Search Results - EGA European Genome-Phenome Archive

Advanced iPSC-CMs maturation by integrating maturation medium, nanopatterning, and electrical stimulation

RNA seq of iPSC-derived cardiomyocytes cultured in lipid-enriched maturation medium (MM), in MM on nanopattern-surfaces (NP) and under the influence of MM, NP and electrical Stimulation (ES, 2Hz, 14 days). 9 Samples from 3 Independent batches/differentiations of cardiomyocytes from 2 different iPSC-lines (iWTD2.1 and isWT7.22).

Dataset EGAD00001011289

OMKar: optical map based automated karyotyping of genomes to identify constitutional disorders

This dataset contains optical genome mapping (OGM) data from 56 samples, processed for structural variation and copy number analysis. The data includes .xmap, .cmap, and .smap files representing high-resolution genome maps and structural variant calls. These samples were used to identify complex rearrangements and reconstruct genome karyotypes.

Dataset EGAD00001015674

Single-cell T-cell receptor sequencing of intraepithelial CD8+ αβ T-cells in celiac disease

Single-cell paired TCR sequencing of intraepithelial CD8+ αβ T-cells in gluten-free diet treated and untreated celiac disease patients and in controls. (Paired end, amplicon sequencing).

Study EGAS00001004989

Non-coding RNAs Activated by the Wnt/Beta-catenin Signaling Pathway in Hepatoblastoma

Hepatoblastoma (HB) is the most common pediatric liver tumor, affecting mostly children under 3 years of age. This rare tumor represents 1% of all pediatric cancers. Genetic studies have shown that HB is characterized by high frequency mutations of the CTNNB1 gene encoding beta-catenin (around 75%) and relative genomic stability. Here we have analyzed the transcriptional profile of 21 HBs compared to matched non-tumor livers by Cap Analysis of Gene Expression (CAGE), which provides accurate and quantitative profiling of all transcripts. CAGE analysis revealed strong upregulation of known Wnt target coding genes in most tumors analyzed, consistent with previous transcriptomic studies. To better define the Wnt-dependent transcriptional landscape of HB, we integrated CAGE data with TCF4 ChIP-seq data from a CTNNB1-mutated cancer cell line and with the FANTOM5 genomic coordinates of TCF/LEF binding motifs. Both TCF/LEF binding motifs and ChIP-seq peaks were strongly enriched in the immediate upstream region, not only for protein-coding genes, but also for non-coding transcripts. Among the selected 112 top Wnt target genes at FDR<1.0E-6 and fold change>8, we found clear over-representation (66%) of distant transcription start sites (TSSs) representing lncRNAs and enhancer RNAs, which raises the question of their role in HB pathogenesis. Analysis of the 112 promoters using CAGEd-oPOSSUM confirmed the predominant involvement of Tcf/Lef transcription factors, together with HNF4G, GATA2, Sox3 and Ets-related genes. Finally, the 112 Wnt target signature defined 3 tumor subclasses, T1, T2 and T3, characterized by progressive alteration of the non-coding part of the transcriptome and significant differences in clinical behavior.

Study phs001433

Mitochondrial DNA deletion detection in POLG patients

Accumulation of deletions in the mitochondrial genome is a pathological hallmark of both aging and a broad range of neurometabolic disorders. Prior mtDNA deletion studies have been limited by reliance upon either long range PCR or NGS strategies that target specific regions of the mitochondrial genome. We developed an ultrasensitive high throughput sequencing process (LostArc) to identify and quantify all deletions in circular DNA molecules while minimizing interference from linear DNA and PCR artefacts. We applied this process to skeletal muscle biopsies from 19 unaffected individuals (aged 17 to 93 years) and from 22 patients with heritable mitochondrial disease (17 to 80 years) bearing pathogenic variants in POLG, the nuclear gene encoding the catalytic subunit of the mitochondrial replicative DNA polymerase ɣ (Pol ɣ). To our astonishment, LostArc revealed 35 million mtDNA deletions with ~470,000 unique deletion spans. This unprecedented volume of data enabled detailed and highly informative bioinformatics analyses. We show that ablation of mtDNA is sufficient to explain skeletal muscle phenotypes associated with aging and POLG-derived disease, with a clear threshold separating symptomatic and asymptomatic individuals. Unsupervised hierarchical clustering and principle component analysis reveal distinct age- and disease-correlated deletion patterns that implicate DNA replication by Pol ɣ in the formation of mtDNA deletions. Deletion patterns also point to active mtDNA replication but little or no purifying selection against deleted mtDNA by mitophagy in postmitotic muscle fibers. Monte Carlo simulations of varied hypotheses for deletion formation, based in part on competing models of mtDNA replication, suggest the observed patterns are most consistent with deletions initiated by replication fork stalling during strand displacement mtDNA synthesis. Note that sequence data for HEK293 can be found under BioProject PRJNA642884.

