• Publication type
• Meeting Abstract MeSH

BACKGROUND AND OBJECTIVE: Hearing loss is the most common sensory deficit in humans. The aim of this study was to clarify the genetic aetiology of nonsyndromic hearing loss in the Moravian-Silesian population of the Czech Republic. PATIENTS AND METHODS: This study included 200 patients (93 males, 107 females, mean age 16.9 years, ranging from 4 months to 62 years) with nonsyndromic sensorineural hearing loss. We screened all patients for mutations in GJB2 and the large deletion del(GJB6-D13S1830). We performed further screening for additional genes (SERPINB6, TMIE, COCH, ESPN, ACTG1, KCNQ4, and GJB3) with Sanger sequencing on a subset of patients that were negative for GJB2 mutations. RESULTS: We detected biallelic GJB2 mutations in 44 patients (22%). Among these patients, 63.6%, 9.1% and 2.3% exhibited homozygous c.35delG, p.Trp24*, and p.Met34Thr mutations, respectively. The remaining 25% of these patients exhibited compound heterozygous c.35delG, c.-23+1G>A, p.Trp24*, p.Val37Ile, p.Met34Thr, p.Leu90Pro, c.235delC, c.313_326del14, p.Ser139Asn, and p.Gly147Leu mutations. We found a monoallelic GJB2 mutation in 12 patients (6.6%). We found no pathogenic mutations in the other tested genes. Conclusions: One fifth of our cohort had deafness related to GJB2 mutations. The del(GJB6-D13S1830), SERPINB6, TMIE, COCH, ESPN, ACTG1, GJB3, and KCNQ4 mutations were infrequently associated with deafness in the Moravian-Silesian population. Therefore, we suggest that del(GJB6-D13S1830) testing should be performed only when patients with deafness carry the monoallelic GJB2 mutation.

• MeSH
• Actins genetics   MeSH
• Child MeSH
• Adult MeSH
• KCNQ Potassium Channels genetics   MeSH
• Extracellular Matrix Proteins genetics   MeSH
• Deafness genetics   MeSH
• Infant MeSH
• Connexins genetics   MeSH
• Middle Aged MeSH
• Humans MeSH
• Membrane Proteins genetics   MeSH
• Microfilament Proteins genetics   MeSH
• Adolescent MeSH
• Young Adult MeSH
• Mutation genetics   MeSH
• DNA Mutational Analysis methods   MeSH
• Hearing Loss, Sensorineural genetics   MeSH
• Child, Preschool MeSH
• Serpins genetics   MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Infant MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Child, Preschool MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH

The hotspot c.7541_7542delCT NOTCH1 mutation has been proven to have a negative clinical impact in chronic lymphocytic leukemia (CLL). However, an optimal method for its detection has not yet been specified. The aim of our study was to examine the presence of the NOTCH1 mutation in CLL using three commonly used molecular methods. Sanger sequencing, fragment analysis and allele-specific PCR were compared in the detection of the c.7541_7542delCT NOTCH1 mutation in 201 CLL patients. In 7 patients with inconclusive mutational analysis results, the presence of the NOTCH1 mutation was also confirmed using ultra-deep next generation sequencing. The NOTCH1 mutation was detected in 15% (30/201) of examined patients. Only fragment analysis was able to identify all 30 NOTCH1-mutated patients. Sanger sequencing and allele-specific PCR showed a lower detection efficiency, determining 93% (28/30) and 80% (24/30) of the present NOTCH1 mutations, respectively. Considering these three most commonly used methodologies for c.7541_7542delCT NOTCH1 mutation screening in CLL, we defined fragment analysis as the most suitable approach for detecting the hotspot NOTCH1 mutation.

