3334 results for "*geneti*"

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• Reconstructing the dispersals and adaptive history of Bantu-speaking populations in Africa and North America

  Bantu languages are spoken by ~310 million Africans, yet the genetic history of Bantu-speaking populations remains largely unexplored. We generated genomic data for 1,318 individuals from 35 populations in western central Africa, where Bantu languages originated. We found that early Bantu speakers first moved southward, through the equatorial rainforest, before spreading toward eastern and southern Africa. We also found that genetic adaptation of Bantu speakers was facilitated by admixture with autochthonous populations, particularly for the HLA and LCT loci. Finally, we identified a major contribution of western central African Bantu speakers to the ancestry of African Americans, whose genomes present no strong signals of natural selection. Together, these results highlight the contribution of Bantu-speaking peoples to the complex genetic history of Africans and African Americans.

  Study EGAS00001002078

• RB Loss in Resistant EGFR Mutant Lung Adenocarcinomas that Transform to Small Cell Lung Cancer

  Tyrosine kinase inhibitors (TKIs) are effective treatments for non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) mutations. However, they do not lead to cures, and, on average, relapse occurs typically occurs afterafter an average of one year of continuous treatment. In a subset of patients, aA fundamental histological transformation from NSCLC to small cell lung cancer (SCLC) is observed in a subset of the resistant cancers, but the molecular changes associated with this transformation remain unknown. Analysis of a cohort of tumor samples and cell lines derived from resistant EGFR mutant patients with SCLC transformation revealed that RB is lost in 100% of these SCLC transformed cases, but rarely in those that remain NSCLC. Global changes in gene expression, including increased neuroendocrine marker expression and absence of EGFR expression, are observed in resistant EGFR mutant cancers that transformed to SCLC. Consistent Further, with their similarities to classical SCLC at the genetic and gene expression levelincreased neuroendocrine marker and decreased EGFR expression as well as greater sensitivity to BCL2 family inhibition are observed in resistant SCLC transformed cancers compared to resistant NSCLCs. , cell lines derived from resistant EGFR mutant SCLC biopsies are substantially more sensitive to Bcl-2 family inhibition with ABT-263 compared to those derived from resistant EGFR mutant NSCLCs. Together, these findings suggest that despite developing initially as EGFR mutant adenocarcinomas, this subset of resistant cancers ultimately adopt many of the molecular and phenotypic characteristics of classical SCLC.

  Study EGAS00001001102

• Whole-exome and targeted sequencing of pediatric hyperdiploid B-cell precursor acute lymphoblastic leukemia

  High hyperdiploidy defines the largest genetic entity of childhood acute lymphoblastic leukemia (ALL). Despite its relatively low recurrence risk, this subgroup generates a high proportion of relapses. The cause and origin of these relapses remains obscure. We therefore explored the mutational landscape in high hyperdiploid (HD) ALL with whole-exome (n=19) and subsequent targeted deep sequencing of 60 genes in 100 relapsing and 51 non-relapsing cases. We identified multiple clones at diagnosis that were primarily defined by a variety of mutations in receptor tyrosine kinase (RTK)/Ras pathway and chromatin-modifying genes. The relapse clones consisted of reappearing as well as new mutations, and overall contained more mutations. Although RTK/Ras pathway mutations were similarly frequent between diagnosis and relapse, both intergenic and intragenic heterogeneity was essentially lost at relapse. CREBBP mutations, however, increased from initially 18-30% at relapse, then commonly co-occurred with KRAS mutations (P<0.001) and these relapses appeared primarily early (P=0.012). Our results confirm the exceptional susceptibility of HD ALL to RTK/Ras pathway and CREBBP mutations, but, more importantly, suggest that mutant KRAS and CREBBP might cooperate and equip cells with the necessary capacity to evolve into a relapse-generating clone.

  Study EGAS00001001113

• Neuroblastoma Evolution

  Here, we quantify the somatic evolution of neuroblastomas by deep (80x) whole-genome sequencing, molecular clock analysis and population-genetic modeling in a comprehensive cohort (Hipo_K09R) covering all subtypes.

  Study EGAS00001006533

• cfDNA in Hereditary And High-Risk Malignancies (CHARM)

  Our goal is to improve early cancer detection by developing a blood test to predict cancer development in carriers using circulating DNA. As carriers develop cancer, they may have pre-cancerous cells which release this DNA into the blood (cell-free DNA; cfDNA), which can be detected with novel genetic technologies. We propose to use three complementary cfDNA assays:shallow whole genome sequencing (sWGS), Liquid-Biopsy Sequencing (LB-Seq) and Cell-free Methylated DNA Immunoprecipitation and High-throughput Sequencing (cfMeDip-Seq) for early cancer detection.

