Search Results - EGA European Genome-Phenome Archive

ALPI deficiency causes refractory Inflammation Bowel Disease

Herein, we report the first identification of biallelic-inherited mutations in ALPI as a Mendelian cause of inflammatory bowel disease in two unrelated patients. ALPI encodes for intestinal phosphatase alkaline, a brush border metalloenzyme that hydrolyses phosphate from the lipid A moiety of lipopolysaccharides and thereby drastically reduces Toll-like receptor 4 agonist activity. Prediction tools and structural modelling indicate that all mutations affect critical residues or inter-subunit interactions, and heterologous expression in HEK293T cells demonstrated that all ALPI mutations were loss of function. ALPI mutations impaired either stability or catalytic activity of ALPI and rendered it unable to detoxify lipopolysaccharide-dependent signalling. Furthermore, ALPI expression was reduced in patients' biopsies, and ALPI activity was undetectable in ALPI-deficient patient's stool. Our findings highlight the crucial role of ALPI in regulating host-microbiota interactions and restraining host inflammatory responses. These results indicate that ALPI mutations should be included in screening for monogenic causes of inflammatory bowel diseases and lay the groundwork for ALPI-based treatments in intestinal inflammatory disorders.

Study EGAS00001003350

Dissecting intratumor heterogeneity of nodal B cell lymphoma on the transcriptional, genetic, and drug response level

Tumor heterogeneity encompasses both the malignant cells and their microenvironment. While heterogeneity between individual patients is well-known to affect the efficacy of anti-cancer, most personalized treatment approaches do not account for intratumor heterogeneity. We addressed this issue by studying the heterogeneity of lymph node-derived B cell non-Hodgkin lymphoma (B-NHL) by single cell RNA-sequencing (scRNA-seq) and transcriptome-informed flow cytometry. We identified transcriptionally distinct malignant subclones and compared their drug response and genomic profiles. Malignant subclones of the same patient responded strikingly different to anti-cancer drugs ex vivo, which recapitulated subclone-specific drug sensitivity during in vivo treatment. Tumor infiltrating T cells represented the majority of non-malignant cells, whose gene expression signatures were similar across all donors, whereas the frequencies of T cell subsets varied significantly between the donors. Our data provide new insights into the heterogeneity of B-NHL and highlight the relevance of intratumor heterogeneity for personalized cancer therapies.

Study EGAS00001004335

Molecular subsets in renal cancer determine outcome to checkpoint and angiogenesis blockade

We conducted integrated multi-omics evaluation of 823 tumors from advanced renal cell carcinoma (RCC) patients and identified molecular subsets associated with differential clinical outcomes to angiogenesis blockade alone or with a checkpoint inhibitor. Unsupervised transcriptomic analysis revealed six molecular subsets with distinct angiogenesis, immune, cell cycle, metabolism, and stromal programs. While sunitinib was effective in subsets with high angiogenesis, atezolizumab+bevacizumab improved clinical benefit in tumors with high T-effector and/or cell cycle transcription. Somatic mutations in PBRM1 and KDM5C associated with high angiogenesis and AMPK/Fatty acid oxidation gene expression, while CDKN2A/B and TP53 alterations were more prevalent in tumors with increased cell cycle and anabolic metabolism. Sarcomatoid tumors exhibited low prevalence of PBRM1 mutations and angiogenesis markers, frequent CDKN2A/B, BAP1 and TP53 alterations, and increased PD-L1 expression. These findings can be applied to molecularly stratify advanced RCC patients, explain improved outcomes of sarcomatoid tumors to checkpoint blockade, and develop personalized therapies.