Study phs002052

Investigating the Role of Neddylation in the Repair of Topoisomerase I-Mediated DNA Damage in Colorectal Cancer

Colorectal cancer is one of the most lethal cancers worldwide. First-line chemotherapy for metastatic CRC (mCRC) entails a combination of irinotecan with 5-fluorouracil and leucovorin (FOLFIRI). Irinotecan is a prodrug that is converted within the cell to its active metabolite SN38, a potent TOP1 inhibitor. TOP1 relieves DNA torsional strain arising from DNA metabolism by cleaving one strand of the DNA duplex and forming an enzyme-DNA covalent intermediate that can be trapped by inhibitors. The resulting TOP1 DNA-protein crosslinks (TOP1-DPCs) interfere with replication and transcription and induce cell death if left unrepaired. I have established the role of the ubiquitin-proteasome pathway in TOP1-DPC repair, but it remains unknown how ubiquitylation is activated. One possibility is that collision between advancing replication forks and the DPCs triggers a specific ubiquitin ligase to target DPCs for degradation. The DDB1-CUL4 (Cullin 4)-RBX1 (CRL4) ubiquitin ligase complex performs a salient role in both replication and DNA repair upon its activation by auto-NEDD8 modification (neddylation), but it is unknown whether it plays a role for TOP1-DPC repair. We plan to define the role of neddylation for TOP1-DPC repair during replication and examine irinotecan plus pevonedistat (PEV), a NEDD8-activating enzyme inhibitor in multiple clinical trials, in CRC patient-derived preclinical models including 3D organoids. The three in-house organoids, from which samples have been submitted to dbGaP, were sequenced as a means of verifying their identity as colon cancer organoids, to allow us to investigate the combination of TOP1 inhibitors and PEV and the molecular mechanisms underlying this drug combination in these organoids.

Study phs003257

Center for Inherited Disease Research (CIDR)-National Institute on Aging (NIA) Whole Exome Analysis of Ehlers-Danlos Syndrome

The Ehlers-Danlos syndromes (EDS) are a family of hereditary disorders of connective tissue characterized by joint hypermobility and skin involvement with soft, translucent, stretchy skin, and atrophic scarring. To date, over 12 different types of EDS are known, and the genes causing almost all of them have been found. However, the gene(s) underlying the most common of Ehlers-Danlos syndrome, known as the hypermobile type, remain elusive. The hypermobile type of Ehlers-Danlos syndrome is associated with multiple co-morbidities, including dysautonomia, chronic musculoskeletal pain, gastrointestinal dysmotility, mast cell activation and multiple neurologic complications. Affected persons often suffer from chronic fatigue and may be chronically disabled. While the precise frequency of the condition is not known, it may be as common as between 1/500 and 1/1000 persons. There is a significant overlap with the phenotype of fibromyalgia, and multiple persons diagnosed with fibromyalgia may well have the hypermobile type of Ehlers-Danlos syndrome. The phenotype of hypermobile EDS segregates as a single dominant trait with complete penetrance, variable expressivity, and a markedly evolving phenotype over time. Identification of the genetic cause of this hereditary disorder has the potential to inform rational therapy for this disabling condition. It is hoped that the insight into the pathogenesis of the hypermobile type of EDS will lead to a similar breakthrough in therapy for this disorder. Toward this end, whole exome sequencing (WES) of DNA from a total of 167 patients will be performed at the Center for Inherited Disease Research (CIDR) to identify genes underlying the hypermobile type of Ehlers-Danlos syndrome and those with EDS of an uncharacterized type.

Study phs001779

NINDS Deep Sequencing for the Detection of Viral Sequences in Primary Progressive Multiple Sclerosis Brains

Deep sequencing allows for a rapid, accurate characterization of microbial DNA and RNA sequences in many types of samples. Deep sequencing (also called next generation sequencing or NGS) is being developed to assist with the diagnosis of a wide variety of infectious diseases. In this study, seven frozen brain samples (n = 7) from deceased subjects with recent encephalitis were investigated. RNA from each sample was extracted, randomly reverse transcribed, and sequenced. The sequence analysis was performed in a blinded fashion and confirmed with pathogen-specific PCR. This analysis successfully identified measles virus sequences in two brain samples and herpes simplex virus type-1 sequences in three brain samples. No pathogen was identified in the other two brain specimens. These results were concordant with pathogen-specific PCR and partially concordant with prior neuropathological examinations, demonstrating that deep sequencing can accurately identify viral infections in frozen brain tissue (Chan et al., 2014). Data from the primary progressive multiple sclerosis (PPMS) brain specimens (n = 14) and Normal Control brain specimens (n = 14) are also submitted here. All the subjects studied here (encephalitis, PPMS, and controls) were selected from existing collections at the Rocky Mountain and UCLA brain banks. These selections were performed by the directors at the two centers (Dr. Corboy at RM and Nagra at UCLA) based on clinic information provided at the time of collection. All the specimens are from deidentified deceased individuals. The submitting investigators have no identifying information on any of these subjects. To avoid confusion, the dbGaP Subject IDs are identical to the brain bank identifying numbers.

