@article{RostMuellerKelleretal.2014, author = {Rost, Simone and M{\"u}ller, Elisabeth and Keller, Alexander and Fregin, Andreas and M{\"u}ller, Clemens R.}, title = {Confirmation of warfarin resistance of naturally occurring VKORC1 variants by coexpression with coagulation factor IX and in silico protein modelling}, doi = {10.1186/1471-2156-15-17}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110095}, year = {2014}, abstract = {Background VKORC1 has been identified some years ago as the gene encoding vitamin K epoxide reductase (VKOR) - the target protein for coumarin derivates like warfarin or phenprocoumon. Resistance against warfarin and other coumarin-type anticoagulants has been frequently reported over the last 50 years in rodents due to problems in pest control as well as in thrombophilic patients showing variable response to anticoagulant treatment. Many different mutations have already been detected in the VKORC1 gene leading to warfarin resistance in rats, mice and in humans. Since the conventional in vitro dithiothreitol (DTT)-driven VKOR enzymatic assay often did not reflect the in vivo status concerning warfarin resistance, we recently developed a cell culture-based method for coexpression of VKORC1 with coagulation factor IX and subsequent measurement of secreted FIX in order to test warfarin inhibition in wild-type and mutated VKORC1. Results In the present study, we coexpressed wild-type factor IX with 12 different VKORC1 variants which were previously detected in warfarin resistant rats and mice. The results show that amino acid substitutions in VKORC1 maintain VKOR activity and are associated with warfarin resistance. When we projected in silico the amino acid substitutions onto the published three-dimensional model of the bacterial VKOR enzyme, the predicted effects matched well the catalytic mechanism proposed for the bacterial enzyme. Conclusions The established cell-based system for coexpression of VKORC1 and factor IX uses FIX activity as an indicator of carboxylation efficiency. This system reflects the warfarin resistance status of VKORC1 mutations from anticoagulant resistant rodents more closely than the traditional DTT-driven enzyme assay. All mutations studied were also predicted to be involved in the reaction mechanism.}, language = {en} } @article{MahyeraSchneiderHalligerKelleretal.2018, author = {Mahyera, Alexis S. and Schneider, Tamara and Halliger-Keller, Birgit and Schrooten, Katja and H{\"o}rner, Eva-Maria and Rost, Simone and Kress, Wolfram}, title = {Distribution and Structure of DM2 Repeat Tract Alleles in the German Population}, series = {Frontiers in Neurology}, volume = {9}, journal = {Frontiers in Neurology}, number = {463}, issn = {1664-2295}, doi = {10.3389/fneur.2018.00463}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196252}, year = {2018}, abstract = {Autosomal dominant inherited Myotonic dystrophy type 1 and 2 (DM1 and DM2) are the most frequent muscle dystrophies in the European population and are caused by repeat expansion mutations. For Germany cumulative empiric evidence suggests an estimated prevalence of DM2 of roughly 9 in 100,000, therefore being as prevalent as DM1. In DM2, a (CCTG)n repeat tract located in the first intron of the CNBP gene is expanded. The CCTG repeat tract is part of a complex repeat structure comprising not only CCTG tetraplets but also repeated TG dinucleotides and TCTG tetraplet elements as well as NCTG interruptions. Here, we provide the distribution of normal sized alleles in the German population, which was found to be highly similar to the Slovak population. Sequencing of 34 unexpanded healthy range alleles in DM2 positive patients (heterozygous for a full expansion) revealed that the CCTG repeat tract is usually interrupted by at least three tetraplets which according to current opinion is supposed to render it stable against expansion. Interestingly, only the largest analyzed normal allele had 23 uninterrupted CCTGs and consequently could represent an instable early premutation