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• Molecular Phenotype of Constitutional TET2 Haploinsufficiency in Humans

  In this study, we observed the effects of constitutional heterozygous TET2 loss on blood DNA methylation, chromatin activity and gene expression in carriers of truncating TET2 germline mutations. To provide additional context to findings in TET2 mutation carriers, we analysed DNA methylation in four DNMT3A germline mutation carriers and their age-matched controls.

  Study EGAS00001003454

• The Prediction and Prevention of Preeclampsia

  The Prediction and Prevention of Preeclampsia (PREDO) is a prospective birth cohort study of Finnish women who were pregnant between 2005 and 2010 and their children. The PREDO study cohort was set up to identify novel risk factors and biomarkers in pregnant women associated with the development of preeclampsia and intrauterine growth restriction (IUGR). Two groups of pregnant women were enrolled during the first trimester of their pregnancy: first, pregnant women with a known clinical risk factor status for preeclampsia and IUGR (N=1079; 969 of these women had at least one and 110 had none of the known risk factors for preeclampsia and IUGR), and second, pregnant women who volunteered to participate regardless of their risk factor status for preeclampsia and IUGR (N=3698). Both samples were monitored during pregnancy with four clinical visits and bi-weekly self-reports. The post-delivery follow-up has taken place at approximately 2 weeks, 6 months, and 3.5 years after the delivery. The most recent follow-up started in 2016 and is ongoing. In the high-risk sample, cord blood samples were collected and genome-wide genotyping has been conducted with Illumina OmniExpressExome 1.2 and genome-wide methylation status has been analysed with Illumina 450k HM array.

  Study EGAS00001001898

• This project aims to study human memory capacity, including short-term memory and long-term memory, systematically via genome-wide association studies

  Development of high-throughput genotyping platforms provides an opportunity to identify new genetic elements related to complex cognitive functions. Taking advantage of multi-level genomic analysis, here we studied the genetic basis of human short-term (STM, n=1,620) and long-term (LTM, n=1,526) memory functions. Heritability estimation based on single nucleotide polymorphism showed moderate heritability of short-term memory but very low heritability of long-term memory. In a two-step genome-wide association study, the markers rs13151012 and rs1558360 passed genome-wide significance (p < 5×10-8) in digit-span STM task and for the first principal component shared by two STM tasks; however, none of them survived the replication. In turn, we selected the ten most significant single nucleotide polymorphisms (SNPs) for replication tests. Among them, a SNP near ZFAT was significantly associated with STM performance in another independent population of 2,789; a polymorphism within BCAT2 was significantly associated with LTM in another independent population of 1,865. Furthermore, we performed a pathway analysis based on the current genomic data and found six pathways significantly associated with STM capacity and one pathway associated with LTM capacity.

  Study EGAS00001002875

• Nanopore_and_Illumina_sequencing_of_human_glioblastomas

  Liquid biopsy analysis refers to methods designed to detect tumour-specific material (e.g., circulating tumour cells or tumour DNA) in body fluids, such as urine or blood samples. A widely-used liquid biopsy approach consists of genotyping the circulating tumour DNA (ctDNA) through sequencing of plasma/serum DNA. Although useful in the context of metastatic disease (where the concentration of ctDNA is high), current liquid biopsy technologies show limited sensitivity of detection for the early detection of cancer, and low specificity, as cancer-related mutations accumulate in healthy tissues as part of the ageing process, thus making it difficult to distinguish these from tumour mutations, and because sequencing errors and true mutations show overlapping profiles. Therefore, developing liquid biopsy protocols with increased sensitivity and specificity represents an urgent clinical need. Here we harness extrachromosomal circular DNA (eccDNA) elements, which are circular DNA structures physically separated from the chromosomes of up to several Mbp long pervasive in human cancers, for liquid biopsy analysis. In this pilot study we will focus on the analysis of glioblastomas, because there is strong evidence for the presence of eccDNA in these tumour types, and because developing liquid biopsy approaches for brain tumours to reduce the invasiveness of brain tumour biopsies remains an unmet clinical need.

