|
|
Identification of hereditary alterations predisposing to breast cancer development using "next-gen" sequencing
Lhota, Filip
Summary: Breast cancer (BC) is the most frequent cancer type in female population of Europe. Approximately 5 - 10 % accounts for its hereditary form which is characterized by high penetrance, early onset, risen recurrence risk and development of other cancers. Mutational analyses of high risk patients identify a predisposing mutation in one of the most studied genes (BRCA1, BRCA2, TP53, ATM, CHEK2, NBS1, PALB2) only in less than one third of tested breast cancer patients. Lately, with the use of new methods of next-generation sequencing, a number of other susceptibility or candidate genes were characterized, but the incidence of their pathogenic alteration is often geographically different. A notable proportion of high risk patients from families with hereditary BC can represent carriers of population-specific, or private mutations. Most of the to date identified BC susceptibility genes codes for proteins involved in DNA repair, especially repair of double strand break DNA repair. Nevertheless the mutation analysis was conducted only on a small fraction of these DNA repair genes. We can expect that in the group of yet nontested genes coding for DNA repair proteins a rare, but clinically important genetic alterations predisposing to BC in affected families can be discovered. This work describes a...
|
|
|
Identification of hereditary alterations predisposing to breast cancer development using "next-gen" sequencing
Lhota, Filip ; Kleibl, Zdeněk (advisor) ; Zikán, Michal (referee) ; Mohelníková Duchoňová, Beatrice (referee)
Summary: Breast cancer (BC) is the most frequent cancer type in female population of Europe. Approximately 5 - 10 % accounts for its hereditary form which is characterized by high penetrance, early onset, risen recurrence risk and development of other cancers. Mutational analyses of high risk patients identify a predisposing mutation in one of the most studied genes (BRCA1, BRCA2, TP53, ATM, CHEK2, NBS1, PALB2) only in less than one third of tested breast cancer patients. Lately, with the use of new methods of next-generation sequencing, a number of other susceptibility or candidate genes were characterized, but the incidence of their pathogenic alteration is often geographically different. A notable proportion of high risk patients from families with hereditary BC can represent carriers of population-specific, or private mutations. Most of the to date identified BC susceptibility genes codes for proteins involved in DNA repair, especially repair of double strand break DNA repair. Nevertheless the mutation analysis was conducted only on a small fraction of these DNA repair genes. We can expect that in the group of yet nontested genes coding for DNA repair proteins a rare, but clinically important genetic alterations predisposing to BC in affected families can be discovered. This work describes a...
|
|
|
Anterior segment dysgenesis disorders and their molecular genetic cause
Moravíková, Jana ; Lišková, Petra (advisor) ; Krulová, Magdaléna (referee)
Proper eye development depends on expression and mutual regulation of many genes. Anterior segment dysgenesis (ASD) are a highly heterogeneous group of diseases exhibiting all types of Mendelian inheritance, which manifest as combination of congenital abnormalities of the cornea, iris, anterior chamber angle or lens. Screening of genes associated with ASD does not often lead to the identification of the underlying genetic cause implying that there are still novel variants or genes to be discovered. Molecular genetic analysis in 12 probands with ASD using Sanger and whole-exome sequencing were performed. Functional analysis by Exon trapping assay was provided in variants predicted to effect pre-mRNA splicing. Four PAX6 mutations evaluated as pathogenic or likely pathogenic in a heterozygous state were found in four probands c.183C˃G; p.(Tyr61*), c.1032+1G>A, c.1183+1G>T and c.622C>T; p.(Arg208Trp). One proband was found to be a compound heterozygote for c.244A>G; p.(Met82Val) and c.541delG; p.(Glu181Lysfs*26) mutations in FOXE3. In 7 probands, no potentially pathogenic variants were identified. Exon trapping assay confirmed that mutations c.1032+1G>A and c.1183+1G>T have an effect on pre-mRNA splicing of the PAX6 gene. Detailed molecular-genetic analysis in patients with ASD may contribute to...
|
|
|
Detection of β-glucocerebrosidase gene/pseudogene recombination events leading to pathogenic alleles
Peková, Barbora ; Hřebíček, Martin (advisor) ; Schierová, Michaela (referee)
This diploma thesis provides an overview of gene conversion, its role in the pathogenesis of human diseases and the use of methods based on next-generation sequencing (NGS) for detection rare variants of DNA sequence. Labeling of target DNA molecules by random nucleotides in primer and NGS were used for detection point mutations arising de novo in the β-glucocerebrosidase gene by gene conversion between it and its pseudogene in meiotic and mitotic cells of control subjects. Primers specific for the active gene were used to selectively amplify the ninth and tenth exon of the gene where "recombinant" variants occur most frequently. Sequences generated from 20 genomic DNA samples on Illumina MiSeq platform were quality filtered, sorted by unique labels and consensus sequences were created from alignments of sequences carrying the same DNA tag. The number of potential point mutations in the samples ranged between 12 and 48. The mutations were manually re-evaluated from the alignments. The number of alignments with unique labeling was in the range of 7-15 thousand per sample. Only three samples carried possible recombinant mutations, suggesting a lower frequency of conversion in the region than reported by other techniques. Analysis of unique sequences in primer indicated possible ways to improve the...
