Search Results - EGA European Genome-Phenome Archive

IDH-wildtype untreated human glioblastoma samples (GB-UK cohort), published in Noorani & Haughey et al 2025.

Extrachromosomal DNA (ecDNA) oncogene amplification is associated with treatment resistance and shorter survival in cancer. Currently, the spatial dynamics of ecDNA, and their evolutionary impact, are poorly understood. Here, we investigate the spatiotemporal evolution of ecDNA by integrating computational modeling with samples from 94 treatment-naive human IDH wild-type glioblastoma patients. Random ecDNA segregation combined with ecDNA-conferred fitness advantages induce distinct spatial ecDNA copy number patterns which depend on ecDNA oncogenic makeup. EGFR-ecDNAs often reach high copy numbers and confer strong fitness advantages. In contrast, PDGFRA-ecDNAs reach lower copy numbers and confer weaker fitness advantages. EGFR structural variants occur exclusively on ecDNA, arise from and are intermixed with wild-type EGFR-ecDNAs. Computational modeling suggests wild-type and variant EGFR-ecDNAs often accumulate before clonal expansion. Using a genetically engineered mouse model, we confirm that the accumulation of oncogenic ecDNA prior to clonal expansion under strong positive selection is observable both in vivo and in vitro in mouse neural stem cells. Intermixed wild-type and variant ecDNAs remain prevalent at diagnosis, as less fit wild-type ecDNAs hitchhike on strongly selected variant EGFR-ecDNAs. A dN/dS analysis in the Genomics England cohort further suggests positive selection of variants on EGFR-ecDNAs but not PDGFRA-ecDNAs in glioblastoma. Overall, our results suggest ecDNA oncogenic makeup determines unique evolutionary trajectories in glioblastoma. New concepts like ecDNA tumor clonality, ecDNA heteroplasmy and multi-species ecDNAs require a refined evolutionary interpretation of genomic data in a large subset of glioblastoma patients and likely other solid cancers.

Study EGAS00001008126

RNAseq: Acquired non-permissive bone marrow microenvironment impairs hematopoietic stem cell proliferation and maintenance and B-cell development post-HSCT

Defects in B-cell reconstitution upon hematopoietic stem-cell (HSC) transplantation (HSCT) are a common observation, yet the mechanism remains unexplained. The bone marrow (BM) stroma, including mesenchymal stromal cells (MSCs), guides HSC maintenance and B-lymphopoiesis by secreting crucial cytokines. We report acquired, permanent, selective and complete B-cell deficiency in the context of full donor-chimerism in a patient with X-linked lymphoproliferative disease and aimed to identify the contribution of the BM-microenvironment in disrupted B-cell reconstitution post-HSCT. We studied longitudinal BM samples from the patient and his identical twin, both of whom underwent HSCT with the same donor with opposite outcomes in B-cell reconstitution. In the index patient BM, we observed progressive loss of proliferation of HSCs and a selective block at the pre-BI cell stage. In vitro modeling studies showed limited survival of patient-HSCs and a relative accumulation of pre-B cells. Patient-derived MSCs failed to support survival and proliferation of HSCs and B-cell development of healthy-HSCs which was correlated with reduced CXCL12 levels. Using bulk RNA-sequencing of MSCs and in vitro functional studies, we showed global changes in the patients’ MSCs and a progressive loss of CXCL12 expression. Indeed, survival of patients HSCs improved supplementing in vitro development culture with CXCL12, suggesting a contribution of defective CXCL12 signaling to the phenotype. In summary, our data show that an acquired defect in the BM-stromal microenvironment and exhaustion of HSCs and committed progenitors may cause a permanent non-permissive state for normal B-cell development.

Study EGAS50000001437

ATAC-seq: Acquired non-permissive bone marrow microenvironment impairs hematopoietic stem cell proliferation and maintenance and B-cell development post-HSCT

Defects in B-cell reconstitution upon hematopoietic stem-cell (HSC) transplantation (HSCT) are a common observation, yet the mechanism remains unexplained. The bone marrow (BM) stroma, including mesenchymal stromal cells (MSCs), guides HSC maintenance and B-lymphopoiesis by secreting crucial cytokines. We report acquired, permanent, selective and complete B-cell deficiency in the context of full donor-chimerism in a patient with X-linked lymphoproliferative disease and aimed to identify the contribution of the BM-microenvironment in disrupted B-cell reconstitution post-HSCT. We studied longitudinal BM samples from the patient and his identical twin, both of whom underwent HSCT with the same donor with opposite outcomes in B-cell reconstitution. In the index patient BM, we observed progressive loss of proliferation of HSCs and a selective block at the pre-BI cell stage. In vitro modeling studies showed limited survival of patient-HSCs and a relative accumulation of pre-B cells. Patient-derived MSCs failed to support survival and proliferation of HSCs and B-cell development of healthy-HSCs which was correlated with reduced CXCL12 levels. Using bulk RNA-sequencing of MSCs and in vitro functional studies, we showed global changes in the patients’ MSCs and a progressive loss of CXCL12 expression. Indeed, survival of patients HSCs improved supplementing in vitro development culture with CXCL12, suggesting a contribution of defective CXCL12 signaling to the phenotype. In summary, our data show that an acquired defect in the BM-stromal microenvironment and exhaustion of HSCs and committed progenitors may cause a permanent non-permissive state for normal B-cell development.

