S. Rost

• University of Wuerzburg

(1) Heart transplantation (HTX) improves the overall survival and functional status of end-stage heart failure patients with cardiomyopathies (CMPs). The majority of CMPs have genetic causes, and the overlap between CMPs and inherited myopathies is well documented. However, the long-term outcome in skeletal muscle function and possibility of an und...

Dystrophinopathies are the most common muscle diseases, especially in men. In women, on the other hand, a manifestation of Duchenne muscular dystrophy is rare due to X-chromosomal inheritance. We present two young girls with severe muscle weakness, muscular dystrophies, and creatine kinase (CK) levels exceeding 10,000 U/L. In the skeletal muscle ti...

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 l...

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 (seque...

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 fo...

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...

Dilated cardiomyopathy with ataxia (DCMA) is an autosomal recessive disorder arising from mutations in DNAJC19. Two patient-derived dermal fibroblast cell lines of siblings with the same homozygous splice acceptor site mutation in DNAJC19 (NM_145261.4):c.130-1G>C were reprogrammed into induced pluripotent stem cell (iPSC) lines (LIBUCi001-A and LIB...

Adrenocortical carcinomas (ACC) are aggressive tumors with a heterogeneous prognosis and limited therapeutic options for advanced stages. This study aims to identify novel drug targets for a personalized treatment in ACC. RNA was isolated from 40 formalin-fixed paraffin-embedded ACC samples. We evaluated gene expression of 84 known cancer drug targ...

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...

Dominant mutations in the MYH7 and MYBPC3 genes are common causes of inherited cardiomyopathies, which often demonstrate variable phenotypic expression and incomplete penetrance across family members. Biallelic inheritance is rare, but allows gaining insights into the genetic mode of action of single variants. Here, we present three cases carrying...

Background Increasing knowledge of cancer genomes has triggered the development of specific targeted inhibitors, thus providing a valuable therapeutic pool. Methods In this report, the authors analyze the presence of targetable alterations in 136 tumor samples from 92 patients with melanoma using a comprehensive approach based on targeted DNA sequ...

Context Adrenocortical carcinoma (ACC) has a heterogeneous prognosis and current medical therapies have limited efficacy in its advanced stages. Genome-wide multi-omics-studies identified molecular patterns associated with clinical outcome. Objective Here, we aimed at identifying a molecular signature useful for both personalized prognostic strati...

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 r...

Dystroglycanopathies are a diverse group of neuromuscular disorders caused by aberrant glycosylation of alpha-dystroglycan. TMEM5 is one of many glycosyltransferases recently described to be associated with alpha-dystroglycanopathies. We report the case of a 15-year-old boy suffering from a congenital muscular dystrophy with elevated serum creatine...

Primary cutaneous marginal zone lymphoma (PCMZL) represents an indolent subtype of Non-Hodgkin lymphomas being clinically characterized by slowly growing tumors of the skin, but a very low propensity for systemic dissemination. Up to now, the underlying genetic basis of PCMZL has not been comprehensively elucidated. With the aim to gain deeper insi...

To evaluate the role of constitutive epigenetic changes in normal body cells of BRCA1/BRCA2‐mutation negative patients, we have developed a deep bisulfite sequencing assay targeting the promoter regions of 8 tumor suppressor (TS) genes (BRCA1, BRCA2, RAD51C, ATM, PTEN, TP53, MLH1, RB1) and the estrogene receptor gene (ESR1), which plays a role in t...

Objective: To describe the presentation and identify the cause of a new clinical phenotype, characterized by early severe neurodegeneration with myopathic and myasthenic features. Methods: This case study of 5 patients from 3 families includes clinical phenotype, serial MRI, electrophysiologic testing, muscle biopsy, and full autopsy. Genetic wo...

The practical basis for massive parallel sequencing is described to help clinicians in choosing the most adequate diagnostic approach for childhood myopathies. The key quality feature for massive parallel sequencing is the sequence depth (coverage) as a prerequisite for variant identification and quantification of sequence copy numbers. Our experie...

