3413 results for "*geneti*"

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• Genome-wide search to find the genetic elements underlying visual contour perception

  Contour integration is a key function of the visual system to deal with occlusion and discontinuity in natural scenes. The current study is the first one to investigate the genetic basis of this visual function in humans. A total of 2619 normal participants were tested on their ability to detect continuous contours embedded in a cluttered background with a standard psychophysical protocol. Multi-level genomic analysis was performed, involving heritability estimation based on single nucleotide polymorphism (SNP) and association testing at SNP and gene levels.

  Study EGAS00001003639

• Exome sequencing demonstrates a dual origin of relapses in retinoic-acid resistant acute promyelocytic leukemia.

  Retinoic acid (RA) and arsenic target the PML/RARA driver of Acute Promyelocytic Leukemia (APL), their combination now curing over 95% patients. Here we report exome sequencing of 64 matched diagnosis/remission/relapses patients treated with historical RA/chemotherapy protocols. A first subgroup presents a high incidence of oncogenic mutations disrupting key epigenetic or transcriptional regulators (primarily WT1) or activating MAPK signaling at diagnosis. Relapses retain these cooperating oncogenes and exhibit additional oncogenic alterations and/or mutations impeding therapy response (RARA, NT5C2). The second group primarily exhibits FLT3 activation at diagnosis, which is lost upon relapse together with most other passenger mutations, implying that relapses derive from pre-leukemic PML/RARA-expressing cells that survived RA/chemotherapy. Accordingly, clonogenic activity of PML/RARA-immortalized progenitors ex vivo is only transiently affected by RA, but selectively abrogated by arsenic. Our studies stress the role of cooperating oncogenes in direct relapses and suggest that targeting pre-leukemic cells by arsenic contributes to its clinical efficacy.

  Study EGAS00001002893

• 502 present-day genotypes included in the '137 ancient human genomes from across the Eurasian steppe' publication

  For thousands of years, the Eurasian steppe has been a centre for human migrations and cultural changes. To understand its population history following the Bronze Age migrations, 137 ancient humans were sequenced. These ancient DNA sequences were notably compared to the genetic data of present-day populations from Eurasia. Besides already published data, 502 individuals currently living in Inner Asia and Jordania were sampled and newly genotyped on diverse DNA-arrays. These new data, merged as a single dataset of 242,406 autosomal SNPs, are included in the present ENA study.

  Study EGAS00001002926

• 503 genotypes from Inner Asia used in 'Close inbreeding and low genetic diversity in Inner Asian human populations despite geographical exogamy' publication

  Inner Asia is particularly interesting to understand human history and evolution, as two groups presenting contrasting cultural traits (notably their language, their social organisation and matrimonial system) cohabit. We sampled 503 individuals from these two groups, belonging to 17 populations from 11 distinct ethnic groups (AltaiKizhi, Kazakh, Khakas, Kyrgyz, Mongolian, Shore, Tajik, Telengit, Tubalar, Turkmen and Uzbek). The samples were then genotyped with 5 different DNA-arrays and, after quality-control, the 253,532 autosomal SNPs present in all the arrays were merged together in the present dataset.

  Study EGAS00001002951

• WES analysis in identifying additive genetic factors that may contribute to the occurrence of moyamoya in neurofibromatosis type 1

  Moyamoya is a progressive cerebral vasculopathy, for which genetic susceptibility factors were mainly identified in Asian populations. When associated with other medical conditions, such as neurofibromatosis type 1 (NF1), this vasculopathy is frequently reported as Moyamoya syndrome (MMS). Intriguingly, most cases of MMS-complicated NF1 have been described in Caucasians, inverting the population ratio for moyamoya vasculopathy observed in Asians, despite NF1 prevalence being constant worldwide. This study aims to investigate whether, among Caucasians, additive genetic factors may contribute to the occurrence of MMS in NF1. WES analysis has been carried out on an Italian family with co-occurrence of NF1 and MMS, as well as other cerebral vasculopathies.