Study EGAS00001004353

Genome-wide prediction of human embryos

BACKGROUND: Preimplantation genetic diagnosis (PGD) enables profiling of embryos for genetic disorders prior to implantation. The majority of PGD testing is restricted in the scope of variants assayed or by the availability of extended family members. While recent advances in single cell sequencing show promise, they remain limited by bias in DNA amplification and the rapid turnaround time (<36 h) required for fresh embryo transfer. Here, we describe and validate a method for inferring the inherited whole genome sequence of an embryo for preimplantation genetic diagnosis (PGD). METHODS: We combine haplotype-resolved, parental genome sequencing with rapid embryo genotyping to predict the whole genome sequence of a day-5 human embryo in a couple at risk of transmitting alpha-thalassemia. RESULTS: Inheritance was predicted at approximately 3 million paternally and/or maternally heterozygous sites with greater than 99% accuracy. Furthermore, we successfully phase and predict the transmission of an HBA1/HBA2 deletion from each parent. CONCLUSIONS: Our results suggest that preimplantation whole genome prediction may facilitate the comprehensive diagnosis of diseases with a known genetic basis in embryos.

Study EGAS00001001020

Combined hereditary and somatic mutations of replication error repair genes result in rapid onset of ultra-hypermutated cancers

DNA replication-associated mutations are repaired by two components: polymerase proofreading and mismatch repair. The mutational consequences of disruption to both repair components in humans are not well studied. We sequenced cancer genomes from children with inherited biallelic mismatch repair deficiency (bMMRD). High-grade bMMRD brain tumors exhibited massive numbers of substitution mutations (>250/Mb) – higher than all childhood and most cancers (>7000 analyzed). All ultra-hypermutated bMMRD cancers acquired early somatic driver mutations in DNA polymerases epsilon or delta. The ensuing mutation signatures and numbers are unique and diagnostic of childhood germline bMMRD (p<10e-13). Sequential tumor biopsy analysis revealed that bMMRD/polymerase mutant cancers rapidly amass an excess of simultaneous mutations (~600 mutations/cell division), reaching but not exceeding ~20,000 exonic mutations in <6 months. Thus implying a threshold compatible with cancer cell survival. We suggest a new mechanism of cancer progression in which mutations develop in a rapid burst after ablation of replication repair.

Study EGAS00001001112

MINCR is a MYC-induced lncRNA able to modulate MYC’s transcriptional network in Burkitt lymphoma cells

Despite the established role of the transcription factor MYC in cancer, little is known about the involvement of lncRNAs in mediating MYC’s function. Here we have intersected RNA-sequencing data from MYC-inducible cell lines, from a cohort of 91 mature B-cell lymphomas and from sorted germinal-center B-cells. By this approach, we identified 13 lncRNAs differentially expressed in IG-MYC-positive Burkitt lymphoma and regulated by MYC in the model cell lines. Among them we focused on a lncRNA that we named MINCR, showing a strong correlation with MYC expression in MYC-positive lymphomas and in pancreatic ductal adenocarcinomas. RNAi experiments showed that MINCR controls cellular viability by influencing the expression of MYC-regulated cell cycle genes. Finally we provide evidences that down-regulation of AURKA, AURKB and CTD1 may explain the reduction in cellular proliferation observed upon MINCR knock-down. We therefore suggest that MINCR acts as a modulator of MYC transcriptional control of cell cycle genes.

Study EGAS00001001199

Epigenome and transcriptome profiling of chronic lymphocytic leukemia patients

Chronic lymphocytic leukemia (CLL) is characterized by substantial clinical heterogeneity, despite relatively few genetic alterations. To provide a basis for studying epigenome deregulation in CLL, we established genome-wide chromatin accessibility maps for 88 CLL samples from 55 patients using the ATAC-seq assay, and we also performed ChIPmentation and RNA-seq profiling for ten representative samples. Based on the resulting dataset, we devised and applied a bioinformatic method that links chromatin profiles to clinical annotations. Our analysis identified sample-specific variation on top of a shared core of CLL regulatory regions. IGHV mutation status – which distinguishes the two major subtypes of CLL – was accurately predicted by the chromatin profiles, and gene regulatory networks inferred for IGHV-mutated vs. IGHV-unmutated samples identified characteristic differences between these two disease subtypes. In summary, we discovered widespread heterogeneity in the chromatin landscape of CLL, established a community resource for studying epigenome deregulation in leukemia, and demonstrated the feasibility of chromatin accessibility mapping in cancer cohorts and clinical research.