Dystrophinopathies are X-linked muscle diseases caused by mutations in the large DMD gene. The most common mutations are detected by standard diagnostic techniques. However, some patients remain without detectable mutation, most likely due to changes in the non-coding sequence. We report on a boy with complete absence of dystrophin in muscle biopsy...

Silver syndrome/SPG17 is a motor manifestation of mutations in the BSCL2 gene and usually presents as a complicated form of hereditary spastic paraplegia (HSP). We present clinical data, follow-up, and genetic results of seven patients with Silver syndrome/SPG17 including a family with a variable intrafamilial phenotype ranging from subclinical sig...

Haemophilia A (HA) is caused by a broad spectrum of different mutation types in the factor VIII gene (F8). In our patient cohort of more than 2600 HA patients as well as in other published studies, the most frequent cause are missense mutations in different F8 exons or the recurrent intron 22 inversion. Some exons and several specific nucleotide po...

Children of older fathers carry an increased risk for developing autism and other disorders. To elucidate the underlying mechanisms, we investigated the correlation of sperm DNA methylation with paternal age and its impact on the epigenome of the offspring. Methylation levels of nine candidate genes and LINE-1 repeats were quantified by bisulfite p...

The myotonic dystrophies (DMs) are the most common inherited muscular disorders in adults. In most of the cases, the disease is caused by (CTG)n/(CCTG)n repeat expansions (EXPs) in non-coding regions of the genes DMPK (dystrophia myotonica-protein kinase) and CNBP (CCHC-type zinc-finger nucleic acid-binding protein). The EXP is transcribed into mut...

Current screening methods for factor VIII gene (F8) mutations can reveal the causative alteration in the vast majority of haemophilia A patients. Yet, standard diagnostic methods fail in about 2 % of cases. This study aimed at analysing the entire intronic sequences of the F8 gene in 15 haemophilia A patients by next generation sequencing. All pati...

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant muscular disorder with a wide clinical variability. Contractions of the D4Z4 macrosatellite repeat on chromosome 4q35 are the molecular basis of the pathophysiology. Recently, in a subset of patients without D4Z4 repeat contractions, variants in the SMCHD1 gene have been identif...

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant muscular disorder of wide clinical variability. Contractions of the D4Z4 macro-satellite repeat on the permissive chromosome 4qA haplotype are the molecular basis of the disease. D4Z4 repeats with less than 11 copies are associated with chromatin decondensation and hypomethylati...

We identified the first homozygous and hence recessive mutation in the myotilin gene (MYOT) in a family affected by a severe myofibrillar myopathy (MFM). MFM is a rare, progressive, and devastating disease of human skeletal muscle with distinct histopathological pattern of protein aggregates and myofibrillar degeneration. So far, only heterozygous...

IntroductionMalignant Hyperthermia (MH) related mutations have been identified in the ryanodine receptor type 1 gene (RYR1) and in the dihydropyridine gene (CACNA1S), but about half of the patients do not have causative mutations in these genes. We wanted to study the contribution of other muscle genes to the RYR1 phenotypes.Methods We designed a g...

The identification of pollen plays an important role in ecology, palaeo-climatology, honey quality control and other areas. Currently, expert knowledge and reference collections are essential to identify pollen origin through light microscopy. Pollen identification through molecular sequencing and DNA barcoding has been proposed as an alternative a...

Vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) is an enzyme localized to the endoplasmic reticulum (ER) membrane. VKORC1 catalyzes the reduction of vitamin K 2,3-epoxide to vitamin K and to vitamin K hydroquinone, the latter required by the enzyme γ-carboxylase for γ-carboxylation of all vitamin K-dependent (VKD) proteins. Until now, on...

