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Detection of mutations and intragenic rearrangements in BRCA1 and BRCA2 genes by sequencing and MLPA method
PECHOVÁ, Kristýna
In my bachelor thesis I dealt with the detection of mutations in BRCA genes and their effect on the development of breast cancer. Nowadays, this topic is very important, because breast cancer is the most common cancer among women in the Czech Republic (Weinberger a Zikán, 2016). In the theoretical part I focused on breast cancer, particularly on its diagnosis and consequent treatment. I also dedicated genetic counselling and examination, which is very important for the diagnosis of hereditary forms of cancer. I mentioned basic information about BRCA genes, and their protein products and I summarized the issue of mutations in these genes and their relationship to cancer, particularly breast and ovarian. In the practical part, I focused on the examination of selected areas of BRCA genes by the Sanger sequencing method. At present, BRCA genes are examined by the NGS method, because it allows for the analysis of all exons of one particular gene at once, but this testing wasn't possible to realize in my laboratory conditions, therefore I have chosen the method of Sanger sequencing, which does, however, have certain capacity limitations. By using the PCR method, I prepared samples for testing by Sanger sequencing. This testing was conducted by the firm Genseq s.r.o. In the last part of my thesis I processed the obtained sequences and I evaluated the results. I examined a total of 20 anonymized samples using the sequencing method. Mutation was present in 4 samples of the total amount - one was pathogenic, one benign and two of uncertain significance.
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Molecular genetic analysis in Niemann-Pick type C disease
Marešová, Ivona ; Dvořáková, Lenka (advisor) ; Hřebíček, Martin (referee)
Niemann-Pick disease type C (NPC) is a rare, severe disease with autosomal recessive inheritance. Disease is caused by pathogenic mutations located in genes NPC1/NPC2. These genes encode lysosomal non enzymatic NPC1/NPC2 proteins that are part of lipid transport. As a result of malfunction of these proteins intracellular accumulation of lipids occurs, in particular free cholesterol and glycolipids. Causal therapy is currently still unsatisfactory therefore new therapies are evolved. However these therapies depend on whether the patient cells contain at least residual amount of transcript NPC1 gene. In a group of patiens, for which a fibroblast culture was available, I analyzed the effect of pathogenic mutations on the expression level of the transcript. Results showed that for all pathogenic mutations transcript level is low, but detectable. Moreover, I characterized the structure of the NPC1 gene promoter. By sequence analysis I found polymorphisms rs8099071, rs28403610, rs2981422, rs1652354, rs1788774, rs1788772 in promoter. On the basis of the composition of polymorphisms in individual patiens, I estimate six different haplotypes. I performed mutation analysis in DNA of recently diagnosed patient. I found only one pathogenic mutation p.I1061T (c.3182T> C) in the NPC1 gene. Therefore I tested...
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Frequency and significance of genetic changes in the genome of leukemia cells in children with T-ALL
Sládková, Lucie ; Zemanová, Zuzana (advisor) ; Březinová, Jana (referee)
T-ALL (T-cell acute lymphoblastic leukemia) is identified in 10-15 % cases of pediatric acute lymphoblastic leukemia and it is a clinically and genetically heterogeneous disease. About 50 % of patients have normal karyotype and although a number of cryptic recurrent chromosome aberrations have been reported their prognostic significance is not entirely clear. The aim of the study was to analyze bone marrow cells of children with T-ALL using cytogenomic methods to determine the frequency of cryptic aberrations and to assess their importance for disease prognosis. We examined diagnostic samples of 67 children with T-ALL (19 girls and 48 boys, median age 8 years). We analyzed the changes by G- banding, I-FISH (Dako, Abbott) and MLPA (MRC-Holland) methods. We detected cryptic aberrations in 60 children (91 %). The most frequent changes were deletions of the CDKN2A gene (48×) which were usually observed in combination with other changes and aberrations of loci for TCR genes (20×). TLX3 gene rearrangements were detected in 18 cases and were never associated with rearrangements of TCR loci. Complex karyotype was detected in 10 patients with recurrent breakpoints 5q35 and 10q24. 45 patients live in the first or second complete remission, relapse occurred in 14 children and 20 died. Statistical analysis of...
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Characteristic of chromosomal changes in nephroblastomas using SNP array and MLPA
Štolová, Lucie ; Vícha, Aleš (advisor) ; Daňková, Pavlína (referee)
Nephroblastoma is the most prevalent pediatric kidney tumor, which occurs primarily in younger children with the average age at diagnosis of 42,5 months for girls and 36,5 months for boys. Even though its treatment is currently very succesful and the overall survival rate reaches over 90 %, there are still more things to be discovered and improved. An important role for the right choice of treatment plays not only the histology of tumor, but also the chromosomal changes present at tumor. Some of them (for example 1q gain, simultaneous deletion of 1p and 16q, TP53 deletion) were confirmed as negative prognostic markers because they are associated with an increased risk of relapse or with anaplastic type of nephroblastoma that is included in a high risk group. These changes are therefore used together with the tumor histology for stratification of nephroblastomas. Some of these changes were found in a heterogeneous state (only in a part of the cells) in nephroblastoma, which also complicates the treatment of the patient and which cannot be solved when only one sample is taken from the tumor. In this work we concentrated on the detection of chromosomal changes present in nephroblastomas of 44 patients and their associations with clinical data. We have proved some of the known associations (22q...
