Supernumerary marker chromosomes (sSMCs) are a relatively rare cytogenetic phenomenon. Their laboratory examination is often difficult, and the clinical interpretation is even more challenging. The main reason is that most sSMC carriers have no clinical manifestations. The chromosome origin and exact range of the aberration are very important, as well as the fact that sSMCs are often found in mosaics that can strongly influence both the phenotype and the interpretation of result. Prenatal sSMC finding is one of the most challenging situations in both clinical and laboratory genetics. This work deals with the investigation process of sSMC carriers using molecular cytogenetic techniques, especially fluorescence in situ hybridization (FISH). We investigated a total of 67 families collected both prospectively and retrospectively, and we found 70 unique sSMCs in a total of 74 individuals. Six cases were familial and in three cases two sSMCs were found in one individual. According to the initial karyotype finding, the cases were divided into two groups, sSMCs supernumerary to a normal karyotype (group A) and sSMCT s supernumerary to the Turner karyotype (group B). The chromosomal origin was successfully determined in 88,6 % sSMCs. In group A the most common findings were sSMCs derived from chromosome 15,...

Objective: Mutations in the parkin (PARK2) gene have been associated with autosomal recessive early-onset Parkinson's disease (EOPD) with various frequencies in different populations. The aim of the study is to describe phenotypic characteristics of Czech EOPD patients, to evaluate the influence of environmental risk factors, and to determine the frequency of parkin allelic variants in patients and healthy controls. Methods: A total of 70 EOPD patients (age at onset ≤ 40 years) and 75 controls were phenotyped and screened for the sequence variants and exon rearrangements in the parkin gene. Results: The main features in the phenotype of the patients' sample were: the absence of cognitive deficit, high occurrence of dystonia, depression, hyperhidrosis, an excellent response to dopaminergic therapy, early onset of dyskinesia and motor fluctuation. Patients with mutations in the parkin gene had significantly lower age at onset. The agricultural occupation and work with chemicals increased the risk of EOPD, however the coffee drinking appeared to be a protective factor. Parkin mutations were identified in five patients (7.1%): the p.R334C point mutation was present in one patient, four patients had exon deletions. The detected mutations were observed in the heterozygous state except one homozygous...