allele. In our diagnostic history of DM2 cases, a total of 18 premutations were detected in 16 independent cases. Here, we describe two premutation families, one with an expansion from a premutation allele and the other with a contraction of a full expansion down to a premutation allele. Our diagnostic results support the general assumption that the premutation range of unstable CCTG stretches lies obviously between 25 and 75 CCTGs. However, the clinical significance of premutation alleles is still unclear. In the light of the two described families we suggest incomplete penetrance. Thus, as it was proposed for other repeat expansion diseases (e.g., Huntington's disease), a fluid transition of penetrance is more likely rather than a clear cut CCTG number threshold.}, language = {en} } @article{KolokotronisPlutaKlopockietal.2020, author = {Kolokotronis, Konstantinos and Pluta, Natalie and Klopocki, Eva and Kunstmann, Erdmute and Messroghli, Daniel and Maack, Christoph and Tejman-Yarden, Shai and Arad, Michael and Rost, Simone and Gerull, Brenda}, title = {New Insights on Genetic Diagnostics in Cardiomyopathy and Arrhythmia Patients Gained by Stepwise Exome Data Analysis}, series = {Journal of Clinical Medicine}, volume = {9}, journal = {Journal of Clinical Medicine}, number = {7}, doi = {10.3390/jcm9072168}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236094}, year = {2020}, abstract = {Inherited cardiomyopathies are characterized by clinical and genetic heterogeneity that challenge genetic diagnostics. In this study, we examined the diagnostic benefit of exome data compared to targeted gene panel analyses, and we propose new candidate genes. We performed exome sequencing in a cohort of 61 consecutive patients with a diagnosis of cardiomyopathy or primary arrhythmia, and we analyzed the data following a stepwise approach. Overall, in 64\% of patients, a variant of interest (VOI) was detected. The detection rate in the main sub-cohort consisting of patients with dilated cardiomyopathy (DCM) was much higher than previously reported (25/36; 69\%). The majority of VOIs were found in disease-specific panels, while a further analysis of an extended panel and exome data led to an additional diagnostic yield of 13\% and 5\%, respectively. Exome data analysis also detected variants in candidate genes whose functional profile suggested a probable pathogenetic role, the strongest candidate being a truncating variant in STK38. In conclusion, although the diagnostic yield of gene panels is acceptable for routine diagnostics, the genetic heterogeneity of cardiomyopathies and the presence of still-unknown causes favor exome sequencing, which enables the detection of interesting phenotype-genotype correlations, as well as the identification of novel candidate genes.}, language = {en} } @article{WeissbachHerediaGuerreroBarnsteineretal.2020, author = {Weißbach, Susann and Heredia-Guerrero, Sofia Catalina and Barnsteiner, Stefanie and Großhans, Lukas and Bodem, Jochen and Starz, Hanna and Langer, Christian and Appenzeller, Silke and Knop, Stefan and Steinbrunn, Torsten and Rost, Simone and Einsele, Hermann and Bargou, Ralf Christian and Rosenwald, Andreas and St{\"u}hmer, Thorsten and Leich, Ellen}, title = {Exon-4 Mutations in KRAS Affect MEK/ERK and PI3K/AKT Signaling in Human Multiple Myeloma Cell Lines}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {2}, issn = {2072-6694}, doi = {10.3390/cancers12020455}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200617}, year = {2020}, abstract = {Approximately 20\% of multiple myeloma (MM) cases harbor a point mutation in KRAS. However, there is still no final consent on whether KRAS-mutations are associated with disease outcome. Specifically, no data exist on whether KRAS-mutations have an impact on survival of MM patients at diagnosis in the era of novel agents. Direct blockade of KRAS for therapeutic purposes is mostly impossible, but recently a mutation-specific covalent inhibitor targeting KRAS\(^{p.G12C}\) entered into clinical