Study phs000715

Chromatin Landscape of BET Inhibitor-Treated CD8+ T-cells from Chronic Lymphocytic Leukemia Patients

The pan-BET (bromodomain and extra-terminal) inhibitor, OPN-51107 (OPN5) was found to alleviate features of T-cell exhaustion in models of chronic lymphocytic leukemia (CLL). To evaluate if OPN5 treatment could relieve fixed chromatin states associated with terminal T-cell dysfunction, ATAC-sequencing was performed on CLL patient T-cells. Peripheral blood mononuclear cells (PBMCs) from 4 treatment-naïve CLL patients were treated ex vivo with 0.5 μM OPN5 or equivalent vehicle (DMSO) in the presence of T-cell activating stimuli (10 μg/mL anti-CD3 and 5 μg/mL anti-CD28) for 16 hours. Live CD8+ T-cells were then isolated via fluorescence-activated cell sorting, and approximately 100,000 viable CD8+ T-cells were subjected to ATAC-sequencing. Libraries were prepared using the Active Motif ATAC-seq kit and underwent paired-end sequencing (2 x 50 bp, 100 cycles) on an Illumina NovaSeq 6000 SP sequencer. Analysis of this data revealed that OPN5 treatment induces a unique chromatin landscape in CLL patient T-cells that is less like that of terminally exhausted T-cells and more like that of effector and memory T-cells. In particular, OPN5 treatment reduced chromatin accessibility at promoter regions of terminal exhaustion-associated genes (e.g., CD101, CCR5, LAG3, BATF3) and increased chromatin accessibility at promoter regions of genes associated with progenitor T-cell function (e.g., TCF7, IL2, CXCR5, IFNG). Individual raw sequencing (fastq) files and processed bigwig files (aligned to the hg38 human reference genome), as well as bigwig files for grouped OPN5- and vehicle-treated samples (aggregate of all 4 patient samples per treatment group) are available via authorized access request through dbGaP.

Study phs003613

Transcriptional Response to Hypoxia in iPSC-Derived Endothelial Cells from a High Altitude Adapted Population

We established lymphoblastoid cell lines from 10 adult individuals of Tibetan ancestry living in the Chicago area. These lines were reprogrammed to induced pluripotent stem cells (iPSC). We validated genetic ancestry by genome-wide SNP array genotyping and population genetic analyses. After being subjected to standard quality control testing iPSCs were differentiated into endothelial cells. Following differentiation, endothelial cells were isolated via a pull down protocol using beads coated with an antibody for a canonical surface cell marker of the vascular endothelium (CD144). Purified vascular endothelial cells were cultured in parallel in normoxia (20% O2) and hypoxia (1% O2) for 48 hours prior to harvesting and processing for bulk RNA-sequencing. We provide imputed genotype data and bulk RNA-sequencing data in normoxia and in hypoxia for each of the 10 individuals. We also provide multiplexed scRNA-sequencing data for the 10 Tibetan individuals pooled with 10 CHB individuals from the 1000 Genome Project. Additionally, we provide scRNAseq data for the cardiomyocytes derived from the same iPSC lines from the Tibetan individuals pooled together with cardiomyocytes derived from iPSC lines of 10 CHB individuals from the 1000 Genome Project. Lymphoblastoid cell lines from the CHB were reprogrammed to iPSCs and differentiated to cardiomyocytes using the same protocols as used for the Tibetans. The batches of 4 lines were balanced by sex and population. These iPSC-derived cardiomyocytes were cultured in hypoxia (1% O2) for 48 hours and subjected to scRNAseq in pooled batches of 3 or 4 lines. The CHB individuals included in this analysis were: NA18528, NA18531, NA18557, NA18596, NA18606, NA18608, NA18614, NA18619, NA18633, and NA18748.

Study phs003758

Genomics of Substance Use Disorders in Latin American Populations

This is a subsample of the National Survey of Drug, Alcohol, and Tobacco Use, administered in 2016 between August and October to participants aged 12-65 in urban and rural Mexican households, named Mexican Genomic Database for Addiction Research (MxGDAR). The objective of the survey was to evaluate the patterns of use of different psychoactive substances and mental health problems in Mexico. The sample universe was made up of primary sampling units (PSUs) that were the sum of basic statistical geographic areas, stratified by state and urban-rural communities. An adult aged 18-65 was chosen randomly from each household, and an adolescent aged 12-17 was also chosen randomly from the household which has at least one member under 18. The second administration of the survey included a subsample of 13,130 respondents who agreed to give a saliva sample for DNA analysis, to be used in analyzing the relationship of mental health, addiction, and genetics. This sample was weighted according to selection probability to be representative on the national level. Mental health symptomatology for these individuals was evaluated using the Diagnostic Interview for Psychosis and Affective Disorders (DI-PAD) using the operational criteria for psychotic disorders (OPCRIT v.4.0), administered by interviewers trained in its use. It includes the evaluation of symptomatology of psychosis, depression, anxiety, obsession/compulsion, mania/hypomania, and post-traumatic stress. The study seeks to replicate genetic associations with substance use (LINC01622), psychiatric disorders (PTPRM), or comorbidity between both (MGMT) reported in following paper: https://pubmed.ncbi.nlm.nih.gov/33762635/. Funding for genotyping was provided by the National Institute on Drug Abuse (NIDA), one of the National Institutes of Health (NIH).