Es gibt wenige Erkenntnisse über den Zusammenhang zwischen Lamivudin induzierten Resistenzmutationen und Hepatitis B Genotypen. Die vorliegende Studie untersucht das Verhältnis zwischen diesen Mutationen und den Hepatitis B Genotypen A-D. Die Datenbank der US-amerikanischen Kongressbibliothek (Pubmed) wurde nach den Begriffen „HBV OR hepatitis B”, „YMDD”, „genotype”, und „lamivudine” durchsucht. Alle in dieser Suche gefundenen Arbeiten, die bis Juni 2009 veröffentlicht worden waren, wurden in die Studie eingeschlossen. Die Ergebnisse der Literaturanalyse wurden mit den Hepatitis B-Genomdaten zweier Referenzlabore in Tübingen und Melbourne verglichen. Insgesamt konnten 29 Arbeiten aus der Datenbankrecherche in die Literaturanalyse eingeschlossen werden. Diese Studien enthielten Daten zu insgesamt 827 Patienten, deren Hepatitis B Genotyp bekannt war und die eine Lamivudinresistenzmutation aufwiesen. In statistischen Untersuchungen konnte nachgewiesen werden, dass die rtM204V-Mutation die dominierende Mutation bei Infektionen mit Genotyp A ist. Dieses Ergebnis konnte durch die Analyse der Genomdaten der Referenzlabore bestätigt werden. Ferner konnte gezeigt werden, dass bei den Genotypen A, B, und D die rtL180M-Mutation hochsignifikant mit der rtM204V-Mutation verknüpft ist. Die Dissertationsschrift enthält neben dem Artikel „Mutation pattern of lamivudine resistance in relation to hepatitis B genotypes: hepatitis B genotypes differ in their lamivudine resistance associated mutation pattern“ (Damerow, H, Yuen L et al.; J Med Virol. 2010 Nov; 82(11):1850-8) eine Einführung in die Rationale der Studie, eine Zusammenfassung der Ergebnisse sowie ein Fazit.:1. Einleitung 1.1. Bibliografische Beschreibung und Kurzzusammenfassung, Seite 4 1.2. Inhalt und Aufbau der Arbeit, Seite 5 2. Hintergründe und Rationale 2.1. Therapie der chronischen Hepatitis B-Infektion, Seite 6 2.2. Resistenzen unter Therapie mit Nukleos(t)idanaloga, Seite 7 2.3. Hepatitis B-Genotypen, Seite 9 2.4. Die vorliegende Studie 2.4.1. Rationale der Studie, Seite 10 2.4.2. Arbeitsverteilung, Seite 11 3. Studie “Mutation pattern of lamivudine resistance in relation to hepatitis B genotypes: hepatitis B genotypes differ in their lamivudine resistance associated mutation pattern” 3.1. Abstract, Seite 14 3.2. Introduction, Seite 15 3.3. Methods, Seite 16 3.4. Results, Seite 17 3.5. Discussion, Seite 20 3.6. Reference List, Seite 22 3.7. Appendix, Seite 25 4. Zusammenfassung der vorliegenden Studie 4.1. Mutationsverhalten im YMDD-Motiv 4.1.1. Literaturanalyse, Seite 31 4.1.2. SeqHepB-Datenbank, Seite 32 4.1.3. Tübinger Datenbank, Seite 32 4.2. rtL180M-Mutation in Relation zu HBV-Genotyp und rtM204I/V-Mutation 4.2.1. Literaturanalyse, Seite 34 4.2.2. SeqHepB-Datenbank, Seite 34 4.2.3. Tübinger Datenbank, Seite 35 4.3. Analyse der Polymerase-Mutationen rtL80I/V, rtV173L und rtA181V/T in Abhängigkeit vom HBV-Genotyp, Seite 35 4.4. Analyse der Mutationen im Surface-Antigen, die mit Polymerasemutationen assoziiert sind, Seite 36 5. Fazit 5.1. Literaturübersicht, Seite 37 5.2. Mögliche klinische Relevanz, Seite 38 6. Anhang 6.1. Literaturverzeichnis, Seite 41 6.2. Abbildungs- und Tabellenverzeichnis, Seite 45 6.3.Selbstständigkeitserklärung, Seite 47 6.4. Publikationsverzeichnis, Seite 48 6.5. Danksagungen, Seite 49

På grund av planerat tillverkningsstopp av instrumenten som används idag på Octapharma AB, så syftar detta projekt till nyutvecklingen av en kvantitativ PCR analysmetod för detektion av HIV-1 i human blodplasma, genom TaqMankemi. Projektet inkluderade design, testning och utvärdering av olika set av primer och probe sekvenser. För att säkerställa specificiteten hos metoden designades primrarna och proberna för att vara komplementära till olika konservativa regioner av HIV-1:s genom. Primer och probe set:en (P/P) testades både individuellt och kombinerat i spädningsserier och genotypspaneler. Analyserna visade att det inte fanns någon korrelation mellan felmatchning av P/P och referenssekvenser hos subtyper, och detektionsnivå. När P/P testades i kombination hittades falsk-positiva signaler i negativa kontroller (4 falsk-positiva signaler; n= 106). Detta åtgärdades genom att utesluta specifika prober(0 falsk-positiva signaler; n= 152)(p = 0,030, Fisher’s exact test). Kombinationen av primer och prober, med någraprober uteslutna, hade en högre detektionsnivå för HIV-1 subtyper än de individuella set:en (29 positiva prover vs 23.5; n= 64), och lyckadesäven detektera åtminstone ett positivt prov hos varje subtyp A, B, C, D, AE, F, G och H. Avsaknaden av korrelation mellan felmatchning av P/P och detektionsnivå, visar på att orsaken av den suboptimala detektionsnivån av subtyper var inte på grund av antalet felmatchningar mellan primer och probe set:en till målsekvenserna. Den högre specificiteten vid kombination av P/P indikerar även att primrar och prober som riktar in sig på olika regioner avHIV-1 genomet ytterligare ökar specificiteten och detektionsnivån hos metoden. / As a result of future instrument discontinuation by Octapharma AB’s manufacturers, this project sought to develop a new quantitative PCR analysis method for the detection of HIV-1 in human blood plasma using TaqMan chemistry. The project included the design, testing and statistical analysis of different sets of novel primer and probe sequences. To ensure specificity, the primer and probe sequences were designed to target conserved regions of the HIV-1 genome. The primer and probe sets were tested both individually and in combination in dilution series and genotype tests. Linear regression analyses showed no correlation between mismatches between the primer and probe sets and the subtype reference sequences tested, and detection rate. When the primer and probe setswere tested in combination, false positive signals were obtained in negative control samples (4 false positive signals; n= 106). However, this obstacle was overcome by the omission of certain probes, resulting in no false positive signals (0 false positive signals; n= 152)(p = 0.030, Fisher’s exact test).The combination of primer and probe sets, with certain probes omitted, had an increased HIV-1 subtype detection rate compared to the individual P/P (29 positive samples detected versus 23.5; n= 64), and were also able to detect at least one positive sample from each of the HIV-1 subtypes A, B, C, D, AE, F, G, and H. The absence of correlation between primer and probe set mismatch and detection rate, suggests that the cause of the suboptimal detection rate of the subtypes was not the result of primer and probe set mismatch to the target sequences. The increased subtype detection rate upon combining the P/P also indicates that targeting different region of the HIV-1 genome further improves the detection rate and specificity of the method.