  Study EGAS00001003053

• Genetics of gene expression in primary human immune cells Data Access Committee

  Dac EGAC00001003318

• 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

• The whole blood of female volunteers and sperm from the male volunteer were used to extract genomic DNA to do whole genome sequencing. Distinguished SNPs between parental genomes were retained to analyze parental allele-specific DNA methylation and chromatin accessibility in scCOOL-seq data.

  DNA methylation, chromatin states, and their interrelationships represent critical epigenetic information, but those are largely unknown in human early embryos. Here, we apply scCOOL-seq (Chromatin Overall Omic-scale Landscape Sequencing) to generate a genome-wide map of DNA methylation and chromatin accessibility at single-cell resolution during human preimplantation development. Unlike in mice, the chromatin of paternal genome is already more open than that of maternal genome at the mid-zygote stage in humans, and this state is maintained until the 4-cell stage. After fertilization, genes with high variations in DNA methylation and those with high variations in chromatin accessibility tend to be two different sets. Furthermore, 1,797 (35%) out of 5,155 widely open chromatin regions in promoters closed when transcription activity was inhibited, indicating a feedback mechanism between transcription and open chromatin maintenance. Our work paves the way for dissecting the complex, yet highly coordinated, epigenetic reprogramming during human preimplantation development.

  Study EGAS00001002987

• Reconstituting the transcriptome and DNA methylome landscapes of human implantation at single-cell resolution

  Implantation is a milestone event during mammalian embryogenesis. Due to the extreme difficulty of obtaining in vivo human early post-implantation embryos, the gene regulatory network and epigenetics controlling human embryo implantation remains elusive. Here, combining an in vitro culture system for human post-implantation development and single-cell omics sequencing technologies, over 10,000 single cells at five representative stages of pre/post-implantation development were systematically analyzed. Unsupervised dimensionality reduction and clustering algorithm of the transcriptome data show stepwise implantation routes for the epiblast, primitive endoderm, and trophectoderm lineages, suggesting preparation for the establishment of a mother-to-offspring connection after implantation. Female embryos showed asynchronous progress of dosage loss of X chromosomes during implantation. Furthermore, using the single cell trio-Seq (scTrio-Seq) strategy, re-methylation of the genomes of all the three lineages was unambiguously revealed. Surprisingly, the genome re-methylation of PE lineage were much slower than both EPI and TE lineages during the implantation process, indicating distinct methylome features between EPI and PE although both of which were derived from ICM. Collectively, our work paves the way for understanding the complex molecular mechanisms that regulate human embryo implantation, informing new insights and future efforts in early embryonic development and reproductive medicine.

  Study EGAS00001003443

• Interethnic comparability in blood pressure GWAS

  We carried out a genome-wide association and replication study for blood pressure in a two-stage approach (max N = 289,038) with a discovery stage sample of 130,777 East Asian individuals, identifying 19 new genetic loci. We found a significant genetic heterogeneity between East Asian and European-descent populations at several blood pressure loci, conforming to “a common ancestry-specific variant association model”. At 6 unique loci, distinct non-rare (or common) ancestry-specific variants co-localized within the same linkage disequilibrium block despite the significantly discordant direction of effects for the proxy shared variants between the ethnic groups. The genome-wide transethnic correlation of causal-variant effect sizes is 0.898 and 0.851 for systolic and diastolic blood pressure, respectively. Some of the ancestry-specific association signals were also influenced by a selective sweep. Our results provide new evidence for the role of common ancestry-specific variants and natural selection in the occurrence of ethnic differences in complex traits such as blood pressure.

  Study EGAS00001002991

• Histone acetylome-wide association study on tuberculosis infection

  Epigenetic mechanisms are thought to play an important role in the pathogenesis of infectious diseases. Here, we describe the first histone acetylome-wide association study (HAWAS) of an infectious disease, based on genome-wide H3K27 acetylation profiling of peripheral granulocytes and monocytes from subjects with active Mycobacterium tuberculosis (Mtb) infection and healthy controls (135 ChIP-seq datasets).