We identified the first homozygous and hence recessive mutation in the myotilin gene (MYOT) in a family affected by a severe myofibrillar myopathy (MFM). MFM is a rare, progressive and devastating disease of human skeletal muscle with distinct histopathological pattern of protein aggregates and myofibrillar degeneration. So far, only heterozygous m...

About 10% of mutations in haemophilia A cases generate a premature termination codon in the factor VIII gene (F8). Upon therapeutic FVIII substitution, it was noted that the risk of developing inhibitors is higher when the nonsense mutation is located in the light chain (LC) of the factor VIII (FVIII) protein than in the heavy chain (HC). We analys...

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...

Warfarin and other 4-hydroxycoumarinbased oral anticoagulants targeting vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) are administered to humans, mice and rats with different purposes in mind – to act as pesticides in high-dosage baits for killing rodents, but also to save lives when administered in low dosages as antithrombotic drugs...

Haemophilia A is the most common X-linked inherited coagulation disorder caused by a deficiency of the factor VIII protein (FVIII). A plethora of different mutations in the factor VIII gene (F8) have been identified as causative for this bleeding disease including a few promoter mutations. However, in approximately 2–5% of all haemophilic patients,...

Hereditary hearing loss is the most common human sensorineural disorder. Genetic causes are highly heterogeneous, with mutations detected in >40 genes associated with nonsyndromic hearing loss, to date. Whereas autosomal recessive and autosomal dominant inheritance is prevalent, X-linked forms of nonsyndromic hearing impairment are extremely rare....

Background Warfarin directly inhibits the vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) enzyme to effect anticoagulation. VKORC1 function has historically been assessed in vitro using a dithiothreitol (DTT)-driven vitamin K 2,3-epoxide reductase (VKOR) assay. Warfarin inhibits wild-type VKORC1 function by the DTT–VKOR assay. However, V...

Mutation screenings in haemophilia A (HA) patients identified a great variety of mutations in the factor VIII gene (F8): intron 22 or intron 1 inversions, missense mutations, nonsense mutations, small or large deletions, insertions, duplications and splice site mutations. Mutations which do not result in amino acid substitutions (silent mutations)...

  Intrachromosomal homologous recombination between inverted repeats on the X chromosome account for about half of severe hemophilia A cases. Repeats in F8 intron 1 and intron 22 can recombine with homologous inverted repeats located about 200 kb upstream and 500 kb downstream of F8, respectively, resulting in partial sequence inversion of the F8 o...

Emerging resistance to anticoagulant rodenticides may significantly impair house mouse (Mus musculus L.) control. As in humans and rats, sequence variants in the gene vitamin K epoxide reductase complex subunit 1 (VKORC1) of house mice are strongly implicated in the responses of mice to anticoagulants. This study gives a first overview of the distr...

Unlabelled: Intron 1 and intron 22 inversions, two large rearrangements of the factor VIII gene, are generally associated with a severe phenotype of haemophilia A and a high risk of inhibitor formation. In several haemophiliacs, diagnostic analyses for detection of these inversions revealed unusual band patterns. Upon further examination, differen...

Since the discovery of vitamin K epoxide reductase complex subunit 1 (VKORC1), the key enzyme for the regeneration of vitamin KH₂, numerous studies have addressed the role of VKORC1 in the posttranslational modification of vitamin K-dependent proteins. VKORC1 is also the target protein of anticoagulant drugs of the coumarin type (e.g. warfarin). Ge...

Hemophilia A is caused by a wide spectrum of different mutations in the factor (F)VIII gene (F8), leading to deficiencies in coagulation FVIII activity and thus resulting in an inefficient blood clotting cascade. Large duplications comprising whole exons of F8 have been published for only a few cases so far. In the current study, we characterized t...

Vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) is the molecular target of oral anticoagulants. Mutations in VKORC1 cause partial or total coumarin resistance. To identify new VKORC1 oral anticoagulant (OAC) resistance (OACR) mutations and compare the severity of patient phenotypes across different mutations and prescribed OAC drugs. Six...

