52 research outputs found

    Multigeneration Inheritance through Fertile XX Carriers of an NR0B1 (DAX1) Locus Duplication in a Kindred of Females with Isolated XY Gonadal Dysgenesis

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    A 160 kb minimal common region in Xp21 has been determined as the cause of XY gonadal dysgenesis, if duplicated. The region contains the MAGEB genes and the NR0B1 gene; this is the candidate for gonadal dysgenesis if overexpressed. Most patients present gonadal dysgenesis within a more complex phenotype. However, few independent cases have recently been described presenting with isolated XY gonadal dysgenesis caused by relatively small NR0B1 locus duplications. We have identified another NR0B1 duplication in two sisters with isolated XY gonadal dysgenesis with an X-linked inheritance pattern. We performed X-inactivation studies in three fertile female carriers of three different small NR0B1 locus duplications identified by our group. The carrier mothers did not show obvious skewing of X-chromosome inactivation, suggesting that NR0B1 overexpression does not impair ovarian function. We furthermore emphasize the importance to investigate the NR0B1 locus also in patients with isolated XY gonadal dysgenesis

    Multiplex ligation-dependent probe amplification analysis of the NR0B1(DAX1) locus enables explanation of phenotypic differences in patients with X-linked congenital adrenal hypoplasia

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    BACKGROUND/AIM:X-linked adrenal hypoplasia congenita (AHC) is a rare disorder characterized by primary adrenal insufficiency and hypogonadic hypogonadism. It is caused by deletions or point mutations of the NR0B1 gene, on Xp21. AHC can be associated with glycerol kinase deficiency, Duchenne muscular dystrophy and mental retardation (MR), as part of a contiguous gene deletion syndrome. A synthetic probe set for multiplex ligation-dependent probe amplification analysis was developed to confirm and characterize NR0B1 deletions in patients with AHC and to correlate their genotypes with their divergent phenotypes. RESULTS:In 2 patients, isolated AHC was confirmed, while a patient at risk for metabolic crisis was revealed as the deletion extends to the GK gene. A deletion extending to IL1RAPL1 was confirmed in both patients showing MR. Thus, a good genotype-phenotype correlation was confirmed. CONCLUSIONS:Multiplex ligation-dependent probe amplification analysis is a valuable tool to detect NR0B1 and contiguous gene deletions in patients with AHC. It is especially helpful for IL1RAPL1 deletion detection as no clinical markers for MR are available. Furthermore, multiplex ligation-dependent probe amplification has the advantage to identify female carriers that, depending on the deletion extension, have a high risk of giving birth to children with MR, AHC, glycerol kinase deficiency and Duchenne muscular dystrophy

    Impact of CT Scan Phenotypes in Clinical Manifestations, Management and Outcomes of Hospitalised Patients with COVID-19

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    COVID-19 is such a heterogeneous disease that a one-size-fits-all approach is not recommended, so the management of patients has been based on their clinical and laboratory characteristics. We therefore investigated possible homogeneous groups presenting similar features of lung involvement based on chest CT and laboratory results. We designed a study to identify a possible correlation between CT scan phenotypes, laboratory exams, and clinical outcomes. We retrospectively analysed 120 adult patients with COVID-19 5who underwent chest CT scan during hospitalisation, between March and December 2020 at our COVID-19 Hospital in two different wards: Respiratory Intensive Care Unit (RICU) and Intensive Care Unit (ICU). The analysis of CT scans resulted in the identification of three radiological phenotypes by two blinded pulmonologists (Cohen's κ = 0.9 for Phenotype 1, 0.9 for Phenotype 2 and 0.89 for Phenotype 3), in accordance with what previously described by Robba et al. “Phenotype 1” (PH1) is characterised by modest interstitial oedema with presentation on chest CT of diffuse ground glass opacities (GGO). “Phenotype 2” (PH2) shows predominant consolidation at lung lobes. “Phenotype 3” (PH3) shows a typical CT pattern of moderate-to-severe ARDS, with alveolar oedema. Based on our results, we could hypothesise that phenotype 2 shows a different trend from all the others and would seem to be more related to a coagulopathy, although we cannot exclude the hypothesis that one phenotype evolves from the other. Further studies might focus on the predictive role of D-dimer, and its cut-offs, in delineating the PH2 patients, that could require an early CT scan to avoid excessive pressure support and finally prevent VILI. To further understand the exact basis of the different CT scan phenotype, a longer longitudinal analysis of clinical and laboratory features (e.g., timing of weaning, pressures and FiO2 delivered) in each phenotype and a comparison among them is needed