|
|
|
The relation between microbial diversity and biodegradation of organic pollutants in soils
Adámek, Michael ; Svobodová, Kateřina (advisor) ; Matyska Lišková, Petra (referee)
This work sums up the knowledge of the currently studied microorganisms capable of degradation of organic compounds contaminating soil and of the impact of biodiversity on biodegradation efficiency. As documented in many studies effective soil remediation can be achieved by mixed-species consortia isolated from polluted soils. However, use of these cultures for bioaugumentation requires further research on their influence on the biodiversity of autochthonic soil microflora. Though bioaugumentation provably affects bioremediation effectivity no ideal carrier for microbes has been found yet that would provide survival of the introduced organisms in the competitive soil environment. Next, selection of suitable bioaugumentation agents should be based on previous analyses of autochthonic microbes in the targeted contaminated soils. Further, this work shows that the presence of key species might be more important for the biodegradation efficiency than biodiversity of soil microflora. Biodiversity is more related to the functionality of soil ecosystems which can be affected by the presence of contaminants leading to positive selection of taxa capable of pollutant degradation. However, there are just a few studies on the relationship between biodiversity and degradation of pollutants. Its further research...
|
|
|
Studium celogenomové variability lidského cytomegaloviru.
Dvořák, Jan ; Tachezy, Ruth (advisor) ; Roubalová, Kateřina (referee)
This work is part of a project focused on the study of the variability of human cytomegalovirus (HCMV) among clinical isolates with the aim to map the geographical distribution of HCMV genotypes, reveal the relationships between genotypes and the severity of HCMV-associated diseases, and identify regions in the HCMV genome with a potential for use as diagnostic and therapeutic targets. Attention was paid to the development of the methodology for the preparation of the material for next-generation sequencing (NGS) from HCMV clinical isolates and evaluation of the obtained sequencing data. Blood and urine samples collected from hematopoietic stem cell transplantat recipients and congenitally infected children were analyzed. Samples suitable for NGS were sequenced by the Illumina platform and sequences were created by de novo assembly followed by mapping assembly. Urine samples in comparison to blood samples had higher yield of material for NGS. Of the samples positive for HCMV DNA (7 of 50) after amplification in the cell cultures, only one sample had high purity of the viral DNA (98%) while six samples had purity of less than 7%. The sample containing 98% of the viral DNA was fully sequenced and the sequence was compared to the sequences of other clinical isolates from Belgium in 11 polymorphic...
|
|
|
The analysis of immunoglobulin and T-cell receptor gene rearrangements using next generation sequencing
Hašek, Daniel ; Froňková, Eva (advisor) ; Javorková, Eliška (referee)
DNA sequencing is a molecular genetic method that results in data about sequence and type of nucleotides present in a given sample of deoxyribonucleic acid (DNA), a molecular carrier of genetic information. These data are frequently of a crucial value for many fields; research, medicine, industry, criminalistics or others. During a long period of time almost all the sequencing was performed using a method invented by Frederick Sanger in the 70's, a technique that uses modified nucleotides that once incorporated into a DNA strand prevent this from further elongation. DNA synthesis in presence of such nucleotides leads to a formation of a mixture of fragments of different lenght that are electrophoretically separated by lenght and the sequence is read from the resulting gel. Since the principle of this method entails some inherent drawbacks (e.g. low throughput and coverage) a significant effort is made lately to develop alternative sequencing approaches. These methods colectively refered to as next-generation sequencing (NGS) use several technologies in order to overcome the limitations of the Sanger sequencing. This thesis discusses the most important NGS methods and focuses on their possible application for sequencing of immunoglobulin and T-cell receptor gene rearrangements, an area of undisputable...
|
|
|
Optimization of the Next-Generation Sequencing Data Alignment
Šalanda, Vojtěch ; Bendl, Jaroslav (referee) ; Vogel, Ivan (advisor)
This thesis presents short DNA alignment tools optimization. These short DNA reads are products of next\nobreakdash-generation sequencing technologies. The results produced by existing align\-ment tools can be influenced by various parameters. For this purpose, an optimization framework to find the optimal values of selected parameters was developed. This framework is based on differencial evolution algorithm and its main goal is to maximize the alignment accuracy. The functionality of the framework was tested on both real and generated data sets of short DNA reads. An accurate alignment is crucial for correct prediction of various genetic characteristics.
|
|
|
Localization of Methylation Sites in Transposons
Kmeť, Miroslav ; Martínek, Tomáš (referee) ; Vogel, Ivan (advisor)
This master's thesis deals with the creation of a tool for the extraction of methylation level from transposon sequences. Transposons are DNA elements with ability to move or copy themselves and their activity is regulated by DNA methylation. Sequence methylation information is stored in the bisulfite data and their processing is done with parts of two existing tools in a combination with implemented modules. Created tool takes into consideration unique challenges brought in the methylation calling process by transposable elements and it's functionality is presented on a set of experiments with simulated and real data.
|
|
|
Classification of Small Noncoding RNAs
Žigárdi, Tomáš ; Martínek, Tomáš (referee) ; Vogel, Ivan (advisor)
This masters's thesis contains description of designed and implemented tool for classification of plant microRNA without genome. Properties of mature and star sequences in microRNA duplexes are used. Implemented method is based on clustering of RNA sequences (with CD-HIT) to mainly reduce their count. Selected representants from each clusters are classified using support vector machine. Performance of classification is more than 96% (based on cross-validation method using the training data).
|
guest ::