Coumarin derivatives have been in world-wide use for rodent pest control for more than 50 years. Due to their retarded action as inhibitors of blood coagulation by repression of the vitamin K reductase (VKOR) activity, they are the rodenticides of choice against several species. Resistance to these compounds has been reported for rodent populations...

Die Klonierung des VKORC1-Gens hat maßgeblich zu einem besseren Verständnis des Vitamin-K-Zyklus beigetragen. Das VKORC1-Protein konnte als der molekulare Zielort (Target) der Cumarine identifiziert werden. Mutationen und SNP innerhalb der translatierten und nichttranslatierten Regionen des VKORC1-Gens verursachen eine partielle bis totale Cumarinr...

Zusammenfassung Die Hämophilie A und B werden durch unterschiedliche Mutationen im Faktor VIII (FVIII)- bzw. Faktor IX (FIX)-Gen verursacht. Entsprechend der Schwere des molekularen Defekts gibt es klinisch unterschiedlich schwere Verlaufsformen der Erkrankung. Hämophiliepatienten können heutzutage ausgezeichnet mit aus Plasma oder rekombinant herg...

Coumarin derivatives, e.g. Warfarin, are in world-wide use as effective anticoagulants for therapy of thrombo-embolic diseases in humans as well as for rodent pest control since they effectively inhibit blood coagulation. However, patients under anticoagulant therapy as well as rodent populations have developed resistance to Cumarins soon after the...

Missense mutations in a hitherto unknown gene VKORC1, have recently been shown to confer resistance to anticoagulant rodenticides in rodents. This discovery provided new opportunities for improving resistance-testing methodology by molecular-biological techniques. A PCR-based genetic test for mutations in the VKORC1 gene can successfully identify w...

The genetic diagnosis of a single family with combined vitamin K-dependent clotting factor deficiency (VKCFD2, OMIM #607473) finally led to the identification and molecular characterization of vitamin K epoxide reductase (VKORC1). VKORC1 is the key enzyme of the vitamin K cycle and the molecular target of coumarins, which represent the most commonl...

Vitamin K serves as a cofactor for the post-translational modification by γ-carboxylation of several proteins with Gla-domains. Vitamin K-dependent proteins include the coagulation factors II, VII, IX, and X and proteins S, C and Z, illustrating the therapeutic importance of vitamin K metabolism. Inhibitors of the Coumarin-type like Warfarin or Mar...

Familial multiple coagulation factor deficiency (VKCFD) is a very rare bleeding disorder, with only 15 cases described as yet. The clinical presentation is variable with respect to the residual activities of the affected proteins, the response to oral substitution of vitamin K and to the involvement of skeletal abnormalities. The phenotype may resu...

Mutations in VKORC1 cause coumarin resistance and are also responsible for differing dosing requirements close to the upper therapeutic range. Here we present the data in 16 patients from 14 families revealing 11 different missense mutations, six of which have not been reported previously. Our data may contribute in identifying further functional...

For 60 years, coumarin drugs (e.g. warfarin) are in use for the treatment of thromboembolic events in humans and for the treatment of coagulation via inhibition of the vitamin K epoxide reductase complex (VKOR), and in high doses lead to spontaneous fatal bleedings.VKOR recycles vitamin K 2,3-epoxide to vitamin K hydrochinone, an essential cofactor...

Vitamin K serves as a cofactor for the post-translational modification by gammacarboxylation of the Gla-proteins. Vitamin K-dependent proteins include the coagulation factors II, VII, IX, and X as well as proteins S, C and Z, illustrating the clinical importance of vitamin K-metabolism. Inhibitors of the coumarin-type reduce coagulation activity by...

Congenital combined deficiency of the vitamin-K-dependent coagulation factors (VKCFD) represents a rare autosomal recessive inherited bleeding disorder caused by mutations in either the gamma-glutamyl carboxylase gene (VKCFD type 1) or the vitamin K epoxide reductase gene (VKCFD type 2). Four different mutations of the gamma-glutamyl carboxylase ge...

