Araştırma Çıktıları
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Item De Novo Mutation in Genes Regulating Neural Stem Cell Fate in Human Congenital Hydrocephalus(CELL PRESS, 2018-01-01) Furey, Charuta Gavankar; Choi, Jungmin; Jin, Sheng Chih; Zeng, Xue; Timberlake, Andrew T.; Nelson-Williams, Carol; Mansuri, M. Shahid; Lu, Qiongshi; Duran, Daniel; Panchagnula, Shreyas; Allocco, August; Karimy, Jason K.; Khanna, Arjun; Gaillard, Jonathan R.; DeSpenza, Tyrone; Antwi, Prince; Loring, Erin; Butler, William E.; Smith, Edward R.; Warf, Benjamin C.; Strahle, Jennifer M.; Limbrick, David D.; Storm, Phillip B.; Heuer, Gregory; Jackson, Eric M.; Iskandar, Bermans J.; Johnston, James M.; Tikhonova, Irina; Castaldi, Christopher; Lopez-Giraldez, Francesc; Bjornson, Robert D.; Knight, James R.; Bilguvar, Kaya; Mane, Shrikant; Alper, Seth L.; Haider, Shozeb; Guclu, Bulent; Bayri, Yasar; Sahin, Yener; Apuzzo, Michael L. J.; Duncan, Charles C.; DiLuna, Michael L.; Gunel, Murat; Lifton, Richard P.; Kahle, Kristopher T.Congenital hydrocephalus (CH), featuring markedly enlarged brain ventricles, is thought to arise from failed cerebrospinal fluid (CSF) homeostasis and is treated with lifelong surgical CSF shunting with substantial morbidity. CH pathogenesis is poorly understood. Exome sequencing of 125 CH trios and 52 additional probands identified three genes with significant burden of rare damaging de novo or transmitted mutations: TRIM71 (p = 2.15 x 10(-7)), SMARCC1 (p = 8.15 x 10(-10)), and PTCH1 (p = 1.06 x 10(-6)). Additionally, two de novo duplications were identified at the SHH locus, encoding the PTCH1 ligand (p = 1.2 x 10(-4)). Together, these probands account for similar to 10\% of studied cases. Strikingly, all four genes are required for neural tube development and regulate ventricular zone neural stem cell fate. These results implicate impaired neurogenesis (rather than active CSF accumulation) in the pathogenesis of a subset of CH patients, with potential diagnostic, prognostic, and therapeutic ramifications.Item The genetic structure of the Turkish population reveals high levels of variation and admixture(NATL ACAD SCIENCES, 2021-01-01) Kars, M. Ece; Basak, A. Nazli; Onat, O. Emre; Bilguvar, Kaya; Choi, Jungmin; Itan, Yuval; Caglar, Caner; Palvadeau, Robin; Casanova, Jean-Laurent; Cooper, David N.; Stenson, Peter D.; Yavuz, Alper; Bulus, Hakan; Gunel, Murat; Friedman, Jeffrey M.; Ozcelik, TayfunThe construction of population-based variomes has contributed substantially to our understanding of the genetic basis of human inherited disease. Here, we investigated the genetic structure of Turkey from 3,362 unrelated subjects whose whole exomes (n = 2,589) or whole genomes (n = 773) were sequenced to generate a Turkish (TR) Variome that should serve to facilitate disease gene discovery in Turkey. Consistent with the history of present-day Turkey as a crossroads between Europe and Asia, we found extensive admixture between Balkan, Caucasus, Middle Eastern, and European populations with a closer genetic relationship of the TR population to Europeans than hitherto appreciated. We determined that 50\% of TR individuals had high inbreeding coefficients (>= 0.0156) with runs of homozygosity longer than 4 Mb being found exclusively in the TR population when compared to 1000 Genomes Project populations. We also found that 28\% of exome and 49\% of genome variants in the very rare range (allele frequency < 0.005) are unique to the modern TR population. We annotated these variants based on their functional consequences to establish a TR Variome containing alleles of potential medical relevance, a repository of homozygous loss-of-function variants and a TR reference panel for genotype imputation using high-quality haplotypes, to facilitate genome-wide association studies. In addition to providing information on the