Study EGAS00001001821

Epigenetic dynamics of monocyte to macrophage differentiation

Monocyte to macrophage differentiation involves major biochemical and structural changes in non-dividing cells. In order to elucidate the role of gene regulatory changes during this process, we used high-throughput sequencing to analyze the complete transcriptome and epigenome of human monocytes that were isolated by elutriation and differentiated in vitro by addition of MCSF in serum-free medium. We also investigated the effect of loading the macrophages with modified LDL. We found that many mRNAs and miRNAs were significantly up- or downregulated during differentiation. While there was no correlation between gene expression and DNA methylation changes at transcription start sites, we identified a large number of intra- and intergenic regions that rapidly lost DNA methylation, became nucleosome-free and gained histone marks indicative of active enhancers. Loading of macrophages with modified LDL caused gene expression changes, but no chromatin changes. In summary, our results demonstrate that monocyte to macrophage differentiation is associated with rapid, highly targeted epigenetic changes, whereas lipid uptake mainly affects regulatory circuits of soluble factors.

Study EGAS00001001595

Whole genome, transcriptome and methylome profiling enhances actionable target discovery in high-risk paediatric cancer

Zero Childhood Cancer is a precision medicine program to benefit children with poor-outcome, rare, relapsed or refractory cancer. Utilising tumour and germline whole genome sequencing (WGS) and RNA sequencing (RNAseq) across 252 tumours from high-risk paediatric cancer patients, we identified 968 reportable molecular aberrations (39.9% in WGS and RNAseq, 35.1% WGS-only, 25.0% RNAseq-only). 93.7% of patients had at least one germline or somatic aberration, 71.4% had therapeutic targets and 5.2% had a change in diagnosis. WGS identified pathogenic cancer-predisposing variants in 16.2% of patients. In 76 CNS tumours, methylome analysis confirmed diagnosis in 71.1% and contributed to a change of diagnosis in two cases (2.6%). To date 43 patients have received a recommended therapy, 38 of whom could be evaluated. A small but encouraging proportion of 31% showed some evidence of clinical benefit. Comprehensive molecular profiling resolved the molecular basis of virtually all high-risk cancers, which in some cases has significant clinical impact.

Study EGAS00001004572

Hypertension delays viral clearance and exacerbates airway hyperinflammation in patients with COVID-19

In coronavirus disease 2019 (COVID-19), hypertension and cardiovascular diseases are major risk factors for critical disease progression. However, the underlying causes and the effects of the main anti-hypertensive therapies-angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs)-remain unclear. Combining clinical data (n = 144) and single-cell sequencing data of airway samples (n = 48) with in vitro experiments, we observed a distinct inflammatory predisposition of immune cells in patients with hypertension that correlated with critical COVID-19 progression. ACEI treatment was associated with dampened COVID-19-related hyperinflammation and with increased cell intrinsic antiviral responses, whereas ARB treatment related to enhanced epithelial-immune cell interactions. Macrophages and neutrophils of patients with hypertension, in particular under ARB treatment, exhibited higher expression of the pro-inflammatory cytokines CCL3 and CCL4 and the chemokine receptor CCR1. Although the limited size of our cohort does not allow us to establish clinical efficacy, our data suggest that the clinical benefits of ACEI treatment in patients with COVID-19 who have hypertension warrant further investigation.

Study EGAS00001004772

atrial appendage RNA-seq in non-, paroxysmal and persistent atrial fibrillation

Understanding the interconnectedness of structural remodelling processes atrial fibrillation (AF) in patients could identify targets for future therapies. These data include transcriptome sequencing of atrial tissues of patients without AF, with paroxysmal AF and persistent AF (total n=64). In AF patients, epicardial cell gene expression decreased, contrasting with an upregulation of epithelial to mesenchymal transition (EMT) and mesenchymal cell gene expression. Immunohistochemistry demonstrated thickening of the epicardium and an increased proportion of (myo)fibroblast-like cells in the myocardium, supporting enhanced EMT in AF. We furthermore report an upregulation of endothelial cell proliferation, angiogenesis and endothelial signalling. EMT and endothelial cell proliferation concurred with increased interstitial (myo)fibroblast-like cells and extracellular matrix gene expression including enhanced tenascin-c, thrombospondins, biglycan and versican. Morphological analysis discovered increased and redistributed glycosaminoglycans and collagens in the atria of AF patients. Signalling pathways, including cell-matrix interactions, PI3K-AKT and Notch signalling, that could regulate mesenchymal cell activation, were upregulated. These dynamic processes may provide targets to prevent or reverse structural remodelling.