Study EGAS50000001438

Development and validation of multivariate predictors of primary endocrine resistance to tamoxifen and aromatase inhibitors in luminal breast cancer reveal drug-specific differences

Background: Endocrine therapy is highly effective in blocking the estrogen receptor pathway in HR+/HER2- early breast cancer (EBC). However, up to 40% of patients experience relapse during or after adjuvant endocrine therapy. Here, we investigate molecular mechanisms associated with primary resistance to endocrine therapy and develop predictive models. Results: TP53 mutations were prominently associated with primary resistance to both tamoxifen (TAM) and aromatase inhibitors (AI), with AI non-responders exhibiting resistance in up to 32% of cases. Additionally, we identified distinct DNA methylation patterns in TAM and AI non-responders, with TAM non-responders showing global DNA methylation loss, associated with KRAS signaling, apical junctions and epithelial-mesenchymal transition (EMT). Conversely, we observed methylation gain in AI non-responders affecting developmental transcription factors, hypoxia and estrogen signaling. TAM or AI resistance was associated with increased methylation-inferred proportions of immune cells and decreased proportions of endothelial cells. Based on these findings and patient age, we developed the Predictive Endocrine ResistanCe Index (PERCI). PERCI stratified NR and R cases in both treatment groups and cohorts with high accuracy (ROC AUC TAM discovery 93.9%, validation 83%; AI discovery 98.6%, validation 76.9%). A simplified PERCI efficiently predicted progression-free survival in the TCGA-BRCA sub-cohort (Kaplan-Meier log-rank p-value = 0.03 between low and high PERCI groups). Conclusions: We identified genomic and epigenomic features associated with primary resistance to TMA and AI. By combining information on genomic alterations, patient age, differential methylation and tumor microenvironment (TME) composition, we developed PERCI TAM and PERCI AI as novel predictors of primary resistance, with potential additional prognostic value. Applying PERCI in a clinical setting may allow patient-specific drug selection to overcome resistance.

Study EGAS50000001102

CCR8-targeted specific depletion of clonally expanded Treg cells in tumor tissues evokes potent tumor immunity with long-lasting memory

Foxp3-expressing CD25+CD4+ regulatory T cells (Tregs) are abundantly infiltrating into tumor tissues, hindering effective anti-tumor immunity. Here, assuming that such tumor Tregs were clonally expanding by recognizing tumor-associated antigens, we attempted to characterize them by their gene expression profiling and T-cell receptor (TCR) clonotyping at the single-cell level. We found that they predominantly expressed the chemokine receptor CCR8: ~40% of tumor Tregs, less than 10% of Tregs in other tissues, and few tumor-infiltrating conventional T cells expressed CCR8 in mice and humans. CCR8+ tumor Tregs were phenotypically highly differentiated and functionally stable. One injection of anti-CCR8 mAb with high antibody-dependent cellular cytotoxic activity was indeed able to specifically deplete clonally expanded tumor Tregs and thereby eradicate established tumors in mice. The depletion predominantly expanded tumor-infiltrating CD8+ effector T cells, which were different in activated or exhausted patterns from those seen after immune checkpoint blockade by anti-PD-1 mAb. The treatment also evoked potent secondary immune responses against the same tumor cell line inoculated several months after tumor eradication, indicating that the anti-CCR8-induced memory-type tumor-reactive effector T cells were, once induced, resistant to recovered Treg suppression. In contrast to such evocation of potent tumor immunity, anti-CCR8 treatment scarcely elicited discernable autoimmunity in mice, contrasting with a similar treatment for systemic whole Treg depletion, which induced histologically and serologically evident autoimmunity. Thus, temporary and specific depletion of clonally expanded Tregs in tumor tissues by cell-depleting anti-CCR8 mAb is sufficient to evoke potent tumor immunity with long-lasting memory and without serious autoimmunity.

Study JGAS000312

mutation analysys of Gorlin syndrome

Gorlin syndrome is a genetic disorder of autosomal dominant inheritance that predisposes the affected individual to a variety of disorders that are attributed largely to heterozygous germline patched1 (PTCH1) mutations. PTCH1 is a hedgehog (Hh) receptor as well as a repressor, mutation of which leads to constitutive activation of Hh pathway. Hh pathway encompasses a wide variety of cellular signaling cascades, which involve several molecules; however, no associated genotype?phenotype correlations have been reported. Recently, mutations in Suppressor of fused homolog (SUFU) or PTCH2 were reported in patients with Gorlin syndrome. These facts suggest that multi-layered mutations in Hh pathway may contribute to the development of Gorlin syndrome. We demonstrated multiple mutations of Hh-related genes in addition to PTCH1, which possibly act in an additive or multiplicative manner and lead to Gorlin syndrome. High-throughput sequencing was performed to analyze exome sequences in four unrelated Gorlin syndrome patient genomes. Mutations in PTCH1 gene were detected in all four patients. Specific nucleotide variations or frameshift variations of PTCH1 were identified along with the inferred amino acid changes in all patients. We further filtered 84 different genes which are closely related to Hh signaling. Fifty three of these had enough coverage of over ?30. The sequencing results were filtered and compared to reduce the number of sequence variants identified in each of the affected individuals. We discovered three genes, PTCH2, BOC, and WNT9b, with mutations with a predicted functional impact assessed by MutationTaster2 or PolyPhen-2 (Polymorphism Phenotyping v2) analysis. It is noticeable that PTCH2 and BOC are Hh receptor molecules. No significant mutations were observed in SUFU. Multi-layered mutations in Hh pathway may change the activation level of the Hh signals, which may explain the wide phenotypic variability of Gorlin syndrome.

