers first moved southward, through the equatorial rainforest, before spreading toward eastern and southern Africa. We also found that genetic adaptation of Bantu speakers was facilitated by admixture with autochthonous populations, particularly for the HLA and LCT loci. Finally, we identified a major contribution of western central African Bantu speakers to the ancestry of African Americans, whose genomes present no strong signals of natural selection. Together, these results highlight the contribution of Bantu-speaking peoples to the complex genetic history of Africans and African Americans.

  Study EGAS00001002078

• Molecular and Clonal Evolution in Recurrent Metastatic Gliosarcoma

  We present a rare case of a 37-year-old woman who was initially diagnosed with IDH wild-type gliosarcoma in the frontal lobe and later developed two local recurrences and extracranial metastases to the vertebral and pelvic bones. In order to understand the clonal relationships between the four tumor instances and the origin of metastasis, we performed whole genome sequencing of the intracranial tumors and the tumor located in the right iliac bone. Mutational and copy number profile comparisons of the metastatic to intracranial tumors highlighted a high similarity in molecular profile, but contrasting evidence regarding the origin of the metastasis. Subclonal reconstruction suggested a parallel evolution of the recurrent tumors, and that the metastatic tumor was largely derived from the first recurrence. We conclude that metastasis in glioma can be a late event in tumorigenesis.

  Study EGAS00001004076