{"id":6346,"date":"2026-10-19T09:48:48","date_gmt":"2026-10-19T09:48:48","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-lif-og-laeknavisindum-gudmundur-bragi-walters\/"},"modified":"2026-10-19T09:48:48","modified_gmt":"2026-10-19T09:48:48","slug":"doktorsvorn-i-lif-og-laeknavisindum-gudmundur-bragi-walters","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-lif-og-laeknavisindum-gudmundur-bragi-walters\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed l\u00edf- og l\u00e6knav\u00edsindum &#8211; Gu\u00f0mundur Bragi Walters"},"content":{"rendered":"<div class=\"field-items\">\n<div class=\"field-item even\" property=\"content:encoded\">\n<p>F\u00f6studaginn 9. j\u00fan\u00ed 2023 ver Gu\u00f0mundur Bragi Walters doktorsritger\u00f0 s\u00edna \u00ed l\u00edf- og l\u00e6knav\u00edsindum vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0:\u00a0<\/p>\n<p>Erf\u00f0afr\u00e6\u00f0i tauga\u00feroskaraskana: \u00c1hrif sjaldg\u00e6fra breytileika \u00e1 byggingu og starfsemi heilans.\u00a0Genetics of neurodevelopmental disorders: Effects of rare sequence variants on brain structure and function.<\/p>\n<p>Andm\u00e6lendur eru dr. S\u00e9bastien Jacquemont, d\u00f3sent vi\u00f0 h\u00e1sk\u00f3lann \u00ed Montr\u00e9al, Kanada, og dr. Manuel Mattheisen, pr\u00f3fessor vi\u00f0 Dalhousie University, Kanada.\u00a0<\/p>\n<p>Umsj\u00f3narkennari var K\u00e1ri Stef\u00e1nsson, pr\u00f3fessor emer\u00edtus, og me\u00f0lei\u00f0beinandi var Hreinn Stef\u00e1nsson, forst\u00f6\u00f0uma\u00f0ur hj\u00e1 \u00cdslenskri erf\u00f0agreiningu. Auk \u00feeirra s\u00e1tu \u00ed doktorsnefnd Evald E. S\u00e6mundsen, kl\u00edn\u00edskur pr\u00f3fessor, og G\u00edsli M\u00e1sson, framkv\u00e6mdastj\u00f3ri hj\u00e1 \u00cdslenskri erf\u00f0agreiningu.<\/p>\n<p>Dr. S\u00e6d\u00eds S\u00e6varsd\u00f3ttir, pr\u00f3fessor og varadeildarforseti L\u00e6knadeildar, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl. 13.00.<\/p>\n<p>V\u00f6rninni ver\u00f0ur streymt:\u00a0<\/p>\n<p><a href=\"https:\/\/livestream.com\/hi\/doktorsvorngudmundurbragiwalters\">https:\/\/livestream.com\/hi\/doktorsvorngudmundurbragiwalters<\/a><\/p>\n<p><a href=\"https:\/\/livestream.com\/hi\/doktorsvorngudmundurbragiwaltersson\"><\/a><\/p>\n<p><strong>\u00c1grip<\/strong><\/p>\n<p>\u00deroskunarferli taugakerfisins er fl\u00f3ki\u00f0 kerfi, undir n\u00e1kv\u00e6mri stj\u00f3rn, og truflanir geta leitt til mismunandi raskana \u00e1 heg\u00f0un e\u00f0a vitr\u00e6nni starfsemi sem birtast sem tauga\u00feroskaraskanir og ge\u00f0raskanir. Breytileikar \u00ed erf\u00f0amengi hafa veri\u00f0 tengdir vi\u00f0 tauga\u00feroskaraskanir og ge\u00f0raskanir. \u00de\u00f3 a\u00f0 undirliggjandi l\u00edffr\u00e6\u00f0ilegir \u00fe\u00e6ttir \u00feessara raskana s\u00e9u a\u00f0 mestu leyti \u00f3\u00feekktir hafa ranns\u00f3knir undanfarinna \u00e1ra bent til sameiginlegra erf\u00f0afr\u00e6\u00f0ilegra \u00e1h\u00e6ttu\u00fe\u00e1tta. Til a\u00f0 einangra og rannsaka vitr\u00e6na \u00fe\u00e1ttinn v\u00f6ldum vi\u00f0 arfbera