Study JGAS000099

Immunohistochemical and molecular pathological search in gastrointestinal tumors

Purpose: RSPO fusions are recently identified recurrent genetic alterations in colorectal cancer (CRC), which lead to WNT pathway activation and are potential therapeutic targets. We aimed to investigate the clinicopathological and molecular features of RSPO fusion-positive CRCs. Experimental Design: We screened 1019 CRCs for RSPO fusions using multiplex reverse transcription polymerase chain reaction. RSPO fusion-positive tumors were characterized for their clinicopathological features and subjected to whole exome sequencing (WES). Results: Our analysis identified 29 CRCs with RSPO fusions (2.8%), consisting of 5 with an EIF3E-RSPO2 fusion and 24 with PTPRK-RSPO3 fusions. The patients were 17 females and 12 males with the median age of 64 years. Thirteen tumors were located in the right colon, 8 were in the left colon, and 8 were in the rectum. Histologically, most of the tumors (24/29, 83%) were classified as adenocarcinomas, not otherwise specified. However, about half of the tumors (13/29, 45%) had a focal or extensive mucinous component, which is significantly more frequent compared with RSPO fusion-negative tumors (13%; p = 8.1 �� 10-7). Four tumors (14%) were mismatch repair-deficient, three of which were associated with MLH1 promoter methylation. WES identified KRAS, BRAF, and NRAS mutations in a total of 27 cases (93%). In contrast, pathogenic mutations in major WNT pathway genes other than RSPO fusions were virtually absent. The presence of an RSPO fusion tended to show shorter overall and recurrence-free survivals in stage II and III patients although the differences were not significant. Conclusions: RSPO fusion-positive CRCs constitute a rare subgroup of CRCs with several characteristic clinicopathological and genetic features. The mutual exclusivity with other WNT pathway gene alterations supports RSPO fusions as valid therapeutic targets in CRC.

Study JGAS000538

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

Paediatric Hepatic International Tumour Trial (JPLT2: PHITT)

Hepatoblastoma (HBL) is the most common primary liver tumor in children. Despite their diversity in histopathological phenotype and clinical outcome, the underlying molecular aberrations have not been fully understood. Here we describe a comprehensive landscape of genomic, epigenomic, and transcriptomic heterogeneity among the 163 cases of HBLs and transitional liver cell tumors (TLCTs) collected in the multicenter clinical trial JPLT-2. The total numbers of mutational events in HBLs are very few (0.52 SNVs/Mb on exonic regions) but show a positive correlation with the age of onset. While dysregulation of Wnt-pathway related genes was observed (somatic deletion or mutations of CTNNB1 and germline or somatic mutations of APC) in 83.6% of the HBL cases, TERT promoter mutations are mainly in the elderly HBLs (> 8 years old), meeting with the proposed criteria of TLCT. These TLCT cases are clustered in the hypermethylated epigenotype in promoter and enhancer regions. Copy number analyses also revealed recurrent 11p15.5 UPD/LOHs including the IGF2/H19 region (31.6%), focal deletions in 4q35 (15.8%) and focal amplifications in 2q24.3 (7.0%) predominantly in the child and infant HBLs. Motif enrichment analysis of the specific hypomethylated enhancers in these HBL subtypes suggests specific binding of ASCL2, the regulatory transcription factor for definitive endoderm and digestive systems. Transcriptome and histochemical analysis revealed that ASCL2 is upregulated not in HCC and TLCT but in child and infant HBL, suggesting their ?cell of origin? derived from the premature hepatoblast with high proliferative potential such as intestinal epithelial cells. Systematic molecular profiling of HBL will provide a fundamental understanding of hepatoblast carcinogenesis and clues for risk stratification.

Study JGAS000236

Biallelic variants in the non-protein coding minor spliceosome components RNU6ATAC and RNU6ATAC cause syndromic monogenic autoimmune diabetes

Non-protein coding genes are emerging as critical contributors to the aetiology of rare diseases, providing key insights into human biology and uncovering novel disease mechanisms. We identified 7 individuals from 4 families with early-onset diabetes (diagnosed <5 years) and immune dysregulatory features caused by biallelic variants in RNU6ATAC. RNU6ATAC encodes a small nuclear RNA (snRNA) acting as a catalytic component of the minor spliceosome, a protein-RNA complex mediating splicing of ~700 genes containing U12/minor-type introns. Variant screening of the other 64 minor spliceosome genes in 276 infants with diabetes identified 12 unrelated individuals with biallelic disease-causing variants in RNU4ATAC. Biallelic pathogenic RNU4ATAC variants are known to cause a variable spectrum of clinical features, which until now did not include diabetes. Clinically, 12/19 RNU6ATAC/RNU4ATAC patients had additional immune dysregulatory features, and 50% of patients tested were islet-autoantibody positive, strongly supporting an autoimmune aetiology for their diabetes. RNA-seq in 3 individuals with biallelic RNU6ATAC variants showed a pattern of intron retention in U12 intron-containing genes similar to that seen in RNU4ATAC-individuals (n=3), supporting a shared disease mechanism. Analysis of patients’ transcriptomic, methylation and immune data revealed impaired B cell development and maturation. We conclude that biallelic RNU6ATAC variants cause a novel syndrome of early-onset autoimmune diabetes and immune dysregulation. We further show that infancy-onset diabetes is a previously unrecognised feature of RNU4ATACopathy. Our work highlights the important role of two snRNAs critical to minor spliceosome function in immune system regulation, providing novel insights into the pathogenesis of autoimmune diabetes.

