|
|
Gene sequencing in patients with cancer anamnesis
MARKOVÁ, Iveta
Cancer is the second most common cause of death in the Czech Republic, of which 5-10% are occupied by hereditary cancer syndromes. They are caused by a congenital - hereditary mutation in one of the alleles of the genes, when after the second random intervention in the other allele hereditary cancer develops. It is important to distinguish between hereditary and sporadic carcinomas due to the high risk of inheritance of mutated alleles in the family. The indication may be, for example, the onset of the disease at a young age or the recurrence of the cancer in the family In my work I focused on the analysis and evaluation of data obtained by Sanger sequencing. The aim was to find mutations in the genes mentioned below and to evaluate their pathogenicity by comparison with databases. In the theoretical part of the bachelor thesis I deal with cancer in general and hereditary cancer. I specify the hereditary breast and ovarian cancer syndrome, including genes, that may cause this syndrome - BRCA1, BRCA2, TP53, PTEN, ATM, PALB2, I also deal with Lynch syndrome and the MMR gene system. Last but not least, I describe a familial adenomatous polyposis associated with the APC gene. In the research part I focused on the examination of selected areas of 18 anonymized samples in the gene PALB2 - exon 13 and in the gene BRCA2 - exon 10/4 and exon 11/12. Using the PCR method, I prepared the samples for Sanger sequencing, which then took place in GenSeq s.r.o. In the last part of my work I deal with the analysis and evaluation of the results using the BioEdit program and the NCBI database. I found a mutation in 5 samples - in 4 it was a deletion of one nucleotide with a conflicting interpretation of pathogenicity, the last mutation was pathogenic - causes hereditary breast and ovarian cancer syndrome, it was a nucleotide duplication.
|
|
|
Lynch syndrome in patients with upper urinary tract urothelial carcinoma: One centre study
BUCHOVÁ, Karolína
Lynch syndrome (LS) is an inherited autosomal dominant (AD) disease with predisposition for cancer development in different organs (large intestine, uterus, upper urinary tract, etc.). Typically, young or middle age individuals are affected by cancer. Presented bachelor thesis summarizes the current knowledge about LS in patients with urothelial carcinoma (UC) of the upper urinary tract. We tried to determine the frequency of LS in patients with urothelial carcinoma of the upper urinary tract and design a suitable diagnostic algorithm how to identify suspect patients appropriate for further genetic testing. In the practical part of the thesis, we searched for all patients treated on Urology department Faculty Hospital in Pilsen for UC of the upper urinary tract in the time period I/2010 - XII/2018. All cases were re-evaluated. Immunohistochemical staining of MMR proteins (MLH1, PMS2, MSH2, MSH6) was performed in selected cases. Obtained data were evaluated statistically. We found 215 examinations/biopsies from 182 patients (58 UC of the ureter, 119 UC of the renal pelvis, 5 UC of both the ureter and the renal pelvis). 121 patients were examined by immunohistochemistry (44 UC of the ureter, 73 UC of the renal pelvis, 4 UC of both the ureter and the renal pelvis). Lost expression of some MMR protein was demonstrated in 9/121 examined cases. Definitive examination of peripheral blood for detection of germline mutation was performed in only two patients (2%). One patient (male, 71 years) has confirmed germline mutation of MSH6 gene from peripheral blood. The second patient (male, 73 years) is still waiting for a definitive confirmation of the diagnosis from peripheral blood (patient has a high suspicion for Lynch syndrome, he has personal history of colorectal carcinoma, deficiency of MSH6 protein expression was found in UC of upper urinary tract even in colorectal carcinoma). Based on here presented data, we recommend routine immunohistochemical staining of MMR proteins in all patients with UC of upper urinary tract, regardless of their age or medical history. Universal immunohistochemical screening in patients with UC of upper urinary tract is a good and yielding way how to identify suspicious patients for genetic testing of LS.
|
|
|
Diagnosis of Lynch syndrome based on pathologic examination
KRAUSOVÁ, Lenka
Lynch syndrome is an autosomal dominant disease predisposing to cancer development. Up to 5 % of colorectal cancers may be associated with Lynch syndrome. Due to its familial occurrence the diagnosis is important for family screening. Currently it is based on methods of modern pathology. Theoretical part describes structure of gastrointestinal tract, definition and history of Lynch syndrome, and methods of its laboratory diagnostics. The diagnosis can be based on evaluation of tumor microscopical features (Semi PREDICT score) in tissue sections, imunohistochemical investigation of MMR (mismatch repair) proteins, or molecular genetic MSI (microsatellite instability) testing. Practical part focuses mainly on correlation of immunohistochemistry and MSI testing. Randomly selected cases of colorectal cancer were organized into 2 study groups. The first group consisted of 25 cases with intact MMR immunoexpression, the second group comprised 25 cases with at least one MMR protein being deficient. For further verification molecular genetic MSI testing, along with BRAF gene analysis and MLH1 promoter methylation status to discriminate Lynch syndrome from sporadic cases, were performed. Germline analysis of MMR genes proved the diagnosis of Lynch syndrome in 5 cases of the second group. Semi PREDICT score sensitivity for MMR-deficiency prediction (and indirectly for Lynch syndrome detection) was 84 %, specificity 48 %. Sensitivity of MSI testing was 87 %, but only 50 % in Lynch syndrome subset of cases, specificity was 100 %. The results show major role of MMR immunohistochemistry in the diagnostics of MSI-H cancers, which is the cornerstone of Lynch syndrome screening.
|
|
|
Lynch syndrome - etiology, diagnostics and therapy
MARŠÍKOVÁ, Dominika
Lynch syndrome (hereditary nonpolyposis colorectal cancer, HNPCC) is an inherited disease with an autosomal dominant pattern of inheritance with high penetrance leading to an early development of colorectal cancer, endometrial cancer and other malignancies. This disease is caused by germline mutations of genes MLH1, MSH2, PMS2, MSH6, MLH3 and TGFBR2. Diagnosis of this disease includes Amsterdam Criteria and genetic testing. Therapy takes place by surgical, chemoprevention and chemical medication. The incidence of Lynch syndrome is relatively high: 1:2000 up to 1:660.
|
guest ::