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Molekulární diagnostika deficience lipoproteinové lipásy (LPLD) jako výběr pacientů vhodných pro genovou terapii (AAV1-LPL S447X )
Křížová, Jana
Lipoprotein lipase deficiency is a malfunkction of a key enzyme for lipoprotein metabolism. Lipoprotein lipase deficiency can cause serious episodes of pancreatitis. The deficiency is caused by pathology in the LPL gene. There are many variants in the LPL gene and quite a lot of them are pathogenic.The first gene therapy in Europe was licensed for the treatment of lipoprotein lipase deficienciency using a gain-of-function variant of the LPL gene. A pattern of examination was established to including MLPA, Light SNiP, quantitative real time PCR and sequencing in order to find pacients for the treatment. Three pacients suitable for the gene therapy Alipogene tiparvovec (AAV1-LPL S447X) were found amongst a group of patients with history of pancreatitis.
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Implementation of New Methods for Studying the Molecular Genetic Basis of the CADASIL Disease
Hrubá, Monika ; Vlášková, Hana (advisor) ; Čáp, Michal (referee)
CADASIL is a neurodegenerative autosomal dominant hereditary disease with late onset. Main symptoms are migraines with aura, cerebral ischemic events, cognitive impairment and dementia. The disease is caused by a mutation in the NOTCH3 gene. The major mutation type changes the number of cysteine residues in the EGF-like repeats of the Notch3 protein. In Czech Republic, currently used methods for molecular genetic analysis of the CADASIL disease are Sanger sequencing and MLPA. But there are patients with CADASIL-like symptoms who were not confirmed by these methods. Therefore, the aim of this thesis was to implement transcript analysis by Sanger sequencing of cDNA PCR products and quantitative real-time PCR (qPCR) to analyze gross deletions and duplications to clarify the molecular genetic basis of the disease. By transcript analysis, the existence of the transcript variant X1 was experimentally confirmed in control samples. Moreover, the results from transcript analysis showed that non-typical missense mutation c.1725G>A (p.T575=) which does not directly change the number of cysteine residues, can cause the CADASIL disease via missplicing and subsequent causing deletion including cysteine residues. The other tested variants did not show any changes in the transcript level. The qPCR method did not...
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Verification of somatic mutations important for neuroectodermal tumors (CTNNB1, BRAF, ALK)
Hrindová, Božidara ; Vícha, Aleš (advisor) ; Janatová, Markéta (referee)
The diploma thesis was focused on evidence of selected somatic mutations in genes ALK (Anaplastic lymphoma receptor tyrosine kinase), BRAF (v-Raf murine sarcoma viral oncogene homolog B1) and β-catenin (CTNNB1) through molecular - genetic methods in the target group of neuroectodermal tumors (neuroblastoma, medulloblastoma, brain tumors, paraganglioma and pheochromocytoma). Some of them are already considered as prognostic indicators which help to identify the subtype of various tumors and on the basis of this molecular - biological classification choosing the appropriate treatment. The genetic material of 133 patients was used for the analysis divided by the type of cancer. The presence of the mutation was detected in seven cases, of which two of them beloged to the gene BRAF, one to the gene ALK and four to the gene β-catenin. The subject of research in the cases of this genes were hotspot mutation sites. The purpose was to confirm the presence of the mutation in the hotspots and contribute to the studies which are aimed at the introduction of more suitable treatment through the inhibitors of mutated genes. Keywords: ALK, BRAF, β-catenin (CTNNB1), neuroectodermal tumors, sequencing, MLPA
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Molecular genetic analysis in Niemann-Pick type C disease
Marešová, Ivona ; Dvořáková, Lenka (advisor) ; Hřebíček, Martin (referee)
Niemann-Pick disease type C (NPC) is a rare, severe disease with autosomal recessive inheritance. Disease is caused by pathogenic mutations located in genes NPC1/NPC2. These genes encode lysosomal non enzymatic NPC1/NPC2 proteins that are part of lipid transport. As a result of malfunction of these proteins intracellular accumulation of lipids occurs, in particular free cholesterol and glycolipids. Causal therapy is currently still unsatisfactory therefore new therapies are evolved. However these therapies depend on whether the patient cells contain at least residual amount of transcript NPC1 gene. In a group of patiens, for which a fibroblast culture was available, I analyzed the effect of pathogenic mutations on the expression level of the transcript. Results showed that for all pathogenic mutations transcript level is low, but detectable. Moreover, I characterized the structure of the NPC1 gene promoter. By sequence analysis I found polymorphisms rs8099071, rs28403610, rs2981422, rs1652354, rs1788774, rs1788772 in promoter. On the basis of the composition of polymorphisms in individual patiens, I estimate six different haplotypes. I performed mutation analysis in DNA of recently diagnosed patient. I found only one pathogenic mutation p.I1061T (c.3182T> C) in the NPC1 gene. Therefore I tested...
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Using MLPA method for determining unbalanced changes in genome
KŘÍHOVÁ, Miroslava
Unbalanced chromosomal structural changes are connected with the presence of supernumerary particular part of chromosome, or the chromosome is absenting. MLPA is a method based on PCR principal, which amplifies MLPA probes, not the target sequences. MLPA probes hybridize to target sequences and then ligate them. Only one pair of primers is used. In the theoretical part the MLPA method is presented. Additionally, other diagnostics method of clinical genetic are mentioned (for example PCR, FISH, Array CGH). Diseases caused by unbalanced chromosomal structural changes are disscused too. Mental retardation and BRCA 1, 2 mutation were the main topic. The experimental part took place in Molecular Biology and Genetics Laboratory in the hospital in České Budějovice. I did my experiments under professional care of Mgr. Ondřej Scheinost and his colleagues. The aim of using MLPA method was to diagnose BRCA 1, 2 gene, microdeletion syndroms or subtelomeric deletions. All procedures were done according to standards. The final part of my thesis is concerned on the results interpretation and their comparation with other methods. I also thought over different approach of statistical analysis in MLPA.
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