|
|
Mutations in MLH1 gene and MSI status as molecular characteristics of sporadic colorectal cancer
Čaja, Fabián
Colorectal carcinoma (CRC) is one of the most prevalent malignancies in the Czech Republic. In general, there are two molecular pathways leading to CRC: one is characterized by chromosomal instability, the other by the deficiency in DNA mismatch repair (MMR) genes. MutL homologue 1 (MLH1) gene, a member of the MMR gene-family, represents a key component of the MMR system, responsible for recognition of nucleotide mismatches occurring during DNA replication, and for the recruitment of repair proteins to correct the replication errors. According to literature, somatic mutations in MMR genes, and MLH1 in particular, hallmark sporadic, MMR deficient, CRC cases. We aimed at analyzing somatic events in MLH1 gene and the determination of microsatellite instability (MSI) status in 99 DNA samples from 96 patients with sporadic CRC. Mutations were screened by high resolution melting (HRM) curve analysis. Positive cases in each run were subsequently verified by automated sequencing. Mainly gene variants were found in MLH1 gene: We discovered two new variants, one in exon 2 at position c. 204 C>G, p. Ile68Met (98 C/C, 1C/G) and the other in exon 11 at position c. 973 C>T, p. Arg325Trp (98 C/C, 1 C/T). Only the latter variant c. 973 C>T was identified as somatic mutation. All other variants found in MLH1 gene...
|
|
| |
|
|
Genetics and phenotypic characteristics of early-onset Parkinson's disease
Fiala, Ondřej ; Růžička, Evžen (advisor) ; Seeman, Pavel (referee) ; Bojar, Martin (referee)
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...
|
|
|
Mutations in MLH1 gene and MSI status as molecular characteristics of sporadic colorectal cancer
Čaja, Fabián ; Vodička, Pavel (advisor) ; Kadlecová, Jitka (referee)
Colorectal carcinoma (CRC) is one of the most prevalent malignancies in the Czech Republic. In general, there are two molecular pathways leading to CRC: one is characterized by chromosomal instability, the other by the deficiency in DNA mismatch repair (MMR) genes. MutL homologue 1 (MLH1) gene, a member of the MMR gene-family, represents a key component of the MMR system, responsible for recognition of nucleotide mismatches occurring during DNA replication, and for the recruitment of repair proteins to correct the replication errors. According to literature, somatic mutations in MMR genes, and MLH1 in particular, hallmark sporadic, MMR deficient, CRC cases. We aimed at analyzing somatic events in MLH1 gene and the determination of microsatellite instability (MSI) status in 99 DNA samples from 96 patients with sporadic CRC. Mutations were screened by high resolution melting (HRM) curve analysis. Positive cases in each run were subsequently verified by automated sequencing. Mainly gene variants were found in MLH1 gene: We discovered two new variants, one in exon 2 at position c. 204 C>G, p. Ile68Met (98 C/C, 1C/G) and the other in exon 11 at position c. 973 C>T, p. Arg325Trp (98 C/C, 1 C/T). Only the latter variant c. 973 C>T was identified as somatic mutation. All other variants found in MLH1 gene...
|
|
|
Mutation Analysis in MLBR /Major Ligand Binding Regions/ of COL1A1 gene of the Czech Individuals with Osteogenesis Imperfecta, Type I-IV Diagnosis.
Šormová, Lucie ; Mazura, Ivan (advisor) ; Včelák, Josef (referee)
Osteogenesis imperfecta is an inherited disorder caused mainly by collagen type I genes mutations, COL1A1 and COL1A2. These mutations affect especially connective tissue. Disease is characterized by fragile bones, deformations and increased frequency of fractures. It's worldwide extensive disorder regardless of age, sex, nationality or races. The incidence is 1: 16 - 20 000 births. Currently, we described nine clinically distinct forms of Osteogenesis imperfecta. Only the first four types OI, type I-IV, are caused by collagen type I genes mutations . In these nine types there are distinguished mild and severe forms. Type II and III are lethal forms, death occur offen during prenatal period or in the first days of the life affected individuals. Characteristic clinical features of collagen forms OI are an increased incidence of fractures, deformations of bones, blue sclera, hearing loss, Dentinogenesis imperfecta small or subnormal growth (Marini, 2010). This study alignment is mainly the description of the clinical forms, exploring the molecular basis of disease and determine the relationship between the type and position of the mutation and the resulting phenotype of affected individuals. We have analysed exons 31-40, including associated non-coding regions, of the COL1A1 gene (so-called MLBR =...