• MeSH
• Leukemia, Lymphocytic, Chronic, B-Cell genetics   MeSH
• Humans MeSH
• Mutation * MeSH
• DNA Mutational Analysis methods   MeSH
• Peptide Fragments analysis   MeSH
• Receptor, Notch1 genetics   MeSH
• High-Throughput Nucleotide Sequencing MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

• MeSH
• Alleles MeSH
• Single-Cell Analysis methods   MeSH
• Leukemia, Lymphocytic, Chronic, B-Cell diagnosis   drug therapy   genetics   MeSH
• Genotype MeSH
• Clonal Evolution genetics   MeSH
• Humans MeSH
• DNA Mutational Analysis methods   MeSH
• Tumor Suppressor Protein p53 genetics   MeSH
• Receptor, Notch1 genetics   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Letter MeSH
• Research Support, Non-U.S. Gov't MeSH

The canonical Wnt pathway, dependent on β-catenin-controlled transcription, is the most explored Wnt pathway, known to drive the malignant transformation of multiple cell types. Several reports have suggested that this pathway also participates in chronic lymphocytic leukaemia (CLL) pathogenesis. To get a better insight into the role of the Wnt/β-catenin pathway in CLL we analysed in detail the expression of the most overexpressed Wnt ligand, encoded by the WNT3 gene, in a well-defined cohort of 137 CLL patients. Our analysis demonstrated that (i) untreated patients with more aggressive disease (with a notable exception of patients with 11q deletion) express less WNT3, (ii) WNT3 declines with disease progression in a significant proportion of patients and (iii) low WNT3 was identified as a strong independent marker indicating shorter treatment-free survival in CLL patients with IGHV mutation. Interestingly, CLL-related lymphoid cell lines, but not stromal cells, failed to respond to the ligand-induced activation of the Wnt/β-catenin pathway. This opens the possibility that CLL cells use Wnt-3 to communicate with the cells in the microenvironment. We thus propose that the Wnt/β-catenin pathway plays a more complex role in CLL pathogenesis than previously anticipated.

• MeSH
• Cell Line MeSH
• Leukemia, Lymphocytic, Chronic, B-Cell diagnosis   genetics   metabolism   MeSH
• Genes, Immunoglobulin Heavy Chain genetics   MeSH
• Cohort Studies MeSH
• Humans MeSH
• Cell Communication MeSH
• Mutation MeSH
• Prognosis MeSH
• Disease Progression MeSH
• Wnt3 Protein genetics   MeSH
• Gene Expression Regulation, Neoplastic * MeSH
• Wnt Signaling Pathway MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

TP53 gene defects represent a strong adverse prognostic factor for patient survival and treatment resistance in chronic lymphocytic leukemia (CLL). Although various methods for TP53 mutation analysis have been reported, none of them allow the identification of all occurring sequence variants, and the most suitable methodology is still being discussed. The aim of this study was to determine the limitations of commonly used methods for TP53 mutation examination in CLL and propose an optimal approach for their detection. We examined 182 CLL patients enriched for high-risk cases using denaturing high-performance liquid chromatography (DHPLC), functional analysis of separated alleles in yeast (FASAY), and the AmpliChip p53 Research Test in parallel. The presence of T53 gene mutations was also evaluated using ultra-deep next generation sequencing (NGS) in 69 patients. In total, 79 TP53 mutations in 57 (31 %) patients were found; among them, missense substitutions predominated (68 % of detected mutations). Comparing the efficacy of the methods used, DHPLC and FASAY both combined with direct Sanger sequencing achieved the best results, identifying 95 % and 93 % of TP53-mutated patients. Nevertheless, we showed that in CLL patients carrying low-proportion TP53 mutation, the more sensitive approach, e.g., ultra-deep NGS, might be more appropriate. TP53 gene analysis using DHPLC or FASAY is a suitable approach for mutation detection. Ultra-deep NGS has the potential to overcome shortcomings of methods currently used, allows the detection of minor proportion mutations, and represents thus a promising methodology for near future.

