Publications by authors named "Wollnik Bernd"

Context: Duplications occurring upstream of the SOX9 gene have been identified in a limited subset of patients with 46,XX testicular/ovotesticular differences/disorders of sex development (DSD). However, comprehensive understanding regarding their clinical presentation and diagnosis is limited.

Objective: To gain further insight into the diagnosis of a large cohort of 46,XX individuals with duplications upstream of SOX9.

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Brain organoids offer unprecedented insights into brain development and disease modeling and hold promise for drug screening. Significant hindrances, however, are morphological and cellular heterogeneity, inter-organoid size differences, cellular stress, and poor reproducibility. Here, we describe a method that reproducibly generates thousands of organoids across multiple hiPSC lines.

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Article Synopsis
  • * Direct KRAS inhibitors are showing promise in clinical trials, but resistance to treatment is a concern, prompting the search for combination therapies.
  • * Unbiased drug screening identified effective combinations involving SOS1 inhibitors, PTPN11/SHP2 inhibitors, and multi-kinase inhibitors, validated using a unique KRAS-mutated patient-derived organoid model.
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Noonan syndrome patients harboring causative variants in LZTR1 are particularly at risk to develop severe and early-onset hypertrophic cardiomyopathy. In this study, we investigate the mechanistic consequences of a homozygous variant LZTR1 by using patient-specific and CRISPR-Cas9-corrected induced pluripotent stem cell (iPSC) cardiomyocytes. Molecular, cellular, and functional phenotyping in combination with in silico prediction identify an LZTR1-specific disease mechanism provoking cardiac hypertrophy.

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  • Dysmorphologists face challenges due to the diverse phenotypic variability of human faces, particularly when using Next-Generation Phenotyping (NGP) tools, which are often trained on limited data.
  • To address this, the GestaltMatcher Database (GMDB) was created, compiling over 10,980 facial images from various global populations, significantly improving the representation of underrepresented ancestries, especially African and Asian patients.
  • The study found that incorporating data from non-European patients enhanced NGP accuracy by over 11% without compromising performance for European patients, highlighting the importance of diverse datasets in identifying genetic disorders.
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Filamin C (FLNC) is a highly important actin crosslinker and multi-adaptor protein in striated skeletal and cardiac muscle. Mutations have been linked to a range of cardiomyopathy types. Here, we generated induced pluripotent stem cells (iPSC) from a patient with dilated cardiomyopathy (DCM) harboring a new, unique heterozygous FLNC mutation p.

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We present novel workflows for Q-FISH nanoscopy with the potential for prognostic applications and resolving novel chromatin compaction changes. DNA-fluorescence in situ hybridization (DNA-FISH) is a routine application to visualize telomeres, repetitive terminal DNA sequences, in cells and tissues. Telomere attrition is associated with inherited and acquired diseases, including cancer and cardiomyopathies, and is frequently analyzed by quantitative (Q)-FISH microscopy.

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Introduction: Counseling osteogenesis imperfecta (OI) pregnancies is challenging due to the wide range of onsets and clinical severities, from perinatal lethality to milder forms detected later in life.

Methods: Thirty-eight individuals from 36 families were diagnosed with OI through prenatal ultrasonography and/or postmortem clinical and radiographic findings. Genetic analysis was conducted on 26 genes associated with OI in these subjects that emerged over the past 20 years; while some genes were examined progressively, all 26 genes were examined in the group where no pathogenic variations were detected.

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Gene variants in are implicated to cause Noonan syndrome associated with a severe and early-onset hypertrophic cardiomyopathy. Mechanistically, deficiency results in accumulation of RAS GTPases and, as a consequence, in RAS-MAPK signaling hyperactivity, thereby causing the Noonan syndrome-associated phenotype. Despite its epidemiological relevance, pharmacological as well as invasive therapies remain limited.

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The fibroblast growth factor receptors comprise a family of related but individually distinct tyrosine kinase receptors. Within this family, FGFR2 is a key regulator in many biological processes, e.g.

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Lysinuric protein intolerance (LPI) is a rare, inherited aminoaciduria caused by biallelic pathogenic variants in the amino acid transporter gene (OMIM *603593). Individuals with LPI show extreme variability in their clinical presentation, and LPI is included in the differential diagnosis of several disorders such as urea cycle disorders, lysosomal storage diseases, malabsorption diseases, autoimmune disorders, hemochromatosis, and osteoporosis. The phenotypic variability of LPI and the lack of a specific clinical presentation have caused various misdiagnoses.

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Article Synopsis
  • - The study explores pre-mRNA splicing, its critical role in neurodevelopment, and how mutations in spliceosome-related genes U2AF2 and PRPF19 contribute to neurodevelopmental disorders (NDDs).
  • - Researchers found multiple pathogenic variants in U2AF2 and PRPF19 across unrelated individuals, with functional analysis showing that specific U2AF2 variants disrupted normal splicing and neuritogenesis in human neurons.
  • - Additionally, investigations in Drosophila models revealed that the loss of function in U2AF2 and PRPF19 caused severe developmental defects and social issues, pointing to a genetic network wherein splicing factors like Rbfox1 play a significant role in brain development and function. *
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Background & Aims: The highly heterogeneous cellular and molecular makeup of pancreatic ductal adenocarcinoma (PDAC) not only fosters exceptionally aggressive tumor biology, but contradicts the current concept of one-size-fits-all therapeutic strategies to combat PDAC. Therefore, we aimed to exploit the tumor biological implication and therapeutic vulnerabilities of a clinically relevant molecular PDAC subgroup characterized by SMAD4 deficiency and high expression of the nuclear factor of activated T cells (SMAD4/NFATc1).

