{"637076":{"#nid":"637076","#data":{"type":"event","title":"PhD Defense by Aroon Chande","body":[{"value":"\u003Cp\u003EIn partial fulfillment of the requirements for the degree of\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDoctor of Philosophy in Bioinformatics\u003C\/p\u003E\r\n\r\n\u003Cp\u003Ein the School of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAroon T. Chande\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDefends his thesis:\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Ca name=\u0022_Hlk41640322\u0022\u003E\u003C\/a\u003E\u003Cstrong\u003EBioinformatic platforms and methods for worldwide polygenic risk scores\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThursday, July 30\u003Csup\u003Eth\u003C\/sup\u003E, 2020\u003C\/p\u003E\r\n\r\n\u003Cp\u003E11:00 AM Eastern Time\u003C\/p\u003E\r\n\r\n\u003Cp\u003EBlueJeans: \u003Ca href=\u0022https:\/\/bluejeans.com\/683430155\u0022\u003Ehttps:\/\/bluejeans.com\/683430155\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EThesis Advisor:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. I. King Jordan\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Soojin Yi\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Gregory Gibson\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Joseph Lachance\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Ca name=\u0022_Hlk44493424\u0022\u003EDr. Augusto Valderamma-Aquirre\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EFaculty of Health\u003C\/p\u003E\r\n\r\n\u003Cp\u003EUniversidad Santiago de Cali\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAbstract\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGenetic diversity underpins much of observed human phenotypic diversity and plays an important role in human health and disease.\u0026nbsp; This dissertation is focused on exploring the genetic architecture of phenotypic diversity among global populations and studying common complex disease in genetically diverse but geographically close communities.\u0026nbsp; This work is motivated by prevalent health disparities that disproportionately affect disadvantaged populations across the world, and in particular, those in the Americas.\u0026nbsp; I utilize thousands of genomes from diverse populations worldwide, along with hundreds of genome-wide association studies (GWAS) on thousands of human traits, to address three overarching questions: (1) which phenotypes vary among populations, and what explains that variance?; (2) is it possible to predict and stratify risk for common complex diseases across diverse populations?; and (3) can we apply already discovered genetic associations to risk prediction in new and ancestrally distinct populations?\u003C\/p\u003E\r\n\r\n\u003Cp\u003EPolygenic risk scores (PGS) are increasingly used to quantify individuals\u0026rsquo; genetic predisposition for disease.\u0026nbsp; I developed the first of its kind web platform for PGS computation and visualization, GADGET, The Global Distribution of Genetic Traits webserver (\u003Ca href=\u0022https:\/\/gadget.biosci.gatech.edu\/\u0022\u003Ehttps:\/\/gadget.biosci.gatech.edu\/\u003C\/a\u003E).\u0026nbsp; GADGET enables biomedical researchers to easily test hypotheses and generate publication-ready visualizations of PGS for thousands of individuals in 27 global populations.\u0026nbsp; I also developed a specialized, country and population-specific PGS server, the Colombian Phenotype-Genotype Browser (CPGB; \u003Ca href=\u0022https:\/\/map.chocogen.com\/\u0022\u003Ehttps:\/\/map.chocogen.com\/\u003C\/a\u003E), to support precision public health efforts in Colombia.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ENext, I leveraged the PGS curation from GADGET to explore the differentiation of single loci and polygenic traits between neighboring populations of Afro-Colombians in Choc\u0026oacute; and Euro-Colombians in Antioquia.\u0026nbsp; I developed PGS and found that they largely reflect the observed health disparities for seven high-cost and high-burden common complex diseases in Colombia.\u0026nbsp; Interestingly, PGS for type 2 diabetes (T2D) significantly over-predicted risk in Afro-Colombians.\u0026nbsp; Further analysis of T2D in Colombia revealed the importance of environmental and lifestyle effects on T2D.\u0026nbsp; In Colombia, in contrast to much of the developed world, low socioeconomic status was correlated with decreased prevalence for T2D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EMy final study brings the focus back to the US and developed a correction method for applying already ascertained SNP-trait associations, again for T2D, in diverse populations.\u0026nbsp; I predicted T2D risk in Mexican-Americans and European-Americans and validated my predictions at the population level using epidemiological data.\u0026nbsp; A simulation-based correction method utilizing the derived allele frequency spectrum for trait-associated variants was used to correct PGS bias between ancestrally divergent populations.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003ETogether, these studies underscore how genetic diversity contributes to global phenotypic variance.\u0026nbsp; Differences in population PGS distributions are generally an accurate indicator of relative disparities between populations in a country; although, differences in ancestry impact the accuracy of individuals\u0026rsquo; PGS.\u0026nbsp; In cases where predictions do not match observed disparities, there are significant socioeconomic and environmental effects that mediate the genetic component of disease risk.\u0026nbsp; Finally, simulation-based controls showed promise for helping to account for and correct bias in PGS when transferring associations between populations with distinct ancestry.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Bioinformatic platforms and methods for worldwide polygenic risk scores"}],"uid":"27707","created_gmt":"2020-07-17 20:46:17","changed_gmt":"2020-07-17 20:46:17","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2020-07-30T12:00:00-04:00","event_time_end":"2020-07-30T14:00:00-04:00","event_time_end_last":"2020-07-30T14:00:00-04:00","gmt_time_start":"2020-07-30 16:00:00","gmt_time_end":"2020-07-30 18:00:00","gmt_time_end_last":"2020-07-30 18:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78761","name":"Faculty\/Staff"},{"id":"78771","name":"Public"},{"id":"174045","name":"Graduate students"},{"id":"78751","name":"Undergraduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}