Study EGAS00001005295

Circulating Tumor DNA Analysis Detects Minimal Residual Disease and Predicts Recurrence in Patients with Stage II Colon Cancer

Detection of circulating tumor DNA (ctDNA) after resection of stage II colon cancer may identify those at the highest risk of recurrence and help inform adjuvant treatment decisions. We used massively-parallel-sequencing–based assays to evaluate the ability of ctDNA to detect minimal residual disease in 1046 plasma samples from a prospective cohort of 230 patients with resected stage II colon cancer. In patients not treated with adjuvant chemotherapy, ctDNA was detected post-operatively in 14 of 178 (7.9%) patients, 11 (79%) of whom had recurred at a median follow-up of 27 months; recurrence occurred in only 16 (9.8 %) of the 164 patients with negative ctDNA (HR, 18; 95% confidence interval [CI], 7.9 to 36; P<0.001). In patients treated with chemotherapy, the presence of ctDNA following completion of chemotherapy was also associated with an inferior recurrence-free survival (HR, 11; 95% CI, 1.8 to 68; P=0.001). ctDNA detection after stage II colon cancer resection provides direct evidence of residual disease and identifies patients at very high risk of recurrence.

Study EGAS00001001839

Reference exome data for Australian Aboriginal populations to support health-based research

Whole exome sequencing (WES) is a popular and successful technology which is widely used in both research and clinical settings. However, there is a paucity of reference data for Aboriginal Australians to underpin the translation of health-based genomic research. Here we provide a catalogue of variants called after sequencing the exomes of 50 Aboriginal individuals from the Northern Territory (NT) of Australia and compare these to 72 previously published exomes from a Western Australian (WA) population of Martu origin. Sequence data for both NT and WA samples were processed using an ‘intersect-then-combine’ (ITC) approach, using GATK and SAMtools to call variants. A total of 289,829 variants were identified in at least one individual in the NT cohort and 248,374 variants in at least one individual in the WA cohort. Of these, 166,719 variants were present in both cohorts, whilst 123,110 variants were private to the NT cohort and 81,655 were private to the WA cohort. Our data set provides a useful reference point for genomic studies on Aboriginal Australians.

Study EGAS00001003745

Clonal expansion and epigenetic reprogramming following deletion or amplification of mutant IDH1

IDH1 mutation is the earliest genetic alteration in low-grade gliomas (LGGs), but its role in tumor recurrence is unclear. Mutant IDH1 drives overproduction of the oncometabolite D-2-hydroxyglutarate (2HG) and a CpG island (CGI) hypermethylation phenotype (G-CIMP). To investigate the role of mutant IDH1 at recurrence, we performed a longitudinal analysis of 50 IDH1 mutant LGGs. We discovered six cases with copy number alterations (CNAs) at the IDH1 locus at recurrence. Deletion or amplification of IDH1 was followed by clonal expansion and recurrence at a higher grade. Successful cultures derived from IDH1 mutant, but not IDH1 wild-type, gliomas systematically deleted IDH1 in vitro and in vivo, further suggestive of selection against the heterozygous mutant state as tumors progress. Tumors and cultures with IDH1 CNA had decreased 2HG, maintenance of G-CIMP, and DNA methylation reprogramming outside CGI. Thus, while IDH1 mutation initiates gliomagenesis, in some patients, mutant IDH1 and 2HG are not required for later clonal expansions.