  Study EGAS00001003118

• Host whole genome variations are associated with neurocognitive outcome in survivors of pediatric medulloblastoma

  Host whole genome analysis is a promising source of predictive information for long-term morbidity in cancer survivors. However, studies on genetic predictors of long-term outcome, particularly neurocognitive function following chemoradiation in pediatric oncology are limited. In the present study, we evaluated variations in host whole genome single nucleotide polymorphisms (SNPs) and their association with cognitive outcome. Whole-genome SNP analysis of host peripheral blood was conducted on 22 medulloblastoma long-term survivors, of whom 18 completed neuropsychological testing. First, unsupervised consensus clustering of the most variable SNPs within 409 genes involved in DNA repair was performed. Discrete variant groups were identified, although they were not associated with cognitive outcome, suggesting that variations in genes corresponding to a single functional group may be insufficient to predict long-term outcome alone. In support of this interpretation, unsupervised hierarchical clustering analysis using disease-associated gene variants by cognitive impairment status yielded two distinct variant clusters comprised of 36 variants, 34 of which were in noncoding regions. These findings illustrate for the first time that cognitively impaired survivors have a distinct variant profile compared to other medulloblastoma survivors. Future research in larger cohorts is needed to validate host genome predictors of cognitive impairment that may impact clinical management.

  Study EGAS00001002996

• Allele Balance Bias Identifies Systematic Genotyping Errors and False Disease Associations

  In recent years, Next Generation Sequencing (NGS) has become a cornerstone of clinical genetics and diagnostics. Many clinical applications require high precision, especially if rare events such as somatic mutations in cancer or genetic variants causing rare diseases need to be identified. Although random sequencing errors can be modeled statistically and deep sequencing minimizes their impact, systematic errors remain a problem even at high depth of coverage. Understanding their source is crucial to increase precision of clinical NGS applications. In this work, we studied the relation between recurrent biases in allele balance (AB), systematic errors and false positive variant calls across a large cohort of human samples analyzed by whole exome sequencing (WES). We have modeled the allele balance distribution for biallelic genotypes in 987 WES samples in order to identify positions recurrently deviating significantly from the expectation, a phenomenon we termed allele balance bias (ABB). Furthermore, we have developed a genotype callability score based on ABB for all positions of the human exome, which detects false positive variant calls that passed state-of-the-art filters. Finally, we demonstrate the use of ABB for detection of false associations proposed by rare variant association studies (RVAS).

  Study EGAS00001003027

• The evolutionary history of human colitis-associated colorectal cancer

  Inflammatory bowel disease confers an increased lifetime risk of developing colorectal cancer (CRC), and colitis-associated CRC (CA-CRC) is molecularly distinct from sporadic CRC (S-CRC). Here we have dissected the evolutionary history of CA-CRC using multi-region sequencing. Exome sequencing was performed on fresh-frozen multiple regions of carcinoma, adjacent non-cancerous mucosa and blood from 12 CA-CRC patients (n=55 exomes), and key variants were validated with orthogonal methods. Genome-wide copy number profiling was performed using SNP arrays and low-pass whole genome sequencing on archival non-dysplastic mucosa (n=9), low-grade dysplasia (LGD, n=30), high-grade dysplasia (HGD, n=13), mixed LGD/HGD (n=7) and CA-CRC (n=19). Phylogenetic trees were reconstructed, and evolutionary analysis used to reveal the temporal sequence of events leading to CA-CRC. 10/12 tumors were microsatellite stable with a median mutation burden of 3.0 single nucleotide alterations (SNAs) per Mb, around 20% higher than S-CRC (2.5 SNAs/Mb), and consistent with elevated aging-associated mutational processes. Non-dysplastic mucosa had considerable mutation burden (median 47 SNAs), including mutations shared with the neighboring CA-CRC, indicating a pre-cancer mutational field. CA-CRCs were often near-triploid (42%) or near-tetraploid (21%) and phylogenetic analysis revealed that copy number alterations (CNAs) began to accrue in non-dysplastic bowel, but the LGD/HGD transition often involved a punctuated catastrophic CNA increase.