Study phs003558

Germline Genomic Analyses of Breast Cancer in Latinas

In this case-control study of breast cancer among Hispanic/Latina (H/L) women, the goals were to identify breast cancer susceptibility genes and genetic variants for risk of developing breast cancer in H/L women. There were two phases with whole exome sequencing (WES) done in a discovery phase and targeted sequencing of candidate genes in the replication phase. The candidate genes selected for replication came from the first phase and from genes known to affect breast cancer risk in prior studies. Cases and controls were drawn from several studies. Breast cancer cases for discovery phase included women from the City of Hope (COH) Clinical Cancer Genomics Community Research Network (CCGCRN), UCSF Cancer Genetics Clinic and USC Cancer Genetics clinic. Controls for discovery phase included women who did not have breast and were recruited through City of Hope community fairs. A separate group of controls included women from the California Teachers Study. Additional controls for discovery were obtained from WES already generated by the Multi-ethnic cohort (MEC) study. The discovery/WES results of known breast cancer genes were published (PMID 31206626). In the replication phase, we included cases and controls from the Cancer de Mama (CAMA) study which is a case-control study of breast cancer in Mexico, MEC for those not included in the discovery dataset, the San Francisco Bay Area Cancer study (phs000912), the Northern California Breast Cancer Registry, and the California Pacific Medical Center Research Institute Women's Cohort (phs000395). Cases from the PATHWAYS study who were recruited from Northern California Kaiser Permanente were also included. Results from the combined discovery and replication analyses are reported in PMID 36747679.

Study phs003144

Clonal Lineage Tracing of Primary Human Cortical Progenitors, Cell Type Profiles in the Brain Vasculature and Genotyping Data for 22q11DS and Control iPS Lines

We sought to characterize the cell types produced by individual human cortical progenitors and describe their lineage relationships. We labeled individual human cortical cells with a massively complex lentivirus library encoding a GFP reporter gene and a molecular barcode that could be captured by standard 3' scRNA-seq methodologies. We then cultured the labeled human cells for 6 weeks in either a 1) mouse cortical astrocyte co-culture system or 2) in the mouse cortex as a xenograft. In a separate experiment, we maintained human cortical tissue slices in organotypic slice culture for 12 days. GFP+ cells were then isolated by FACS and then captured on the 10x chromium scRNA-seq platform. An additional sample was labeled by lentivirus and briefly cultured for 3 days prior to being mixed with mouse 3T3 cells in order to perform a cell mixing experiment ("barnyard") to benchmark our methodologies. We found that human individual cortical progenitors gave rise to both excitatory and inhibitory neurons as well as glia.We also sought to characterize the adult brain vasculature in both vascular malformations and non-malformed tissue. We use the 10x chromium scRNA-seq platform across 10 individuals (5 control and 5 arteriovenous malformations). We find broad disregulation across multiple cell types including the immune cells and find a specific monocyte subtype to contribute to a rupture phenotype. We also find a novel population of fibromyocytes in both conditions.Finally, we confirmed the genotype status of iPS lines that were derived from either karyotypically normal control individuals or from DiGeorge Syndrome patients carrying the 22q11.2 deletion using the Illumina Infinium Global Screening Array v3.0.

Study phs002624

High Frequency Ventilation in Premature Infants (HIFI-BioLINCC)

Data Access NOTE: Please refer to the “Authorized Access” section below for information about how access to the data from this accession differs from many other dbGaP accessions. Objectives: To evaluate the hypothesis that high frequency oscillatory ventilation in preterm infants would reduce the incidence of mortality and pulmonary complications compared to conventional mechanical ventilation.Background: With the introduction of mechanical ventilation in preterm infants, mortality and morbidity significantly improved but remained high. The improvement in survival that accompanied the use of mechanical ventilation also brought about an increase in the incidence of pulmonary complications. The principal complication occurs in the form of bronchopulmonary dysplasia. Barotrauma and oxygen toxicity are considered to be in the pathogenesis for this disorder. Considerable interest in high frequency ventilation for preterm infants was generated when animal studies indicated high frequency ventilation to be effective in promoting gas exchange without apparent adverse effects. High Frequency Ventilation (HFV) delivers small tidal volumes at high frequencies of 4 to 15 Hz, and animal studies had indicated that HFV was associated with effective gas exchange, less barotrauma, and lower mean airway pressure. However, the efficacy and safety of HFV in preterm infants had not been studied. The HIFI Planning Phase was initiated in August 1984, and recruitment and intervention began in February, 1986. Follow-up studies continued thru September, 1988.Participants: A total of 673 infants were enrolled.Conclusions: Bronchopulmonary dysplasia incidence was similar in the two groups as was mortality and the need for ventilatory support during the first 28 days. There was a significantly greater rate of pneumoperitoneum of pulmonary origin in the high frequency group as was a greater incidence rate of intracranial hemorrhage. (HIFI Study Group, 1989, PMID: 2643039)