Study EGAS00001001854

Genetic control of the transcriptomic response of monocytes to bacterial and viral stimuli assessed by RNA-seq in Africans and Europeans

Humans differ in the outcome that follows exposure to life-threatening pathogens, yet the extent of population differences in immune responses, and their genetic and evolutionary determinants, remain undefined. Here, we characterized, using RNA-sequencing, the transcriptional response of primary monocytes from Africans and Europeans to bacterial and viral stimuli - ligands activating Toll-like receptors pathways (TLR1/2, TLR4 and TLR7/8) and influenza virus - and mapped expression quantitative trait loci (eQTL). We identify multiple cis- and trans-eQTL that contribute to the marked differences in immune responses detected within and between populations, including a TLR1 master regulator that decreases expression of pro-inflammatory genes in Europeans only. We show that regulatory variants have been privileged targets of natural selection, uncovering evolutionarily advantageous mechanisms, such as attenuated inflammation. Finally, we demonstrate that admixture with Neandertals introduced regulatory variants into European genomes, affecting preferentially responses to viral challenges, and identify archaic haplotypes that contributed to population genetic adaptation.

Study EGAS00001001895

Primary prostate Hi-C

Prostate cancer is a heterogeneous disease whose progression is linked to genome instability. Despite large-scale tumour sequencing efforts, the impact of mutations on the genetic architecture in cancer remains ill-defined due to limited integration of genomics data across dimensions. We addressed this limitation by assessing the impact of structural variants on the chromatin states and the three-dimensional organization across benign and malignant primary prostate genomes. We find high concordance in the three-dimensional genome organization between malignant and benign prostate tissues, arguing for constraints to the three-dimensional genome of prostate tumours. Moreover, we identify structural variants as effectors of changes to focal chromatin interactions, guiding cis-regulatory element hijacking that imposes opposing expression changes on genes found at antipodes of a rearrangement. This leads to the repression of tumour suppressor gene expression and up-regulation of oncogenes, such as at the TMPRSS2-ERG and PMEPA1-ZNF156 loci. Collectively, our results argue that cis-regulatory element hijacking by structural variants overshadows large-scale topological changes to alter gene regulation and promote oncogenesis.

Study EGAS00001005014

An essential role for MYB in driving oncogenic EVI1 expression in enhancer-rearranged leukemias

In acute myeloid leukemia (AML) with inv(3)(q21;q26) or t(3;3)(q21;q26), a translocated GATA2 enhancer drives oncogenic expression of EVI1. We generated an EVI1-GFP AML model and applied an unbiased CRISPR/Cas9 enhancer scan to uncover sequence motifs essential for EVI1 transcription. Using this approach, we pinpoint a single regulatory element in the translocated GATA2 enhancer that is critically required for aberrant EVI1 expression while being dispensable for GATA2 expression from its endogenous locus. This element contains a DNA binding motif for the transcription factor MYB that heavily occupies this site specifically at the translocated allele. MYB knockout as well as peptidomimetic blockade of p300-dependent MYB function resulted in downregulation of EVI1 but not of GATA2. Targeting MYB or mutating its DNA-binding motif within the GATA2 enhancer resulted in myeloid differentiation and cell death, suggesting that interference with MYB-driven EVI1 transcription provides a potential entry point for therapy of inv(3)/t(3;3) AMLs.

Study EGAS00001004839

The ICGC-TCGA DREAM Somatic Mutation Calling - Tumour Heterogeneity Challenge

Tumors are composed of many different cell types, ranging from the normal tissue micro-environment, infiltrating immune cells and tumour cells. This group of tumour cells is itself intrinsically highly heterogeneous, driven by the rapid mutation rate of cancer cells to become a mixture of different sub-populations. These different types of cells, called subclones, have different sets of mutations in their DNA. Because some subclones evolve from others, many subclones share mutations. While it is increasingly easy to determine what mutations are present in the tumor, it remains very difficult to determine which subclones have which mutations. The task of assigning mutations to subclones is called subclonal reconstruction.The ICGC-TCGA DREAM Somatic Mutation Calling - Tumour Heterogeneity Challenge (SMC-Het) is an international effort to improve standard methods for subclonal reconstruction: to quantify and genotype each individual cell population present within a tumor. The goal of this challenge is to identify the best subclonal reconstruction algorithms and to identify the conditions that affect their performance.