Study EGAS50000001565

Confronting historical legacies of biological anthropology in South Africa—Restitution, redress and community-centered science: The Sutherland Nine

We describe a process of restitution of nine unethically acquired human skeletons to their families, together with attempts at redress. Between 1925–1927 C.E., the skeletonised remains of nine San or Khoekhoe people, eight of them known-in-life, were removed from their graves on the farm Kruisrivier, near Sutherland in the Northern Cape Province of South Africa. They were donated to the Anatomy Department at the University of Cape Town. This was done without the knowledge or permission of their families. The donor was a medical student who removed the remains from the labourers’ cemetery on his family farm. Nearly 100 years later, the remains are being returned to their community, accompanied by a range of community-driven interdisciplinary historical, archaeological and analytical (osteobiographic, craniofacial, ancient DNA, stable isotope) studies to document, as far as possible, their lives and deaths. The restitution process began by contacting families living in the same area with the same surnames as the deceased. The restitution and redress process prioritises the descendant families’ memories, wishes and desire to understand the situation, and learn more about their ancestors. The descendant families have described the process as helping them to reconnect with their ancestors. A richer appreciation of their ancestors’ lives, gained in part from scientific analyses, culminating with reburial, is hoped to aid the descendant families and wider community in [re-]connecting with their heritage and culture, and contribute to restorative justice, reconciliation and healing while confronting a traumatic historical moment. While these nine individuals were exhumed as specimens, they will be reburied as people.

Study EGAS50000000971

Repotrectinib in NTRK fusion–positive advanced solid tumors: a phase 1/2 trial

Early-generation TRK tyrosine kinase inhibitors (TKIs) approved for treating NTRK fusion–positive (NTRK+) solid tumors provide clinical benefit; however, resistance emerges. Repotrectinib is a next-generation ROS1/TRK TKI with a compact macrocyclic structure designed to improve durability of response. TRIDENT-1 is a registrational phase 1/2 trial assessing repotrectinib, a next-generation ROS1/TRK TKI, in adults with advanced solid tumors, including NTRK+ disease. The primary endpoint was confirmed objective response; secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival and safety. Median follow-up ranged between 21.3 months and 25.7 months. In the TKI-naive cohort (n = 51; 95% confidence interval (CI)), the response rate was 59% (44–72); the median DOR was not estimable (NE); and the median PFS was 30.3 months (9.0–NE). In the TKI-pretreated cohort (n = 69; 95% CI), the response rate was 48% (36–60); the median DOR was 9.8 months (7.4–13.0); and the median PFS was 7.4 months (3.9–9.7). Of 30 TKI-pretreated patients with NTRK solvent front mutations, 16 had a response (53%; 95% CI: 34–72). Intracranial responses were observed in two of three TKI-naive patients and in four of six TKI-pretreated patients with measurable intracranial disease at baseline. Among all treated patients (n = 565), the most common any-grade treatment-related adverse event (TRAE) was dizziness (57%); most TRAEs were low grade; and 4% discontinued repotrectinib due to a TRAE. Overall, repotrectinib demonstrated durable systemic and intracranial responses with generally low-grade adverse events in patients with NTRK+ solid tumors, including those with previous TRK TKI treatment and solvent front mutations. These results support the use repotrectinib to treat patients with NTRK+ solid tumors. ClinicalTrials.gov identifier: NCT03093116 .

Study EGAS50000001572

Recurrent somatic DICER1 mutations in non-epithelial ovarian tumors

Background: Germline truncating mutations in DICER1, an RNase III-type endoribonuclease essential for processing of microRNAs, are seen in families with the pleuropulmonary blastoma-family tumor and dysplasia syndrome; these individuals have a propensity to develop non-epithelial ovarian tumors (i.e. sex-cord stromal and germ cell tumors). Methods: We sequenced the whole transcriptomes or exomes of 14 non-epithelial ovarian tumors and noted closely clustered mutations in the RNase IIIb domain of DICER1 in four cases. Using Sanger sequencing, we then analyzed additional ovarian tumors for mutations in this region. The impact of the mutations on the enzymatic activity of Dicer1 was determined using in vitro RNA cleavage assays. Results: RNase IIIb domain DICER1 mutations were found in 30/102 non-epithelial ovarian tumors (29%), predominantly Sertoli-Leydig cell tumors (26/43, 60%), including 4/4 from individuals with germline DICER1 mutations. The mutations were restricted to metal binding sites within the RNase IIIb catalytic centres critical for miRNA interaction and cleavage, and were somatic in all 14 cases where germline DNA was available for testing. Of 266 epithelial ovarian and endometrial cancers tested, one case, an ovarian carcinosarcoma, had a hotspot mutation. In vitro, the mutant DICER proteins showed reduced RNase IIIb activity but retained RNase IIIa activity. Conclusions: Somatic missense mutations of the RNase IIIb domain of DICER1 are common in non-epithelial ovarian tumors. Genetic, pathologic, and functional evidence suggest that these mutations do not obliterate DICER1 function, rather, they alter it in specific cell types, a novel mechanism through which perturbed microRNA expression is oncogenic.