trials. However, other KRAS hotspot-mutations exist in MM patients, including the less common exon-4 mutations. For the current study, the coding regions of KRAS were deep-sequenced in 80 newly diagnosed MM patients, uniformely treated with three cycles of bortezomib plus dexamethasone and cyclophosphamide (VCD)-induction, followed by high-dose chemotherapy and autologous stem cell transplantation. Moreover, the functional impact of KRAS\(^{p.G12A}\) and the exon-4 mutations p.A146T and p.A146V on different survival pathways was investigated. Specifically, KRAS\(^{WT}\), KRAS\(^{p.G12A}\), KRAS\(^{p.A146T}\), and KRAS\(^{p.A146V}\) were overexpressed in HEK293 cells and the KRAS\(^{WT}\) MM cell lines JJN3 and OPM2 using lentiviral transduction and the Sleeping Beauty vector system. Even though KRAS-mutations were not correlated with survival, all KRAS-mutants were found capable of potentially activating MEK/ERK- and sustaining PI3K/AKT-signaling in MM cells.}, language = {en} } @article{JanzZinkCirnuetal.2021, author = {Janz, Anna and Zink, Miriam and Cirnu, Alexandra and Hartleb, Annika and Albrecht, Christina and Rost, Simone and Klopocki, Eva and G{\"u}nther, Katharina and Edenhofer, Frank and Erg{\"u}n, S{\"u}leyman and Gerull, Brenda}, title = {CRISPR/Cas9-edited PKP2 knock-out (JMUi001-A-2) and DSG2 knock-out (JMUi001-A-3) iPSC lines as an isogenic human model system for arrhythmogenic cardiomyopathy (ACM)}, series = {Stem Cell Research}, volume = {53}, journal = {Stem Cell Research}, doi = {10.1016/j.scr.2021.102256}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259846}, pages = {102256}, year = {2021}, abstract = {Arrhythmogenic cardiomyopathy (ACM) is characterized by fibro-fatty replacement of the myocardium, heart failure and life-threatening ventricular arrhythmias. Causal mutations were identified in genes encoding for proteins of the desmosomes, predominantly plakophilin-2 (PKP2) and desmoglein-2 (DSG2). We generated gene-edited knock-out iPSC lines for PKP2 (JMUi001-A-2) and DSG2 (JMUi001-A-3) using the CRISPR/Cas9 system in a healthy control iPSC background (JMUi001A). Stem cell-like morphology, robust expression of pluripotency markers, embryoid body formation and normal karyotypes confirmed the generation of high quality iPSCs to provide a novel isogenic human in vitro model system mimicking ACM when differentiated into cardiomyocytes.}, language = {en} } @article{ZaumNandaKressetal.2022, author = {Zaum, Ann-Kathrin and Nanda, Indrajit and Kress, Wolfram and Rost, Simone}, title = {Detection of pericentric inversion with breakpoint in DMD by whole genome sequencing}, series = {Molecular Genetics \& Genomic Medicine}, volume = {10}, journal = {Molecular Genetics \& Genomic Medicine}, number = {10}, doi = {10.1002/mgg3.2028}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-293940}, year = {2022}, abstract = {Background Dystrophinopathies caused by variants in the DMD gene are a well-studied muscle disease. The most common type of variant in DMD are large deletions. Very rarely reported forms of variants are chromosomal translocations, inversions and deep intronic variants (DIVs) because they are not detectable by standard diagnostic techniques (sequencing of coding sequence, copy number variant detection). This might be the reason that some clinically and histologically proven dystrophinopathy cases remain unsolved. Methods We used whole genome sequencing (WGS) to screen the entire DMD gene for variants in one of two brothers suffering from typical muscular dystrophy with strongly elevated creatine kinase levels. Results Although a pathogenic DIV could not be detected, we were able to identify a pericentric inversion with breakpoints in DMD intron 44 and Xq13.3, which could be confirmed by Sanger sequencing in the index as well as in his brother and mother. As this variation affects a major part of DMD it is most likely disease causing. Conclusion Our findings elucidate that WGS is capable of detecting large structural rearrangements and might be suitable for the genetic diagnostics of dystrophinopathies in the future. In particular, inversions might be a more frequent cause for dystrophinopathies as anticipated and should be considered in genetically unsolved dystrophinopathy cases.