eintakabreytileika, sem auka \u00e1h\u00e6ttu \u00e1 einhverfur\u00f3fsr\u00f6skun e\u00f0a ge\u00f0klofa, en \u00feeir hafa ekki fengi\u00f0 greiningu \u00e1 \u00feessum r\u00f6skunum. \u00ddmis vitr\u00e6n pr\u00f3f voru l\u00f6g\u00f0 fyrir \u00feessa einstaklinga og heilar \u00feeirra kanna\u00f0ir me\u00f0 segul\u00f3mun. Ranns\u00f3knin leiddi \u00ed lj\u00f3s s\u00e9rt\u00e6kar greindarsker\u00f0ingar og heilabreytingar sem svipar til \u00feeirra sem eiga s\u00e9r sta\u00f0 hj\u00e1 \u00feeim sem greinast me\u00f0 ge\u00f0klofa. \u00dat fr\u00e1 \u00feessum ni\u00f0urst\u00f6\u00f0um spratt s\u00fa tilg\u00e1ta a\u00f0 breytingar \u00e1 vitsmunum s\u00e9u ekki endilega aflei\u00f0ing ge\u00f0raskana, heldur geti \u00fe\u00e6r jafnvel mi\u00f0la\u00f0 hluta af sj\u00fakd\u00f3ms\u00e1h\u00e6ttunni. A\u00f0 auki s\u00fdndum vi\u00f0 fram \u00e1 \u00e1\u00f0ur \u00f3\u00feekkt tengsl \u00e1 milli \u00feessara eintakabreytileika og \u00e1h\u00e6ttu \u00e1 ADHD sem bendir til \u00feess a\u00f0 tauga\u00feroskaraskanir og ge\u00f0raskanir eigi sameiginlegar l\u00edffr\u00e6\u00f0ilegar undirst\u00f6\u00f0ur. Vi\u00f0 beittum s\u00f6mu ranns\u00f3knara\u00f0fer\u00f0um til a\u00f0 uppg\u00f6tva tengsl \u00e1 milli eintakabreytileika 15q11.2(brotsv\u00e6\u00f0i 1-2) brottfellingar og s\u00e9rt\u00e6krar n\u00e1msr\u00f6skunar, \u00e1n greindarsker\u00f0ingar, og breytinga \u00ed uppbyggingu og virkni heilans, sem \u00e1\u00f0ur h\u00f6f\u00f0u veri\u00f0 tengdar vi\u00f0 lesskilning og margf\u00f6ldunarskilning. A\u00f0 auki fundum vi\u00f0 breytingar \u00ed basar\u00f6\u00f0 sem styttir pr\u00f3teinafur\u00f0 MAP1B gensins og tengjast mj\u00f6g sterklega vi\u00f0 greindarsker\u00f0ingu og verulegum breytingum \u00ed hv\u00edta efni heilans. Ranns\u00f3knirnar auka skilning \u00e1 \u00e1hrifum breytileika \u00ed erf\u00f0amenginu \u00e1 vitsmuni, byggingu og virkni heilans og tengslum \u00feeirra vi\u00f0 ge\u00f0- og tauga\u00feroskaraskanir.<\/p>\n<p><strong>Abstract<\/strong><\/p>\n<p>Development of the nervous system is a complex and highly regulated process that, when impaired, can result in a multitude of disorders of varying behavioural, cognitive, and functional severity that may present as neurodevelopmental (NDDs) and psychiatric disorders. Variations in the genome have been associated with NDDs and psychiatric disorders. Although the underlying biological mechanisms are largely unknown research in recent years has revealed shared genetic risk factors. To study the cognitive element, independent of the clinical state, we identified carriers of copy number variants (CNVs), that confer risk of NDDs and psychiatric disorders, yet do not have a diagnosis of those disorders. These individuals were administered a battery of cognitive tests and brain MRI that identify specific cognitive impairments and structural changes akin to those seen in schizophrenia diagnosed individuals. This led us to propose that the cognitive impairments are not necessarily consequences of the disorders