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The neural mechanisms underlying genetic risk for schizophrenia, a highly heritable psychiatric condition, are still under investigation. New schizophrenia risk genes discovered through genome-wide association studies (GWAS), such as neurogranin (NRGN), can be used to identify these mechanisms. In this study we examined the association of two common NRGN risk single nucleotide polymorphisms (SNPs) with functional and structural brain-based intermediate phenotypes for schizophrenia. We obtained structural, functional MRI and genotype data of 92 schizophrenia patients and 114 healthy volunteers from the multisite Mind Clinical Imaging Consortium study. Two schizophrenia-associated NRGN SNPs (rs12807809 and rs12541) were tested for association with working memory-elicited dorsolateral prefrontal cortex (DLPFC) activity and surface-wide cortical thickness. NRGN rs12541 risk allele homozygotes (TT) displayed increased working memory-related activity in several brain regions, including the left DLPFC, left insula, left somatosensory cortex and the cingulate cortex, when compared to non-risk allele carriers. NRGN rs12807809 non-risk allele (C) carriers showed reduced cortical gray matter thickness compared to risk allele homozygotes (TT) in an area comprising the right pericalcarine gyrus, the right cuneus, and the right lingual gyrus. Our study highlights the effects of schizophrenia risk variants in the NRGN gene on functional and structural brain-based intermediate phenotypes for schizophrenia. These results support recent GWAS findings and further implicate NRGN in the pathophysiology of schizophrenia by suggesting that genetic NRGN risk variants contribute to subtle changes in neural functioning and anatomy that can be quantified with neuroimaging methods.

The neural mechanisms underlying genetic risk for schizophrenia, a highly heritable psychiatric condition, are still under investigation. New schizophrenia risk genes discovered through genome-wide association studies (GWAS), such as neurogranin (NRGN), can be used to identify these mechanisms. In this study we examined the association of two common NRGN risk single nucleotide polymorphisms (SNPs) with functional and structural brain-based intermediate phenotypes for schizophrenia. We obtained structural, functional MRI and genotype data of 92 schizophrenia patients and 114 healthy volunteers from the multisite Mind Clinical Imaging Consortium study. Two schizophrenia-associated NRGN SNPs (rs12807809 and rs12541) were tested for association with working memory-elicited dorsolateral prefrontal cortex (DLPFC) activity and surface-wide cortical thickness. NRGN rs12541 risk allele homozygotes (TT) displayed increased working memory-related activity in several brain regions, including the left DLPFC, left insula, left somatosensory cortex and the cingulate cortex, when compared to non-risk allele carriers. NRGN rs12807809 non-risk allele (C) carriers showed reduced cortical gray matter thickness compared to risk allele homozygotes (TT) in an area comprising the right pericalcarine gyrus, the right cuneus, and the right lingual gyrus. Our study highlights the effects of schizophrenia risk variants in the NRGN gene on functional and structural brain-based intermediate phenotypes for schizophrenia. These results support recent GWAS findings and further implicate NRGN in the pathophysiology of schizophrenia by suggesting that genetic NRGN risk variants contribute to subtle changes in neural functioning and anatomy that can be quantified with neuroimaging methods.

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