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Uvod in namen dela: Cilj zdravljenja epilepsije je popolna kontrola napadov in omejitev pojava neželenih učinkov, kar je pri otrocih in mladostnikih, kjer je zdravljenje s protiepileptičnimi zdravili večinoma dolgotrajno, še posebno pomembno. Genetske variante v genih, ki sodelujejo v presnovi in transportu protiepileptičnih zdravil, pomembno vplivajo na učinkovitost zdravljenja epilepsije in pojavljanje neželenih učinkov. V doktorski nalogi smo opredelili tiste genetske označevalce pri otrocih in mladostnikih z epilepsijo, ki vplivajo na učinkovitost zdravljenja s tremi pogosteje uporabljenimi zdravili in na pojav neželenih učinkov. Metode: Vključeno je bilo 165 otrok in mladostnikov z epilepsijo, ki se zdravijo na Kliničnem oddelku za otroško, mladostniško in razvojno nevrologijo Pediatrične klinike Univerzitetnega kliničnega centra v Ljubljani. Pridobili smo klinične podatke ter smo preiskovancem, z molekularno genetskimi preiskavami, določili izbrane polimorfizme v genih CYP3A4, CYP2C9, CYP2C19, ABCB1, ABCC2, ABCG2 in SCN1A. S statistično analizo s programom SPSS smo preverili povezave genetskih in kliničnih podatkov. Vključili smo tudi 95 zdravih kontrolnih preiskovancev. Raziskavo je odobrila Komisija za medicinsko etiko. Rezultati in razprava: Pri bolnikih zdravljenih z valproatom in genotipom TT polimorfizma ABCB1 rs1128503 se 4-krat pogosteje pojavlja neželeni učinek kognitivnih motenj v primerjavi z genotipom CT. Ta povezava v literaturi še ni bila opisana. Pri bolnikih z genotipom AG polimorfizma ABCC2 rs2273697 se 3-krat pogosteje pojavlja neželeni učinek kognitivnih motenj v primerjavi z genotipom GG, kar je v skladu z znanimi podatki o tem da je koncentracija valproata pri bolnikih z genotipom AA višja kot pri bolnikih z genotipom GG. Pri bolnikih z genotipom GG polimorfizma CYP2C19 rs4244285 se 2,6-krat pogosteje pojavljajo vedenjske težave kot neželeni učinek v primerjavi z genotipom AA, medtem ko se za genotip AA 2,8-krat pogosteje pojavljajo vedenjske težave kot neželeni učinek v primerjavi s kognitivnimi motnjami. Ta varianta je že bila povezana s pojavom drugih neželenih učinkov, kot sta porast telesne teže in hiperinzulinizem pri bolnicah z epilepsijo, ki so bile zdravljenje z valproatom, ni pa bila opisana v povezavi z vedenjskimi težavami. Pri bolnikih zdravljenih s karbamazepinom oz. okskarbazepinom in genotipom AG polimorfizma ABCC2 rs717620 se 3-krat pogosteje pojavljajo vedenjske težave kot neželeni učinek v primerjavi z genotipom GG, kar še ni bilo opisano v literaturi. Prvič smo dokazali, da je alel G polimorfizma SCN1A rs2298771, predvsem v homozigotni obliki, povezan z večjo učinkovitostjo protiepileptičnega zdravljenja. Hkrati je ta alel povezan tudi z dovzetnostjo za epilepsijo, ki je že bila opisana v azijskih populacijah. Zaključki: Rezultati naše in podobnih raziskav bodo lahko v prihodnosti osnova za določitev priporočil za individualizirano izbiro najprimernejšega protiepileptičnega zdravila, ki bo učinkovitejše in bo imelo čim manjšo možnost pojava neželenih učinkov zdravljenja. Introduction: The goal of the antiepileptic therapy is the complete control of seizures with adverse drug reactions as limited as possible. This becomes even more important in children and adolescents with longstanding therapy, where the effectiveness of the treatment and the possible manifestation of adverse drug reactions are even more crucial. Polymorphisms of genes involved in the metabolism and transport of antiepileptic drugs influence the effect of therapy and in the manifestation of collateral effects. In this dissertation, we evaluated genetic markers in children and adolescents with epilepsy, which may be associated with the effectiveness of therapy and the manifestation of collateral effects. Methods: We included 165 children and adolescents with epilepsy treated at the Department of Child, Adolescent and Developmental Neurology, Children's Hospital, University Medical Centre Ljubljana, Slovenia. Family and personal history were taken. Molecular genetics analysis with qPCR to test for known polymorphisms of the genes CYP3A4, CYP2C9, CYP2C19, ABCB1, ABCC2, ABCG2 and SCN1A were performed. Statistical analysis with genetics and clinical data were performed. A control group of 95 presumably healthy participants was used. Results: Patients treated with valproic acid with genotype TT of the polymorphism ABCB1 rs1128503 have 4 times more frequently present cognitive impairment compared to patients with genotype CT. The association of this variant with cognitive impairment due to valproic acid treatment has not been previously reported. Patients treated with valproic acid with genotype AG of polymorphism ABCC2 rs2273697 have 3 times more frequently present cognitive impairment compared to those with genotype GG. This corroborated the reported higher valproic acid concentrations in patients with AA genotype in comparison to GG genotype. Patients with genotype GG of the polymorphism CYP2C19 rs4244285 have 2.6 times more frequently present adverse drug reactions behavioural disorder compared to genotype AA, while patients with genotype AA have 2.8 times more frequently behavioural disorder compared with cognitive impairment. This variant has been previously reported in correlation with other adverse drug reactions of the valproic acid treatment, such as obesity and hypeinsulinism in female patients with epilepsy, but not in association with behavioural disorders. Patients treated with carbamazepine or oxcarbazepine with genotype AG of the polymorphism ABCC2 rs717620 have 3 times more frequently behavioural disorders compared to genotype GG which has not been previously reported. We have shown that in patients with G allele of the polymorphism SCN1A rs2298771, mainly at the homozygous state, the antiepileptic treatment is more efficient, which has not been previously reported. At the same time, it is associated with predisposition to develop epilepsy, already reported in Asian populations. Conclusions: The results of our and similar studies could be the foundation of the future recommendations for the individualised treatment of the epilepsy that will have sufficient efficiency and limited adverse drug reactions.

Introduction. Developmental delay and dysmorphic features affect 1 - 3 % of paediatric population. In the last few years molecular cytogenetic high resolution techniques (comparative genomic hybridization arrays and single-nucleotide polymorphism arrays) have been proven to be a first-tier choice for clinical diagnostics of developmental delay and dysmorphic features. Methods and results. In the present article we describe the clinical advantages of molecular cytogenetic approach (comparative genomic hybridization arrays and single nucleotide polymorphism arrays) in the diagnostic procedure of two children with developmental delay, dysmorphic features and additional morphological phenotypes. Additionally, we demonstrate the necessity of fluorescent in situ hybridization utilisation to identify the localisation and underlying mechanism of detected chromosomal rearrangement. Conclusions. Two types of chromosomal abnormalities were identified and confirmed using different molecular genetic approaches. Comparative genomic hybridization arrays and single nucleotide polymorphism arrays are hereby presented as important methods to identify chromosomal imbalances in patients with developmental delay and dysmorphic features. We emphasize the importance of molecular genetic testing in patients’ parents for the demonstration of the origin and clinical importance of the aberrations prior determined in the patients. The results obtained using molecular cytogenetic high resolution techniques methods are the cornerstone for proper genetic counselling to the affected families.