}, language = {en} } @article{WagenhaeuserRickertSommeretal.2022, author = {Wagenh{\"a}user, Laura and Rickert, Vanessa and Sommer, Claudia and Wanner, Christoph and Nordbeck, Peter and Rost, Simone and {\"U}{\c{c}}eyler, Nurcan}, title = {X-chromosomal inactivation patterns in women with Fabry disease}, series = {Molecular Genetics \& Genomic Medicine}, volume = {10}, journal = {Molecular Genetics \& Genomic Medicine}, number = {9}, doi = {10.1002/mgg3.2029}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312795}, year = {2022}, abstract = {Background Although Fabry disease (FD) is an X-linked lysosomal storage disorder caused by mutations in the α-galactosidase A gene (GLA), women may develop severe symptoms. We investigated X-chromosomal inactivation patterns (XCI) as a potential determinant of symptom severity in FD women. Patients and Methods We included 95 women with mutations in GLA (n = 18 with variants of unknown pathogenicity) and 50 related men, and collected mouth epithelial cells, venous blood, and skin fibroblasts for XCI analysis using the methylation status of the androgen receptor gene. The mutated X-chromosome was identified by comparison of samples from relatives. Patients underwent genotype categorization and deep clinical phenotyping of symptom severity. Results 43/95 (45\%) women carried mutations categorized as classic. The XCI pattern was skewed (i.e., ≥75:25\% distribution) in 6/87 (7\%) mouth epithelial cell samples, 31/88 (35\%) blood samples, and 9/27 (33\%) skin fibroblast samples. Clinical phenotype, α-galactosidase A (GAL) activity, and lyso-Gb3 levels did not show intergroup differences when stratified for X-chromosomal skewing and activity status of the mutated X-chromosome. Conclusions X-inactivation patterns alone do not reliably reflect the clinical phenotype of women with FD when investigated in biomaterial not directly affected by FD. However, while XCI patterns may vary between tissues, blood frequently shows skewing of XCI patterns.}, language = {en} } @article{PlutaHoffjanZimmeretal.2022, author = {Pluta, Natalie and Hoffjan, Sabine and Zimmer, Frederic and K{\"o}hler, Cornelia and L{\"u}cke, Thomas and Mohr, Jennifer and Vorgerd, Matthias and Nguyen, Hoa Huu Phuc and Atlan, David and Wolf, Beat and Zaum, Ann-Kathrin and Rost, Simone}, title = {Homozygous inversion on chromosome 13 involving SGCG detected by short read whole genome sequencing in a patient suffering from limb-girdle muscular dystrophy}, series = {Genes}, volume = {13}, journal = {Genes}, number = {10}, issn = {2073-4425}, doi = {10.3390/genes13101752}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288122}, year = {2022}, abstract = {New techniques in molecular genetic diagnostics now allow for accurate diagnosis in a large proportion of patients with muscular diseases. Nevertheless, many patients remain unsolved, although the clinical history and/or the muscle biopsy give a clear indication of the involved genes. In many cases, there is a strong suspicion that the cause must lie in unexplored gene areas, such as deep-intronic or other non-coding regions. In order to find these changes, next-generation sequencing (NGS) methods are constantly evolving, making it possible to sequence entire genomes to reveal these previously uninvestigated regions. Here, we present a young woman who was strongly suspected of having a so far genetically unsolved sarcoglycanopathy based on her clinical history and muscle biopsy. Using short read whole genome sequencing (WGS), a homozygous inversion on chromosome 13 involving SGCG and LINC00621 was detected. The breakpoint in intron 2 of SGCG led to the absence of γ-sarcoglycan, resulting in the manifestation of autosomal recessive limb-girdle muscular dystrophy 5 (LGMDR5) in the young woman.}, language = {en} }