Methods: Transcriptomic and clinical data were analyzed to determine the prognostic relevance of SMAD4/NFATc1 cancers.

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N4-hydroxycytidine (NHC), the active compound of the drug Molnupiravir, is incorporated into SARS-CoV-2 RNA, causing false base pairing. The desired result is an "error catastrophe," but this bears the risk of mutated virus progeny. To address this experimentally, we propagated the initial SARS-CoV-2 strain in the presence of NHC.

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The linkeropathies are a group of rare disorders, characterized by overlapping clinical features involving the skeletal and connective tissues. Each "linker" gene encodes an enzyme responsible for the addition of glycosaminoglycan chains to proteoglycans via a common tertrasaccharine linker region. The original descriptions of the autosomal recessive B3GALT6-related disorder showed that the associated clinical features are pleiotropic, spanning the skeletal dysplasia (Spondyloepimetaphyseal dysplasia with joint laxity) (SEMD-JL1) and connective tissue disorder (Ehlers-Danlos syndrome) (EDS spondylodysplastic Type 2) spectrum.

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Article Synopsis
  • The significant phenotypic variability of human faces complicates the work of dysmorphologists by challenging Next-Generation Phenotyping (NGP) tools, especially when analyzing patients from diverse genetic backgrounds.
  • The research established the GestaltMatcher Database (GMDB), which includes over 10,000 facial images from patients with rare genetic disorders worldwide, striving to improve representation of underrepresented populations, particularly Asian and African patients.
  • The analysis showed that incorporating data from non-European patients enhanced the accuracy of NGP in diagnosing facial disorders without negatively affecting performance on European patients, emphasizing the need for more diverse datasets in medical genetics.
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ERI1 is a 3'-to-5' exoribonuclease involved in RNA metabolic pathways including 5.8S rRNA processing and turnover of histone mRNAs. Its biological and medical significance remain unclear.

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Background: The term congenital ocular motor apraxia (COMA), coined by Cogan in 1952, designates the incapacity to initiate voluntary eye movements performing rapid gaze shift, so called saccades. While regarded as a nosological entity by some authors, there is growing evidence that COMA designates merely a neurological symptom with etiologic heterogeneity. In 2016, we reported an observational study in a cohort of 21 patients diagnosed as having COMA.

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Arthrogryposis multiplex congenita forms a broad group of clinically and etiologically heterogeneous disorders characterized by congenital joint contractures that involve at least two different parts of the body. Neurological and muscular disorders are commonly underlying arthrogryposis. Here, we report five affected individuals from three independent families sharing an overlapping phenotype with congenital contractures affecting shoulder, elbow, hand, hip, knee and foot as well as scoliosis, reduced palmar and plantar skin folds, microcephaly and facial dysmorphism.

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Protein translation is an essential cellular process and dysfunctional protein translation causes various neurodevelopmental disorders. The eukaryotic translation elongation factor 1A (eEF1A) delivers aminoacyl-tRNA to the ribosome, while the eEF1B complex acts as a guanine exchange factor (GEF) of GTP for GDP indirectly catalyzing the release of eEF1A from the ribosome. The gene EEF1D encodes the eEF1Bδ subunit of the eEF1B complex.

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Article Synopsis
  • STAG2 is a key part of the cohesin complex, which plays a crucial role in various cellular activities like DNA repair and genome organization. Genetic variants in cohesin-related genes lead to developmental disorders known as cohesinopathies.* -
  • This study identifies a rare mosaic variant linked to developmental issues, including microcephaly and asymmetric growth, in one individual, and a novel splice variant in another female, both of whom share the uncommon trait of supernumerary nipples.* -
  • The research also emphasizes the importance of STAG2 in early brain development, observed through high expression levels during the formation of Bioengineered Neuronal Organoids, offering new insights into STAG2-related conditions.*
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Pancreatic Ductal Adenocarcinoma (PDAC) represents a lethal malignancy with a consistently poor outcome. Besides mutations in PDAC driver genes, the aggressive tumor biology of the disease and its remarkable therapy resistance are predominantly installed by potentially reversible epigenetic dysregulation. However, epigenetic regulators act in a context-dependent manner with opposing implication on tumor progression, thus critically determining the therapeutic efficacy of epigenetic targeting.

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Aminoacylation of transfer RNA (tRNA) is a key step in protein biosynthesis, carried out by highly specific aminoacyl-tRNA synthetases (ARSs). ARSs have been implicated in autosomal dominant and autosomal recessive human disorders. Autosomal dominant variants in tryptophanyl-tRNA synthetase 1 (WARS1) are known to cause distal hereditary motor neuropathy and Charcot-Marie-Tooth disease, but a recessively inherited phenotype is yet to be clearly defined.

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