    Cortical atrophy in chronic subdural hematoma from ultra-structures to physical properties

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    Several theories have tried to elucidate the mechanisms behind the pathophysiology of chronic subdural hematoma (CSDH). However, this process is complex and remains mostly unknown. In this study we performed a retrospective randomised analysis comparing the cortical atrophy of 190 patients with unilateral CSDH, with 190 healthy controls. To evaluate the extent of cortical atrophy, CT scan images were utilised to develop an index that is the ratio of the maximum diameter sum of 3 cisterns divided by the maximum diameter of the skull at the temporal lobe level. Also, we reported, for the first time, the ultrastructural analyses of the CSDH using a combination of immunohistochemistry methods and transmission electron microscopy techniques. Internal validation was performed to confirm the assessment of the different degrees of cortical atrophy. Relative Cortical Atrophy Index (RCA index) refers to the sum of the maximum diameter of three cisterns (insular cistern, longitudinal cerebral fissure and cerebral sulci greatest) with the temporal bones' greatest internal distance. This index, strongly related to age in healthy controls, is positively correlated to the preoperative and post-operative maximum diameter of hematoma and the midline shift in CSDH patients. On the contrary, it negatively correlates to the Karnofsky Performance Status (KPS). The Area Under the Receiver Operating Characteristics (AUROC) showed that RCA index effectively differentiated cases from controls. Immunohistochemistry analysis showed that the newly formed CD-31 positive microvessels are higher in number than the CD34-positive microvessels in the CSDH inner membrane than in the outer membrane. Ultrastructural observations highlight the presence of a chronic inflammatory state mainly in the CSDH inner membrane. Integrating these results, we have obtained an etiopathogenetic model of CSDH. Cortical atrophy appears to be the triggering factor activating the cascade of transendothelial cellular filtration, inflammation, membrane formation and neovascularisation leading to the CSDH formation

    A potent and selective Sirtuin 1 inhibitor alleviates pathology in multiple animal and cell models of Huntington's disease

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    Protein acetylation, which is central to transcriptional control as well as other cellular processes, is disrupted in Huntington's disease (HD). Treatments that restore global acetylation levels, such as inhibiting histone deacetylases (HDACs), are effective in suppressing HD pathology in model organisms. However, agents that selectively target the disease-relevant HDACs have not been available. SirT1 (Sir2 in Drosophila melanogaster) deacetylates histones and other proteins including transcription factors. Genetically reducing, but not eliminating, Sir2 has been shown to suppress HD pathology in model organisms. To date, small molecule inhibitors of sirtuins have exhibited low potency and unattractive pharmacological and biopharmaceutical properties. Here, we show that highly selective pharmacological inhibition of Drosophila Sir2 and mammalian SirT1 using the novel inhibitor selisistat (selisistat; 6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide) can suppress HD pathology caused by mutant huntingtin exon 1 fragments in Drosophila, mammalian cells and mice. We have validated Sir2 as the in vivo target of selisistat by showing that genetic elimination of Sir2 eradicates the effect of this inhibitor in Drosophila. The specificity of selisistat is shown by its effect on recombinant sirtuins in mammalian cells. Reduction of HD pathology by selisistat in Drosophila, mammalian cells and mouse models of HD suggests that this inhibitor has potential as an effective therapeutic treatment for human disease and may also serve as a tool to better understand the downstream pathways of SirT1/Sir2 that may be critical for H

    Studies of a co-chaperone of the androgen receptor, FKBP52, as candidate for hypospadias