Study EGAS00001000135

Driver mutations in histone H3.3 and chromatin remodelling genes in paediatric glioblastoma

Glioblastoma multiforme (GBM) is a lethal brain tumour in adults and children. However, DNA copy number and gene expression signatures indicate differences between adult and paediatric cases. To explore the genetic events underlying this distinction, we sequenced the exomes of 48 paediatric GBM samples. Somatic mutations in the H3.3-ATRX-DAXX chromatin remodelling pathway were identified in 44% of tumours (21/48). Recurrent mutations in H3F3A, which encodes the replication-independent histone 3 variant H3.3, were observed in 31% of tumours, and led to amino acid substitutions at two critical positions within the histone tail (K27M, G34R/G34V) involved in key regulatory post-translational modifications. Mutations in ATRX (alpha-thalassaemia/mental retardation syndrome X-linked) and DAXX (death-domain associated protein), encoding two subunits of a chromatin remodelling complex required for H3.3 incorporation at pericentric heterochromatin and telomeres, were identified in 31% of samples overall, and in 100% of tumours harbouring a G34R or G34V H3.3 mutation. Somatic TP53 mutations were identified in 54% of all cases, and in 86% of samples with H3F3A and/or ATRX mutations. Screening of a large cohort of gliomas of various grades and histologies (n=784) showed H3F3A mutations to be specific to GBM and highly prevalent in children and young adults. Furthermore, the presence of H3F3A/ATRX-DAXX/TP53 mutations was strongly associated with alternative lengthening of telomeres and specific gene expression profiles. This is, to our knowledge, the first report to highlight recurrent mutations in a regulatory histone in humans, and our data suggest that defects of the chromatin architecture underlie paediatric and young adult GBM pathogenesis.

Study EGAS00001000226

Molecular_diagnosis_of_albinism

Albinism is genetically heterogeneous rare genetic condition affecting 1:17000 in the Western world (but more frequent in Africa) whose main feature is a profound visual impairment, characterised by foveal hypoplasia, abnormal chiasmatic connections, nystagmus and photofobia. All these features result in severly altered visual acuity (<0,1), absent depth perception and poor night vision. People with albinism are primarily visually handicapped. In addition, for some types of albinism, the visual phenotype can be presented with partial or total hypopigmentation, hence resulting in a secondary phenotype which can lead to skin cancer if skin is not adequately protected. Recently a new syndrome has been described, FHONDA, with the same visual abnormalities of albinism but without pigment alteration. The traditional classification differentiates Oculoculatenous albinism (OCA), where hypopigmentation involves hair, skin and eyes versus Ocular Albinism (OA), where hypopigmentation only affects the eyes. These are non-sydrimic types of albinism. Some syndromic forms (Hermansky-Pudlak=HPS, Chediak-Higashi=CHS) affect cells beyond pigment cells, present in the lungs, immune system, platelets and intestines, resulting in more severe phenotypes that can be fatal. Mutations in at least 19 genes are assocaited with the corresponding types of albinism. Most hospitals will only diagnose the most frequent cases using traditional Sanger, MLPA approaches. Some will use CGH arrays. We aim to diagnose all cases of albinism through the Albinochip proposal, which combines a Sequenom first step of known mutations combined with subsequent NGS approaches. In some cases we fail to find a second mutation, these are good candidates for further full exome analyses. 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 EGAS00001002068

Resolving the Full Spectrum of Human Genome Variation using Linked-Reads

Large-scale population based analyses coupled with advances in technology have demonstrated that the human genome is more diverse than originally thought. Standard short-read approaches, used primarily due to accuracy, throughput and costs, fail to give a complete picture of a genome. They struggle to identify large, balanced structural events, cannot access repetitive regions of the genome and fail to resolve the human genome into its two haplotypes. Here we describe an approach that retains long range information while harnessing the power of short reads. Starting from only 1ng of DNA, we produce barcoded short read libraries. The use of novel informatic approaches allows for the barcoded short reads to be associated with the long molecules of origin producing a novel datatype known as 'Linked-Reads'. This approach allows for simultaneous detection of small and large variants from a single Linked-Read library. We have previously demonstrated the utility of whole genome Linked-Reads (lrWGS) for performing diploid, de novo assembly of individual genomes. In this manuscript, we show the utility of reference based analysis using a single Linked-Read library for full spectrum genome analysis. We demonstrate the ability of Linked-Reads to reconstruct megabase scale haplotypes and to recover parts of the genome that are typically inaccessible to short reads, including phenotypically important genes such as STRC, SMN1 and SMN2. We demonstrate the ability of both lrWGS and Linked-Read Whole Exome Sequencing (lrWES) to identify complex structural variations, including balanced events, single exon deletions, and single exon duplications. The data presented here show that Linked-Reads provide a scalable approach for comprehensive genome analysis that is not possible using short reads alone.