genetic structure of the modern TR population, these data provide an invaluable resource for future studies to identify variants that are associated with specific phenotypes as well as establishing the phenotypic consequences of mutations in specific genes.Item Comparative transmissibility of SARS-CoV-2 variants Delta and Alpha in New England, USA(ELSEVIER, 2022-01-01) Earnest, Rebecca; Uddin, Rockib; Matluk, Nicholas; Renzette, Nicholas; Turbett, Sarah E.; Siddle, Katherine J.; Loreth, Christine; Adams, Gordon; Tomkins-Tinch, Christopher H.; Petrone, Mary E.; Rothman, Jessica E.; Breban I, Mallery; Koch, Robert Tobias; Billig, Kendall; Fauver, Joseph R.; Vogels, Chantal B. F.; Bilguvar, Kaya; De Kumar, Bony; Landry, Marie L.; Peaper, David R.; Kelly, Kevin; Omerza, Greg; Grieser, Heather; Meak, Sim; Martha, John; Dewey, Hannah B.; Kales, Susan; Berenzy, Daniel; Carpenter-Azevedo, Kristin; King, Ewa; Huard, Richard C.; Novitsky, Vlad; Howison, Mark; Darpolor, Josephine; Manne, Akarsh; Kantor, Rami; Smole, Sandra C.; Brown, Catherine M.; Fink, Timelia; Lang, Andrew S.; Gallagher, Glen R.; Pitzer, Virginia E.; Sabeti, Pardis C.; Gabriel, Stacey; MacInnis, Bronwyn L.; Tewhey, Ryan; Adams, Mark D.; Park, Daniel J.; Lemieux, Jacob E.; Grubaugh, Nathan D.; Team, New England Variant InvestThe SARS-CoV-2 Delta variant rose to dominance in mid-2021, likely propelled by an estimated 40\%???80\% increased transmissibility over Alpha. To investigate if this ostensible difference in transmissibility is uniform across populations, we partner with public health programs from all six states in New England in the United States. We compare logistic growth rates during each variant???s respective emergence period, finding that Delta emerged 1.37???2.63 times faster than Alpha (range across states). We compute variant-specific effective reproductive numbers, estimating that Delta is 63\%???167\% more transmissible than Alpha (range across states). Finally, we estimate that Delta infections generate on average 6.2 (95\% CI 3.1???10.9) times more viral RNA copies per milliliter than Alpha infections during their respective emergence. Overall, our evidence suggests that Delta???s enhanced transmissibility can be attributed to its innate ability to increase infectiousness, but its epidemiological dynamics may vary depending on underlying population attributes and sequencing data availability.Item Whole-exome sequencing identifies recessive WDR62 mutations in severe brain malformations(NATURE PUBLISHING GROUP, 2010-01-01) Bilguvar, Kaya; Ozturk, Ali Kemal; Louvi, Angeliki; Kwan, Kenneth Y.; Choi, Murim; Tatli, Burak; Yalnizoglu, Dilek; Tuysuz, Beyhan; Caglayan, Ahmet Okay; Gokben, Sarenur; Kaymakcalan, Hande; Barak, Tanyeri; Bakircioglu, Mehmet; Yasuno, Katsuhito; Ho, Winson; Sanders, Stephan; Zhu, Ying; Yilmaz, Sanem; Dincer, Alp; Johnson, Michele H.; Bronen, Richard A.; Kocer, Naci; Per, Hueseyin; Mane, Shrikant; Pamir, Mehmet Necmettin; Yalcinkaya, Cengiz; Kumandas, Sefer; Topcu, Meral; Ozmen, Meral; Sestan, Nenad; Lifton, Richard P.; State, Matthew W.; Gunel, MuratThe development of the human cerebral cortex is an orchestrated process involving the generation of neural progenitors in the periventricular germinal zones, cell proliferation characterized by symmetric and asymmetric mitoses, followed by migration of post-mitotic neurons to their final destinations in six highly ordered, functionally specialized layers(1,2). An understanding of the molecular mechanisms guiding these intricate processes is in its infancy, substantially driven by the discovery of rare mutations that cause malformations of cortical development(3-6). Mapping of disease loci in putative Mendelian forms of malformations of cortical development has been hindered by marked locus heterogeneity, small kindred sizes and diagnostic classifications that may not reflect