  Study EGAS00001005812

• UK10K_RARE_HYPERCHOL

  In the UK10K project we propose a series of complementary genetic approaches to find new low frequency/rare variants contributing to disease phenotypes. These will be based on obtaining the genome wide sequence of 4000 samples from the TwinsUK and ALSPAC cohorts (at 6x sequence coverage), and the exome sequence (protein coding regions and related conserved sequence) of 6000 samples selected for extreme phenotypes. Our studies will focus primarily on cardiovascular-related quantitative traits, obesity and related metabolic traits, neurodevelopmental disorders and a limited number of extreme clinical phenotypes that will provide proof-of-concept for future familial trait sequencing. We will analyse directly quantitative traits in the cohorts and the selected traits in the extreme samples, and also use imputation down to 0.1% allele frequency to extend the analyses to further sample sets with genome wide genotype data. In each case we will investigate indels and larger structural variants as well as SNPs, and use statistical methods that combine rare variants in a locus or pathway as well as single-variant approaches.Familial Hypercholesterolemia is a condition where the affected person has a consistently high level of LDL which can lead to early clogging of the coronary arteries. All patients selected for this study will have been found not to carry the common APOB and PCSK9 mutations, and to have no detectable LDLR mutations by testing for 18 common mutations. For further information with regard to this cohort please contact Steve Humphries(steve.humphries@ucl.ac.uk).

  Study EGAS00001000129

• UK10K NEURO ASD BIONED

  In the UK10K project we propose a series of complementary genetic approaches to find new low frequency/rare variants contributing to disease phenotypes. These will be based on obtaining the genome wide sequence of 4000 samples from the TwinsUK and ALSPAC cohorts (at 6x sequence coverage), and the exome sequence (protein coding regions and related conserved sequence) of 6000 samples selected for extreme phenotypes. Our studies will focus primarily on cardiovascular-related quantitative traits, obesity and related metabolic traits, neurodevelopmental disorders and a limited number of extreme clinical phenotypes that will provide proof-of-concept for future familial trait sequencing. We will analyse directly quantitative traits in the cohorts and the selected traits in the extreme samples, and also use imputation down to 0.1% allele frequency to extend the analyses to further sample sets with genome wide genotype data. In each case we will investigate indels and larger structural variants as well as SNPs, and use statistical methods that combine rare variants in a locus or pathway as well as single-variant approaches. The BioNED (Biomarkers for Childhood onset neuropsychiatric disorders) study has been carrying out detailed phenotypic assessments evaluating children with an autism spectrum disorder. These assessments included ADI-R, ADOS, neuropsychology, EEG etc. There are 56 DNA samples from this study (25 extracted from blood). For further information with regard to this cohort please contact Patrick Bolton (patrick.bolton@kcl.ac.uk).

  Study EGAS00001000111

• Genomic Alterations in Gingivo-buccal Cancer: ICGC-India Project_YR01

  As a part of the ICGC, India has undertaken genomic studies on gingivobuccal cancer of the oral cavity, which is the most prevalent form of cancer among men in India. There are various known environmental (life-style) correlates of this cancer, the most important of which are tobacco chewing and HPV infection. Paired DNA samples – isolated from the tumor tissue and from the blood of fifty patients – have been analyzed to catalog germline and somatic mutations. Association between each observed genomic alteration and exposure to environmental risk factors is being explored.Detailed clinical characterization of the patients, collection of data on demographic and environmental exposures, and isolation of DNA samples from blood and tumor tissues collected from each patient are being done at the Advanced Centre for Research, Treatment and Education on Cancer, Mumbai. Exome capture and deep resequencing are being performed at the National Institute of Biomedical Genomics, Kalyani. We have analyzed the exomes of paired blood and tumor DNA samples using two orthogonal platforms – exome capture by Roche-Nimblegen SeqCap Ez kit followed by sequencing on Roche-454 GS FLX, and exome capture by Illumina TrueSeq Exome Enrichment kit followed by sequencing on Illumina HiSeq-2000. Each exome is being sequenced at a mean depth of 30x. In addition, we have used Illumina Omni Quad SNP-chips to generate genotype data at 1.14 million genomic markers. The average concordance between SNP-chip and sequence data is 99.8%.