Study EGAS00001002092

Pilot_experiment_on_functional_genomics_in_osteoarthritis

The aim of this work is to apply an integrated systems approach to understand the biological underpinnings of large joint (hip and knee) osteoarthritis which culminates in the need for total joint replacement (TJR). In this pilot we will assess the feasibility of the approach in the relevant tissue. We will obtain diseased and non-diseased tissue (cartilage and endochondral bone) following TJR, coupled with a blood sample, from 12 patients. We will generate genotype data on the HumanCoreExome array and will characterise the 12 pairs of diseased and non-diseased tissue samples in terms of methylation (Illumina 450k array), transcription (RNASeq) and expression (quantitative proteomics). The pilot will help assess the feasibility of isolating sufficient levels of starting material for the different approaches, and will instigate the development of analytical approaches to synthesising the resulting data. If successful, it is envisaged that we will proceed with expanding the work to 500 patients in the first year, with a target total sample size of 3,000 in the longer term. The key collaborators in this work are Mark Wilkinson (Sheffield) and Jyoti Choudhary

Study EGAS00001001213

WGS of T-cell and NK-cell lymphoma for ICGC (NKTL-SG)

Lymphomas are malignancies originating from the lymphatic system and there is a worldwide significant increase in incidences of this cancer. Lymphomas can be further classified into 2 categories namely Hodgkinâ€™s (HL), and Non-Hodgkinâ€™s lymphoma (NHL). The latter can be divided further into B, T and NK cell NHL. Peripheral T-cell lymphoma (PTCL) and Natural Killer/ T-cell lymphoma (NKTL) arise from mature T lymphocytes and NK cells. The more common subtypes include NKTL, PTCL not-otherwise-specified (PTCL-NOS), systemic anaplastic large cell lymphoma (ALCL), follicular PTCL (F-PTCL), angioimmunoblastic T-cell lymphoma (AITL) and enteropathy-associated T-cell lymphoma (EATL). Whole genome analyses on T-cell and NK-cell lymphoma samples from various countries to gain a better understanding of the pathogenesis and biology of these tumors. The comprehensive profiling and comparison among patients from various countries with different etiopathogenesis will hopefully facilitate the elucidation of key pathways and underlying molecular mechanisms driving these cancers, opening up novel therapeutic strategies in the future.

Study EGAS00001002398

Cell-free DNA TAPS for early cancer detection

Multimodal, genome-wide characterization of epigenetic and genetic information in circulating cell-free DNA (cfDNA) could enable more sensitive early cancer detection. However, due to technological challenges associated with DNA methylation sequencing in low input cfDNA samples, most studies have been limited by DNA damage caused by bisulfite sequencing, or the qualitative nature of enrichment-based sequencing. Recently, we developed TET-assisted Pyridine Borane Sequencing (TAPS), which is a mild, bisulfite-free method for base-resolution direct DNA methylation sequencing. Here we optimized TAPS for cfDNA (cfTAPS) to provide high-quality and high-depth whole-genome cell-free methylomes. We applied cfTAPS to 85 cfDNA samples from patients with hepatocellular carcinoma (HCC) or pancreatic ductal adenocarcinoma (PDAC) and non-cancer controls. From just 10 ng cfDNA (1-3 mL of plasma), we generated the most comprehensive cfDNA methylome to date. We demonstrated that cfTAPS provides multimodal information about cfDNA characteristics, including DNA methylation, tissue of origin, and DNA fragmentation. Integrated analysis of these epigenetic and genetic features enables accurate identification of early HCC and PDAC.