Study phs004032

Somatic Mutation in Normal Bladder Study

Adult human somatic tissues are landscapes of mutant clones, but little is known about how these landscapes are shaped by known cancer risk factors. The goal of this study was to determine how the main bladder cancer risk factors (sex and smoking) change the mutational landscape of the normal urothelium. We collected normal urothelium from 45 donors at autopsy by brushing ~2cm² of the surface epithelium in the upper part (dome) and lower part (trigone) of the bladder (79 samples total). To identify mutations with high sensitivity we employed ultradeep (~5000x) DNA error-correcting duplex-sequencing on a panel of 15 protein coding genes and the TERT promoter, previously described to be under positive selection in normal urothelium or relevant to bladder cancer. We identified thousands of clonal driver mutations, which demonstrate pervasive positive selection in the normal urothelium. Males showed a significantly higher number of driver truncating mutations in RBM10, CDKN1A and ARID1A, despite similar rates of non-coding mutations, indicating stronger positive selection and clonal expansion in the male urothelium. We also discovered clonal expansions driven by activating TERT promoter mutations in the normal bladder, which were strongly associated with age and smoking. These results demonstrate that sex and smoking shape the clonal landscape of the normal bladder and indicate that the high mutational content of normal tissues might be leveraged to study the effect of mutations in vivo (i.e. natural saturation mutagenesis). We will deposit in dbGaP de-identified relevant clinical information from the 45 donors and the fastq files derived from duplex sequencing of the 79 samples in the study. We will also deposit fastq files derived from duplex sequencing of 3 control cord blood samples.

Study phs004105

Center for Common Disease Genomics [CCDG] - Neuropsychiatric: Epilepsy: Epi25 Consortium

Epilepsy genetics research is at an exciting stage where it is now feasible, with the power of a large cohort, to understand the more complex genetic components of epilepsy. The driving principle behind the Epi25 Consortium is collaboration and synergy - it is only possible to achieve this type of research by working together. The Epi25 Consortium was formed by the unification of various consortia, including Epi4K, EPIGEN, EuroEPINOMICS, the Epilepsy Phenome/Genome Project, EpiPGX, SANAD, and EpiCURE, and individual epilepsy investigators. The consortium's sample collection is the best resource in the world for this disease, both in terms of numbers of patients and quality of phenotypic information. As part of the NHGRI Centers for Common Disease Genomics (2016-2020), we aggregated a global sample collection from the various repositories for whole genome genotyping and whole exome sequencing (WES) at the Broad Institute (Cambridge, MA), initiating the largest and most ethnically diverse genetic study of epilepsy to date. The primary epilepsy phenotypes for Epi25 are based on strict standards agreed upon by the epilepsy community. The epilepsy cases contributed by Epi25 sites can be broadly defined as genetic generalized epilepsy (GGE), non-acquired focal epilepsy (NAFE), epileptic encephalopathies (EE), and lesional focal epilepsies. More information about eligibility criteria and phenotyping forms for Epi25, as well as the contributing centers, can be found here: epi-25.org The genomic data will be analyzed iteratively to identify genes and variants that explain these types of epilepsy. Summary clinical data compiled in the Epi25 clinical database will allow retrospective phenotypic analyses of groups of subjects with common genomic variant(s).

Study phs001489

Genome and gene analysis of gastrointestinal cancer and elucidation of its clinicopathological significance

Cancer develops through the accumulation of genetic and epigenetic aberrations. To identify sequential molecular alterations that occur during the development of hepatocellular carcinoma (HCC), we molecularly compared 52 early and 108 overt HCC samples by genome sequencing. Gene mutations in the p53/RB1 pathway, WNT pathway, MLLs, SWI/SNF complexes, and AKT/PI3K pathway were common in HCC. In the early phase of all entities, TERT was the most frequently upregulated gene owing to diverse mechanisms. Despite frequent somatic mutations in driver genes, including CTNNB1 and TP53, early HCC was a separate molecular entity from overt HCC as each had a distinct expression profile. Notably, WNT target genes were not activated in early HCC, regardless of CTNNB1 mutation status, because ?-catenin did not translocate into the nucleus due to the E-Cadherin/?-catenin complex at the membrane. Conversely, WNT targets were definitively upregulated in overt HCC with CTNNB1 mutation associated with downregulation of CDH1 and hypomethylation of CpG islands in the target genes. Similarly, cell cycle genes downstream of the p53/RB pathway were upregulated only in overt HCC with TP53 and/or RB1 gene mutations associated with chromosomal deletion of 4q and/or 16q. Differing from the expression profile, HCC was epigenetically distinguished into four subclasses: normal-like methylation, global-hypomethylation (favorable prognosis), stem-like methylation (poor prognosis), and CpG island methylation. These methylation statuses were globally maintained through HCC progression. Taken together, additional molecular events besides driver gene mutations cooperatively contribute to transcriptional activation of downstream targets as HCC progresses, according to the methylation status of the associated genes.