Vitamin K ist ein essentieller Cofaktor für die posttranslationale Gamma-Carboxylierung von sog. Vitamin K-abhängigen Gerinnungsfaktoren, Knochenproteinen, Zellwachstum-regulierenden und weiteren Proteinen mit noch unbekannter Funktion. Defekte im Vitamin K-Stoffwechsel führen einerseits zu zwei verschiedenen Formen des familiären Mangels aller Vit...

Chinese and Malay subjects have been reported to require less maintenance warfarin than Indians that could not be accounted for by cytochrome P450 (CYP) 2C9 variants. Vitamin K epoxide reductase complex 1 (VKORC1) is the target enzyme of warfarin, and VKORC1 intronic variants and haplotypes have recently been shown to influence VKORC1 activity and...

Natural and site-directed mutagenesis experiments are important tools for studying the role of individual amino acids of the VKORCl protein and their involvement in the binding sites for the substrate vitamin K and the antagonist warfarin. Our study supports the hypothesis of different binding sites for vitamin K epoxide and Coumarins and underline...

So far a number of rare genetic variations of VKORC1 have been found to contribute to a broad range of coumarin requirement. It would be of interest, whether future studies may also discover more common haplotypes of the VKORC1 gene that affect coumarin dosing. Such studies will be helpful to understand the anticoagulant response to coumarin deriva...

Coumarin and homologous compounds are the most widely used anticoagulant drugs worldwide. They function as antagonists of vitamin K, an essential cofactor for the posttranslational gamma-glutamyl carboxylation of the so-called vitamin K-dependent proteins. As vitamin K hydroquinone is converted to vitamin K epoxide (VKO) in every carboxylation step...

Anticoagulant compounds, i.e., derivatives of either 4-hydroxycoumarin (e.g., warfarin, bromadiolone) or indane-1,3-dione (e.g., diphacinone, chlorophacinone), have been in worldwide use as rodenticides for >50 years. These compounds inhibit blood coagulation by repression of the vitamin K reductase reaction (VKOR). Anticoagulant-resistant rodent p...

Coumarins target blood coagulation via inhibition of the vitamin K epoxide reductase multiprotein complex (VKOR). This complex recycles vitamin K 2,3-epoxide to vitamin K hydroquinone, an essential cofactor for the post-translational gamma-carboxylation of several blood coagulation factors. Recently, two groups including ours identified a key compo...

Hereditary combined deficiency of the vitamin K-dependent coagulation factors II, VII, IX, X, protein C, S and protein Z (VKCFD) is a very rare autosomal recessive inherited bleeding disorder. The phenotype may result from functional deficiency of either the gamma-glutamyl carboxylase (GGCX) or the vitamin K epoxide reductase (VKOR) complex. We rep...

Coumarin derivatives such as warfarin represent the therapy of choice for the long-term treatment and prevention of thromboembolic events. Coumarins target blood coagulation by inhibiting the vitamin K epoxide reductase multiprotein complex (VKOR). This complex recycles vitamin K 2,3-epoxide to vitamin K hydroquinone, a cofactor that is essential f...

Familial multiple coagulation factor deficiency (FMFD) of factors II, VII, IX, X, protein C and protein S is a very rare bleeding disorder with autosomal recessive inheritance [1]. The disease may result either from a defective resorption/transport of vitamin K to the liver, or from a mutation in one of the genes encoding gamma-carboxylase (GGCX) o...

Hereditary combined deficiency of all vitamin K-dependent coagulation factors (FMFD, Familial Multiple Coagulation Factor Deficiency) is a very rare bleeding disorder, with only 14 cases described as yet [1]. The clinical presentation is variable with respect to the residual activities of the affected proteins, the response to oral substitution of...