but may in fact mediate some of the disorder risk instead. In addition, a previously unidentified association was demonstrated between these CNVs and ADHD that suggests a common biological foundation for the NDDs and psychiatric disorders. Using these same tools, we identified an association between the CNV 15q11.2(breakpoint 1-2) deletion and specific learning disorders, independent of IQ, and structural and functional changes in the brain previously identified as being important for reading and arithmetic. We also discovered protein truncating variants in MAP1B that associate strongly with intellectual impairments and dramatic changes in brain white matter. These results broaden understanding of the effects of variants in the genome on cognition, structural and functional changes in the brain and their relation to NDDs and psychiatric disorders.<\/p>\n<p><strong>Um doktorsefni\u00f0<\/strong><\/p>\n<p>Gu\u00f0mundur Bragi Walters er f\u00e6ddur \u00e1ri\u00f0 1973 \u00ed Reykjav\u00edk. Hann lauk st\u00fadentspr\u00f3fi \u00e1ri\u00f0 1991 fr\u00e1 Kelvin Grove State High School og B.Sc-gr\u00e1\u00f0u \u00ed l\u00edffr\u00e6\u00f0i vi\u00f0 Griffith University (Brisbane, Queensland) \u00ed \u00c1stral\u00edu \u00e1ri\u00f0 1994. Bragi h\u00f3f doktorsn\u00e1m vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands \u00e1ri\u00f0 2014 og hefur s\u00ed\u00f0an starfa\u00f0 a\u00f0 doktorsverkefni s\u00ednu. Samhli\u00f0a n\u00e1minu hefur hann veri\u00f0 verkefnastj\u00f3ri hj\u00e1 \u00cdslenskri erf\u00f0agreiningu (\u00cdE). Bragi h\u00f3f st\u00f6rf hj\u00e1 \u00cdE 1997 og s\u00ed\u00f0an \u00fe\u00e1 teki\u00f0 \u00fe\u00e1tt \u00ed erf\u00f0aranns\u00f3knum margv\u00edslegra sj\u00fakd\u00f3ma, raskana og annarra svipger\u00f0a, veri\u00f0 \u00fe\u00e1tttakandi \u00ed fj\u00f6lm\u00f6rgum al\u00fej\u00f3\u00f0legum samstarfsverkefnum og me\u00f0h\u00f6fundur \u00e1 yfir 60 greinum. Fr\u00e1 2011 hefur hann veri\u00f0 verkefnastj\u00f3ri tauga\u00feroskaraskana, auk \u00feess a\u00f0 sinna \u00fdmsum verkefnum b\u00e6\u00f0i innan mi\u00f0taugakerfisdeildar \u00cdE og v\u00ed\u00f0ar innan fyrirt\u00e6kisins. Helstu ranns\u00f3knir Braga tengjast \u00fev\u00ed a\u00f0 varpa lj\u00f3si \u00e1 \u00e1hrif erf\u00f0a\u00fe\u00e1tta \u00e1 vitsmuni, heilastarfsemi og tauga\u00feroskaraskanir. Foreldrar hans eru Sigr\u00ed\u00f0ur Gu\u00f0n\u00fd Ingvad\u00f3ttir og David Llewellyn Walters. Eiginkona Braga er S\u00f3lborg Unnur Hafsteinsd\u00f3ttir og eiga \u00feau tv\u00f6 b\u00f6rn, Andreu Sif og R\u00f3bert Breka.<\/p>\n<\/div><\/div>","protected":false},"featured_media":5649,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2023-06-09T13:00:00+00:00","_phd_date_end":"2023-06-09T16:00:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0asalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Erf\u00f0afr\u00e6\u00f0i tauga\u00feroskaraskana: \u00c1hrif sjaldg\u00e6fra breytileika \u00e1 byggingu og starfsemi heilans. 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