|
|
|
Human F1Fo-ATPsynthase deficiency
Suldovská, Sabina ; Tesařová, Markéta (advisor) ; Černá, Leona (referee)
F1FO-ATPsynthase is a key enzyme in energy metabolism of the cell. Its deficit is caused usually by mutations in two structural genes MT-ATP6 and MT-ATP8 encoded by the mitochondrial DNA or in nuclear genes ATPAF2 and TMEM70 encoding the biogenesis factors and structural gene ATP5E. Deficiency of the F1FO-ATPsynthase leads to progressive and serious phenotype affecting organs with high energy demands. The first symptoms usually occurs in neonatal age and prognosis of the disease is fatal. Mutations in these genes result in both qualitative and quantitative defects of the F1FO-ATPsynthase. The study of molecular bases of mitochondrial disorders including F1FO-ATPsynthase deficiency uses large number of biochemical and molecular-genetic methods to determine a proper diagnosis which is essential for the symptomatic therapy and genetic counselling in affected families. The aim of the diploma thesis was to characterise the F1FO-ATPsynthase deficiency in isolated mitochondria from the lines of cultured cells by the determination oligomycin- sensitive ATP-hydrolytic activity of the F1FO-ATPsynthase, enzymatic activities of the respiratory chain complexes and to analyse changes in the steady-state levels of the representative subunits and whole complex of the F1FO-ATPsynthase in comparison with controls. 3...
|
|
|
Evolutionary models for evaluation of organisms relationship
Gregorová, Kateřina ; Maděránková, Denisa (referee) ; Škutková, Helena (advisor)
The work is focused on the study and description of evolutionary models for the evaluation of the evolutionary distances of DNA sequences and protein sequences in the amino acids and the codon representation. In the framework of this work was created a program that evaluates the genetic distance between DNA sequences and protein sequences for the use of some evolutionary models. The program calculates the genetic distance of the compared sequences and on the basis thereof renders the phylogenetic tree. This can be relatively easily and quickly evaluate the affinity of the organisms. For easy operation is part of the evaluation program also graphical user interface (GUI).
|
|
|
Comparison of genomes by synteny block analysis
Pavel, Tomáš ; Škutková, Helena (referee) ; Maděránková, Denisa (advisor)
The theoretical part of this bachelor thesis is aimed at basics of genetics. Term of gene and mutation are introduced in this section. There are gene and chromosome mutations mentioned and described. Following section is devoted to comparative genomics and especially to synteny. There is described what the synteny actually is and how the synteny arises. The end of the theoretical part of this thesis is about the evolution and there are described ways of sorting permutation vectors. The practical part of this bachelor thesis includes description of developed software. Output of this software is a dot-plot which shows detected synteny blocks. Indexes of these blocks are listed in GUI. The second important output is number of permutation steps. This number determines evolutionary distance between two analysed DNA sequences. The very last section is aimed at analyse of synthetic and real DNA sequences.
|
|
|
Attributes Calculating for Prediction of Effects of Mutation on Protein Function
Matějíček, Jiří ; Burgetová, Ivana (referee) ; Jaša, Petr (advisor)
This bachelor thesis deals with the bioinformatics techniques for the acquisition of attributes useful for prediction of mutation effects on the protein function. The work primarily aims to develop a user-friendly application for calculation of attributes of mutations from the protein sequence and structure. The developed application serves for integration of specialized tools such as FoldX. The standardized interface enables to implement additional computational tools and collect a diverse set of attributes from different sources. These attribute sets can then serve as an input for different prediction methods and help to improve predictions of mutation effects.
|
|
|
Predictor of the Effect of Amino Acid Substitutions on Protein Function
Musil, Miloš ; Martínek, Tomáš (referee) ; Bendl, Jaroslav (advisor)
This thesis discusses the issue of predicting of the effect of amino acid substitutions on protein funkcion, based on phylogenetic analysis method, inspired by tool MAPP. Significant number of genetic diseases is caused by nonsynonymous SNPs manifested as single point mutations on the protein level. The ability to identify deleterious substitutions could be useful for protein engineering to test whether the proposed mutations do not damage protein function same as for targeting disease causing harmful mutations. However the experimental validation is costly and the need of predictive computation methods has risen. This thesis describes desing and implementation of a new in silico predictor based on the principles of evolutionary analysis and dissimilarity between original and substituting amino acid physico-chemical properties. Developed algorithm was tested on four datasets with 74,192 mutations from 16,256 sequences in total. The predictor yields up to 72 % accuracy and in the comparison with the most existing tools, it is substantially less time consuming. In order to achieve the highest possible efficiency, the optimization process was focused on selection of the most suitable (a) third-party software for calculation of a multiple sequence alignment, (b) overall decision threshold and (c) a set of physico-chemical properties.
|
guest ::