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    BACKGROUND: Hypospadias is a common inborn error of the male urethral development, for which the aetiology is still elusive. Polymorphic variants in genes involved in the masculinisation of male genitalia, such as the androgen receptor, have been associated with some cases of hypospadias. Co-regulators of the androgen receptor start being acknowledged as possible candidates for hormone-resistance instances, which could account for hypospadias. One such molecule, the protein FKBP52, coded by the FKBP4 gene, has an important physiological role in up-regulating androgen receptor activity, an essential step in the development of the male external genitalia. The presence of hypospadias in mice lacking fkbp52 encouraged us to study the sequence and the expression of FKBP4 in boys with isolated hypospadias. PATIENTS AND METHODS: The expression of FKBP52 in the genital skin of boys with hypospadias and in healthy controls was tested by immunohistochemistry. Mutation screening in the FKBF4 gene was performed in ninety-one boys with non syndromic hypospadias. Additionally, two polymorphisms were typed in a larger cohort. RESULTS: Immunohistochemistry shows epithelial expression of FKBP52 in the epidermis of the penile skin. No apparent difference in the FKBP52 expression was detected in healthy controls, mild or severe hypospadias patients. No sequence variants in the FKBP4 gene have implicated in hypospadias in our study. CONCLUSION: FKBP52 is likely to play a role in growth and development of the male genitalia, since it is expressed in the genital skin of prepubertal boys; however alterations in the sequence and in the expression of the FKBP4 gene are not a common cause of non-syndromic hypospadias

    A species-level trait dataset of bats in Europe and beyond

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    Knowledge of species' functional traits is essential for understanding biodiversity patterns, predicting the impacts of global environmental changes, and assessing the efficiency of conservation measures. Bats are major components of mammalian diversity and occupy a variety of ecological niches and geographic distributions. However, an extensive compilation of their functional traits and ecological attributes is still missing. Here we present EuroBatrait 1.0, the most comprehensive and up-to-date trait dataset covering 47 European bat species. The dataset includes data on 118 traits including genetic composition, physiology, morphology, acoustic signature, climatic associations, foraging habitat, roost type, diet, spatial behaviour, life history, pathogens, phenology, and distribution. We compiled the bat trait data obtained from three main sources: (i) a systematic literature and dataset search, (ii) unpublished data from European bat experts, and (iii) observations from large-scale monitoring programs. EuroBatrait is designed to provide an important data source for comparative and trait-based analyses at the species or community level. the dataset also exposes knowledge gaps in species, geographic and trait coverage, highlighting priorities for future data collection.Additional co-authors: Lisette Cantú-Salazar, Dina K. N. Dechmann, Tiphaine Devaux, Katrine Eldegard, Sasan Fereidouni, Joanna Furmankiewicz, Daniela Hamidovic, Davina L. Hill, Carlos Ibáñez, Jean-François Julien, Javier Juste, Peter Kaňuch, Carmi Korine, Alexis Laforge, Gaëlle Legras, Camille Leroux, Grzegorz Lesiński, Léa Mariton, Julie Marmet, Vanessa A. Mata, Clare M. Mifsud, Victoria Nistreanu, Roberto Novella-Fernandez, Hugo Rebelo, Niamh Roche, Charlotte Roemer, Ireneusz Ruczyński, Rune Sørås, Marcel Uhrin, Adriana Vella, Christian C. Voigt & Orly Razgou

    A potent and selective Sirtuin 1 inhibitor alleviates pathology in multiple animal and cell models of Huntington's disease

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    Protein acetylation, which is central to transcriptional control as well as other cellular processes, is disrupted in Huntington's disease (HD). Treatments that restore global acetylation levels, such as inhibiting histone deacetylases (HDACs), are effective in suppressing HD pathology in model organisms. However, agents that selectively target the disease-relevant HDACs have not been available. SirT1 (Sir2 in Drosophila melanogaster) deacetylates histones and other proteins including transcription factors. Genetically reducing, but not eliminating, Sir2 has been shown to suppress HD pathology in model organisms. To date, small molecule inhibitors of sirtuins have exhibited low potency and unattractive pharmacological and biopharmaceutical properties. Here, we show that highly selective pharmacological inhibition of Drosophila Sir2 and mammalian SirT1 using the novel inhibitor selisistat (selisistat; 6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide) can suppress HD pathology caused by mutant huntingtin exon 1 fragments in Drosophila, mammalian cells and mice. We have validated Sir2 as the in vivo target of selisistat by showing that genetic elimination of Sir2 eradicates the effect of this inhibitor in Drosophila. The specificity of selisistat is shown by its effect on recombinant sirtuins in mammalian cells. Reduction of HD pathology by selisistat in Drosophila, mammalian cells and mouse models of HD suggests that this inhibitor has potential as an effective therapeutic treatment for human disease and may also serve as a tool to better understand the downstream pathways of SirT1/Sir2 that may be critical for HD