Study EGAS00001004962

A combined circulating tumor DNA and protein biomarker-based liquid biopsy for the earlier detection of pancreatic cancer

The earlier diagnosis of cancer is one of the keys to reducing future cancer deaths. Here we describe our efforts to develop a non-invasive, blood test for the detection of pancreatic ductal adenocarcinoma. We combined blood tests for KRAS gene mutations with carefully thresholded protein biomarkers to determine whether the combination of these markers was superior to any single marker. The cohort tested included 221 patients with resectable pancreatic ductal adenocarcinoma and 185 control patients without known cancers. KRAS mutations were detected in the plasma of 66 patients (30%) and every mutation found in the plasma was identical to that subsequently found in the patients' primary tumor (100% concordance). The use of KRAS in conjunction with two thresholded protein biomarkers (CA19-9 and prolactin) increased the sensitivity to 67%. Only one of the 185 plasma samples from the control cohort were positive for any of the three markers (99.5% specificity). This combinatorial approach may prove useful for the earlier detection of many cancer types.

Study EGAS00001002444

Mutations in SPINK2 induce azoospermia

Azoospermia, characterized by the absence of spermatozoa in the ejaculate is a common cause of male infertility with a poorly characterized etiology. Exome sequencing analysis of two azoospermic brothers allowed the identification of a homozygous splice mutation in SPINK2, encoding a serine protease inhibitor believed to target acrosin, the main sperm acrosomal protease. In accord with these findings we observed that homozygous Spink2 KO male mice had azoospermia. Moreover, despite normal fertility, heterozygous male mice had a high rate of morphologically abnormal spermatozoa and a reduced sperm motility. Further analysis demonstrated that in the absence of Spink2, protease-induced stress initiates Golgi fragmentation and prevents acrosome biogenesis leading to spermatid differentiation arrest. We also observed a deleterious effect of acrosin overexpression in HEK cells, effect that was alleviated by SPINK2 coexpression confirming its role as acrosin inhibitor. These results demonstrate that SPINK2 is necessary to neutralize proteases during their cellular transit towards the acrosome and that its deficiency induces a pathological continuum ranging from oligoasthenoteratozoospermia in heterozygotes to azoospermia in homozygotes.

Study EGAS00001002450

Integrative genomic analysis identifies multiple subtypes and therapeutic targets in acute erythroid leukemia

Acute erythroid leukemia (AEL) is a high risk leukemia of poorly understood genetic basis, and controversy regarding diagnosis in the spectrum of myelodysplasia and myeloid leukemia. We compared genomic and clinical features of 159 childhood and adult AEL cases to non-AEL myeloid disorders, and identified patterns of mutation that describe 5 age-related subgroups with distinct transcriptional profiles: adult, TP53-mutated; NPM1-mutated; KMT2A-mutated/rearranged; adult, DDX41-mutated; and pediatric, NUP98-rearranged. Mutational spectra were age-dependent and significantly associated with outcome, with NPM1 mutations and high HOXB9 expression being associated with favorable prognosis, and TP53, FLT3 and RB1 alterations associated with poor survival. Targetable signaling mutations were present in 45% of cases, and include recurrent mutations of ALK and NTRK1, the latter of which drive erythroid leukemogenesis sensitive to TRK inhibition. This genomic landscape of AEL provides the framework for accurate diagnosis and risk stratification of this disease, and the rationale for testing targeted therapies in this form of leukemia that has hitherto and dismal outcome.

Study EGAS00001002537

Genetic history of the Comorian populations.

At the dawn of the second millennium, the expansion of the Indian Ocean trading network aligned with the emergence of an outward-oriented community along the East African coast to create a cosmopolitan cultural and trading zone known as the Swahili Corridor. Based on analyses of genome-wide genotyping data in 140 individuals from coastal Kenya and the Comoros islands, along with 3,477 individuals from the Indian Ocean rim, we reconstruct historical population dynamics showing that the Swahili Corridor is largely an East Bantu genetic continuum. Within this continuity significant gene flows from the Middle East can be seen in the Swahili and Comorians at dates corresponding to the Islamization of East Africa. However the main external gene flow into insular populations of the Swahili Corridor, such as Comorian and Malagasy groups, came from Island Southeast Asia as early as the 10th century. Remarkably, our results reflect archaeological and linguistic data in suggesting that the Comoros archipelago is the oldest place of contact between Austronesian and African populations in the Swahili Corridor.

Study EGAS00001002565

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