  Study EGAS00001003028

• SLC9A3R1 variant associated with age-related hearing loss

  Age-related hearing loss (ARHL) is the most common sensory impairment in the elderly affecting millions of people worldwide. To shed light on the genetics of ARHL, a large cohort of 464 Italian patients has been deeply analyzed at clinical and molecular level. A missense variant in SLC9A3R1 has been identified in two unrelated ARHL patients. A knock-in zebrafish model confirmed the pathogenic effect of the variant.

  Study EGAS00001003072

• Patient-derived neuroblastoma model system OHC-NB1

  Accurate disease modeling presents a bottleneck against effective translation of novel neuroblastoma therapies into the clinic. Recently, considerable intra-tumor genetic heterogeneity has been observed in neuroblastoma, which calls for preclinical models that reflect this feature. Flexibility in a testing platform is also desirable to support assessment of different endpoints and tumor cell characteristics. We present the novel neuroblastoma model OHC-NB1, propagated from a bone marrow metastasis from a patient with INRG stage M, MYCN-amplified neuroblastoma at first diagnosis. To model different aspects of the disease, several preclinical models were developed from the bone marrow aspirate: a tissue plastic-adherent cell line, a 3-dimensional (3D) spheroid culture, and cell line-derived xenografts that were subcutaneously passaged in mice. Typical aspects of MYCN-amplified neuroblastoma, such as MYCN amplification in double minutes, 1p deletion, 17q gain, and a diploid karyotype, are present in OHC-NB1 and persist in all culture types. Whole exome sequencing revealed intra-tumor heterogeneity in the bone marrow metastasis reflected in the culture models. The set of OHC-NB1 cultures with a genetically heterogeneous MYCN-amplified neuroblastoma background provide a flexible preclinical testing system that recapitulates important features of metastatic neuroblastoma.

  Study EGAS00001003031

• Molecular analysis of giant cell lesions

  Giant cell lesions of the jaws are aggressive proliferative conditions that affect young and adult patients. The genetic profile of the tumour has not been established yet. In this project we performed whole exome sequencing of 18 samples and RNAseq (n=6) of giant cell lesions of the jaws. All the tumours are sporadic and only non-syndromic patients were included.

  Study EGAS00001002910

• An exome sequencing approach to defining the genetic risk factors for Achilles tendinopathy

  Musculoskeletal soft tissue injuries are complex phenotypes. Case control association studies using the candidate gene approach have predominantly been used to identify risk loci for these injuries. However, the ability to identify all risk conferring variants using this approach alone is unlikely. Therefore, this study aimed to define the genetic profile of these injuries using whole exome sequencing and a customized analysis pipeline. The exomes of ten exemplar asymptomatic controls and ten exemplar cases with Achilles tendinopathy were individually sequenced using a platform that included the coverage of the untranslated regions and miRBase miRNA genes. These results provide a proof of concept for the use of a customized pipeline for the exploration of a larger genomic dataset. This approach, using previous research to guide a targeted analysis of the data has generated new genetic signatures in the biology of musculoskeletal soft tissue injuries.

  Study EGAS00001003234

• Integrated genetic and epigenetic analysis of myxofibrosarcoma

  Myxofibrosarcoma (MFS) is a common histological subtype of adult soft tissue sarcoma characterized by an infiltrative growth pattern and a high propensity for local recurrence. We underwent whole exome sequencing, RNA sequencing, and methylation analysis of MFS.

  Study EGAS00001002889

• Physiological and genetic adaptations to diving in Sea Nomads

  Understanding the physiology and genetics of human hypoxia tolerance has important medical implications, but this phenomenon has thus far only been investigated in high-altitude human populations. Another system, yet to be explored, is humans who engage in breath-hold diving. The indigenous Bajau people (“Sea Nomads”) of Southeast Asia live a subsistence lifestyle based on breath-hold diving and are renowned for their extraordinary breath holding abilities. However, it is unknown whether this has a genetic basis. Using a comparative genomic study, we show that natural selection on genetic variants in the PDE10A gene have increased spleen size in the Bajau, providing them with a larger reservoir of oxygenated red blood cells. We also find evidence of strong natural selection specific to the Bajau on BDKRB2, a gene affecting the human diving reflex. Thus, the Bajau, and possibly other natural diving populations, provide a new opportunity to study human adaptation to hypoxia tolerance.