• MeSH
• Leukemia, Lymphocytic, Chronic, B-Cell genetics   MeSH
• Adult MeSH
• Genes, p53 * MeSH
• In Situ Hybridization, Fluorescence MeSH
• Polymorphism, Single Nucleotide MeSH
• Middle Aged MeSH
• Humans MeSH
• Mutation * MeSH
• Oligonucleotide Array Sequence Analysis MeSH
• Aged MeSH
• High-Throughput Nucleotide Sequencing MeSH
• Chromatography, High Pressure Liquid MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

Chronická lymfocytární leukemie je nejčastější typ leukemie v západním světě postihující zejména starší dospělé osoby. Navzdory stále se zdokonalující léčbě zůstává z důvodu značné biologické i klinické variability nadále nevyléčitelným onemocněním. Patogeneze chronické lymfocytární leukemie není dodnes plně objasněna, nicméně velkou roli hrají antigenní stimulace, narušená apoptóza a vliv mikroprostředí. Mezi nejvýznamnější molekulární prognostické faktory s jasným klinickým dopadem patří mutační stav genů pro těžký řetězec imunoglobulinů (IGHV), cytogenetické aberace a mutace genů TP53 a ATM. Zavedení nových sekvenačních technologií umožnilo v posledních letech zpřesnění analýzy stávajících i detekci nových potenciálních prognostických markerů chronické lymfocytární leukemie. Významnými kandidáty jsou mutace genů SF3B1, NOTCH1 a BIRC3, jejichž klinický dopad je předmětem intenzivního výzkumu. V neposlední řadě jsou nadále studovány také další mechanizmy patogeneze chronické lymfocytární leukemie, mezi něž patří deregulace signalizace přes B buněčný receptor a regulace genové exprese pomocí microRNA. Přesná charakterizace molekulárních abnormalit je klíčová pro lepší rozdělení rizikových skupin pacientů s chronickou lymfocytární leukemií, kteří mohou profitovat z nových terapeutických přístupů.

Chronic lymphocytic leukemia is the most common leukemia in Western countries affecting particularly elderly adults. Despite the constantly improving therapy options, chronic lymphocytic leukemia is still an incurable disease owing to considerable clinical and bio­logical heterogeneity. Pathogenesis of chronic lymphocytic leukemia is not fully understood; however, aberrant antigenic stimulation, apoptosis deregulation and microenvironmental interactions play a crucial role in disease development. The most important molecular prognostic markers with clinical relevance include mutation status of heavy‑chain immunoglobulin genes (IGHV), presence of cytogenetic aberrations and TP53 and ATM gene mutations. Recent implementation of next generation sequencing technologies has enabled more accurate analysis of both well‑established and novel potential prognostic markers. The most relevant candidates are mutations in SF3B1, NOTCH1 and BIRC3 genes, which are now intensively studied with respect to their clinical importance. The other examined molecular mechanisms of chronic lympho­cytic leukemia pathogenesis include deregulation of B‑cell receptor signalization and abnormal regulation of gene expression by microRNA. The precise characterization of molecular abnormalities improves the risk stratification of chronic lymphocytic leukemia patients, which could possibly benefit from new treatment approaches. Key words: chronic lymphocytic leukemia – biological markers – chromosome aberations – mutations – prognosis This work was supported by the grants IGA MH CZ NT13493-4/2012, NT13576-4/2012, NT13576, AZV MZ ČR No. 15-30015A-4/2015 a 15-31834A-4/2015 a TAČR TE02000058. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 30. 7. 2015 Accepted: 4. 8. 2015

• Keywords
• komplexní karyotyp,
• MeSH
• Ataxia Telangiectasia Mutated Proteins genetics   MeSH
• Chromosome Aberrations * MeSH
• Chromosome Deletion * MeSH
• Leukemia, Lymphocytic, Chronic, B-Cell * genetics   MeSH
• Genes, p53 MeSH
• Genes, Immunoglobulin Heavy Chain MeSH
• Humans MeSH
• Chromosomes, Human, Pair 11 MeSH
• Chromosomes, Human, Pair 12 MeSH
• Chromosomes, Human, Pair 13 MeSH
• Chromosomes, Human, Pair 17 MeSH
• MicroRNAs MeSH
• Mutation MeSH
• Biomarkers, Tumor * genetics   MeSH
• Prognosis MeSH
• Proto-Oncogene Proteins c-bcr physiology   MeSH
• Trisomy MeSH
• Check Tag
• Humans MeSH