    Mechanisms in disorders of sex development

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    Is it a boy or a girl? This is usually the first question that parents have when their baby is born. Sometimes it is not possible to give an immediate answer. This is the case when the newborn presents ambiguous external genitalia and an immediate sex assignment is not possible. This situation represents the most typical and dramatic presentation of a disorder of sex development (DSD). Other DSDs can manifest later in life, for example in a girl with primary amenorrhea, who finds out that she has a 46,XY karyotype and will never be fertile. The overall aim of this thesis was to identify mechanisms in DSD, in order to better understand normal and atypical sex development, and furthermore to offer better diagnostics and genetic counselling to patients with DSD and their families. Congenital adrenal hyperplasia (CAH) due to CYP21A2 deficiency is the single most common cause of ambiguous external genitalia in the newborn. The wide spectrum of clinical manifestations ranges from prenatal virilisation in XX girls and salt-wasting in the neonatal period to precocious pubarche and late-onset hyperandrogenic symptoms during adulthood, depending on the CYP21A2 genotype. By in vitro expression of CYP21A2 we have evaluated the residual enzyme activities of four mutant enzymes that carry novel or rare missense mutations identified in patients with CAH. All mutants had a residual activity below 1%, and are thus associated with severe enzyme deficiency. Therefore, these mutations are predicted to cause classic CAH if found in trans with other severe mutations (Paper I). Mutations in the androgen receptor (AR) gene cause androgen insensitivity syndrome (AIS). Patients with completely female external genitalia are classified as having complete AIS (CAIS). However, some of these patients have signs of internal male genital differentiation due to missense mutations that show a low degree of residual function. We studied the expression of two isoforms of the AR in two CAIS patients in relation to the development of male internal genital structures. One patient had a mutation (L7fsX33) that affects only the full-length AR-B form of the AR, whereas the other had a nonsense mutation (Q733X) affecting both isoforms, as shown by Western blot analysis of proteins from gonadal and genital skin fibroblasts. No signs of Wolffian duct development were present in any of the patients, indicating that the AR-A form is not sufficient for Wolffian duct maintenance and differentiation (Paper II). A genome wide investigation by high resolution BAC array CGH (Comparative Genomic Hybridization) was used to identify gene dosage imbalances in 10 patients with female external genitalia due to XY gonadal dysgenesis (GD). We identified and characterised a 637 kb duplication at Xp21 containing DAX1 in a girl with isolated 46,XY GD (Paper III). We also identified another XY patient with isolated partial GD and ambiguous external genitalia, by MLPA (Multiplex Ligation Probe-dependent Amplification) analysis using a synthetic probe set that we designed to identify gene dosage imbalances for known genes involved in DSD (Paper IV). These reports describe the first duplications on Xp21.2 identified in patients with isolated GD because all previously described XY subjects with Xp21 duplications presented with GD as part of a more complex phenotype, including mental retardation and/or malformations. These data support DAX1 as a dosage sensitive gene responsible for GD and highlight the importance of considering DAX1 locus duplications in the evaluation of all cases of 46,XY GD. More recently, we identified an additional family with several members affected with XY GD, where a small DAX1 duplication is segregating through the female line. These data suggest that DAX1 duplications might be as common as SRY mutations causing 46,XY GD. A terminal 9p deletion, of a region already involved in DSD, was also identified by array-CGH, and confirmed by a MLPA probe set, designed to enable screening of loss of candidate DSD genes at 9p23.4. The identification of submicroscopic deletions at 9p24 is of help to understand the mechanisms that lead to GD in some patients with 9p deletions, and to narrow down the monosomy 9p syndrome candidate region (Paper V). By array-CGH we have also identified two novel chromosomal imbalances that are candidate regions for XY GD: a duplication of 3.7 Mb at chromosome band 12q21.31 and a duplication on chromosome 6 that extends from exon 5 to exon 12 of the SUPT3H gene. These regions will be the subjects of further investigations in order to identify new genes involved in gonadal development (Paper VI). The work of this thesis has led to the establishment of the genetic diagnosis in several patients with DSD, thus allowing not only a better genetic counselling but also, at least in some cases, a better patient management. Furthermore, our genetic diagnostic arsenal has been expanded, as we can offer sequencing of more genes and gene dosage investigations by MLPA
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