  Study EGAS00001002823

• Comprehensive genetic analysis of Epstein-Barr virus-associated hematological malignancy

  Comprehensive genetic analyses including whole-exome sequencing, targeted sequencing, and whole-genome sequencing of the human genome and the Epstein-Barr virus (EBV) genome were performed to reveal the molecular pathogenesis of EBV-associated hematological malignancy.

  Study EGAS00001003159

• Single cell exome sequencing of lung adenocarcinoma

  Single cell exome sequencing was performed on 200 single cells isolated from a lung adenocarcinoma, female, non-smoker patient. The cells were derived from two distant tumour sectors and a far normal sector. The single cells were amplified on the Fluidigm C1 machine using the GE Healthcare illustra GenomiPhi V2 DNA Amplification Kit prior to sequencing library preparation. In addition, bulk exome sequencing was also conducted for each tumour sectors. For this study, somatic variations were detected from the single cells and phylogenetic clustering was conducted to elucidate the evolutionary trajectory of lung cancer.

  Study EGAS00001002972

• Exome Sequencing of Spanish Patients with rare genetic diseases.

  Whole exome sequencing of Spanish patients suffering from a rare genetic disease. The study was carried out in 2013 as a part of a public call from CNAG (Centro Nacional de Análisis Genómico), where data of eight spanish families were sent to analyse. The study concluded with three solved cases: two of aniridia and one syndromic RP.

  Study EGAS00001004028

• Exome sequencing in bipolar disorder families

  Bipolar disorder (BD) is a major psychiatric disorder affecting around 1% of the global population. BD is characterized by recurrent manic and depressive episodes, and has an estimated heritability of around 70% Research has identified the first BD susceptibility genes. However, the underlying pathways and regulatory networks remain largely unknown. Since research has shown that the cumulative impact of common alleles with small effect appears to explain only around 25-38% of the phenotypic variance for BD, rare variants of high penetrance may also contribute to BD risk. The present study investigated the role of rare, nonsynonymous, and potentially functional variants via whole exome sequencing in 15 BD cases from two large, multiply affected families from Cuba. The high prevalence of BD in these pedigrees renders them promising in terms of the identification of genetic risk variants with large effect sizes. In addition, SNP array data were used to calculate polygenic risk scores for affected and unaffected family members. After correction for multiple testing, polygenic risk scores for common, BD-associated genetic variants were not significantly higher in BD cases than in healthy relatives. Exome sequencing identified a total of 17 rare and potentially damaging variants in 17 genes. The identified variants were shared by all investigated BD cases in the respective pedigree. The most promising variant was located in the gene SERPING1 (p.L349F), which has been reported as a genome-wide significant risk gene for schizophrenia. A further promising variant was located in CAPN2, which has been implicated in synaptic plasticity. The present data suggest novel candidate genes for BD susceptibility, and may facilitate the discovery of disease-relevant pathways and regulatory networks.

  Study EGAS00001003085

• CTCF/cohesin-binding sites are frequently mutated in cancer

  Cohesin is present in almost all active enhancer regions, where it is associated with transcription factors. Cohesin frequently colocalizes with CTCF (CCCTC-binding factor), affecting genomic stability, expression and epigenetic homeostasis. Cohesin subunits are mutated in cancer, but CTCF/cohesin-binding sites (CBSs) in DNA have not been examined for mutations. Here we report frequent mutations at CBSs in cancers displaying a mutational signature where mutations in A•T base pairs predominate. Integration of whole-genome sequencing data from 213 colorectal cancer (CRC) samples and chromatin immunoprecipitation sequencing (ChIP-exo) data identified frequent point mutations at CBSs. In contrast, CRCs showing an ultramutator phenotype caused by defects in the exonuclease domain of DNA polymerase ɛ (POLE) displayed significantly fewer mutations at and adjacent to CBSs. Analysis of public data showed that multiple cancer types accumulate CBS mutations. CBSs are a major mutational hotspot in the noncoding cancer genome.

  Study EGAS00001003010