molecular pathogenesis. Here we demonstrate the use of whole-exome sequencing to overcome these obstacles by identifying recessive mutations in WD repeat domain 62 (WDR62) as the cause of a wide spectrum of severe cerebral cortical malformations including microcephaly, pachygyria with cortical thickening as well as hypoplasia of the corpus callosum. Some patients with mutations in WDR62 had evidence of additional abnormalities including lissencephaly, schizencephaly, polymicrogyria and, in one instance, cerebellar hypoplasia, all traits traditionally regarded as distinct entities. In mice and humans, WDR62 transcripts and protein are enriched in neural progenitors within the ventricular and subventricular zones. Expression of WDR62 in the neocortex is transient, spanning the period of embryonic neurogenesis. Unlike other known microcephaly genes, WDR62 does not apparently associate with centrosomes and is predominantly nuclear in localization. These findings unify previously disparate aspects of cerebral cortical development and highlight the use of whole-exome sequencing to identify disease loci in settings in which traditional methods have proved challenging.Item Recessive loss of function of the neuronal ubiquitin hydrolase UCHL1 leads to early-onset progressive neurodegeneration(NATL ACAD SCIENCES, 2013-01-01) Bilguvar, Kaya; Tyagi, Navneet K.; Ozkara, Cigdem; Tuysuz, Beyhan; Bakircioglu, Mehmet; Choi, Murim; Delil, Sakir; Caglayan, Ahmet O.; Baranoski, Jacob F.; Erturk, Ozdem; Yalcinkaya, Cengiz; Karacorlu, Murat; Dincer, Alp; Johnson, Michele H.; Mane, Shrikant; Chandra, Sreeganga S.; Louvi, Angeliki; Boggon, Titus J.; Lifton, Richard P.; Horwich, Arthur L.; Gunel, MuratUbiquitin C-terminal hydrolase-L1 (UCHL1), a neuron-specific deubiquitinating enzyme, is one of the most abundant proteins in the brain. We describe three siblings from a consanguineous union with a previously unreported early-onset progressive neurodegenerative syndrome featuring childhood onset blindness, cerebellar ataxia, nystagmus, dorsal column dysfuction, and spasticity with upper motor neuron dysfunction. Through homozygosity mapping of the affected individuals followed by whole-exome sequencing of the index case, we identified a previously undescribed homozygous missense mutation within the ubiquitin binding domain of UCHL1 (UCHL1(GLU7ALA).), shared by all affected subjects. As demonstrated by isothermal titration calorimetry, purified UCHL1(GLU7ALA), compared with WT, exhibited at least sevenfold reduced affinity for ubiquitin. In vitro, the mutation led to a near complete loss of UCHL1 hydrolase activity. The GLU7ALA variant is predicted to interfere with the substrate binding by restricting the proper positioning of the substrate for tunneling underneath the cross-over loop spanning the catalytic cleft of UCHL1. This interference with substrate binding, combined with near complete loss of hydrolase activity, resulted in a >100-fold reduction in the efficiency of UCHL1(GLU7ALA) relative to WT. These findings demonstrate a broad requirement of UCHL1 in the maintenance of the nervous system.Item Longitudinal analysis of treatment-induced genomic alterations in gliomas(BIOMED CENTRAL LTD, 2017-01-01) Erson-Omay, E. Zeynep; Henegariu, Octavian; Omay, S. Bulent; Harmanci, Akdes Serin; Youngblood, Mark W.; Mishra-Gorur, Ketu; Li, Jie; Ozduman, Koray; Carrion-Grant, Geneive; Clark, Victoria E.; Caglar, Caner; Bakircioglu, Mehmet; Pamir, M. Necmettin; Tabar, Viviane; Vortmeyer, Alexander O.; Bilguvar, Kaya; Yasuno, Katsuhito; DeAngelis, Lisa M.; Baehring, Joachim M.; Moliterno, Jennifer; Gunel, MuratBackground: Glioblastoma multiforme (GBM) constitutes nearly half of all malignant brain tumors and has a median survival of 15 months. The standard treatment for these lesions includes maximal resection, radiotherapy, and chemotherapy