  Study EGAS00001006539

• Genome-wide association analysis on five isolated populations - Erasmus Rucphen Family (ERF) Study

  ERF is embedded in the Genetic Research in Isolated Population (GRIP) program. Genealogy of GRIP is available from its founding (1600-1650). For ERF, we selected 22 related (first and second degree, non-consanguineous) couples living in GRIP between 1850-1900, and having at least six children baptized in the community church. All living descendants of those couples were invited to participate in ERF1. About 4,000 relatives included in the study form a very complex pedigree, which consists of more than 23,000 members. The participants aged between 18-20 years constitute a unique single family spanning over 23 generations. Around 3,000 individuals have been extensively phenotyped for several psychiatric and somatic traits. All phenotyped individuals are genotyped on genome-wide genotyping arrays.

  Study EGAS00001001134

• Genesis of Two Most Prevalent Variants Causing Combined Pituitary Hormone Deficiency in 21 Populations

  Two variants (c.[301_302delAG];[301_302delAG] and c.[150delA];[150delA]) in the PROP1 gene are the most common genetic causes of recessively inherited combined pituitary hormones deficiency (CPHD). Our objective was to analyze in detail the origin of the two most prevalent variants. In the multicentric study were included 237 patients with CPHD and their 15 relatives carrying c.[301_302delAG];[301_302delAG] or c.[150delA];[150delA] or c.[301_302delAG];[ 150delA]. They originated from 21 different countries worldwide. We genotyped 21 single nucleotide variant markers flanking the 9.6Mb region around the PROP1 gene that are not in mutual linkage disequilibrium in the general populations - a finding of a common haplotype would be indicative of ancestral origin of the variant. Haplotypes were reconstructed by Phase and Haploview software, and the variant age was estimated using an allelic association method. We demonstrated ancestral origin of both variants: c.[301_302delAG] was carried on 0.2Mb-long haplotype in a majority of European patients arising approximately 101 generations ago (confidence interval 90.1-116.4). Patients from the Iberian Peninsula displayed a different haplotype which was estimated to have emerged 23.3 (20.1-29.1) generations ago. Subsequently, the data indicated that both haplotypes were transmitted to Latin American patients approximately 13.8 (12.2-17.0) and 16.4 (14.4-20.1) generations ago, respectively. The c.[150delA] variant that was carried on a haplotype spanning about 0.3Mb was estimated to appear 43.7 (38.4-52.7) generations ago. We present strong evidence that the most frequent variants in the PROP1 gene are not a consequence of variant hot-spots as previously assumed, but are founder variants.

  Study EGAS00001001165

• GWAS study on arsenic-exposed population

  Genetic analysis of women from the Andes Mountains that are exposed to arsenic in drinking water.

  Study EGAS00001001168

• Sequencing of heritable Bleeding and Platelet Disorders

  The BRIDGE-BPD study aims to discover new causal genes for Bleeding and Platelet Disorders (BPD) by high throughput sequencing using cluster analyses based on improved and standardized deep phenotyping of cases. BPD is one of the 13 Rare Disease projects under the NIHR BioResource Rare Diseases BRIDGE consortium, which is a collaboration aiming to discover the genetic sequence variants underlying unresolved inherited disorders and to improve identification of already identified high penetrance variants.

  Study EGAS00001001172

• Prediction of pigmentation phenotypes by SNP typing in a Northern German population

  Human pigmentation traits are of great interest to many research areas, from ancient DNA analysis to forensic science. We aimed to develop a gene-based predictive model for pigmentation phenotypes in a realistic target population for forensic case work from Northern Germany. Our aim was to determine whether better prediction accuracy can be achieved, or fewer genetic markers may suffice, than in previously studied, genetically more heterogeneous populations. We investigated the association between eye, hair and skin colour, and 12 candidate single nucleotide polymorphisms (SNPs) from six genes. Our study comprised two samples of 300 and 100 individuals from Northern Germany who were carefully characterized with regard to pigmentation phenotypes. The first sample was used to select trait-associated SNPs whereas the second sample served to estimate odds ratios (ORs) and to quantify the predictive capability of the respective SNP genotypes. SNP rs12913832 in HERC2 was found to be strongly associated with blue eye colour (OR=15.6, p<1.2•10-4) and to yield reasonable predictive power (90% sensitivity, 63% specificity). SNP associations with hair and skin colour were weaker and genotypes less predictive. A comparison to two recently published sets of markers to predict eye and hair colour revealed that the consideration of additional SNPs with weak to moderate effect increases the predictive power in Northern Germans for eye colour, but not for hair colour. In addition, fine phenotyping and differentiation of hair colour (light / dark and red tint / no red tint) were found to increase the number of significant genotype-phenotype associations.

  Study EGAS00001001174