Study JGAS000233

The EGA at the International Congress of Human Genetics

Today is the start of the International Congress of Human Genetics (ICHG). This event, hosted by the African Society of Human Genetics (AfSHG) and the Southern African Society for Human Genetics (SASHG), will reunite international experts to highlight how genomic technologies are being managed to address challenges generated by the current status of Human Health and Genomics. The European Genome-phenome Archive (EGA) will be at the Congress participating in workshops, meetings and talks where topics such as data access and discovery as well as the Federated EGA will be present. Data access and discovery In the context of the “Federated data analysis workshop“ that will be held the 26ᵗʰ, managed in the context of the CINECA project, a hands-on-session on Beacon v2 Discovery will be led by Mauricio Moldes. Another session on authorisation and data access will be presented by Mallory Freeberg and Coline Thomas, with and introduction by Thomas Keane. During the workshop, an end-to-end federated data analysis use case will be presented. Data access and discovery In the context of the “ Federated data analysis workshop“ that will be held the 26ᵗʰ, managed in the context of the CINECA project, a hands-on-session on Beacon v2 Discovery will be led by Mauricio Moldes. Another session on authorisation and data access will be presented by Mallory Freeberg and Coline Thomas, with and introduction by Thomas Keane. During the workshop, an end-to-end federated data analysis use case will be presented. During the last four years, CINECA has been identifying gaps in data sharing between Africa, Canada and Europe in order to build a federated solution for data access. Thomas Keane will present the project within the sessions happening the 24ᵗʰ. The Federated EGA at the ICHG A Federated EGA poster will be shown during the Poster Session 1 that will take place the 23ʳᵈ. The objective is to bring awareness of the European Genome-phenome Archive as a resource for permanent archive and secure data sharing. In this context, the network generated by the Federated EGA is key for cases where research data cannot be shared outside local jurisdictions. The Federated EGA was officially launched on 2022 with research institutes from five countries becoming the first nodes of this network. Nowadays, with more than 20 nodes preparing to join, it aims to become the largest human omics data sharing initiative towards understanding human health and disease. The H3Africa Initiative and the African research represented in the EGA 1.1% of the EGA studies include samples from African populations. Countries such as South Africa, Kenya, Uganda or Egypt, among others, are present in the 72.577 samples from African individuals archived at the EGA. 23 EGA datasets are managed by the Human Heredity and Health in Africa Initiative (H3Africa). This Initiative will celebrate its Consortium Meeting the 27ᵗʰ and 28ᵗʰ, back-to-back with the ICHG. H3ABioNet, the Pan African Bioinformatics Network for the H3Africa consortium, will also take this context to celebrate its 10-Year Symposium during the Congress. Members of the EGA team will attend both of them, as the H3ABioNet works in conjunction with H3Africa projects, to submit data to the European Genome-Phenome Archive.

Blog the-ega-at-the-international-congress-of-human-genetics

Toxigenic Clostridium perfringens isolated from at-risk pediatric inflammatory bowel disease patients

With the goal of studying mucosal-associated bacteria and products detrimental to inflammatory bowel disease (IBD) patients, we directly cultured bacterial communities from mucosal biopsies and examined for detrimental traits. Focusing on red blood cell lysis, a virulence trait, communities from 5 of 9 patients exhibited hemolytic activity. Clostridium perfringens was isolated from each hemolytic community, and whole-genome sequencing confirmed presence of hemolytic toxins – alpha toxin in all 5 strains, perfringolysin O (PFO) in 4 strains, alveolysin in 2 strains – and absence of enterotoxins. In vitro cytotoxicity experiments demonstrated strain supernatants were toxic to various cell types located beneath the intestinal epithelial barrier, including endothelial, neuroblasts, and neutrophils, while impact on epithelial cells was less pronounced. These findings suggest C. perfringens may be damaging particularly when intestinal barrier integrity is compromised, such as in IBD patients. Further characterization using purified toxins and genetic insertion mutants confirmed PFO toxin was sufficient for cell toxicity. C. perfringens supernatants also induced activation of neuroblast and dorsal root ganglion (DRG) neuron cells in vitro, suggesting C. perfringens in inflamed mucosal tissue may directly contribute to abdominal pain, a frequent IBD symptom. Strikingly, C. perfringens was detected in biopsies of 8 of 9 pediatric patients while not in all corresponding stool samples, and in other datasets, C. perfringens was in stool samples of IBD adults (18.7-27.1%) much more frequently versus healthy (5.1%). Our findings showcase C. perfringens may have an important pathogenic impact on IBD patients. Similar to Clostridioides difficile, routine monitoring of C. perfringens and PFO toxins in patients may be beneficial.