Study EGAS00001003121

A genome scan for genes underlying adult body size differences between Central African hunter-gatherers and farmers.

The evolutionary and biological bases of the Central African pygmy phenotype, a characteristic of rainforest huntergatherers defined by reduced body size compared with neighboring farmers, remain largely unknown. Here, we perform a joint investigation in Central African hunter-gatherers and farmers of adult standing height, sitting height, leg length, and body mass index (BMI), considering 358 hunter-gatherers and 169 farmers with genotypes for 153,798 SNPs. In addition to reduced standing heights, hunter-gatherers have shorter sitting heights and leg lengths and higher sitting/standing height ratios than farmers and lower BMI for males. Standing height, sitting height, and leg length are strongly correlated with inferred levels of farmer genetic ancestry, whereas BMI is only weakly correlated, perhaps reflecting greater contributions of non-genetic factors to body weight than to height. Single- and multi-marker association tests identify one region and eight genes associated with hunter-gatherer/farmer status, and 24 genes associated with the height-related traits. Many of these genes have putative functions consistent with roles in determining their associated traits and the pygmy phenotype, and they include three associated with standing height in non-Africans (PRKG1, DSCAM, MAGI2). We find evidence that European height-associated SNPs or variants in linkage disequilibrium with them contribute to standing- and sitting-height determination in Central Africans, but not to the differential status of hunter-gatherers and farmers. These findings provide new insights into the biological basis of the pygmy phenotype, and they highlight the potential of cross-population studies for exploring the genetic basis of phenotypes that vary naturally across populations. Pemberton et al. Human Genetics 2018 https://doi.org/10.1007/s00439-018-1902-3

Study EGAS00001002975

Indonesian Genome Diversity Project

Indonesia, the world’s fourth largest country by population, comprises an archipelago of about 900 permanently inhabited islands in tropical Asia, and hosts an astonishing array of human diversity that remains largely underrepresented in modern biological surveys. The region is unique for its key role in both the early and recent evolution of Homo outside of Africa. It has one of the first traces of anatomically modern humans in Eurasia, and was the focus of extensive interaction between archaic hominins and humans – both in the likely co-existence of H. floresiensis with modern humans, and in the introgression of Denisovans into the ancestors of its present inhabitants. More recently, Indonesia was a center of the spread of Neolithic culture by Austronesian speakers. Advancing maritime technologies allowed farming populations to treat this region as a springboard to reach oceanic islands as remote as Madagascar, Hawaii, Easter Island and New Zealand. Here we present complete human genomes from healthy individuals from multiple key islands in Indonesia and Papua. The genomes were sequenced to high depth (30x). The purpose of this dataset is to address different questions of human evolution in Island Southeast Asia and beyond, including early settlement of the area by anatomically modern humans, population structure, genetic admixture and adaptation, and contacts with archaic hominins. We employed a sampling strategy to capture a broad range of diversity across the region incorporating an average of 12 samples from each of 14 islands spanning Indonesia and Papua, from Sumatra in the west to New Britain in the east. Genomes from this dataset form part of an ongoing project to describe and understand human evolutionary history in Island Southeast Asia and Eurasia in general.

Study EGAS00001003054

Genetic characterization of B-cell prolymphocytic leukemia: a hierarchical prognostic model involving MYC and TP53 abnormalities - WXS

B-PLL is a rare disease, whose molecular pathology is largely unknown. We report here the cytogenetic and molecular findings in a large series of 34 B-PLL. Karyotype (K) was complex (≥3 abnormalities) in 73%, and highly complex (HCK≥5) in 45%. The most frequent chromosomal aberrations were: translocation targeting the MYC gene [t(MYC)] (62%), 17p deletion including TP53 gene (38%), trisomy 18/18q (30%), 13q14 deletion (29%), trisomy 3 (24%), trisomy 12 (24%) and 8p deletion (23%). Whole-Exome Sequencing performed in 16 patients revealed recurrent mutations in TP53 (6/16, 38%), MYD88 (n=4), BCOR (n=4), MYC (n=3), SF3B1 (n=3), FAT1 (n=3), SETD2 (n=2), CHD2 (n=2), CXCR4 (n=2) and BCLAF1 (n=2). The main group of patients (21/34, 62%) had a t(MYC) associated with a higher percentage of prolymphocytes (p=0.03), CD38 expression (p<0.001), lower K complexity (p=0.0004), mutations in MYC and in genes involved in RNA metabolism and chromatin remodeling. Principal component analysis of gene expression data showed that patients with t(MYC) clustered together. A second group with MYC gain (5/34, 15%), was associated with HCK≥5 (p=0,01) and trisomy 3 (p=0,008). Altogether, 26/34 patients (76%) had a MYC activation, translocation or gain, that were mutually exclusive. We identified 3 distinct cytogenetic prognostic groups (p=0.0006): lower risk: absence of MYC activation (median not reached); intermediate risk: MYC activation without del17p (125 months); high risk: MYC activation + del17p (11 months). Our results show that cytogenetic analysis is a useful diagnostic tool in B-PLL that improves prognostic stratification.