• Publication type
• Meeting Abstract MeSH

In chronic lymphocytic leukemia (CLL), the worst prognosis is associated with TP53 defects with the affected patients being potentially directed to alternative treatment. Therapy administration was shown to drive the selection of new TP53 mutations in CLL. Using ultra-deep next-generation sequencing (NGS), we performed a detailed analysis of TP53 mutations' clonal evolution. We retrospectively analyzed samples that were assessed as TP53-wild-type (wt) by FASAY from 20 patients with a new TP53 mutation detected in relapse and 40 patients remaining TP53-wt in relapse. Minor TP53-mutated subclones were disclosed in 18/20 patients experiencing later mutation selection, while only one minor-clone mutation was observed in those patients remaining TP53-wt (n=40). We documented that (i) minor TP53 mutations may be present before therapy and may occur in any relapse; (ii) the majority of TP53-mutated minor clones expand to dominant clone under the selective pressure of chemotherapy, while persistence of minor-clone mutations is rare; (iii) multiple minor-clone TP53 mutations are common and may simultaneously expand. In conclusion, patients with minor-clone TP53 mutations carry a high risk of mutation selection by therapy. Deep sequencing can shift TP53 mutation identification to a period before therapy administration, which might be of particular importance for clinical trials.

• MeSH
• Survival Analysis MeSH
• B-Lymphocytes drug effects   metabolism   pathology   MeSH
• Clone Cells MeSH
• Leukemia, Lymphocytic, Chronic, B-Cell drug therapy   genetics   mortality   pathology   MeSH
• Adult MeSH
• Clonal Evolution drug effects   genetics   MeSH
• Middle Aged MeSH
• Humans MeSH
• Mutation MeSH
• Tumor Suppressor Protein p53 genetics   metabolism   MeSH
• Antineoplastic Agents administration & dosage   adverse effects   MeSH
• Recurrence MeSH
• Gene Expression Regulation, Leukemic * MeSH
• Retrospective Studies MeSH
• Aged MeSH
• Signal Transduction MeSH
• High-Throughput Nucleotide Sequencing MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Through the European Research Initiative on chronic lymphocytic leukemia (CLL) (ERIC), we screened 3490 patients with CLL for mutations within the NOTCH1 (n=3334), SF3B1 (n=2322), TP53 (n=2309), MYD88 (n=1080) and BIRC3 (n=919) genes, mainly at diagnosis (75%) and before treatment (>90%). BIRC3 mutations (2.5%) were associated with unmutated IGHV genes (U-CLL), del(11q) and trisomy 12, whereas MYD88 mutations (2.2%) were exclusively found among M-CLL. NOTCH1, SF3B1 and TP53 exhibited variable frequencies and were mostly enriched within clinically aggressive cases. Interestingly, as the timespan between diagnosis and mutational screening increased, so too did the incidence of SF3B1 mutations; no such increase was observed for NOTCH1 mutations. Regarding the clinical impact, NOTCH1 mutations, SF3B1 mutations and TP53 aberrations (deletion/mutation, TP53ab) correlated with shorter time-to-first-treatment (P<0.0001) in 889 treatment-naive Binet stage A cases. In multivariate analysis (n=774), SF3B1 mutations and TP53ab along with del(11q) and U-CLL, but not NOTCH1 mutations, retained independent significance. Importantly, TP53ab and SF3B1 mutations had an adverse impact even in U-CLL. In conclusion, we support the clinical relevance of novel recurrent mutations in CLL, highlighting the adverse impact of SF3B1 and TP53 mutations, even independent of IGHV mutational status, thus underscoring the need for urgent standardization/harmonization of the detection methods.

• MeSH
• Time Factors MeSH
• Leukemia, Lymphocytic, Chronic, B-Cell diagnosis   genetics   MeSH
• Cytogenetics MeSH
• Gene Deletion MeSH
• Phosphoproteins genetics   MeSH
• Polymorphism, Single Nucleotide MeSH
• Middle Aged MeSH
• Humans MeSH
• Ribonucleoprotein, U2 Small Nuclear genetics   MeSH
• Multivariate Analysis MeSH
• Mutation * MeSH
• DNA Mutational Analysis MeSH
• Tumor Suppressor Protein p53 genetics   MeSH
• Prognosis MeSH
• Receptor, Notch1 genetics   MeSH
• Recurrence MeSH
• Aged MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Europe MeSH