Study EGAS50000000334

The Genomic Landscape of Response to EGFR Blockade in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer world-wide with 1.2 million patients diagnosed yearly. In late stage CRC, the most commonly used targeted therapies are monoclonal antibodies cetuximab and panitumumab, which inactivate EGFR. Recent studies have identified alterations in KRAS and other genes as likely mechanisms of primary and secondary resistance to anti-EGFR antibody therapy. Despite these efforts, additional mechanisms of resistance to EGFR blockade are thought to be present in CRC and little is known about determinants of sensitivity to this therapy. To examine the effect of somatic genetic changes in CRC on response to anti-EGFR antibody therapy, we performed complete exome sequence and copy number analyses of 129 patient-derived tumorgrafts and targeted genomic analyses of 55 patient tumors, all of which were KRAS wild-type. We analyzed the response of tumors to anti-EGFR antibody blockade in tumorgraft models or in clinical settings. In addition to previously identified genes, we detected mutations in ERBB2, EGFR, FGFR1, PDGFRA, and MAP2K1 as potential mechanisms of primary resistance to this therapy. Novel alterations in the ectodomain of EGFR were identified in patients with acquired resistance to EGFR blockade. Amplifications and sequence changes in the tyrosine kinase receptor adaptor gene IRS2 were identified in tumors with increased sensitivity to anti-EGFR therapy. Therapeutic resistance to EGFR blockade could be overcome in tumorgraft models through combinatorial therapies targeting actionable genes. These analyses provide a systematic approach to evaluate response to targeted therapies in human cancer, highlight new mechanisms of responsiveness to anti-EGFR therapies, and provide new avenues for intervention in the management of CRC.

Study EGAS00001001305

Enhanced detection of circulating tumor DNA by fragment size analysis

Existing methods to improve detection of circulating tumor DNA (ctDNA) have focused on sensitivity for detecting genomic alterations but have rarely considered the biological properties of plasma cell-free DNA (cfDNA). We hypothesized that differences in fragment lengths of circulating DNA could be exploited to enhance sensitivity for detecting the presence of ctDNA and for non-invasive genomic analysis of cancer. We surveyed ctDNA fragment sizes in 344 plasma samples from 200 cancer patients using low-pass whole-genome sequencing (0.4×). To establish the size distribution of mutant ctDNA, tumor-guided personalized deep sequencing was performed in 19 patients. We detected enrichment of ctDNA in fragment sizes between 90–150 bp, and developed methods for in vitro and in silico size selection of these fragments. Selecting fragments between 90–150 bp improved detection of tumor DNA, with more than 2-fold median enrichment in &gt;95% of cases, and more than 4-fold enrichment in &gt; 10% of cases. Analysis of size-selected cfDNA identified clinically actionable mutations and copy number alterations that were otherwise not detected. Identification of plasma samples from patients with advanced cancer was improved by predictive models integrating fragment length and copy number analysis of cfDNA, with AUC&gt; 0.99 compared to AUC &lt; 0.80 without fragmentation features. Increased identification of cfDNA from patients with glioma, renal, and pancreatic cancer was achieved with AUC &gt; 0.91, compared to AUC &lt; 0.5 without fragmentation features. Fragment size analysis and selective sequencing of specific fragment sizes can boost ctDNA detection. This could reduce the required depth of cfDNA sequencing for clinical applications, earlier diagnosis and study of tumor biology.

Study EGAS00001003258

Genome wide association study on coronary heart disease in patients with familial hypercholesterolemia

Mutations in the low-density lipoprotein receptor (LDLR) gene cause familial hypercholesterolemia (FH), a disorder characterized by coronary heart disease (CHD) at young age. We aimed to apply an extreme sampling method to enhance the statistical power to identify novel genetic risk variants for CHD in individuals with FH. We selected cases and controls with an extreme contrast in CHD risk from 17 000 FH patients from the Netherlands, whose functional LDLR mutation was unequivocally established. The genome-wide association (GWA) study was performed on 249 very young FH cases with CHD and 217 old FH controls without CHD (above 65 years for males and 70 years of age for females) using the Illumina HumanHap 550K chip. In the next stage, two independent samples (one from the Netherlands and one from Italy, Norway, Spain, and the United Kingdom) of FH patients were used as replication samples. In the initial GWA analysis we identified 29 independent single nucleotide polymorphisms (SNPs) with suggestive associations with premature CHD (p<1×10-4). We examined the association of these SNPs with CHD risk in the replication samples. After Bonferroni correction, none of the SNPs either replicated or reached genome-wide significance after combining the discovery and replication samples. Therefore, we conclude that the genetics of CHD risk in FH is complex and even applying an ‘extreme genetics’ approach we did not identify new genetic risk variants. Most likely, this method is not as effective in leveraging effect size as anticipated, and may therefore not lead to significant gains in statistical power. (NB submitten and conditionally accepted at European Journal of Human Genetics-please use abstract only for internal review until submission complete)