Study EGAS00001003275

Mutational patterns and regulatory networks in epigenetic subgroups of meningioma (H033)

DNA methylation patterns delineate clinically relevant subgroups of meningioma. We previously established the six meningioma methylation classes (MC) benign-1, 2, 3, intermediate-A, B and malignant. Here, we set out to identify subgroup-specific mutational patterns and pathway regulation. Whole-genome-sequencing was performed on 62 samples across all MCs and WHO grades from 62 patients with matched blood control, including 40 sporadic and 22 radiation-induced (Mrad) meningiomas. RNA sequencing was added for 18 cases and chromatin-immunoprecipitation for the enhancer mark H3K27ac followed by sequencing (ChIP-seq) for 16 samples. Besides the known mutations in meningioma, structural alterations were found to contribute to the spectrum of mechanisms inactivating NF2 in sporadic meningioma similar to previous reports for Mrad. Aberrations of DMD were found to be enriched in MCs with NF2 mutations and DMD was among the most differentially upregulated genes in NF2 mutant compared to NF2 wild-type cases. The mutational signature AC3 was detected in both sporadic meningioma and Mrad, but distributed across the genome in sporadic cases and enriched near genomic breakpoints in Mrad. In general, the malignant MC presented a significantly higher exposure to AC3 and higher genomic instability beyond the mutational load than the other MCs. Pathway analysis of the ChIP-seq clusters revealed that the FOXM1 is most differentially activated in high-grade cases, along with super enhancer recruitment near HOX genes and respective upregulation of expression. This data further elucidate the biological mechanisms differentiating meningiomas of different WHO grade and epigenetic subgroups and suggest leveraging the genomic instability as novel therapeutic targets.

Study EGAS00001003481

An integrative model of pathway convergence in genetically heterogeneous blast crisis chronic myeloid leukemia (CML)

Targeted therapies against the BCR-ABL1 kinase have revolutionized treatment of chronic phase (CP) chronic myeloid leukemia (CML). In contrast, management of blast crisis (BC) CML remains challenging because BC cells acquire complex molecular alterations that confer stemness features to progenitor populations and resistance to BCR-ABL1 tyrosine kinase inhibitors. Comprehensive models of BC transformation have proved elusive because of the rarity and genetic heterogeneity of BC, but are important for developing biomarkers predicting BC progression and effective therapies. To better understand BC, we performed an integrated multiomics analysis of 74 CP and BC samples using whole-genome and exome sequencing, transcriptome and methylome profiling, and chromatin immunoprecipitation followed by high-throughput sequencing. Employing pathway-based analysis, we found the BC genome was significantly enriched for mutations affecting components of the polycomb repressive complex (PRC) pathway. While transcriptomically, BC progenitors were enriched and depleted for PRC1- and PRC2-related gene sets respectively. By integrating our data sets, we determined that BC progenitors undergo PRC-driven epigenetic reprogramming toward a convergent transcriptomic state. Specifically, PRC2 directs BC DNA hypermethylation, which in turn silences key genes involved in myeloid differentiation and tumor suppressor function via so-called epigenetic switching, whereas PRC1 represses an overlapping and distinct set of genes, including novel BC tumor suppressors. On the basis of these observations, we developed an integrated model of BC that facilitated the identification of combinatorial therapies capable of reversing BC reprogramming (decitabine+PRC1 inhibitors), novel PRC-silenced tumor suppressor genes (NR4A2), and gene expression signatures predictive of disease progression and drug resistance in CP.

Study EGAS00001001751

Genomic and epigenomic characterization of juvenile myelomonocytic leukemia (JMML)

Juvenile myelomonocytic leukemia (JMML) is an aggressive myeloproliferative disorder of early childhood. While some cases show spontaneous remission, allogeneic hematopoietic stem cell transplantation (HSCT) remains the only curative treatment option for the majority of patients, however, the 5-year event-free survival reaches only about 50%. Hyperactive RAS signaling is assumed to be the main driving event in JMML. It is caused by genetic alterations in CBL, KRAS, NF1, NRAS, or PTPN11 in about 90% of patients. So far, there is no clear understanding of how RAS pathway mutations relate to the heterogeneous disease biology and variable clinical outcome seen in JMML patients. As a consequence, established clinical and genetic markers fail to fully represent the observed disease heterogeneity. We hypothesized that DNA methylation profiling, either alone or in combination with genetic alterations, might provide a molecular basis for disease classification. Genome wide DNA methylation analysis using the HumanMethylation450 Bead Chip array was performed in a discovery cohort of 20 patients (19 JMML, 1 Noonan syndrome). The clinical relevance of our findings was assessed in an unselected sample set consisting of 147 consecutive patients with JMML (n=129) or Noonan syndrome (n=18) associated myeloproliferative disorder (n=18) registered in the EWOG-MDS 1998 & 2006 trials. Data integration was performed in a subset of patients with available exome sequencing (n=50) and expression profiling (n=15) data. This integrated approach identified three JMML subgroups characterized by distinct clinical and biological features. This analysis further suggested a molecular mechanism by which additional genetic events, presumably further activating the RAS-RAF-MEK-ERK pathway, mediate DNA hypermethylation via up-regulation of DNMTs in more aggressive JMML cases.