  Study EGAS00001000249

• Genetic variability in exon 1 of the glucocorticoid receptor gene NR3C1 is associated with postoperative complications

  Patients having major surgery experience inflammation post-operatively, which may contribute to post-operative morbidity. Endogenous glucocorticoids (GCs) are an essential part of the stress response, but this response varies between individuals, which may in turn affect clinical outcome in general, and post-operative inflammation, specifically. Exon 1 of the NR3C1 gene, encoding the glucocorticoid receptor, contains an established region of differential regulation. DNA methylation patterns in this region have been found to differ between individuals. We investigated the methylation status and genotype in the Cytosine-phosphate-Guanine (CpG) island in exon 1 of NR3C1 in 24 patients who underwent major abdominal surgery and correlated it with post-operative complications. DNA was extracted from peripheral blood leukocytes and underwent targeted bisulfite sequencing of the CpG island. Complications were graded according to the Clavien-Dindo classification and 14 out of 24 had post-operative complications. Multifactorial and partial least square methods were used to analyse the data. A homogenous demethylated pattern was observed in all patients and no single CpG methylation was associated with post-operative complications. Four single nucleotide polymorphisms (SNPs) were significantly correlated with higher Clavien-Dindo scores. Genetic variability in the chr5:143,402,505-143,405,805 region of exon 1 of the glucocorticoid receptor gene NR3C1, but not DNA methylation, was associated with more severe post-operative complications in patients having major abdominal surgery. This indicates that the response to GCs may be of clinical importance for inflammatory conditions.

  Study EGAS00001005737

• Loss of SDHB promotes dysregulated iron homeostasis, oxidative stress and sensitivity to ascorbate

  Succinate dehydrogenase is a key enzyme in the tricarboxylic acid cycle and the electron transport chain. All four subunits of succinate dehydrogenase are tumor suppressor genes predisposing to paraganglioma, but only mutations in the SDHB subunit are associated with increased risk of metastasis. Here we generated an Sdhd knockout chromaffin cell line and compared it to Sdhb-deficient cells. Both cell types exhibited similar SDH loss of function, metabolic adaptation, and succinate accumulation. In contrast, Sdhb-/- cells showed hallmarks of mesenchymal transition associated with increased DNA hypermethylation and a stronger pseudo-hypoxic phenotype compared to Sdhd-/- cells. Loss of SDHB specifically led to increased oxidative stress associated with dysregulated iron and copper homeostasis in the absence of NRF2 activation. High-dose ascorbate exacerbated the increase in mitochondrial reactive oxygen species, leading to cell death in Sdhb-/- cells. These data establish a mechanism linking oxidative stress to iron homeostasis that specifically occurs in SDHB deficient cells and may promote metastasis. They also highlight high-dose ascorbate as a promising therapeutic strategy for SDHB-related cancers.

  Study EGAS00001005279

• Transcriptome profiling of patient derived neural stem cells highlights the importance of CTNND2 and WNT signaling in early neuralization

  Loss of CTNND2/δ-catenin function is implicated in neurodevelopmental disorders, including Cri-du-chat syndrome, autism spectrum disorder and attention deficit hyperactivity disorder. CTNND2, the encoded protein, is crucial for the cadherin-catenin cell adhesion complex in the brain. However, the specific impact on neurodevelopment remains unclear. To investigate, we used neuroepithelial stem cells (NESCs) derived from patient-specific induced pluripotent stem cells (iPSCs) with loss of CTNND2. In monolayer cultures, we observed abnormal neural rosette formation and failure to establish stable neural stem cells. 3D organoid cultures confirmed delayed neurogenesis and slower growth in patient-derived iPSC lines. We have built a transcriptomic catalog and observed a dysregulation of the WNT signaling pathway linked to our observed cellular phenotypes. To validate we excluded the WNT activator CHIR99021 from the media, which partially rescued the transcriptomic and morphological phenotype of the patient neural induction. This study enhances our understanding of how CTNND2 loss affects early neurogenesis and neuronal maturation in patient specific cells.

  Study EGAS50000000323