Study EGAS00001000734

Tracing the origin of disseminated tumor cells in breast cancer using single-cell sequencing

Background Single-cell micro-metastases of solid tumors often occur in the bone marrow. These disseminated tumor cells (DTCs) may resist therapy and lay dormant or progress to cause overt bone and visceral metastases. The molecular nature of DTCs remains elusive, as well as when and from where in the tumor they originate. Here, we apply single-cell sequencing to identify and trace the origin of DTCs in breast cancer. Results We sequence the genomes of 63 single cells isolated from six non-metastatic breast cancer patients. By comparing the cells DNA copy number aberration (CNA) landscapes with those of the primary tumors and lymph node metastasis, we establish that 53% of the single cells morphologically classified as tumor cells are DTCs disseminating from the observed tumor. The remaining cells represent either non-aberrant ‘normal’ cells or aberrant cells of unknown origin that have CNA landscapes discordant from the tumor. Further analyses suggest that the prevalence of aberrant cells of unknown origin is age-dependent, and that at least a subset is hematopoietic in origin. Evolutionary reconstruction analysis of bulk tumor and DTC genomes enables ordering of CNA events in molecular pseudo-time and traced the origin of the DTCs to either the main tumor clone, primary tumor subclones, or subclones in an axillary lymph node metastasis. Conclusions Single-cell sequencing of bone marrow epithelial-like cells, in parallel with intra-tumor genetic heterogeneity profiling from bulk DNA, is a powerful approach to identify and study DTCs, yielding insight into metastatic processes. A heterogeneous population of CNA-positive cells is present in the bone marrow of non-metastatic breast cancer patients, only part of which are derived from the observed tumor lineages.

Study EGAS00001002102

Transcriptional_profiling_of_tauopathies_in_human_IPS_derived_neurons

This project is a pilot study, in collaboration with Maria Grazia Spillantini and Mariangela Iovino (Cambridge Centre for Brain Repair), to investigate the utility of IPS-derived neurons for the study of neurodegenerative disorders. Our aim is to characterise the transcriptional consequences of tauopathies using neurons derived from differentiated IPSCs as a model system. We will use IPS cells derived from six individuals, four with known mutations in the tau protein, 2 without. RNA will be extracted at Day 0 and Day 65 of differentiation by which time the neuronal tauopathy is apparent. RNA will be extracted and the transcriptome of each line characterised using RNAseq. We will then search for genes that are differentially expressed between the transcriptomes of individuals with tau mutations versus those in controls. My lab will analyse the RNAseq data, comparing both affected and controls and both time-points, to establish candidate genes. Darren Logan’s lab, along with our collaborators, will experimentally verify and further investigate these genes in additional lines and animal models. From this analysis we will generate a list of candidate genes that are differentially expressed between cases and controls. This study will not only help us understand the molecular basis of tauopathies, but also identify gene candidates for biomarkers of neurodegenerative disease. It will serve as a proof of principle for future planned studies into generating and transcriptomically analysing an allelic series of Tau mutations in IPSCs with a controlled genetic background.This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

Study EGAS00001000382

Altered oligodendrocyte heterogeneity in Multiple sclerosis revealed by single nuclei RNA sequencing

This study is currently hosted by the European Nucleotide Archive. To access the data contained within the Study please follow the link below: https://www.ebi.ac.uk/ena/browser/view/PRJEB39323 Oligodendrocyte (OL) pathology is increasingly implicated in neurodegenerative diseases, as they are involved in metabolic support of axons and functional cross-talk with other brain cells. Rodent OLs are heterogeneous, with developmental and biological differences, but the extent of heterogeneity in the normal human brain and its contribution to any changes to disease remains unknown. Here we performed single nuclei RNA-sequencing (snRNA-seq) from white matter (WM) areas of post mortem human brain both in control (Ctr) and multiple sclerosis (MS) patients. We identified several sub-clusters of oligodendroglia in the Ctr human WM, some similar to those in mouse, and defined new markers for these cell states. Strikingly, some of these sub-clusters were under-represented in MS tissue, while others were more prevalent than in controls. We found a lack of OL precursor cells (OPCs) and an OL subcluster in an intermediate stage of differentiation in MS lesions and in normal appearing white matter (NAWM), suggesting either depletion by the disease or by a regenerative response. The differences in mature OL sub-clusters indicate different functional states of OLs in MS tissue and, as this is similar in NAWM to lesions, that MS is a more diffuse brain disease than the focal demyelinating lesions suggest. We were also able to identify new putative markers of different MS lesion subtypes. Our findings of an altered heterogeneity of oligodendroglia in MS may have an important contribution to our understanding of disease progression and may alter therapeutic approaches to MS.

Study EGAS00001003412

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