(magistrsko delo)
Igor Sovec (Author), Uroš Potočnik (Mentor), Pavel Skok (Co-mentor)

Abstract

Kronično vnetna črevesna bolezen (KVČB) je kompleksna avtoimunska bolezen, na razvoj katere vplivajo številni dejavniki, med njimi tudi polimorfizmi v številnih genih. Namen magistrskega dela je bil na temeljih znanih rizičnih genotipov za polimorfizme posameznega nukleotida (SNP-jev) v oz. bližini kandidatnih genov, ki smo jih povezali s slovenskimi bolniki s KVČB, CB, CBr in UC, izdelati genetske profile pri bolnih in zdravih posameznikih ter na podlagi analize razlik v porazdelitvah ugotoviti, pri katerih pragih, številu oz. deležu genotipov z rizičnimi aleli, genetski profili najbolje napovejo tveganje za razvoj KVČB, CB, CBr in UC v slovenski populaciji. V ta namen smo pri različnih pragih računali parametre za ugotavljanje napovedne moči diagnostičnega testa. V magistrskem delu smo 16 kandidatnih genov in 2 genetska lokusa od 30 na podlagi 19 kandidatnih SNP-jev od 32 statistično značilno, P ≤ 0,05, povezali s slovenskimi bolniki s KVČB in/ali s CB, CBr in UC. Med njimi tudi gen PTGER4, ki smo ga na podlagi SNP-ja rs10512734, za katerega smo gensko tipizacijo izvedli sami, povezali s CBr in UC. Pri pragih, pri katerih je imelo 16 genetskih profilov največjo napovedno moč, je bila specifičnost visoka, saj se je gibala med 82 % in 98 %, vendar pa je bila takrat občutljivost nizka in se je gibala med 9 % in 38 %. LR+ genetskih profilov pri teh pragih se je gibal med 1,75 in 3,65, razen v primeru genetskega profila za napoved povečanega tveganja za razvoj CBr, kjer je bila pri pragu ³ 5 homozigotnih genotipov z rizičnimi aleli vrednost LR+ 15,10, zaradi česar je to genetski profil z največjo napovedno močjo. Na podlagi genetskih profilov, izdelanih na testni populaciji, smo ugotovili, da se tveganje za razvoj KVČB, CB, CBr in UC poveča pri posameznikih z večjim številom genotipov z rizični aleli, vendar pa je njihova napovedna moč prešibka, Youdenov indeks se je gibal med 0,07 in 0,24, za napoved tveganja v splošni slovenski populaciji, v kateri je prevalenca KVČB in njenih podtipov nizka. Vseeno pa lahko rečemo, da je naša raziskava pomemben korak k razvoju napovednih modelov, ki bi jih z nadaljnjim raziskovanjem in vključitvijo večjega števila vzorcev, dodatnih SNP-jev ter kombinacije biooznačevalcev s kliničnimi lastnostmi v prihodnosti lahko uporabili za napovedovanje tveganja.

Keywords

kronično vnetna črevesna bolezen (KVČB);Crohnova bolezen (CB);refraktorna oblika Crohnove bolezni (CBr);ulcerozni kolitis (UC);genetski profil;diagnostični test;polimofizem posameznega nukleotida;genotip;homozigot;heterozigot;alel;asociacijska analiza;prag;

Data

Language: Slovenian
Year of publishing:
Source: Maribor
Typology: 2.09 - Master's Thesis
Organization: UM FZV - Faculty of Health Sciences
Publisher: [I. Sovec]
UDC: 616.34-002(043.2)
COBISS: 1901476 Link will open in a new window
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Downloads: 140
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Other data

Secondary language: English
Secondary title: A comparsion of distribution of selected genetic profiles in inflammatory bowel disease patients and in a control group of healthy individuals
Secondary abstract: Inflammatory bowel disease (IBD) is a complex autoimmune disease development of which is under the influence of many factors including polymorphisms in wide range of genes. The main aim of this Master thesis was, on basis of known risk genotypes for the single nucleotide polymorphisms (SNPs) in or near candidate genes, that have been associated with Slovenian patients with IBD, CD, CDr and UC, constructed genetic profiles for groups of IBD patients and healthy subjects, and on basis of analysis of differences in the distribution determine at which cutoff points (different numbers or portions of genotypes with risk alells) have genetic profiles peak power for prediction of risk for IBD, CD, CDr and UC in Slovenian population. For this purpose, we calculated at different cutoff points parameters to estimate predicting power of diagnostic test. In our master thesis we statistically significant, P ≤ 0,05, associate 16 candidate genes and 2 genetic loci from 30 captured on basis of 19 candidate SNPs with Slovenian patients with IBD and/or patients with CD, CDr and UC. Among them gene PTGER4 which was associated with Slovenian patients with CBr and UC on basis of SNP rs10512734 for which genotyping was performed by us. At cutoff points at which 16 genetic profiles have peak power for prediction of risk, specificity was high and ranged between 82% in 98%, however, sensitivity was at that cutoff point low and ranged between 9% in 38%. LR+ of genetic profiles at that cutoff points was ranged between 1,75 and 3,65 with exception of CBr genetic risk profile at cutoff point ³ 5 homozygous genotypes with risk alleles, at which was value of LR+ 15,10 what suggested that this genetic profile has the highest predictive power. On the basis of genetic profiles, designed on examined population we found out, that the risk for IBD, CD, CDr and UC development increase in individuals with a higher number or proportion of genotypes with risk alleles, however their ¸predictive power is to weak, Youden index was ranged between 0,07 in 0,24, for prediction of risk in general Slovenian population in which is prevalence of IBD and its subtypes low. However, we can say that our study is an important step closer to the development of effective predictive models for prediction of risk in the future, which will be possible with further research and integration of larger number of samples, additional SNPs and combination of biomarkers with clinical features.
Secondary keywords: inflammatory bowel disease (IBD);Crohn's disease (CD);refractory Chrohnʼs disease (cdR);ulcerative colitis (UC);genetic profile;diagnostic test;single nucleotide polymorphism;genotype;homozygote;heterozygote;alele;association analysis;cutoff point;
URN: URN:SI:UM:
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za zdravstvene vede
Pages: XXI, 154 str., 3 f. pril.
Keywords (UDC): applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;medical sciences;medicina;pathology;clinical medicine;patologija;klinična medicina;pathology of the digestive system;complaints of the alimentary canal;bolezni prebavil;gastroenterologija;
ID: 16282