Study EGAS00001002511

The application of RNA sequencing for the diagnosis and genomic classification of pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukaemia (ALL) is the most common childhood malignancy, and implementation of risk-adapted therapy has been instrumental in the dramatic improvements in clinical outcomes. A key to risk-adapted therapies includes the identification of genomic features of individual tumors, including chromosome number (for hyper- and hypodiploidy) and gene fusions, notably ETV6-RUNX1, TCF3-PBX1 and BCR-ABL1 in B-cell ALL (B-ALL). RNA-sequencing (RNA-seq) of large ALL cohorts has expanded the number of recurrent gene fusions recognized as drivers in ALL, and identification of these new entities will contribute to refining ALL risk stratification. We used RNA-seq on 126 ALL patients from our clinical service to test the utility of including RNA-seq in standard of care diagnostic pipelines to detect gene rearrangements and IKZF1 deletions. RNA-seq identified 86% of rearrangements detected by standard of care diagnostics. KMT2A-rearrangements (MLL), whilst usually identified, were the most commonly missed by RNA-seq as a result of low expression. RNA-seq identified rearrangements that were not detected by standard of care testing in nine patients. These were found in patients who were not classifiable using standard molecular assessment. We developed an approach to detect the commonest IKZF1 deletion from RNA-seq data and validated this using a RQ-PCR assay. We applied an expression classifier to identify Ph-like B-ALL patients. T-ALL proved a rich source of novel gene fusions which have clinical implications or provide insights into disease biology. Our experience shows that RNA-seq can be implemented within an individual clinical service to enhance the current molecular diagnostic risk classification of ALL.

Study EGAS00001004212

A Multifactorial Tumor and Immune Cell Profile Determines Response to Immune Checkpoint blockade in Melanoma

The complex crosstalk between tumor and immune cells during immune checkpoint blockade mandates the development of integrated models that interpret the anti-tumor immune response and predict clinical outcome. We have integrated genome-wide sequence and structural alterations with pre and on-therapy transcriptomic and T cell repertoire features for a cohort of 64 immunotherapy-naïve melanomas treated with anti-PD1 monotherapy or combined anti-PD1 and anti-CTLA4 therapy. While tumor mutation burden (TMB) was associated with improved response to therapy, expressed mutation burden was superior to TMB in predicting outcome. An increased pre-existing T cell density differentiated responding from non-responding tumors independent of therapy. Importantly, T cell repertoire reshaping determined by T cell receptor (TCR) clonotypic regressions and expansions reflected response to therapy such that a more dynamic repertoire predicted improved clinical outcome. Through whole-transcriptome analyses, we discovered differential abundance of B cell subsets in responding tumors, which highlights the importance of the interplay between pre-existing T and B cell immunity in shaping therapeutic response. Tumor temporal trajectories during therapy revealed distinct patterns of molecular response related to expressed mutation elimination or retention that accurately interpreted clinical response. High-dimensional genomic, transcriptomic and immune repertoire data were integrated by both a machine learning and a censored regression approach, resulting in a harmonized multi-modal predictor of response to immune checkpoint blockade. B cell abundance, expressed mutation load and tumor aneuploidy were combined to identify patients at high risk for recurrence, such that high risk patients had a significantly shorter progression-free survival (HR=9.18, 95% CI: 3.14-26.85, p=3.4e-06) especially in the anti-PD1/anti-CTLA4 group (HR=20.34, 95% CI: 4.08-101.32, p=1.68e-06).

Study EGAS00001004548

Circulating Tumor DNA in Checkpoint Inhibitor treated Lung Cancer

BackgroundImmune checkpoint inhibitors (ICI) are increasingly used to treat non-small cell lung cancer (NSCLC) and there is a critical need for novel predictive/prognostic biomarkers. We evaluated whether dynamics of circulating tumor (ctDNA) can identify NSCLC patients who benefit from single agent ICI.MethodsCirculating cell-free DNA (cfDNA) from 177 patients was analyzed prior ICI and at first treatment evaluation using a Commercial 77-gene panel. We performed de novo mutation calling and corrected for variants related clonal hematopoiesis. ctDNA changes were evaluated as predictors of tumor response estimated with PET/diagnostic CT and survival.ResultsMutations were detected in 159 of 174 (91.4%) analyzable patients. Most responders presented decreasing ctDNA levels, while non-responders had mixed molecular responses. Patients with a >50% molecular ctDNA decrease or no detectable ctDNA demonstrated improved PFS (5.9 versus 1.8 months; HR 0.49, 95%CI, 0.35-0.67, P < .001), and OS (18.9 versus 9.9 months; HR 0.41, 95%CI, 0.30-0.57, P < .001) compared to patients not achieving these endpoints. Clearance of mutations (and no detected ctDNA) had a similar effect (PFS HR 0.45, 95%CI, 0.32-0.61, P < .001; OS 0.37,95%CI, 0.27-0.52, P < .001) compared to patients having stable or additional mutations. After adjusting for clinical factors both >50% ctDNA decrease (HR 0.4, 95% CI, 0.3-0.6, P < .001) and clearance of mutations (HR 0.42, 95% CI, 0.3-0.6, P < .001) remained independent predictors for PFS and OS.ConclusionsctDNA testing reveals significant prognostic albeit not predictive information in ICI treated advanced NSCLC. This relevant information can be obtained with a commercial easy-to-implement ctDNA test that will facilitate extensive testing.

Study EGAS00001004847

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